Toward understanding of differences in current cloud retrievals of ARM ground-based measurements

Journal Article · Wed May 30 04:00:00 EDT 2012 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/2011JD016792· OSTI ID:1048191

Zhao, C; Dunn, M; Xie, S; Klein, S A; Protat, A; Shupe, M D; McFarlane, S A; Comstock, J M; Delanoë, J; Deng, M; Hogan, R J; Huang, D; Jensen, M P; Mace, G G; McCoy, R; O’Connor, E J; Turner, D D; Wang, Z

Accurate observations of cloud microphysical properties are needed for evaluating and improving the representation of cloud processes in climate models and better estimate of the Earth radiative budget. However, large differences are found in current cloud products retrieved from ground-based remote sensing measurements using various retrieval algorithms. Understanding the differences is an important step to address uncertainties in the cloud retrievals. In this study, an in-depth analysis of nine existing ground-based cloud retrievals using ARM remote sensing measurements is carried out. We place emphasis on boundary layer overcast clouds and high level ice clouds, which are the focus of many current retrieval development efforts due to their radiative importance and relatively simple structure. Large systematic discrepancies in cloud microphysical properties are found in these two types of clouds among the nine cloud retrieval products, particularly for the cloud liquid and ice particle effective radius. Note that the differences among some retrieval products are even larger than the prescribed uncertainties reported by the retrieval algorithm developers. It is shown that most of these large differences have their roots in the retrieval theoretical bases, assumptions, as well as input and constraint parameters. This study suggests the need to further validate current retrieval theories and assumptions and even the development of new retrieval algorithms with more observations under different cloud regimes.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1048191
• Report Number(s): BNL--98106-2012-JA; KP1701000
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: D10 Vol. 117; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ALGORITHMS
BOUNDARY LAYERS
CLIMATE MODELS
CLOUDS
REMOTE SENSING