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Title: Estimation of Cloud Fraction Profile in Shallow Convection Using a Scanning Cloud Radar

Large spatial heterogeneities in shallow convection result in uncertainties in estimations of domain-averaged cloud fraction profiles (CFP). This issue is addressed using large eddy simulations of shallow convection over land coupled with a radar simulator. Results indicate that zenith profiling observations are inadequate to provide reliable CFP estimates. Use of Scanning Cloud Radar (SCR), performing a sequence of cross-wind horizon-to-horizon scans, is not straightforward due to the strong dependence of radar sensitivity to target distance. An objective method for estimating domain-averaged CFP is proposed that uses observed statistics of SCR hydrometeor detection with height to estimate optimum sampling regions. This method shows good agreement with the model CFP. Results indicate that CFP estimates require more than 35 min of SCR scans to converge on the model domain average. Lastly, the proposed technique is expected to improve our ability to compare model output with cloud radar observations in shallow cumulus cloud conditions.
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [4] ;  [4] ;  [5]
  1. Stony Brook Univ., Stony Brook, NY (United States)
  2. Stony Brook Univ., Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. McGill Univ., Montreal, QC (Canada)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
  5. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
OSTI Identifier:
1329783
Report Number(s):
BNL--112725-2016-JA
Journal ID: ISSN 1944-8007; R&D Project: 2016-BNL-EE630EECA-Budg; KP1701000
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Geophysical Research Letters (Online)
Additional Journal Information:
Journal Name: Geophysical Research Letters (Online); Journal ID: ISSN 1944-8007
Publisher:
American Geophysical Union (AGU)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES