Ship-based Cloud and Precipitation Air-Sea Interaction Studies in EPIC2001:

C. Fairall, T. Uttal, J. Intrieri, K. Gage, A. S. Frisch, B. Orr, D. Hazen, G. Feingold

NOAA Environmental Technology Laboratory

December 10, 1999

A. Project Summary

This is a proposal for participation in the Eastern Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC) as described in the EPIC Overall Project Description. Three groups at Environmental Technology Laboratory (ETL) and one at the Aeronomy Laboratory (AL) will combine to collaborate with other investigators on several aspects of the ITCZ the ABL/Cold Tongue and the Stratocumulus studies during the EPIC 2001 field program. More detail on these EPIC subprojects can be found in their individual descriptions (ITCZ - D. J. Raymond; ABL - S. Esbensen; Stratocumulus - C. Bretherton).

The work proposed here will involve analysis of some existing data sets and equipment preparation in the first two years, the installation of four sets of systems on the R/V Ron Brown (the flux/PBL system, the cloud radar and microwave radiometer system, S-band radar, and the lidar systems) plus a precipitation radar on the R/V New Horizon for the field program in the second year, and analysis and modeling in the third year.

The scientific objectives of the ITCZ study involve improved parameterizations of turbulent and radiative fluxes and new descriptions of PBL structure in precipitating systems, plus application of multiple remote sensors for better quantitative precipitation estimates of area-
average rain rates and evaluation of convective heating profiles. For the turbulent fluxes the issue is the role of mesoscale variability as the existing bulk parameterization is extended to be valid for large-scale volume-average numerical applications. The ship-based remote sensors will allow us estimate microphysical properties of the convective outflows (midlevel and cirrus) and relate them to the cloud radiative properties.

For the ABL/Cold Tongue study we will investigate the role of surface fluxes in driving diurnal and spatial variability of entire PBL (cloud and sub-cloud layers). This will involve comprehensive characterization of clouds, surface fluxes, and PBL profiles from the stratocumulus region, into the shallow convection and finally into the ITCZ. We will also examine the relative contributions of turbulent and radiative fluxes to the surface heat budget of the ocean and get high-quality measurements of cloud forcing of surface fluxes in a region that is a problem for coupled ocean-atmospheric models.

The scientific objectives of the Stratocumulus study involve improved bulk cloud-
radiative parameterizations, expansion of methods for retrieving stratocumulus cloud microphysical properties, and investigation of the relative roles of cloud-top entrainment and drizzle production on the dynamics of stratocumulus. This will involve comprehensive characterization of clouds, surface fluxes, and PBL profiles using a variety of in situ and remote sensing systems on the R/V Ronald H. Brown. With good determinations of cloud microphysics (integrated liquid water, drop size and number concentration) we can evaluate various bulk models of stratocumulus cloud radiative transfer properties. The lidar, cloud radar, and aerosol observations combined with LES simulations with explicit cloud/aerosol microphysics will an unprecedented look at the coupling of condensation dynamics, microphysics, and precipitation production.

B. Table of Contents

A. Project Summary	A-1

B. Table of Contents	B-1

C. Project Description	C-1

1. Introduction	C-1

1.1	Background on EPIC	C-1

1.2	EPIC 2001 Observational Tools	C-1

1.3	EPIC2001 Operational Plans	C-2

1.4	EPIC2001 Modeling and Theory	C-4

1.5	Background on This Proposal	C-4

2. Results from Prior NSF/ NOAA C&GC	C-5

3. Scientific Objectives	C-6

3.1	ITCZ Studies	C-6

3.2	ABL Studies	C-7

3.3	Stratocumulus Studies	C-8

4. Background on Measurements	C-9

4.1	Flux system, ceilometer, and wind profiler	C-10

4.2	Precipitation radars	C-11

4.3	Cloud radar and microwave radiometers	C-11

4.4	Lidars	C-11

5. Figures	C-13

D. References Cited	D-1

E. Biographical Summaries	E-1

F. Budget Details	F-1

1. Tasks	F-1

2. Miscellaneous	F-2

3. Personnel Duties	F-2

4. Component Costs	F-3

G. Current and Pending Support	G-1

H. Facilities	H-1

C. Project Description

1. Introduction

1.1	Background on EPIC

The EPIC (Eastern Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System; Weller et al., 1999) program was born out of the inability of coupled ocean-atmosphere models to adequately predict the behavior of the atmosphere and ocean in the east Pacific region. EPIC is a part of the U. S. CLIVAR (Climate Variability and Predictability) program (see http://www.usgcrp.gov/usgcrp/usclivar/programs.html ) and consists of a combination of long term monitoring (PACS,1999), intensive process studies, and modeling designed to increase our understanding of the east Pacific system and its interactions with its surroundings. EPIC2001 is a particular set of closely related process studies which are proposed for a 6 week period between 15 July and 15 September of 2001 under the aegis of the overall EPIC program. These studies are focused on the dynamics of the cross-equatorial Hadley circulation along 95W, during the period in which it is strongest, and on associated processes which govern the SST and upper ocean structure.

The National Science Foundation requested that proposals to fund this study be bundled into ``super proposals'', each dealing with a particular aspect of the problem. The four bundles respectively address (1) the east Pacific ITCZ, (2) the cross-equatorial ITCZ inflow, (3) ocean processes, particularly in the east Pacific warm pool, and (4) the southern hemisphere stratus region. Each bundle consists of a section common to all bundles (which you are now reading), a section peculiar to each bundle, and sections describing the details of work proposed by individuals and groups of investigators. Separate budgets are presented for each group. The scientific background for this project is given in the EPIC plan (Weller et al., 1999) and in the EPIC2001 Overview and Implementation Plan (Raymond et al., 1999).

1.2	EPIC 2001 Observational Tools

The specific observational tools we expect to bring to bear and the primary scientific goals associated with them are listed briefly below:

* NCAR Electra aircraft (in situ and radar) : Study characteristics of convection and its environment over the east Pacific warm pool as far south as the south edge of the ITCZ.

* NOAA WP-3D aircraft (in situ and radar) : Study the airmass transformations in the cross-equatorial inflow into ITCZ convection.

*Atmospheric dropsondes (Electra and/or WP-3D) : Document the atmospheric environment along the 95W line and the structure of impinging easterly waves.

*Aircraft expendable ocean probes (AXBTs, AXCTDs, AXCPs) (Electra and/or WP-3D) : Document the north-south structure and variability in time of ocean currents, temperature, and salinity profiles along 95W . Examine the spatial structure of ocean perturbations due to easterly waves.

*Galapagos Islands-based Aerosondes : Document air mass transformations and their temporal variability in the cross-equatorial flow along 95 W.

*NOAA ship Ron Brown atmospheric measurements (soundings, C-band radar, numerous remote sensing systems, air-sea fluxes, aerosols) : Document the structure of atmospheric convection as well as rainfall and its temporal variability in the ITCZ, ITCZ inflow, and stratus regions, and characterize fluxes (turbulent and radiative) and atmospheric aerosols.

*NOAA ship Ron Brown ocean measurements (microstructure measurements, temperature, salinity, current, and light absorption profiles) : Examine the response of the ocean to atmospheric forcing, with particular emphasis on shortwave radiation absorption and entrainment from below into the ocean mixed layer.

*Mexican oceanographic vessel (WOCE-ARGOS surface drifters, atmospheric soundings) : Document the surface currents in the east Pacific warm pool and the large scale spatial and temporal variability of SST.

*NSF-sponsored ship (ocean temperature, salinity, light transmission, and conductivity microstructure profiles, horizontal currents, air-sea fluxes and precipitation, vertically pointing S-band radar) : Examine the small scale spatial variability of the ocean in the ITCZ near the Ron Brown and along 95 W .

*Enhanced TAO moorings along 95 W : Document surface atmosphere temperature, pressure, wind, humidity, incoming shortwave and longwave radiation, and upper ocean temperature, salinity, and currents along 95 W .

*IMET mooring at 18 S , 85 W : Document atmospheric energy fluxes in the stratus region south of the equator.

In addition to these measurements, enhanced soundings over land areas surrounding the region of interest as well as various satellite-based measurements will be useful in sorting out the processes occurring in this region. See the EPIC2001 Overview and Implementation Plan (Raymond et al., 1999) for more detail. Figure 1 illustrates the deployment of the tools proposed for this experiment.

1.3	EPIC2001 Operational Plans

* NOAA Ship Ron Brown. We have requested 55 days of R/V Ron Brown ship time. After departing San Diego on 1 August 2001, the Ron Brown will operate near 10 N , 95 W for roughly the first three weeks of August, making microstructure, optical, and other measurements in the ocean, and in situ, sounding, radar, and remote sensing measurements in the atmosphere. The Ron Brown will then steam south along the 95 W line while continuing to make atmospheric measurements, briefly interrupting this transect to make a port call the the Galapagos to exchange scientists and crew as needed. Stops will be made at 1 degree intervals to make CTD/Rosette and optics casts. After reaching the south end of the TAO line, the Brown will steam to the IMET buoy at 18 S , 85 W. A transect to the Peruvian coast will follow, with a port call likely at Lima. The reverse track will then be followed (excluding the Galapagos stop), with the Brown arriving at Manzanillo near the end of September (see Figure 2).

* NSF Ship. This ship will start from Acapulco and spend roughly three weeks working near the Ron Brown during its stay near 10 N . The ship will slowly steam in predetermined patterns in the vicinity of the Brown. Oceanographic measurements will include conductivity and temperature measurements with a towed Seasoar, horizontal currents with the ship's ADCP, and near-surface temperature and salinity. Meteorological measurements will include sea-air fluxes and precipitation. The ship will subsequently make a transect south along the 95 W line to the equator and back, and then return to Acapulco.

*NCAR Electra/Eldora . We are requesting 120 h of research time, which will be split into 16 flights of roughly 7.5 h duration from Huatulco, Mexico. We wish to operate for a 6 week period which includes all of August 2001, so as to overlap the presence of the Ron Brown in the ITCZ. The Electra flights will all follow a similar pattern. After departure from Huatulco, the Electra will fly south along the 95 W line in the planetary boundary layer at about 300 m elevation to the location of the ITCZ, roughly 8-10 N . This will take 1.7 - 2.2 h . The ITCZ will be identified by the wind shift from easterlies to southwesterlies at low levels, which according to satellite scatterometer data is quite sharp. The aircraft will then ascend to 3 km elevation and make a 2 degree square convergence-vorticity box in the region of the ITCZ. Following this, cloud penetrations will be made at various elevations with a strategy which will be determined by existing conditions in the ITCZ. Return to base at 4 - 5 km will take 1.5 - 2 h , which leaves 1 - 2 h for the cloud penetrations. The Eldora radar will be operated for the entire flight. Cloud penetrations will be coordinated with Ron Brown radar observations for a certain number of flights. Flight launches need to be spaced (in a convenient fashion for crew and observers) around the clock, so as to cover the full diurnal cycle. Flights may be launched in sequence so as to document a particular easterly wave passage, or they may be spaced at regular intervals so as to build up a composite pattern from several wave passages.

*NOAA WP-3D. We are requesting 144 h of research time, which will be split into 16 flights of roughly 9 h duration from Huatulco. We wish to operate for the same 6 week period as the Electra, with most WP-3D flights coinciding with Electra flights. The WP-3D would climb to 5 - 6 km upon departure, deploying dropsondes every 1 - 2 degrees as it flies south along the 95 W line. Upon reaching the equator (4 h ), the WP-3D would descend to the boundary layer and proceed northward, making gradual ascents and descents through the marine layer. This pattern would be periodically interrupted by level flight segments designed to capture fluxes. Expendable ocean probes would be dropped periodically during this return segment. The belly and tail radars will be operated through the entire flight to capture the cloud patterns all along 95 W. On some flights east-west patterns would be flown in the ITCZ in order to document mesoscale variability in the atmosphere and ocean in this region. The turnaround point would necessarily be moved northward in these cases.

*Aerosondes . The Aerosondes will operate out of the Galapagos Islands in pairs for 6 weeks overlapping the Electra and WP-3D operational periods. Both will first head directly west to the 95W line. One will then turn north, the other south, proceeding to 5N and 5S , and then returning directly to the Galapagos. During their flights, the Aerosondes will make slow ascents and descents through the atmospheric marine layer, measuring wind, temperature, and humidity. We plan 16 Aerosonde missions to coincide with the proposed 16 Electra and WP-3D missions.

*Enhanced TAO Moorings. The TAO moorings at 95 W on the equator and at 2 , 5 , and 8 degrees north and south are being augmented with moorings at 3.5 N , 10 N , and 12 N . All 10 moorings will have surface atmospheric temperature, humidity, wind, barometric pressure, incoming shortwave and longwave radiation sensors, as well as one or two current meters, 7 conductivity sensors, and 2 additional thermistors in the ocean. Daily averages of all measurements will be telemetered to PMEL and made available within one day via world wide web and ftp sites. These enhancements have been funded and are currently being put in place.

*IMET Mooring in Stratus. An IMET mooring will be established at 18 S , 85 W . This will measure atmospheric energy fluxes in the stratus region. This project is currently funded.

1.4	EPIC2001 Modeling and Theory

Close connections with groups working on coupled ocean-atmosphere problems are crucial to a successful transfer of knowledge from this project to research and operational models. Contacts with the following modeling and theory groups will be maintained:

Chris Bretherton of the University of Washington plans to extend his work with large eddy simulations to the stratocumulus problem of the southeast Pacific.

Graham Feingold of the NOAA Environmental Technology Laboratory plans to use the data with and LES model including explicit microphysics to examine aerosol, cloud droplet, and drizzle formation physics.

Arun Kumar at NCEP is interested in using EPIC2001 results in conjunction with single column models to improve parameterizations.

Roberto Mechoso's group at UCLA is heavily involved in the development of coupled ocean-atmosphere global models and much of the work of this group is of interest to EPIC2001.

Mitch Moncrieff's group at NCAR has expressed interest in modeling the atmospheric component of the system.

David Randall's coupled modeling group at CSU has expressed interest in the experiment.

David Raymond at New Mexico Tech is modeling ITCZs with simulations of atmospheric motion over increasingly realistic fixed SSTs.

Joe Zehnder's group at the University of Arizona is using idealized models and MM5 to study the interactions of easterly waves with Central American topography and the ITCZ.

1.5	Background on This Proposal

Three groups at Environmental Technology Laboratory (ETL) and the Aeronomy Laboratory (AL) will combine to collaborate with other investigators on several aspects of the ITCZ the ABL/Cold Tongue and the Stratocumulus studies during the EPIC 2001 field program. This proposed work will involve analysis of some existing data sets and equipment preparation in the first two years, the installation of three sets of systems on the R/V Ron Brown (the flux/PBL system, the cloud radar and microwave radiometer system, and the lidar systems) plus a precipitation radar on the R/V New Horizon for the field program in the second year, and analysis and modeling in the third year.

The scientific objectives of the Stratocumulus study involve improved bulk cloud-
radiative parameterizations, expansion of methods for retrieving stratocumulus cloud microphysical properties, and investigation of the relative roles of cloud-top entrainment and drizzle production on the dynamics of stratocumulus. This will involve comprehensive characterization of clouds, surface fluxes, and PBL profiles using a variety of in situ and remote sensing systems on the R/V Ronald H. Brown. The scientific objectives of the ITCZ study involve improved parameterizations of turbulent and radiative fluxes and new descriptions of PBL structure in precipitating systems plus application of multiple remote sensors for better quantitative precipitation estimates of area-average rain rates and evaluation of convective heating profiles. For the ABL/Cold Tongue study we will investigate the role of surface fluxes in driving diurnal and spatial variability of entire PBL (cloud and subcloud layers). This will involve comprehensive characterization of clouds, surface fluxes, and PBL profiles from the stratocumulus region, into the shallow convection and finally into the ITCZ.

2. Results from Prior NSF/ NOAA C&GC

NOAA award	: Climate Global Change Program, ATM-9319471, 10/1/93 - 9/31/96

Amount	: $352,000

Title	: Air-sea flux and PBL studies during TOGA/COARE. C. Fairall, PI

The goal of this work was to improve air-sea flux parameterizations in GCM's and other numerical models. The approach involved the development of shipboard flux measurement technology and shipboard remote sensing systems for monitoring boundary layer structure. This project led to the development of the COARE bulk flux algorithm, a flux database used by numerous investigators, and about 20 refereed publications (http://www7.etl.noaa.gov/programs/COARE/).

NSF award	ATM-8720797, 1988-1992: ATM-9214800, 1993-1996

Amount	$852,000; $888,000

Title	Tropical Convection Studies Using a Trans-Pacific Wind Profiler Network; Continuing Research Using the NOAA/CU Tropical Pacific Profiler Network, K. Gage, PI.

These projects covered the design, construction and use of the joint NOAA/CU wind profiling network in the tropical Pacific including the 50-MHz wind profilers at Piura, Peru; Pohnpei, Federated States of Micronesia (FSM) and Biak, Indonesia. Ten formal publications acknowledged support under the first grant, and eighteen formal publications resulted from the second grant.

NSF award	: ATM-9819618, 5/15/99 - 4/30/01

Amount	: $226,000

Title	: The Joint Air-Sea Monsoon Investigation (JASMINE99): A pilot study. P. Webster, PI

JASMINE is a study of oceanic and atmospheric aspects of the Indian monsoon including air-sea fluxes, atmospheric convection, and the ocean mixed layer. A 40-day cruise was successfully completed in June 1999 with a powerful suite of in situ sensors and radars. Ocean mixed layer evolution and atmospheric processes were observed in active and break periods of the Indian Monsoon. Early results will be given at the AMS Tropical Meteorology meeting in Miami in late May, 2000; see also http://www7.etl.noaa.gov/programs/JASMINE/ and related links.

NOAA award	: Climate Global Change Program, GC99-364, 5/1/99 - 9/31/01

Amount	: $445,000

Title	: Shipboard monitoring of stratocumulus cloud properties in PACS. C. Fairall, PI

Twice a year a NOAA R/V is sent to service TAO buoys at the 95 W and 110 W longitude lines. We instrument the ship to measure near-surface bulk meteorology, turbulent and radiative fluxes, integrated cloud liquid water and integrated atmospheric water vapor, cloud base height and cloud statistics, and cloudtop height to characterize the bulk properties of a stratocumulus cloud. Our interest is to obtain some simple statistics on tropical and subtropical stratocumulus clouds and to investigate cloud/radiative coupling properties. The first cruise was completed on Dec. 15, 1999; no results are available yet.

