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Title: RACORO long-term, systematic aircraft observations of boundary layer clouds

Abstract

Our knowledge of boundary layer cloud processes is insufficient to resolve pressing scientific problems. Boundary layer clouds often have liquid-water paths (LWPs) less than 100 gm{sup 2}, which are defined here as being 'thin' Clouds with Low Optical Water Depths (CLOWD). This type of cloud is common globally, and the Earth's radiative energy balance is particularly sensitive to small changes in their optical properties. However, it is difficult to retrieve accurately their cloud properties via remote sensing because they are tenuous and often occur in partly cloudy skies. This interferes with our ability to obtain the routine, long-term statistics needed to improve their representation in climate models. To address this problem, in-situ data are needed to investigate cloud processes and to evaluate and refine existing retrieval algorithms. Coordinated by the ARM Aerial Facility (AAF), the Routine AAF CLOWD Optical Radiative Observations (RACORO) field campaign conducted long-term, systematic flights in boundary layer, liquid-water clouds over the ARM Southern Great Plains (SGP) site between 22 January and 30 June 2009. This was the first time that a long-term aircraft campaign was undertaken for systematic in-situ sampling of cloud properties. Using the CIRPAS Twin Otter aircraft equipped with a comprehensive set of instrumentsmore » to measure solar and thermal radiation, cloud microphysics, aerosol properties and atmospheric state, the RACORO team logged an unprecedented 59 flights and 259 research hours above the SGP site. Data gathered during the RACORO campaign will provide researchers with a statistically relevant data set of boundary-layer cloud and aerosol properties for future study. These data can be used to validate retrieval algorithms and support process studies and model simulations of boundary layer clouds and, in particular, CLOWD-type clouds. In addition to cloud observations, complementary clear-sky flight patterns were conducted to map the surface albedo, characterize the aerosol and cloud condensation nuclei, and study boundary layer turbulence. For RACORO to operate as a routine, long-term program, flight operations had to be kept as simple as possible to achieve its objectives, which required an operating paradigm different from typical, short-term, intensive aircraft field programs. This poster summarizes RACORO operations, measurements and instruments.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
BROOKHAVEN NATIONAL LABORATORY (BNL)
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
982745
Report Number(s):
BNL-91362-2010-CP
R&D Project: 2012-BNL-EE630EECA-BUDG; KP1701000; TRN: US201014%%67
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Conference
Resource Relation:
Conference: American Meteorological Society 13th Conference on Cloud Physics; Portland, OR; 20100627 through 20100702
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; AEROSOLS; AIRCRAFT; ALBEDO; ALGORITHMS; BOUNDARY LAYERS; CLIMATE MODELS; CLOUDS; CONDENSATION NUCLEI; ENERGY BALANCE; OPTICAL PROPERTIES; PHYSICS; PRESSING; REMOTE SENSING; SAMPLING; STATISTICS; THERMAL RADIATION; TURBULENCE; WATER

Citation Formats

Vogelmann, A.M., McFarquhar, G., Ogren, J., Turner, D. D., Comstock, J. M., Feingold, G., Long, C. N., Jonsson, H. H., Bucholtz, A., Collins, D. R., Diskin, G., Gerber, H., Lawson, R. P., Woods, R. K., Hubbe, J., Tomlinson, J., and Schmid, B. RACORO long-term, systematic aircraft observations of boundary layer clouds. United States: N. p., 2010. Web.
Vogelmann, A.M., McFarquhar, G., Ogren, J., Turner, D. D., Comstock, J. M., Feingold, G., Long, C. N., Jonsson, H. H., Bucholtz, A., Collins, D. R., Diskin, G., Gerber, H., Lawson, R. P., Woods, R. K., Hubbe, J., Tomlinson, J., & Schmid, B. RACORO long-term, systematic aircraft observations of boundary layer clouds. United States.
Vogelmann, A.M., McFarquhar, G., Ogren, J., Turner, D. D., Comstock, J. M., Feingold, G., Long, C. N., Jonsson, H. H., Bucholtz, A., Collins, D. R., Diskin, G., Gerber, H., Lawson, R. P., Woods, R. K., Hubbe, J., Tomlinson, J., and Schmid, B. Sun . "RACORO long-term, systematic aircraft observations of boundary layer clouds". United States. https://www.osti.gov/servlets/purl/982745.
@article{osti_982745,
title = {RACORO long-term, systematic aircraft observations of boundary layer clouds},
author = {Vogelmann, A.M. and McFarquhar, G. and Ogren, J. and Turner, D. D. and Comstock, J. M. and Feingold, G. and Long, C. N. and Jonsson, H. H. and Bucholtz, A. and Collins, D. R. and Diskin, G. and Gerber, H. and Lawson, R. P. and Woods, R. K. and Hubbe, J. and Tomlinson, J. and Schmid, B.},
abstractNote = {Our knowledge of boundary layer cloud processes is insufficient to resolve pressing scientific problems. Boundary layer clouds often have liquid-water paths (LWPs) less than 100 gm{sup 2}, which are defined here as being 'thin' Clouds with Low Optical Water Depths (CLOWD). This type of cloud is common globally, and the Earth's radiative energy balance is particularly sensitive to small changes in their optical properties. However, it is difficult to retrieve accurately their cloud properties via remote sensing because they are tenuous and often occur in partly cloudy skies. This interferes with our ability to obtain the routine, long-term statistics needed to improve their representation in climate models. To address this problem, in-situ data are needed to investigate cloud processes and to evaluate and refine existing retrieval algorithms. Coordinated by the ARM Aerial Facility (AAF), the Routine AAF CLOWD Optical Radiative Observations (RACORO) field campaign conducted long-term, systematic flights in boundary layer, liquid-water clouds over the ARM Southern Great Plains (SGP) site between 22 January and 30 June 2009. This was the first time that a long-term aircraft campaign was undertaken for systematic in-situ sampling of cloud properties. Using the CIRPAS Twin Otter aircraft equipped with a comprehensive set of instruments to measure solar and thermal radiation, cloud microphysics, aerosol properties and atmospheric state, the RACORO team logged an unprecedented 59 flights and 259 research hours above the SGP site. Data gathered during the RACORO campaign will provide researchers with a statistically relevant data set of boundary-layer cloud and aerosol properties for future study. These data can be used to validate retrieval algorithms and support process studies and model simulations of boundary layer clouds and, in particular, CLOWD-type clouds. In addition to cloud observations, complementary clear-sky flight patterns were conducted to map the surface albedo, characterize the aerosol and cloud condensation nuclei, and study boundary layer turbulence. For RACORO to operate as a routine, long-term program, flight operations had to be kept as simple as possible to achieve its objectives, which required an operating paradigm different from typical, short-term, intensive aircraft field programs. This poster summarizes RACORO operations, measurements and instruments.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2010},
month = {6}
}

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