Brief communication: Surface energy balance differences over Greenland between ERA5 and ERA-Interim

We compare the main atmospheric drivers of the melt season over the Greenland Ice Sheet (GrIS) in ERA5 and ERA-Interim (ERAI) in their overlapping period 1979–2018. In summer, ERA5 differs significantly from ERAI, especially in the melt regions: averaged over the lower parts of the GrIS, mean near-s...

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Bibliographic Details
Main Authors: Krebs-Kanzow, Uta, Rodehacke, Christian B., Lohmann, Gerrit
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2023
Subjects:
Online Access:https://doi.org/10.5194/egusphere-2023-525
https://noa.gwlb.de/receive/cop_mods_00065579
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064096/egusphere-2023-525.pdf
https://egusphere.copernicus.org/preprints/2023/egusphere-2023-525/egusphere-2023-525.pdf
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Summary:We compare the main atmospheric drivers of the melt season over the Greenland Ice Sheet (GrIS) in ERA5 and ERA-Interim (ERAI) in their overlapping period 1979–2018. In summer, ERA5 differs significantly from ERAI, especially in the melt regions: averaged over the lower parts of the GrIS, mean near-surface temperature is 1 K lower, while the mean downward shortwave radiation at the surface is on average 15 Wm−2 higher than in ERAI. Comparison with observational weather station data shows a significant warm bias in ERAI and for ERA5 a significant positive bias in downward shortwave radiation. Consequently, methods that previously estimated the GrIS surface mass balance from the ERAI surface energy balance need to be carefully recalibrated before converting to ERA5 forcing.