Retrievals of Latent Heating associated with Shallow Convection from ARM profiling Ka-band radar during the DYNAMO field campaign

 

Authors

Arunchandra S. Chandra — University of Miami
Chidong Zhang — NOAA/PMEL

Category

Shallow-Deep Convective Transition

Description

Latent heating is the primary tropical convective heat source in the creation, growth and defining the vertical structure of long-lived convective systems. There has been lot of studies dedicated to derive latent heating rates from many different methods using Satellites observations, Cloud resolving models (CRMs) or from budget studies. TRMM satellite retrievals and variational analysis approach using precipitation radar data (e.g., C band) have gained lot of popularity because of its success in capturing the realistic features in the latent heating profiles in consistent with other variables. The degree of consistency between different TRMM algorithms for the latent heating due to shallow convection mode is very poor compared to the heating due to deep convection. In the recent past, the heating due to shallow convection received more attention because of its possible linkage in explaining the convective dependence of low-level moisture (e.g., preconditioning of deep convection) in the context of large-scale tropical phenomena such as Madden-Julian Oscillation (MJO) and others. Though few of the TRMM algorithms and radar estimates have shown some skill in retrieving the differences between shallow and deep heating modes, the reliable estimates of the shallow heating its variability still needs thorough validation. Recently, there has been a progress in utilizing Ka-band profiling radars for routine precipitation rate retrievals beyond the main capabilities of probing the clouds. This added advantage offers a great opportunity to use Ka-band ARM Zenith Radars (KAZRs) for retrieving rain rates and thereby shallow heating rates. The KAZR observations collected during the DYNAMO period have been used to retrieve rain rates and in turn the shallow heating rates. The retrieved heating rates are compared with the ones retrieved from C-band radar products and some of the TRMM algorithm derived estimates during the DYNAMO period. The similarities and differences between different methods are assessed. The future use of profiling Ka-band radars to derive routine shallow heating, and total heating in complement with other methods is proposed.

Lead PI

Chidong Zhang — NOAA/PMEL