NOAA award	Pan American Climate Study, 1997-1998

Amount	$168,000

Title	Shipboard Profiler Study of the Structure of Precipitating Cloud Systems within the Intertropical Convergence Zone of the eastern Pacific Ocean, K. Gage, PI

This project supported the Tropical Eastern Pacific Process Study (TEPPS) Campaign led by the University of Washington. The purpose of the campaign was to improve the understanding of the convection within the ITCZ of the eastern tropical pacific, especially the reasons for the discrepancy between satellite precipitation estimates obtained by microwave sounders such as the Special Sensor Microwave/Imager (SSM/I) and infrared based instruments. The campaigns were led by Bob Houze and Sandra Yuter of the University of Washington; the AL installed and maintained two profilers on the R/V Ronald H. Brown. The profilers complemented a scanning radar that was installed on the ship especially for this campaign. The profiler observations can be found on the Aeronomy Laboratory and PACS web sites. The campaign took place in August 1997 and the results are now being published.

3. Scientific Objectives

The scientific objects of this ITCZ/ABL/Cold tongue include studies of the effects of mesoscale variability on air-sea fluxes, spatial and temporal variability of the PBL and clouds, the microphysics and radiative properties of convective outflows, and comprehensive precipitation retrievals. Some of the scientific issues of interest here are applicable to both the ITCZ and ABL studies, so this subject division is somewhat arbitrary.

3.1	ITCZ Studies

Quantitative Precipitation. EPIC 2001 provides an opportunity to diagnose the structure of the precipitating cloud systems over the eastern Pacific ITCZ. The issues addressed in this research are pertinent to the determination of the vertical heating profile in the atmosphere associated with convective systems over the ocean and land surfaces. The vertical profile of latent heating associated with these systems depends critically on the relative amounts of convective and stratiform rain (Hartmann et al., 1984; Houze, 1989) as well as on the radiative heating and cooling associated with elevated cloud systems (Ackerman, 1988). The classification scheme used in this research will identify the vertical structure and relative amounts of elevated cloud systems over ITCZ and contrast them with the western Pacific warm pool region.

The precipitation focus of this proposal is involves multiple sensors on the R/V Ronald H. Brown and the R/V New Horizon. The parameters that will be measured by the S-band and 0.92 GHz profilers are as follows. Doppler spectra are recorded at the profiler and processed to yield spectral moments that give radial velocity, backscattered power ( or equivalent reflectivity for hydrometeors) and spectral width. Observations will be recorded in two modes: high vertical resolution (60 m) for measurements at up to 100 heights from the surface up to 6 km and a low resolution mode (500 m) for profiles from the surface up to 12 km. This is the same observational strategy that was used for UHF profilers in Nauru99 and other field campaigns. The primary observable from the UHF profilers will be vertically-resolved time height cross sections of equivalent reflectivity, Doppler velocity and spectral width. The profiler reflectivities will be intercompared with the reflectivities observed by the C-band scanning radar aboard the R/V Ronald H. Brown. This will provide a calibration of the C-band radar as described in Gage et al. (2000).

Flux Parameterization. Developing and improving assessments of turbulent and radiative fluxes at the surface are critical to the PACS program. Bulk algorithms are widely used to estimate surface fluxes in numerical models and in applications (e.g., satellite retrievals) where highly detailed local information is not available. These are based upon similarity representations of the fluxes in terms of mean quantities

<w'x'> = Cx X S = Cx X (U2 + Ug2)1/2

where x can be the u,v wind components, the potential temperature, , the water vapor mixing ratio, q, etc, and Cx is the total transfer coefficient. X is the sea-air difference in the mean value of x and S is the mean wind speed which is composed of a mean vector part (U and V components) and a gustiness part (Ug) to account for subgridscale variability. Fairall et al. (1996a) linked Ug to variability associated with local boundary-layer convection. The COARE bulk algorithm is still being improved and version 2.6 was just released. The EPIC 2001 cruise will provide more data to refine the algorithm; one major issue that still requires attention is the treatment of the effects of deep convection.

Several mechanisms for convective forcing and variability which involve the air-sea fluxes are discussed in the ITCZ subproject writeup (see also Young et al. 1992,1995). Large scale models (i.e., one that do not explicitly resolve convection), must account for variability associated with mesoscale convection (Vickers and Esbensen, 1998; Tong et al., 1998) to properly represent the balance of dynamics and thermodynamics driving the ITCZ cold-tongue complex. Numerical modeling work by Jabouille et al. (1995), Redelsberger et al. (1998) suggested that Ug can be additionally parameterized in terms of rainrate while Krueger and Zulauf (1997) used cumulus convective mass flux. The combination of the C-band Doppler radar, the vertically pointing precipitation profilers, and the direct flux measurements offer us a unique opportunity to examine such parameterizations with atmospheric data.

Radiative fluxes have fairly simplified representations in present climate models (e.g., Slingo 1989).	Deep convective updraft regions in the EPIC region have strong radiative effects, but occupy a very small area: midlevel convective outflows near the freezing level and cirrus clouds occupy much larger areas (Ackerman 1988). Cirrus clouds are essentially all ice and have modest optical thickness, but the midlevel outflow clouds can be super-cooled liquid, ice, or mixtures. Because liquid droplets tend to greatly increase optical thickness, diagnosis/modeling of cloud microphysics is a major problem. The combination of the DABUL lidar (which can distinguish ice and liquid), the cloud radar, microwave radiometer, and surface downward radiative fluxes will allow us to examine this problem.

3.2	ABL Studies

The main focus of the ABL studies will be the balance of various terms of the surface energy budget coupled with the evolution of the atmospheric boundary layer structure as the flow crosses the equator and moves into the convergence zone. The presence of a fairly strong sea surface temperature gradient and a spatially varying large-scale convergence/divergence pattern will lead to significant but poorly documented variations in surface fluxes and ABL properties. Some very preliminary information on the surface flux variations has been obtained in the first monitoring cruise (see section 2) conducted aboard the R/V Ronald Brown in November-
December, 1999. The ship made a transect from 12 N to 12 S along 110 W, went due east to 95 W, and then made a transect from 12 S to 12 N along 95 W. The disposition of the surface fluxes is shown in Figure 3. The wind direction (Figure 4) clearly shows the ITCZ at about 8 N. Note that the maximum cooling of the ocean is well south of the deep convection of the ITCZ and that there is substantial input of moisture by evaporation on the southern inflow to the ITCZ. In EPIC2001 we will obtain much more detailed information on ABL profile properties from the comprehensive ship-based remote sensors and the aircraft flights.

A variety of remote and in situ sensors will be used to address the diurnal cycle issues raised in the ITCZ and ABL writeups. The properties in this region are almost unexplored (Bond et al. 1992). The surface fluxes (turbulent and radiative) will provide the surface forcing and the combination of the wind profiler, HRDL lidar, and cloud radar will provide mean velocity and turbulence structure throughout the PBL up to an beyond the trade inversion. The dial lidar will provide information on the evolution of moisture profiles in the same layers. These measurements will complement the rawinsonde, C-band radar and aircraft measurements and will provide a continuous link between surface forcing and convective activity. This will provide an unprecedented look at shallow ('popcorn') convection and its role in moistening the upper PBL. The data will indicate the surface heat balance of the ocean in the ITCZ, shallow convection, and stratocumulus regimes. We will also provide an evaluation of the importance of diurnal warm layers in the ocean (Fairall et al., 1996b).

3.3	Stratocumulus Studies

Our proposed investigations are based on a comprehensive characterization of the PBL and stratocumulus properties using the suite of systems described in section 4. Such multiple sensors have been applied to marine stratocumulus on only one other occasion (Miller et al. 1998) and our proposed measurements will be much more comprehensive. We will expand cloud retrieval methods pioneered by Frisch et al. (1995a) to obtain profiles of cloud liquid water content and effective radius. These data will be combined with measurements of downward radiative fluxes to improve bulk cloud-radiative parameterizations. The turbulence profiles will be obtained subcloud from the HRDL lidar, in the cloud from the cloud radar, and throughout the PBL from the 0.92 GHZ wind profiler. This will provide information for comparisons with LES model simulations and semi-empirical methods to continuously estimate entrainment rate. The surface aerosol measurements and the water vapor lidar will give important information on the parameterization of drizzle formation and radiative fluxes. The data will be used with a special LES with explicit cloud/aerosol microphysics to examine retrieval methods and entrainment/drizzle aspects in more detail.

Cloud Microphysics Retrievals. Retrievals of cloud or drizzle microphysics using a combination of a cloud radar and microwave radiometer were first demonstrated by Frisch et al. (1995a). The method is based on relating measurements to three parameters that characterize the cloud droplet spectrum as a lognormal distribution. Subsequent explicit modeling studies (Frisch et al. 1998) have shown the method is well-founded (essentially there is strong correlation between the 3rd and 6th moments of the distribution) and that the retrieval of the profile of liquid water is independent of the assumed distribution width. Work is also underway to reduce the sensitivity of the method to the assumed value of the droplet distribution normalized width (Frisch et al. 2000). The addition of the lidar and S-band radar will simplify the diagnosis of the presence of drizzle and improve retrievals (Eberhard et al. 1997). Also, the PBL aerosol measurements will allow us to examine relationships between aerosol and droplet concentrations (see below). So far, cloud retrievals have not been possible when drizzle swamps the cloud signal. In those conditions, the Frisch method gives complete characterization of profiles of drizzle size and number concentration which, combined with the surveys of the C-band radar, will give a unique view of drizzle in marine stratocumulus. Furthermore, the S-band radar spectra and lidar may allow us to extend cloud retrievals to greater drizzle concentrations.

Cloud Radiative Flux Parameterization. One critical part of characterization of stratocumulus clouds is their effects on the radiative balance. Fairall et al (1990) and Dong et al. (1997;1998) have developed methods based on measurement of downward radiative flux and cloud integrated liquid water content. Such parameterizations are similar to those found in climate models (e. g., Stevens et al. 1984; Slingo 1989; Chou et al. 1995; Gultepe et al. 1996). The Fairall model was extended to broken clouds by Chertock et al. (1993). One source of ambiguity in these models is the number of cloud droplets. However, this is thought to be closely linked to the aerosol CCN concentration (White et al. 1995). This cruise, which will be the first to combine solar flux, cloud liquid water, cloud radar, and aerosol measurements, will allow us to examine this issue.

Stratocumulus Dynamical Processes. The dynamics of stratocumulus clouds are a balance of entrainment, drizzle production, cloudtop radiative cooling, and possible decoupling of the cloud layer from the lower PBL (Krueger et al. 1995). Entrainment rate is the single most critical and most difficult parameter (Moeng et al. 1996). Considerable effort has been made in attempting to develop simple closures that allow parameterization of entrainment rate for numerical models (Moeng et al. 1999; van Zanten et al. 1999). Frisch et al. (1995b) demonstrated the use of cloud radar to obtain vertical velocity statistics profiles in clouds and the HRDL lidar will provide turbulence statistics profiles below the cloud. Thus, decoupling can be unambiguously diagnosed from direct measurements. Entrainment is closed linked to turbulence properties in the entrainment zone at the top of the PBL and there are theoretical scaling models available to compute entrainment velocity from the standard deviation of vertical velocity or the refractive index structure function parameter (see White et al. 1991, 1995, 1996). LES simulations will allow us to refine these scaling relations and use them to obtain estimates of the entrainment rate throughout the cruise. These can be studied as a function of drizzle, decoupling, surface forcing, and entrainment zone scaling parameters to test various entrainment rate parameterizations used in numerical models.

The collocation of a suite of instruments on board the RV Ron Brown affords an excellent opportunity to address issues related to aerosol-cloud interactions, precipitation formation, and the effect of precipitation on boundary layer dynamics (Albrecht 1989).

Aerosol-cloud interactions. In-situ aerosol measurements will provide detailed measurement of aerosol size distributions and chemical composition. DABUL will be used to put these surface measurements in a broader context by measuring backscatter at 30-m spatial resolution. The water vapor DIAL and DABUL will together provide information on aerosol hygroscopicity by exploring backscatter as a function of relative humidity (Wulfmeyer and Feingold 2000). Finally, these components will be combined with radar/radiometer-derived cloud microphysical properties (effective radius and drop number concentration) to investigate the relationship between subcloud aerosol properties, vertical velocity, and drop number concentration (Feingold et al 1998). The combination of lidar and radar is also an alternative method of deriving drop number concentration (Eberhard et al. 1997).

Precipitation formation. This will be addressed using surface observations of aerosol as well as cloud radar, radiometer, and lidar. Together these measurements provide important constraints for our large eddy simulation (LES) model. The LES is coupled to a size-resolving cloud microphysical model, as well as a radiation model that responds to cloud drop size. (e.g., Feingold et al. 1999a). We will use LES to explore sensitivity to aerosol parameters, liquid water path, boundary layer depth, and entrainment rates, and attempt to parameterize precipitation production in terms of such parameters.

Effect of precipitation on boundary layer dynamics. Precipitation redistributes heat and water vapor in the vertical and has a strong effect on boundary layer stability. The 35 GHz radar will be used to quantify rainrate using the technique of Frisch et al. (1995a). Doppler radars can also measure turbulence properties from velocity spectra so that a link between precipitation amount and boundary layer turbulence can be inferred (e.g. Stevens et al., 1998; Feingold et al. 1999b). Both model simulations and observations will be used to study this problem.

4. Background on Measurements

ETL proposes to bring a suite of measurement systems (Table 1) to continuously sample atmospheric properties from the sea surface through the troposphere. The systems have been deployed together at sea previously on the CSP (Post et al. 1998) and Nauru99 programs. The flux system (items 1&2) provides the basic characterization of the direct interaction of the ocean and atmospheric boundary layers (Fairall et al. 1997). The combination of Doppler radars (items 4,5, and 7) provide multi-wavelength characterization of precipitation profiles (Rajopadhyaya et al. 1999) to complement C-band radar and raingauge measurements. The ceilometer, lidars, cloud radar, and microwave radiometer provide comprehensive information on cloud properties. The wind profiler, HRDL lidar, and cloud radar can provide profiles of mean winds and turbulence throughout the boundary layer (subcloud and incloud) for characterization of stratocumulus dynamics (see White et al. 1996 for a review). Some additional details follow in this section.

Table 1. Instruments and measurements for proposed ship-based ITCZ and stratus/MBL field program in EPIC2001.
Item	System	Measurement
1	Direct flux measurement system	Direct covariance turbulent, radiative, rain fluxes
2	Near-surface bulk meteorology	Ts, Ta, RH, wind speed/direction; bulk fluxes
3	Ceilometer	Cloud-base height, statistics
4	3 GHz Doppler radar profiler	Precipitation Doppler spectra; calibrated dBZ
5	0.92 GHz Doppler radar wind profiler*	MBL wind & turbulence profiles; calibrated dBZ
6	20.6, 31.65 GHz wave radiometer	Integrated column vapor and cloud liquid water
7	35 GHz Doppler cloud radar	Cloud/precipitation microphysical properties
8	Upward pointed IR thermometer	Cloud-base radiative temperature
9	HRDL Doppler Lidar	Sub-cloud wind/turbulence profiles
10	Miniature water vapor Lidar	Water vapor profiles, cloud base heights
11	DABUL depolarization Lidar*	Aerosol/cloud backscatt., liquid/ice phase discrim.
12	BNL Portable Radiation *	Direct/diffuse solar, IR fluxes
*EPIC funds not requested to deploy these systems.

4.1	Flux system, ceilometer, and wind profiler

The primary role of the three-instrument combination (0.92 GHz wind profiler, ceilometer, flux system) is the measurement of boundary layer (PBL) structure (Fairall et al. 1997). The air-sea fluxes are fundamental drivers at the interface of both fluids. Turbulent fluxes are obtained using motion-corrected eddy covariance (Edson et al. 1998), inertial dissipation (Fairall et al. 1990; Edson et al. 1991), and bulk aerodynamic methods (Fairall et al. 1996a). Radiative fluxes are obtained using redundant, carefully calibration pyranometers and pyrgeometers (Fairall et al. 1998). Precipitation is obtained using redundant, carefully calibrated optical rain gauges. For EPIC2001, the rain gauges will be calibrated Dr. Frank Bradley in the rain tower at CSIRO, Canberra; both sensitivity and cosine response will be determined. The wind profiler gives profiles of wind and turbulence in the lower few km, even in the absence of precipitation and below cloud base (by virtue of "clear air" refractive index Bragg scattering). From the profile of clear-air backscatter intensity, it also give PBL depth in almost all conditions. The ceilometer gives continuous measurement of the cloud base height. For the purposes of EPIC, these instruments provide information on the modulation of PBL dynamics in the presence of precipitating systems (both deep and shallow) and the contrast with suppressed and stratocumulus conditions.

4.2	Precipitation radars

The wind profiler (Ecklund et al. 1988), the S-band radar (Ecklund et al. 1999), and K-
band cloud radar (Moran et al. 1998; Clothiaux et al. ) can improve quantitative precipitation estimates from the ship's scanning C-band Doppler radar. The UHF profilers originally developed by the AL for the measurement of lower tropospheric winds in the tropics (Rogers et al. 1993) have now been applied to precipitation research (Gage et al., 1994, 1996; Ecklund et al., 1995; Williams et al., 1995). The UHF profilers are sensitive to hydrometeors and provide a highly-resolved time-height cross section of precipitating cloud systems in the tropics. The ETL/AL systems look straight up, so they sense precipitation when it occurs directly overhead and, except for ship tilt, offer unambiguous sensing of the vertical velocity component. However, these radars offer additional information. Their Doppler spectral measurements give more complete and less ambiguous information (i.e., not convolved with some component of horizontal wind) on the precipitation fall speed distribution (Babb et al. 1999). The radars have been calibrated to ±1 dB, so they give good information on the dBZ profile directly above the ship, which can be linked to C-band radar near-zenith scans. The low Rayleigh scattering efficiency at 35 cm wavelength (0.92 GHz frequency) means that the wind profiler does not suffer from significant scattering attenuation effects, simplifying analysis. The radars give high vertical resolution (60-m) profiles of dBZ down to very close to the surface (about 0.2 km). Thus, information is obtained on the change in rain rate from (say) the typical 1 km height deduced from scanning precipitation radars to near the surface (where the rain gauges sample).

