The Arctic is among the fastest warming regions on Earth, but it is also one with limited spatial coverage of multi-decadal instrumental surface air temperature measurements. Consequently, atmospheric reanalyses are relatively unconstrained in this region, resulting in a large spread of estimated 30-year recent warming trends, which limits their use to investigate the mechanisms responsible for this trend.
Here, we present a surface temperature reconstruction over 1982-2011 at NEEM (51∘ W, 77∘ N), in North Greenland, based on the inversion of borehole temperature and inert gas isotope data. We find that NEEM has warmed by 2.7±0.33∘C over the past 30 years, from the long-term 1900-1970 average of -28.55±0.29∘C. The warming trend is principally caused by an increase in downward longwave heat flux. Atmospheric reanalyses underestimate this trend by 17%, underlining the need for more in situ observations to validate reanalyses.
Authors : Anais J. Orsi, Kenji Kawamura, Valérie Masson-Delmotte, Xavier Fettweis, Jason E.Box, Dorthe Dahl-Jensen, Gary D. Clow, Amaelle Landais, Jeffrey P. Severinghaus
Reference : Geophysical Research Letters,
doi: 10.1002/2016gl072212, 2017