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Title: A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features

Abstract

Traditionally, radar-based latent heating retrievals use rainfall to estimate the total column-integrated latent heating and then distribute that heating in the vertical using a model-based look-up table (LUT). In this study, we develop a new method that uses size characteristics of radar-observed precipitating echo (i.e., area and mean echo-top height) to estimate the vertical structure of latent heating. This technique (named the Convective-Stratiform Area [CSA] algorithm) builds on the fact that the shape and magnitude of latent heating profiles are dependent on the organization of convective systems and aims to avoid some of the pitfalls involved in retrieving accurate rainfall amounts and microphysical information from radars and models. The CSA LUTs are based on a high-resolution Weather Research and Forecasting model (WRF) simulation whose domain spans much of the near-equatorial Indian Ocean. When applied to S-PolKa radar observations collected during the DYNAMO/CINDY2011/AMIE field campaign, the CSA retrieval compares well to heating profiles from a sounding-based budget analysis and improves upon a simple rain-based latent heating retrieval. The CSA LUTs also highlight the fact that convective latent heating increases in magnitude and height as cluster area and echo-top heights grow, with a notable congestus signature of cooling at mid levels. Stratiformmore » latent heating is less dependent on echo-top height, but is strongly linked to area. Unrealistic latent heating profiles in the stratiform LUT, viz., a low-level heating spike, an elevated melting layer, and net column cooling were identified and corrected for. These issues highlight the need for improvement in model parameterizations, particularly in linking microphysical phase changes to larger mesoscale processes.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1329451
Report Number(s):
PNNL-SA-107838
Journal ID: ISSN 1558-8424; KP1701000
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Meteorology and Climatology; Journal Volume: 55; Journal Issue: 9
Country of Publication:
United States
Language:
English

Citation Formats

Ahmed, Fiaz, Schumacher, Courtney, Feng, Zhe, and Hagos, Samson. A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features. United States: N. p., 2016. Web. doi:10.1175/JAMC-D-15-0038.1.
Ahmed, Fiaz, Schumacher, Courtney, Feng, Zhe, & Hagos, Samson. A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features. United States. doi:10.1175/JAMC-D-15-0038.1.
Ahmed, Fiaz, Schumacher, Courtney, Feng, Zhe, and Hagos, Samson. Thu . "A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features". United States. doi:10.1175/JAMC-D-15-0038.1.
@article{osti_1329451,
title = {A Retrieval of Tropical Latent Heating Using the 3D Structure of Precipitation Features},
author = {Ahmed, Fiaz and Schumacher, Courtney and Feng, Zhe and Hagos, Samson},
abstractNote = {Traditionally, radar-based latent heating retrievals use rainfall to estimate the total column-integrated latent heating and then distribute that heating in the vertical using a model-based look-up table (LUT). In this study, we develop a new method that uses size characteristics of radar-observed precipitating echo (i.e., area and mean echo-top height) to estimate the vertical structure of latent heating. This technique (named the Convective-Stratiform Area [CSA] algorithm) builds on the fact that the shape and magnitude of latent heating profiles are dependent on the organization of convective systems and aims to avoid some of the pitfalls involved in retrieving accurate rainfall amounts and microphysical information from radars and models. The CSA LUTs are based on a high-resolution Weather Research and Forecasting model (WRF) simulation whose domain spans much of the near-equatorial Indian Ocean. When applied to S-PolKa radar observations collected during the DYNAMO/CINDY2011/AMIE field campaign, the CSA retrieval compares well to heating profiles from a sounding-based budget analysis and improves upon a simple rain-based latent heating retrieval. The CSA LUTs also highlight the fact that convective latent heating increases in magnitude and height as cluster area and echo-top heights grow, with a notable congestus signature of cooling at mid levels. Stratiform latent heating is less dependent on echo-top height, but is strongly linked to area. Unrealistic latent heating profiles in the stratiform LUT, viz., a low-level heating spike, an elevated melting layer, and net column cooling were identified and corrected for. These issues highlight the need for improvement in model parameterizations, particularly in linking microphysical phase changes to larger mesoscale processes.},
doi = {10.1175/JAMC-D-15-0038.1},
journal = {Journal of Applied Meteorology and Climatology},
number = 9,
volume = 55,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 2016},
month = {Thu Sep 01 00:00:00 EDT 2016}
}