Global Detection of Mesoscale Convective Systems and Surprise Findings over High-latitudes from the GPM Ku-band Spaceborne Radar
Abstract
The Global Precipitation Measurement (GPM) core observatory satellite launched in 2014 features more extended latitudinal coverage (65°S-65°N) than its predecessor Tropical Rainfall Measuring Mission (TRMM, 35°S-35°N). The Ku-band radar onboard of the GPM is known to be capable of characterizing the 3D structure of deep convection globally. In this study, GPM's capability for detecting mesoscale convective systems (MCSs) is evaluated. Extreme convective echoes seen by GPM are compared against a newly developed long-term MCS database based on tracking convective entities over the contiguous US. The tracking is based on geostationary satellite and ground-based Next Generation Radar (NEXRAD) network data obtained during the 2014-2016 warm seasons. Results show that more than 70% of the GPM-detected Deep-Wide Convective Core (DWC) and Wide Convective Core (WCC) objects are part of NEXRAD identified MCSs, indicating that GPM-classified DWCs and WCCs correlate well with typical MCSs containing large convective features. By applying this method to the rest of the world, a global view of MCS distribution is obtained. Over a 5-year period (2014-2018), global MCS distribution revealed by GPM observations are largely consistent with previous studies in the low-latitudes. The most surprising result is that extremely intense deep convective storms, possibly associated with MCSs, do occur often during the warm season (April-September) in the high-latitude continents (60°N-65°N). These regions have been experiencing the largest increases of mean surface temperature in the last century. The associated thermodynamical environments suggest that high-latitude extreme convection could be more common in a continually warming world.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A53U3034W
- Keywords:
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- 3314 Convective processes;
- ATMOSPHERIC PROCESSES;
- 3329 Mesoscale meteorology;
- ATMOSPHERIC PROCESSES;
- 3354 Precipitation;
- ATMOSPHERIC PROCESSES;
- 4313 Extreme events;
- NATURAL HAZARDS