Search

The surface mass balance of the Greenland ice sheet has decreased in recent decades with important implications for global sea level rise. Here a climate reanalysis model is used to examine observed circulation variability and changes in precipitation across southern Greenland to gain insight into the future climate in the region. The influence on precipitation from the North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), Icelandic Low, Azores High, regional blocking patterns, and near‐surface temperature and winds are explored. Statistically significant correlations are higher between precipitation and the Icelandic Low and near‐surface winds (0.5–0.7; p< 0.05) than correlations between precipitation and either the NAO or AMO climate indices (southwest Greenland: r= 0.12 and 0.28, respectively; and southeast Greenland: r= 0.25 and −0.07, respectively). Moreover, the recent enhanced warming in the Arctic (Arctic amplification) and the increase in the Greenland Blocking Index coincide with increased mean annual precipitation and interannual variability in southwest Greenland. Southern Greenland precipitation is largely driven by topography and wind directionRecent enhanced increase of Arctic temperature linked with increase of southwest Greenland precipitationPositive feedback mechanisms in Arctic amplification linked with increase in southwest Greenland precipitation

A key indicator of changes in the terrestrial carbon cycle is shifting dissolved organic carbon (DOC) concentrations in surface waters. Arctic permafrost holds twice as much C as the atmosphere, thus recent warming and changes in atmospheric deposition to the region raise the need for a better understanding of how DOC is changing in arctic surface waters. In Kangerlussuaq, Greenland, lakewater DOC concentrations declined by 14 to 55% (absolute changes of 1 to 24 mg L−1) between 2003 and 2013, without significant changes in quality. Lakewater sulfate concentrations, but not chloride or conductivity, increased. These results suggest that similar to processes that have occurred at northern midlatitudes, increases in soil ionic strength as a result of sulfate enrichment may be linked to declining surface water DOC concentrations. Such enrichment may be occurring with enhanced non‐sea‐salt sulfate deposition. Our results reveal that rapid changes are occurring in the carbon cycle of this region of southwest Greenland. Lakewater DOC in SW Greenland declined by 14 to 55% between 2003 and 2013Lakewater sulfate concentrations, but not chloride or conductivity, increasedRapid change is occurring in the C cycle of this region