Open AccessAssessing the Vertical Latent Heating Structure of the East Pacific ITCZ Using the CloudSat CPR and TRMM PR
Author(s) -
L. Huaman,
Courtney Schumacher
Publication year - 2018
Publication title -
journal of climate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.315
H-Index - 287
eISSN - 1520-0442
pISSN - 0894-8755
DOI - 10.1175/jcli-d-17-0590.1
Subject(s) - intertropical convergence zone , climatology , precipitation , convection , environmental science , hadley cell , latent heat , zonal and meridional , atmospheric sciences , geology , meteorology , general circulation model , climate change , geography , oceanography
In the east Pacific (EP) intertropical convergence zone (ITCZ), Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) latent heating retrievals suggest a top-heavy structure; however, light precipitation and its associated low-level heating are underestimated by the PR. This study uses stratiform and deep convective precipitation from the TRMM PR and shallow precipitation from the more sensitive CloudSat radar to assess the seasonal latent heating structure in the EP ITCZ (130°–90°W) for 1998–2014. This study also uses reanalyses (MERRA-2, ERA-Interim, and NCEP–NCAR) to analyze the meridional circulation linked to variations in ITCZ heating. The TRMM/ CloudSat heating profiles suggest a distinct seasonality. During DJF, latent heating peaks at 800 hPa because of the predominance of shallow convection and rises to 700 hPa during MAM as the contribution from deep convective rain increases. During JJA and SON, stratiform precipitation increases and the latent heating has a double peak at 700 and 400 hPa. Additionally, the EP ITCZ heating has a meridional slope throughout most of the year as a result of the prevalence of shallow (deep) convection in the southern (northern) part of the ITCZ. While the reanalyses agree that the most bottom-heavy heating occurs in DJF and the most top-heavy heating occurs in JJA, they underestimate heating aloft compared to the satellite retrievals throughout the year and show varying ability in representing the shallow meridional circulation and deeper Hadley cell overturning.