4.3	Cloud radar and microwave radiometers

ETL has an integrated system in a seatainer that includes a Doppler Ka-band cloud radar (MMCR) and a microwave radiometer (Snider and Hazen 1998); the system has been used on two cruises on the Ron Brown in 1999. Matrosov et al. (1995) and subsequent papers have outlined methods for deriving microphysical quantities of ice clouds (cirrus) using these instruments. Frisch et al. (1996a) and subsequent papers by various authors have discussed methods to combine the data from these systems to deduce profiles of cloud droplet size, number concentration, liquid water concentration etc. in stratus clouds. If drizzle (i.e., droplets of radius greater than about 50 m) is present in significant amounts, then the microphysical properties of the drizzle can be obtained from the first three moments of the Doppler spectrum. The system has similar applications in deep convective clouds, but microphysical retrievals are complicated by mean vertical motion in the air column. The radar is extremely sensitive and can detect most tropical cirrus and fair weather cumulus clouds. The Doppler capability can also be used to measure in-cloud vertical velocity statistics (Frisch et al., 1996b).

4.4	Lidars

Three ETL lidars are candidates for this field program. We are requesting EPIC funds for the first two; we will seek separate funds for the DABUL lidar. The high resolution Doppler lidar (HRDL) is a stabilized scanning system that can measure a variety of sub-cloud layer turbulence properties including stress and TKE profiles (Wulfmeyer et al. 1998). The Doppler lidar can obtain detailed information on the vertical and horizontal structure of the BL wind fields. Both systems have full-hemispheric scanning capabilities with motion compensation for shipboard operation. The specifications for the 2 micron system is approximately 3 km max range (depending on atmospheric conditions), 30 m range gate spacing, and .5 - 2 s (adjustable) time resolution. With the combined Doppler-DIAL system it will be possible to obtain water vapor profiles (with lesser time resolution) as well as high-resolution radial wind velocity field measurements.

A new compact, high-resolution water vapor profiling lidar will be used for a variety of studies of boundary layer sub-cloud moisture variability and structure (Machol et al. 1998). The miniature DIAL (differential absorption lidar) system has been developed to obtain continuous, vertical water vapor profiles, averaged for ~15 minutes, up to a height of ~2.5 km with a resolution of 90 m. In addition to water vapor profiles the lidar measurements can also provide cloud base heights throughout the troposphere as a subset of information since clouds provide such large signal returns. In this way, the lidar provides high-resolution water vapor structure and characteristics of the boundary layer air in concert with ceilometer-type cloud data.

The depolarization backscatter system (DABUL) yields profiles of backscatter and depolarization ratio for information on aerosol, clouds, and cloud phase (Alvarez et al. 1998). The DABUL system obtains continuous profiles of cloud and aerosol backscatter and depolarization ratios in scanning or vertically staring modes. This provides information on the structure of BL aerosol as well as cloud occurrence and the phase of the clouds throughout the troposphere. The system has a time resolution as short as 1 s, with range gates of 30 m, and a maximum range of 30 km, nominally. DABUL obtained measurements of low-level stratus clouds in addition to documenting high tropopause level (up to 18 km) cirrus clouds during the recent NAURU99 experiment.

5. Figures

Figure 1. Schematic illustration of core facilities requested for EPIC2001.

Figure 2. Proposed track for the R/V Ronald H. Brown.

Figure 3. Summary of surface heat flux components from the fall 1999 monitoring cruise on the R/V Ronald H. Brown. Fluxes are plotted vs latitude for the 110 W (blue) and 95 W (red) transects. The upper panel gives the net radiation (x's, dashed), the sensible heat (o's), and latent heat fluxes (no symbol). The lower panel is the total net flux to the ocean. The ITCZ is at about 8 N.

Figure 4. Mean wind direction vs latitude fo4r the PACS monitoring cruise in the fall of 1999.

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E. Biographical Summaries

CHRISTOPHER W. FAIRALL

Dr. Christopher Fairall received his Ph.D. in Physics from Michigan State University in 1970. He then received an NRC Postdoc at the Department of Physics at the Naval Postgraduate School in Monterey, California. In 1976 he began working in atmospheric physics while an Adjunct Professor of Physics at NPS. In 1983 he joined the Department of Meteorology at the Pennsylvania State University, receiving tenure in 1988. In 1989 he joined the Meteorological Applications and Assessments division at the NOAA Environmental Technology Laboratory in Boulder CO. In 1999 he was elected a fellow of the University of Colorado Cooperative Institute for Research in Environmental Sciences.

Dr. Fairall currently serves as a member of the Science teams for the NASA First ISSCP Regional Experiment (FIRE-III), the DOE Atmospheric Radiation Measurement (ARM) program, the NOAA CGCP Ocean Atmosphere Carbon Exchange Studies (OACES), and the NSF Surface Heat Budget of the Arctic (SHEBA) program. He is also member of the SHEBA science steering committee, the ARM Science Team Executive Committee, and is chairman of the ARM Tropical Western Pacific Science Advisory Committee. Past service includes: chairman of the AMS Committee on Boundary Layers and Turbulence (1987-1990), member of the AMS Committee on Meteorology and Oceanography of the Coastal Zone, the National Academy of Sciences Committee on Coastal Meteorology (1990-1993), the NSF Coastal Ocean Processes (CoOP) advisory committee (1991-1994), the NSF/NOAA TOGA COARE Science Team (1988-1998), and Associate Editor of the Journal of the Atmospheric Sciences (1991-
1994).

Dr. Fairall's current research includes air-sea-ice interactions, boundary-layer processes, clouds, optical/radio propagation in the atmosphere, and instrumentation/measurement techniques. He is the author/coauthor of more than 85 refereed publications in more than 20 different journals. His paper "Bulk parameterization of air-sea fluxes for TOGA COARE" (Fairall et al. JGR, 1996) received a NOAA outstanding publication award in 1997. He has presented invited papers at international symposia in France, Japan, Australia, and the US and has been invited to present short courses in Australia and Denmark. He has been invited to write review papers on such diverse subjects as sea spray effects on hurricanes, radar observations of clouds and turbulence, and the progress on air-sea interaction in the last 25 years.

Dr. Fairall has been an active leader in various aspects of NOAA research activities. He played a key role in the TOGA COARE experiment and was a leader of the COARE Flux Working Group. This work has led to greatly improved accuracy of air-sea fluxes by the NOAA TAO buoy array in the equatorial Pacific. He has recently helped form a consortium of four NOAA labs (PMEL, CMDL, AOML, and ETL) in a new program to advance parameterizations of air-sea exchange of CO2 . He recently participated in the joint NSF/ONR/DOE Surface Heat Budget of the Arctic (SHEBA) and the associated NASA FIRE Arctic Clouds study in the Beaufort Sea and the NSF/NOAA/NASA Joint Air-Sea Monsoon Experiment (JASMINE) in the Bay of Bengal.

FIVE RELEVANT PUBLICATIONS

Fairall, C. W., 1991: The humidity/temperature sensitivity of clear-air radars in the convective boundary layer. J. Appl. Meteor., 30, 1064-1074.

Frisch, A. S., D. H. Lenschow, C. W. Fairall, W. H. Schubert, and J. S. Gibson, 1995: Doppler radar measurements of turbulence in marine stratocumulus cloud during ASTEX. J. Atmos. Sci., 52, 2800-2808.

Fairall, C.W., E.F. Bradley, D.P. Rogers, J.B. Edson, and G.S. Young, 1996: Bulk parameterization of air-sea fluxes for TOGA COARE. J. Geophys. Res.,101, 3747-3767.

White, A. B., C W. Fairall, A. S. Frisch, B. W. Orr, and J. B. Snider, 1996: Recent measurements of turbulence and microphysical parameters in marine boundary layer clouds. Atmos. Res., 40, 177-221.

Fairall, C.W., A.B. White, J.B. Edson, and J.E. Hare, 1997: Integrated shipboard measurements of the marine boundary layer. J. Atmos. Oceanic Tech., 14, 338-359.

FIVE OTHER SIGNIFICANT PUBLICATIONS

Fairall, C. W., J. E. Hare, and J. B. Snider, 1990: An eight-month sample of marine stratocumulus cloud fraction, albedo, and integrated liquid water. J. Clim., 3, 847-864.

Chertock, B., C. W. Fairall, and A. B. White, 1993: Surface-based measurements and satellite retrievals of broken cloud properties in the equatorial Pacific. J. Geophys. Res., 98, 18,489-18,500.

White, A. B., C. W. Fairall, and J. B. Snider, 1995: Surface-based remote sensing of marine boundary layer cloud properties. J. Atmos. Sci., 52, 2827-2838.

Edson, J. B. and C. W. Fairall, 1998: Similarity relationships in the marine atmospheric surface layer for terms in the TKE and scalar variance budgets. J. Atmos. Sci., 55, 2311-2338.

Fairall, C. W., J. E. Hare, J. B. Edson, and W. McGillis, 1999: Parameterization and measurement of air-sea gas transfer. Bound.-Layer Meteorol., to appear.

COLLABORATORS IN THE LAST FOUR YEARS (Excluding those listed above)

Tom Ackerman	Robert J. Anderson	Judith Curry

Carl Friehe	J. Stuart Godfrey	Andrey Grachev

Peter Hacker	Lutz Hasse	Robert Houze

Kristina B.Katasaros	Steve Krueger	Roger Lukas

Wiebe A. Oost	Clayton Paulson	Wayne H. Schubert

Stuart D. Smith	Timothy P. Stanton	Pieter Tans

Osamu Tsukamoto	Peter J. Webster	Rik Wanninkhof

Robert Weller	Ed Westwater	Kunio Yoneyama

TANEIL UTTAL

Research Meteorologist

NOAA Environmental Technology Laboratory

325 Broadway, CO 80303

(303) 497-6409

tuttal@etl.noaa.gov

Education:	1979 - B.S. Physics Colorado College

1985 - M.S. Atmospheric Science - Colorado State University

Research Areas:	Radar meteorology, Arctic clouds, radiation and

climate studies.

Current Activities:	Science team member/lead PI on SHEBA, FIRE-ACE, and NASA/EOS Validation projects.

Field Experience:	15 field programs since 1978

Five Relevant Publications:

Uttal, T., E.E. Clothiaux, W.L. Eberhard, J. Intrieri, and T. Ackerman, 1995: Cloud boundary statistics during FIRE II, 1995. J. Atmos. Sci., 52, 4276-4284.

Intrieri, J.M., T. Uttal, W. Eberhard, J.Snider, Y.Han, B.Orr, and S. Matrosov, 1994: Multi-wavelength observations of cirrus clouds during FIRE-II, 1995. J.Atmos. Sci., 52, 4079-4093.

Uttal, T., S.Y.Matrosov, J.B.Snider, and R.A. Kropfli, 1994: Relationships between ice water path and downward longwave radiation for clouds optically thin in the infrared: Observations and model calculations, 1994. J.Appl. Meteor., 33, 348-357.

Intrieri, J.M., G.L. Stephens, W.L.Eberhard, and T. Uttal, 1993: A method for estimating cirrus cloud particle sizes using a radar/lidar backscatter tecnique. J.Appl. Meteor., 32, 1074-1082.

Palmer, A.J., S.Y. Matrosov, B.E. Martner, T.Uttal, D.K. Lynch, and M.A. Chatelain, 1993: Combined infrared emission spectra and radar reflectivity studies of cirrus clouds. IEEE Trans. Geosci. Remote Sensing, 97-D11, 11567-11574.

Five Other Publications

Uttal, T., R.A. Kropfli, T.A. Sutherland: Effect of pulse length on radar reflectivity statistics. Submitted to J. Appl. Meteor.

Baum, B.A., T.Uttal, M.Poellot, T.P.Ackerman, J.M. Alverez, J.Intrieri, D,O'C. Starr, J.Titlow, V.Tovinkere, and E.E. Clothiaux, 1995: Satellite remote sensing of multiple cloud layers. J.Atmos Sci., 52, 4210-4230.

Uttal, T., J.B. Snider, R.A. Kropfli, and B.W. Orrr, 1990: A remote sensing method of measuring atmospheric vapor fluxes: Application to winter mountain storms. J.Appl. Meteor., 29, 22-34.

Sassen, K., D. O'C. Starr and T. Uttal, 1989: Mesoscale and microscale structure of cirrus clouds: Three case studies, J.Atmos Sci., 46, 371-396

Uttal, T. R.M. Rauber, L.O. Grant, 1988: Distributions of Liquid, Vapor and Ice in an Orographic Cloud from Field Observations, J.Amos. Sci., 45, 1110-1122.

COLLABORATORS IN THE LAST FOUR YEARS (Excluding those listed above)

Bob Bantsa	Paul Ciesielski	Judith Curry

Frank Evans	Shelby Frisch	Ismail Gultupe

Gerald Mace	Patrick Minnis	Peter Pilewski

Roger Reinking	Junhong Wang	Ed Westwater

Paquita Zuidema

JANET M. INTRIERI

Atmospheric Research Scientist

NOAA/ Environmental Technology Laboratory/ Atmospheric Lidar Division

325 Broadway, Boulder, CO 80303

(303) 497-6594, jintrieri@etl.noaa.gov

PROFESSIONAL PREPARATION:

Pennsylvania State University	Meteorology	B.S., 1985

Colorado State University	Atmospheric Sciences	M.S., 1991

University of Colorado	Aerospace Engineering	M.S., 1996

University of Colorado	Aerospace Engineering	Ph.D., in progress

APPOINTMENTS:

NOAA/ETL, Atmospheric Lidar Division, 5/87 - present

NOAA/ETL, Meteorological Applications Division, 9/85 - 4/87

NOAA/Forecast Systems Laboratory, Summer of 1985

GRADUATE ADVISORS:

Dennis Thomson	Pennsylvania State University

Graeme Stephens	Colorado State University

Judith Curry	University of Colorado

FIVE RELEVANT PUBLICATIONS

Intrieri, J.M., A.J. Bedard, Jr., and R.M. Hardesty, 1990: Details of colliding thunderstorm outflows as observed by Doppler lidar. J. Atmos. Sci., 47, 1081-1098.

Intrieri, J.M., G.L. Stephens, W.L. Eberhard, and T. Uttal, 1993: A method for determining cirrus cloud particle sizes using a lidar and radar backscatter technique. J. Appl. Meteor., 32, 1074-1082.

Intrieri, J.M., W.L. Eberhard, T. Uttal, J.B. Snider, Y. Han, J.A. Shaw, B.W. Orr, and S.Y. Matrosov, 1995: Multi-wavelength observations of a developing cloud system: The FIRE II 26 November 1991 case study. J. Atmos. Sci., 52, 4079-4093.

Matrosov, S.Y., A.J. Heymsfield, J.M. Intrieri, B.W. Orr, and J.A. Snider, 1995: Ground-based remote sensing pf cloud particle sizes during the 26 November 1991 FIRE II cirrus case: Comparisons with in situ data. J. Atmos. Sci., 52, 4128-4142.

Key, J.R., and J.M. Intrieri, 2000: Cloud particle phase determination with the AVHRR. J. Appl. Meteor. (submitted).

FIVE OTHER PUBLICATIONS

Intrieri, J.M., C.G. Little, W.J. Shaw, P.A. Durkee, R.M. Banta, and R.M. Hardesty, 1990: The Land/Sea Breeze Experiment (LASBEX). Bull. Amer. Meteor. Soc., 71, 656-664.

Pinto, J.O., J.A. Curry, J.M. Intrieri, 2000: Cloud-aerosol interactions during autumn over the Beaufort Sea. J. Geophys. Res. (submitted).

Beesley, J.A., C.S. Bretherton, C. Jakob, E.L. Andreas, J.M. Intrieri, and T. Uttal, 2000: A comparison of cloud and boundary-layer variables in the ECMWF forecast model with observations at SHEBA. J. Geophys. Res. (submitted)

Intrieri, J.M., S.P. Sandberg, and C. Palovski, 2000: Observations of tropical cirrus clouds from ETL's depolarization lidar during NAURU99. 10th Annual DOE/ARM Sceince Team Meeting, 13-17, 2000, San Antonio, TX, (submitted).

COLLABORATORS:

Judith Curry	University of Colorado

Jeffrey Key	University of Wisconsin

Don Perovich	Cold Regions Research and Engineering Laboratory

Tony Beesley	University of Illinois

James Pinto	University of Colorado

Chris Bretherton	University of Washington

Dick Moritz	University of Washington

Edgar Andreas	Cold Regions Research and Engineering Laboratory

KENNETH S. GAGE

Program Leader

Tropical Dynamics and Climate Program

NOAA Aeronomy Laboratory

Boulder, Colorado

RESEARCH INTERESTS:

Application of wind profilers to tropical dynamics and climate research; radar meteorology;	large-scale ocean atmosphere interactions; geophysical fluid dynamics; mesoscale convective systems; multiple-scale interactions; and dynamics of climate variability.

EDUCATION:

B.S.	1964	Brandeis University (Physics)

Ph.D	1968	University of Chicago (Geophysical Sciences)

PROFESSIONAL EXPERIENCE:

1968-1972	Assistant Professor, Graduate Meteorology

Program of the Institute for Fluid Dynamics and Applied

Mathematics, University of Maryland, College Park, MD.

1972-1973	Visiting Associate Professor, Engineering

Experiment Station and Department of Meteorology,

University of Wisconsin, Madison, WI.

1973-1976	Principal Scientist, Meteorology Department,

Control Data Corporation, Minneapolis, MN.

1976-1985	Physicist, Atmospheric Dynamics Program,

Aeronomy Laboratory, NOAA, Boulder, CO.

1985-1990	Physicist, Tropical Dynamics and Climate Program,

Aeronomy Laboratory, NOAA, Boulder, CO.

1990-present Program Leader, Tropical Dynamics and Climate Program,
Aeronomy Laboratory, NOAA, Boulder, CO.

HONORS AND AWARDS:

Ford Foundation Fellowship, University of Chicago, 1964 -1965

Research Corporation Award, University of Maryland, 1970

NOAA, ERL, Outstanding Paper Awards, 1981, 1983, 1991, 1999

Department of Commerce, Technology Transfer Award, 1993

Department of Commerce Bronze Award for Superior Federal Service, 1997

SCIENTIFIC MEMBERSHIPS, COMMITTEES AND SERVICE APPOINTMENTS:

Scientific Research Society of America

American Meteorological Society

American Geophysical Union

United States National Committee of URSI-Commission F

AMS Committee on Atmospheric and Oceanic Waves and Stability, 1983-1985

AMS, Committee on Radar Meteorology, 1987-1993; Chairman, 1992-1993

Advisory Board, CIMMS, University of Oklahoma, 1985-1992

Advisory Group, International Center for Equatorial Atmospheric Radar (ICEAR), 1992-

Associate Editor, Journal of Climate and Applied Meteorology, 1982-1990

Associate Editor, Radio Science, 1987-1993

Editor, Journal of Geophysical Research-Atmospheres, 1988-1992

Management Review Board, CRADA for the Lower Tropospheric Wind Profiler, 1991-

Science Team, DOE, ARM Program, 1990-present.

Scientific Advisory Board, The Western Pacific Site of DOE ARM, 1994-present.

TOGA COARE Sounding Implementation Group, 1990-1993

Coordinator for joint U.S.-Indonesian research under bi-lateral climate research MOU, 1992-

Program Co-Chair, Third International Symposium on Tropospheric Profiling, Hamburg, 1994

Guest Editor, Radio Science, Taiwan MST Radar Workshop, 1994-1995.

Guest Editor, Contr. to Atmospheric Physics, Special Issue on Tropospheric Profiling, 1995

TRMM Science Team Member 1997-present.

MOST RECENT AND MOST RELEVENT PUBLICATIONS:

Gage, K.S., B.B. Balsley, W.L. Ecklund, D.A. Carter, and J.R. McAfee. Wind profiler related research in the
tropical Pacific, J. Geophys. Res., 96, 3206-3220, 1991.

Gage, K.S., J.R. McAfee, D.A. Carter, W.L. Ecklund, A.C. Riddle, G.C. Reid, and B.B. Balsley. Direct
measurement of long-term mean vertical motions over the tropical

Pacific using wind-profiling Doppler radar, Science, 254, 1771-1773, 1991.

Gage, K.S., J.R. McAfee, D.A. Carter, A.C. Riddle, P.E. Johnston, and B.B. Balsley, Wind profiler yields
observations of ENSO signal, Eos Transactions of the AGU, 74, 137, 142, 1993.

Gage, K.S., J.R. McAfee, W.L. Ecklund, D.A. Carter, C.R. Williams, P.E. Johnston, and A.C. Riddle, The
Christmas Island wind profiler: A prototype VHF wind-profiling radar for the tropics, J. Atmos. and Oceanic Tech., 11, 22-31, 1994.

Gage, K.S., C.R. Williams and W.L. Ecklund, Application of the 915 MHz profiler for diagnosing and classifying
tropical precipitating cloud systems, Meteorology and Atmospheric Physics, 59, 141-151, 1996.

Gage, K.S., JR. McAfee and C.R. Williams, On the annual variation of tropospheric zonal winds	observed above
Christmas Island in the central equatorial Pacific, J. Geophys. Res., 101,15,061-15,070, 1996.

Gage, K.S., J.R. McAfee and C.R. Williams, Recent Changes in tropospheric circulation over the central equatorial
Pacific, Geophys. Res. Lett., 23, 2,149-2,152,1996.

McPhaden, M.J.,et al., The Tropical Ocean	Global Atmosphere (TOGA) Observing System: A decade of
progress, J. Geophys. Res., 103, 14,169-14,240, 1998.

Gage, K.S., C.R. Williams, W.L. Ecklund, and P.E. Johnston, Use of two profilers during MCTEX for
unambiguous identification of Bragg scattering and Rayleigh scattering. J. Atmos. Sci., 56, 3679-
3691,1999.

Gage, K.S., C.R. Williams, W.L. Ecklund, and P.E. Johnston, Development and application of Doppler radar
profilers to ground validation of satellite precipitation measurements, Adv. In Space Sci., in press, 1999.

Hartten, L.M., and K.S. Gage, ENSOÕs impact on the annual cycle: The view from the Gal‡pagos,
Geophys. Res. Lett., in press, 2000.

GRAHAM FEINGOLD

Education:

1989:	Ph.D, Geophysics and Planetary Sciences (summa cum laude),

Tel Aviv University, Israel.

1985:	M.Sc, Geophysics and Planetary Sciences (summa cum laude),

Tel Aviv University, Israel.

1982:	B.Sc:Geophysics and Atmospheric Sciences,

Tel Aviv University, Israel.

Appointments:

Present:	Research Scientist, CIRA

Colorado State University, Fort Collins.

1994-1997:	Research Associate, CIRA.

1991-1994:	Research Associate, CIRES, CU, Boulder

1993-1994:	Adjunct Faculty, Department of Atmospheric Science

Colorado State University, Fort Collins.

1990-1991:	Post-doctoral fellow at Mesoscale and Microscale

Meteorology Division, NCAR.

Sample of Relevant Publications:

Feingold, G., W. R. Cotton, S. M. Kreidenweis, and J. T. Davis, 1999: Impact of giant cloud condensation nuclei on drizzle formation in marine stratocumulus: Implications for cloud radiative properties. J. Atmos. Sci., 56, 4100-4117.

Feingold, G., S. Yang, R. M. Hardesty, and W. R. Cotton, 1998: Retrieving cloud condensation nucleus properties from Doppler cloud radar, microwave radiometer, and lidar. J. Atmos. Ocean. Tech., 15, 1189-1196.

Stevens, B., W. R. Cotton, G. Feingold, and C.-H. Moeng, 1998: Large-eddy simulations of strongly precipitating, shallow, stratocumulus-topped boundary layers. J. Atmos. Sci., 55, 3616-3638.

Feingold, G. A. S. Frisch, B. Stevens, and W. R. Cotton, 1999: The stratocumulus-capped boundary layer as viewed by K-band radar, microwave radiometer and lidar. J. Geophys. Res., 104, 22,195-22,203.

Wulfmeyer, V., and G. Feingold, 2000: On the relationship between relative humidity and particle backscattering coefficient in the marine boundary layer determined with differential absorption lidar. In Press J. Geophys. Res.

Synergistic Activities:

Development of numerical models for community use

Volunteer work for youth education in South and Central America

Collaborators and other Affiliations:

Prof. W. R. Cotton (Colorado State University)

Dr. Y. Kaufman (NASA/Goddard)

Prof. S. M. Kreidenweis (Colorado State University)

Dr. W. R. Leaitch (AES-Canada)

Prof. Z. Levin (Tel Aviv University)

Prof. B. Stevens (UCLA)

Graduate and Post-Doctoral Advisors:

Graduate advisor: Prof. Z. Levin (Tel Aviv University)

Postdoctoral advisor: Dr. A. Heymsfield (NCAR/MMM)

Thesis Advisor and Postgraduate-Scholar Sponsor

Ph.D: Bjorn Stevens (UCLA),Yiping Zhang (NCAR/CGD), Jerry Harrington (Geophysical Institute, Alaska)

MS: Wendy Richardson (EPA),Kristi Schueler (CSU)

Postdoctoral scholar: Cheol-Hee Kim (CSU)

Total: 1 Postdoctoral scholar, 3 PhD students, 2 MS students

F. Budget Details

1. Tasks

This is a three-year proposed effort. The first year will be devoted to processing some existing data and preparation of some measurement systems. The second year will have further instrument preparation and the execution of the field program on the research vessels. The third year will be devoted to data processing, analysis, and modeling studies.

Data Processing.

Fairall and Frisch are currently acquiring cloud and PBL data from twice-yearly routine cruises along 110 W and 95 W tao buoy lines (see section C2). The on cruises by the R/V Ron Brown, the ship's C-band Doppler radar is being operated and archived. These C-band radar data will be turned over to Bob Houze and UW for analysis for drizzle. We will work with the UW group on examining joint drizzle and stratocumulus situations. This is a simple preliminary study for EPIC2001.

In June 1999 some measurements were made on the R/V Ron Brown in the tropical western Pacific as part of the Nauru99 study (see section C2). These included simultaneous cloud, S-band, 0.92 GHz radar measurements plus the HRDL and DABUL lidars. The DABUL only operated part of the time, but this data gives us an opportunity to examine outflows from convection (midlevel and cirrus) as discussed in the proposal.

In May 1999 some measurements were made on the R/V Ron Brown in the Indian Ocean as part of the Jasmine study (see section C2). These included air-sea fluxes, rainrate, and indexes of deep convection from the C-band radar. The cruise included prolonged periods of disturbed and undisturbed conditions. These data will give us an opportunity for a preliminary examination of surface flux variability and comparisons of precipitation retrievals with the C-
band other radars as discussed in the proposal.

Instrument Preparation

The water vapor lidar has never been deployed at sea and will need to be hardened for shipboard operations. Both HRDL and DABUL were operated as sea during Nauru99 and several problems were encountered that need to be corrected. The DABUL scanner must be beefed up for ship use and the HRDL motion-correction software needs to be completely redone.

An installation for the S-band radar must be prepared for the R/V New Horizon. The microwave radiometer had alignment problems in the 1999 campaigns and the setup must be re-engineered for better performance at sea. The cloud radar operated without problems. We are planning an extensive calibration period for 0.92 GHz, S-band, and cloud radars in Boulder. These systems will be cross-calibrated against the ETL scanning Ka-band radar system, which has a vary narrow beam and can be directly calibrated against a sphere at the Boulder Atmospheric Observatory. This will also establish and indirect calibration for the Brown's C-band radar.

Because of the importance of accurate rain rate measurements, in the second year of the project Dr. E. F. Bradley of CSIRO (Canberra, Australia) will be commissioned to calibrate all in situ raingauges for both reseach vessels in the CSIRO rain tower. He will also bring the well-
calibrated CSIRO raingauges on the R/V Ron Brown during the field program.

Field Program

All instruments will be shippped to San Diego, installed on the ship, operated throughout both cruise legs, offloaded in Manzanillo, and shipped back to Boulder.

Post-processing and Analysis

A certain amount of straightforward (operational) processing is done realtime, while the ship is at sea, and immediately after the cruise. Some systems (e.g., the flux system, cloud radar, HRDL) require massive post-processing to obtained the required derived quantities. In most cases, a second stage of processing is required to account for calibration issues, reduce time series to derived quantities, and to combine data from different instruments.

