Seminar: Dr. Allison Collow | UMBC/NASA GMAO
In-Person PHYS 401
Location
Physics : 401
Date & Time
April 9, 2025, 11:00 am – 12:00 pm
Description
TITLE: "From MERRA-2 to MERRA-21C: An Aerosol Perspective”
ABSTRACT: Reanalyses, such as NASA’s Modern Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) produced using the Goddard Earth Observing System (GEOS) are an invaluable tool to study weather, climate, and the atmosphere due to their temporally and spatially consistent record over the past four decades. To our knowledge, MERRA-2 was the first global reanalysis to include interactive aerosols that run alongside the meteorology. There are numerous applications of GEOS reanalysis data, with the air quality community being documented as one of the largest users of MERRA-2 data. As it has been nearly ten years since MERRA-2 was released, production is underway for MERRA-21C, or Modern Era Retrospective analysis for Research and Applications for the early 21 st century. This latest reanalysis effort is considered a stepping-stone towards a coupled Earth-system reanalysis and will provide the basis for additional reanalyses focused on atmospheric chemistry, polar processes, and the land surface. Important configuration decisions pertaining to aerosols will be discussed focusing on the assimilation of aerosol optical depth (AOD), anthropogenic and biomass burning aerosol emissions, and improvements to the underlying aerosol model that have been incorporated over the past decade. A preliminary look at aerosol output from MERRA-21C will be shared in comparison to surface and satellite observations as well as other GEOS reanalysis products. Finally, contingency plans will be discussed for the loss of MODIS aboard Aqua and Terra as MERRA-21C is dependent on the instrument for AOD assimilation and biomass burning emissions.
ABSTRACT: Reanalyses, such as NASA’s Modern Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) produced using the Goddard Earth Observing System (GEOS) are an invaluable tool to study weather, climate, and the atmosphere due to their temporally and spatially consistent record over the past four decades. To our knowledge, MERRA-2 was the first global reanalysis to include interactive aerosols that run alongside the meteorology. There are numerous applications of GEOS reanalysis data, with the air quality community being documented as one of the largest users of MERRA-2 data. As it has been nearly ten years since MERRA-2 was released, production is underway for MERRA-21C, or Modern Era Retrospective analysis for Research and Applications for the early 21 st century. This latest reanalysis effort is considered a stepping-stone towards a coupled Earth-system reanalysis and will provide the basis for additional reanalyses focused on atmospheric chemistry, polar processes, and the land surface. Important configuration decisions pertaining to aerosols will be discussed focusing on the assimilation of aerosol optical depth (AOD), anthropogenic and biomass burning aerosol emissions, and improvements to the underlying aerosol model that have been incorporated over the past decade. A preliminary look at aerosol output from MERRA-21C will be shared in comparison to surface and satellite observations as well as other GEOS reanalysis products. Finally, contingency plans will be discussed for the loss of MODIS aboard Aqua and Terra as MERRA-21C is dependent on the instrument for AOD assimilation and biomass burning emissions.
