Quantifying Energy and Mass Fluxes Controlling Godthåbsfjord Freshwater Input in a 5-km Simulation (1991–2012)*,+

• DOI: 10.1175/jcli-d-14-00271.1
• Publication Date: 2015-02-24T00:10:21Z
• Authors: P. L. Langen; R. H. Mottram; J. H. Christensen; F. Boberg; C. B. Rodehacke; M. Stendel; D. van As; A. P. Ahlstrøm; J. Mortensen; S. Rysgaard; D. Petersen; K. H. Svendsen; G. Aðalgeirsdóttir; J. Cappelen
• Keywords: Greenland ice sheet; Glacier mass balance; Shortwave radiation; Albedo (alchemy); Downwelling; Fjord

Abstract Freshwater runoff to fjords with marine-terminating glaciers along the Greenland Ice Sheet margin has an impact on fjord circulation and potentially ice sheet mass balance through increasing heat transport glacier front. Here, authors use high-resolution (5.5 km) HIRHAM5 regional climate model, allowing high detail in topography surface types, estimate freshwater input Godthåbsfjord southwest Greenland. Model output is compared hydrometeorological observations and, while simulated daily variability temperature downwelling radiation shows correlation (typically >0.9), there are biases that results. In particular, overestimated albedo leads underestimation of melt at low elevations. model simulation (1991–2012), experiences energy from turbulent flux (up elevations 2000 m) shortwave (at all elevations). Southerly wind anomalies declining cloudiness due increase atmospheric pressure over north contribute increased summer melt. This results (SMB), runoff, upward shift equilibrium line altitude. SMB reconstructed back 1890 though regression between observed precipitation, added uncertainty period 1890–1952 because possible inhomogeneity precipitation record. as recent years appears have occurred before, most notably around 1930, 1950, 1960. While previous SMBs were mainly caused by accumulation, those 1930 2000s warming.