2. Miscellaneous

Shipping

Three seatainers will be shipped to San Diego for the R/V Ron Brown:

1.1	Cloud radar and microwave radiometer

1.2	DABUL

1.3	Flux system, DABUL, and water vapor lidar.

The shipping of the S-band radars will be decided when the port for the R/V New Horizon is known.

Cloud radar transmitter tube amortization

The cloud radar uses a special traveling wave transmitter tube with a life time of 1 year of continuous operation. Replacement cost is $240,000 or about $20,000 per month of operation. ETL cost shares 50% of the cost of replacement with the funding agency.

3. Personnel Duties

C. Fairall will be the PI. General division of duties will be as follows:

Air-Sea flux system:	J. Hare, C. Fairall

Cloud radar:	T. Uttal, B. Orr, and D. Hazen

Microwave radiometer:	D. Hazen

Lidar systems:	J. Intrieri plus two engineers

S-band radars:	Paul Johnston, Werner Ecklund

Precipitation analysis:	K. Gage, A. White, B. Orr, G. Feingold

Flux parameterization:	C. Fairall, A. White

ABL analysis:	A. White, C. Fairall

ITCZ cloud retrievals:	T. Uttal and J. Intrieri

Stratocumulus cloud retrievals:	A. S. Frisch and J. Intrieri

Stratocumulus modeling:	G. Feingold

The costs of this proposal include analysis, creation of datasets for sharing with other EPIC investigators, scientific interpretation, and modeling. The investigators will work closely with S. Rutledge on quantitative precipitation and the C-band radar, with N. Bond (PMEL) on radiosondes and aircraft boundary-layer analysis, with B. Albrecht (U. Miami) and P. Minnis (NASA) on satellite interpretation, with R. Houze and S. Yuter on C-band radar analysis and calibration, and with C. Bretherton on application of the data to LES. The air-sea flux data will be made available to the oceanographic component as quickly as possible; the flux investigators will require ocean mixed layer data.

4. Component Costs

This proposed work involves six distinct measurement systems being applied to three different EPIC bundles. Most of the systems have different priorities for different bundles. Some personnel costs are associated with the operation and processing of a particular system while others are with a other processing, analysis, or modeling efforts. It is not possible to unambiguously assign a cost for a bundle or the deployment of a system. For example, if two systems are shipped in the same seatainer (e.g. DABUL lidar and flux system), then not deploying the lidar system does not save shipping costs. Similarly, if one technician takes care of two lidar systems, then not deploying one of the lidar does not save technician costs, although it does save preparation and processing costs.

For reference purposes only, we have attempted to compute a breakdown of costs associated with preparation, deployment and postprocessing costs (designated below by the term 'field') for each measurement system plus data integration and analysis/modeling costs allocated to the ITCZ/ABL and Stratocumulus efforts.

Function	Cost (k$)

Flux field	114.5

HRDL	field	184

Water Vapor Lidar field	121

Radar/microwave radiometers field	154.5

S-band radars field	92

Data Integration	46.5

ITCZ/ABL	80.5

Stratocumulus	103

Total	896

Based on an evaluation of the distribution of resources for the three bundles, we estimate the individual costs as follows:

ITCZ	305 k$

ABL	234 k$

Stratocumulus	357 k$

G. Current and Pending Support

1	C. W. Fairall

CURRENT

PI: C. Fairall, seven Co-I's.

C. Fairall person months: 2 mo./yr

Source: Dept. Energy ARM, DE-AL02-92ER61366

Title: Shipboard measurements of cloud-radiative properties in the tropical western Pacific - The Nauru-99 experiment

Amount: $1,260,00 for FY98-00

PI: C. Fairall, 2 Co-Is.

C. Fairall person months: 2 mo./yr

Source: Office of Naval Research, N00014-96-F-0011

Title: Parameterization of air-sea fluxes for high wind conditions

Amount: $235,000 for FY98-00

PI: P. Webster, 1 Co-I

C. Fairall person months: 1 mo./yr

Source: NSF-ATM

Title: JASMINE, the Joint Air-Sea Monsoon Interaction Experiment: A pilot shipboard study of air-sea fluxes and precipitation.

Amount: $226,000 for FY99-00

PI: C. Fairall, 1 Co-I

C. Fairall person months: 1 mo/yr

Source: NASA FIRE program

Title: Shipboard monitoring of tropical marine cirrus cloud properties in the Jasmine region

Amount: $100,000 for FY00-01

PI: C. Fairall, 1 Co-I

C. Fairall person months: 2 mo/yr

Source: NOAA Climate and Global Change PAS Program

Title: Shipboard monitoring of stratocumulus cloud properties in the PACS region

Amount: $419,400 for FY99-01

PENDING

PI: M. Post, 4 Co-I

C. Fairall person months: 2 mo/yr

Source: NASA TRMM program

Title: Analysis of TRMM Kawjex data from the R/V Ronald H. Brown

Amount: $325,000 for FY00-01

PI: J. Curry, 6 Co-I

C. Fairall person months: 2 mo/yr

Source: NASA

Title: Investigation of satellite methods to retrieve air-sea fluxes.

Amount: $1,925,000 for FY00-02

PI: C. Fairall, 1 Co-I

C. Fairall person months: 2 mo/yr

Source: NOAA CGCP

Title: Establishment of the first integrated in situ air-sea flux database.

Amount: $197,500 for FY00-01

2. G. Feingold

PI: Kaufman, 3 Co-I's

Title: Satellite Study of Smoke Indirect Radiative Forcing

Supporting Agency: National Aeronautics & Space Administration (NASA)

Annual Award: $40,000

Period Covered: 08/01/98-07/31/01

Location of Research: NOAA Environmental Technology Laboratory

Person-Months: 4.3

PIs: Kreidenweis and Feingold, 1 Co-I

Title: Impact of Clouds on Nitrogen Species and Ozone in the NARE Boundary Layer

Supporting Agency: NOAA Office of Global Programs

Annual Award: $130,000

Period Covered: 04/01/98-03/31/01

Location of Research: Colorado State University

Person-Months: 4.3

PIs: Martner, Eberhard, Uttal, Feingold

Title: Climate Related Remote Sensing Studies of Clouds: Arctic Focus

Supporting Agency: NOAA Office of Global Programs

Annual Award: $80,000

Period Covered: 06/01/98-05/31/01

Location of Research: NOAA Environmental Technology Laboratory

Person-Months: 1.0

PIs: Cotton and Feingold, 3 Co-I's

Title: Fundamental Studies of aerosol/boundary layer cloud interactions

Supporting Agency: National Science Foundation (NSF)

Annual Award: $120,000

Period Covered: 05/01/99-04/30/02

Location of Research: Colorado State University

Person-Months: 2.0

3. K. Gage

CURRENT

PI: S. K. Avery, 3 Co-I

K. Gage person months: 1 mo/yr

Source: NSF ATM-9614613

Title: The Pacific Profiler Network: Tropical Dynamics Research

Amount: $1,325,000 for FY97-00

PI: C. Fairall, seven Co-I's.

K. Gage: 2 mo./yr

Source: Dept. Energy ARM, DE-AL02-92ER61366

Title: Shipboard measurements of cloud-radiative properties in the tropical western Pacific - The Nauru-99 experiment

Amount: $1,260,00 for FY98-00

PI: K. Gage, 2 Co-I

K. Gage person months: 1 mo/yr

Source: NOAA PACS

Title: Lower-Troposphere Dynamics Over the Eastern Pacific

Amount: $137,123 for FY97-00

PENDING

PI: K. Gage, 2 Co-I

K. Gage person months: 3 mo/yr

Source: NASA TRMM

Title: Comparative Analyses of TRMM Profiler Observations

Amount: $2444,488 for FY00-02

PI: S. K. Avery, 3 Co-I

K. Gage person months: 3 mo/yr

Source: NOAA CLIVAR

Title: A Trans-Pacific Profiler Network for Climate Observations

Amount: $1,808,000 for FY00-04

4. T. Uttal

CURRENT

PI: Taneil Uttal, 4 Co-I

T. Uttal person months: 3.0/year

Source: NASA/CIRES/EOS

Title: Validation of CERES Cloud Retrievals over the Arctic with Surface-Based Millimeter-
Wave Radar

Amount: $407,500 for FY98-00

PI: Chris Fairall, 1 Co-I

T. Uttal Person Months: 2.0/yr

Source: NASA/FIRE

Title: Shipboard Monitoring of Tropical Marine Cloud Properties in the Jasmine Region

FY 99-00 $100,000

PI- Taneil Uttal - 6 Co-I

T. Uttal person months: 1.3 months/year

Source: NASA FIRE-ACE

Title: Ground Based and Remote Sensing of the Microphysical and Radiative Properties of Clouds: Comparisons with Mid-Latitude and Sub-Tropical Systems

Taneil Uttal - PI

Amount: FY 99-00 $304,000

5. J. Intrieri

None

H. Facilities

The NOAA Environmental Technology Laboratory and Aeronomy Laboratory are located in the DSRC, 325 Broadway, Boulder, CO. Each laboratory has about 200 employees and the normal complement of computer, field, and laboratory resources. More information on the labs can be found at http://www.etl.noaa.gov/ and http://www.al.noaa.gov/ . The measurement systems proposed for this work already exist and are committed to the field work if it is funded.