Characterization of the summer surface mesoscale dynamics at Dome F, Antarctica

This article characterizes the mesoscale surface air temperature (SAT) gradients around the Dome F on the Antarctic Plateau combining ERA5 reanalysis outputs and in-situ weather observations. For this we took advantage of a mobile automatic weather station (M-AWS) that allowed us to record meteorological observations in interesting areas not covered by other AWS. We found that night-time SAT gradients are very variable from night to night. ERA5 does not adequately represent thermal gradients and their daily changes and tends to underestimate them. In particular, it fails to reproduce the cold pool observed by M-AWS over the depressed areas of the terrain. The performance of ERA5 over the plateau is better when observed SAT gradients are weak. Besides, we observed surface meso-beta eddies with warm cores and horizontal gradients of more than 5 degrees C 100 km(-1) simulated by ERA5 that have implications for site selection to establish new telescopes for astronomical observations. This study helps to interpret the daily performance of SAT values provided by reanalyisis on the Antarctic Plateau and complements climatological evaluations of SAT in the region. Finally, this study raises the necessity to increase in-situ weather observations, not only on the ridges of the Antarctic plateau where the majority are located, but also in the areas of depression to have a better picture of the weather and climate of the plateau.

Automated summary

This study characterizes the mesoscale surface air temperature gradients around Dome F on the Antarctic Plateau by combining ERA5 reanalysis outputs and in-situ weather observations. The study found that nighttime SAT gradients are highly variable and ERA5 tends to underestimate them. Surface meso-beta eddies observed have implications for site selection for astronomical observations.