March 10, 2021 - 2:00 pm
March 10, 2021 - 3:00 pm
CategoriesWeather and Climate Systems
Weather and Climate Systems Seminar
Global Analysis of Characteristics of Tropical Easterly Waves in MERRA-2 and Related Precipitation
Wednesday, March 10th
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Tropical easterly waves (TEWs) are important components of tropical convection and precipitation, and sometimes develop into tropical cyclones (TCs). African easterly waves (AEWs) have been well documented in these regards, and are linked to mesoscale convective systems in the region, Sahel rainfall, and Atlantic TC activity. Despite the importance of TEWs to tropical rainfall and convection, TEWs in other regions are less studied, and their rainfall contributions are not as well quantified as those of AEWs. Where such studies exist, they are typically regional in focus. In order to globally analyze the activity of and precipitation contributions of TEWs, this project creates and analyzes a global climatology of TEWs using reanalysis data from MERRA-2 and collocates the tracks with precipitation from IMERG. The track climatology was developed using the TRACK algorithm to identify and track cyclonic curvature vorticity extrema at the 850 and 700hPa levels and then filtered to a database of TEWs. Climatological regional and seasonal analysis of the locations, speeds, and intensities of our TEWs, as well as interannual variability will be presented. Results of note include different regions of peak activity between the 850 and 700hPa levels, the relationship between interannual variation between the northern and southern hemispheres, and the lack of a strong seasonal pattern of wave activity in the southern hemisphere. Preliminary work on precipitation associations will also be shown. Furthering the understanding of TEWs globally will enable future work in comparing TEWs between regions and how they contribute to tropical rainfall.