Global Mesoscale Convective System Latent Heating Characteristics from GPM and IMERG Retrievals
Mesoscale Convective Systems (MCSs) contribute a significant portion of the Earth’s precipitation and generate hazardous weather. The latent heating released by MCSs and its variations are one of the most important physical aspects of the atmosphere that play a crucial role in Earth’s energy and water cycles. To investigate the characteristics of MCS latent heating, a five-year (2014-2019) Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar observations and latent heating retrievals are combined with a newly developed global high-resolution (~10 km, hourly) MCS tracking dataset from joint geostationary infrared temperature and Integrated Multi-satellitE Retrievals for GPM (IMERG) precipitation data. Compared to MCSs in the tropics, extratropical MCSs are shallower and have a lower maximum precipitation rate. However, extratropical MCSs have larger precipitation areas and higher stratiform rain fraction. With a large spatial and seasonal variation, MCS latent heating profiles are more top-heavy in the middle and high latitudes than those in the tropics. Larger magnitudes of the latent heating in the upper troposphere are found over the ocean than over land, which is the case for both tropics and extratropics. The variation of MCS latent heating in the middle and upper troposphere is associated with the 20 dBZ area at low levels and the fraction of stratiform precipitation. This indicates that the structure of the MCS latent heating profile is highly related to the volumetric rainfall, as well as the stratiform precipitation fraction. Implications of these results to interactions between MCS and large-scale circulations will be discussed.