Science Source

Evaluation of Greenland near surface air temperature datasets

States that near-surface air temperature (SAT) over Greenland has important effects on mass balance of the ice sheet, but it is unclear which SAT datasets are reliable in the region
Uses extensive in situ SAT measurements ( ∼  1400 station-years) to assess monthly mean SAT from seven global reanalysis datasets, five gridded SAT analyses, one satellite retrieval and three dynamically downscaled reanalyses
Identifies strengths and weaknesses of these products and finds their biases vary by season and glaciological regime
Finds that MERRA2 reanalysis overall performs best with mean absolute error less than 2 °C in all months
Finds that ice sheet-average annual mean SAT from different datasets are highly correlated in recent decades, but their 1901–2000 trends differ even in sign
Results show that, compared with the MERRA2 climatology combined with gridded SAT analysis anomalies, thirty-one earth system model historical runs from the CMIP5 archive reach ∼  5 °C for the 1901–2000 average bias and have opposite trends for a number of sub-periods