Cold Water Currently Slowing Fastest Greenland Glacier

[25-Mar-2019] Jakobshavn's Interrupted Thinning Explained - NASA research shows that Jakobshavn Glacier, which has been Greenland's fastest-flowing and fastest-thinning glacier for the last 20 years, has made an unexpected about-face. Jakobshavn is now flowing more slowly, thickening, and advancing toward the ocean instead of retreating farther inland. The glacier is still adding to global sea level rise - it continues to lose more ice to the ocean than it gains from snow accumulation - but at a slower rate. The slowdown of this glacier occurred because an ocean current that brings water to the glacier's ocean face grew much cooler in 2016. "Tracing the origin of the cold waters in front of Jakobshavn was a challenge," explained Ian Fenty of JPL, a co-author of the study. "There are enough observations to see the cooling but not really enough to figure out where it came from." ECCO was used to help fill in the gaps, tracing the cool water upstream to a current that carries water around the southern tip of Greenland and northward along its west coast. In 2016, the water in this current cooled by more than 2.7 degrees Fahrenheit (1.5 degrees Celsius).

References

Khazendar, A., Fenty, I., Carroll, D., Gardner, A., Lee, C., Fukumori, I., Wang, O., Zhang, H., Seroussi, H., Moller, D., Noël, B., van den Broecke, M., Dinardo, S., and Willis, J. (2019) Interruption of two decades of Jakobshavn Isbrae acceleration and thinning as regional ocean cools, Nat. Geosci. 12, 277-283, doi: 10.1038/s41561-019-0329-3.2019-03-25