English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Melt onset over Arctic sea ice controlled by atmospheric moisture transport

MPS-Authors

Kapsch,  Marie-Louise
Ocean Physics, The Ocean in the Earth System, MPI for Meteorology, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)

grl54557.pdf
(Publisher version), 4MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Mortin, J., Svensson, G., Graversen, R., Kapsch, M.-L., Stroeve, J., & Boisvert, L. (2016). Melt onset over Arctic sea ice controlled by atmospheric moisture transport. Geophysical Research Letters, 43, 6636-6642. doi:10.1002/2016GL069330.


Cite as: http://hdl.handle.net/11858/00-001M-0000-002B-0942-0
Abstract
The timing of melt onset affects the surface energy uptake throughout the melt season. Yet the processes triggering melt and causing its large interannual variability are not well understood. Here we show that melt onset over Arctic sea ice is initiated by positive anomalies of water vapor, clouds, and air temperatures that increase the downwelling longwave radiation (LWD) to the surface. The earlier melt onset occurs; the stronger are these anomalies. Downwelling shortwave radiation (SWD) is smaller than usual at melt onset, indicating that melt is not triggered by SWD. When melt occurs early, an anomalously opaque atmosphere with positive LWD anomalies preconditions the surface for weeks preceding melt. In contrast, when melt begins late, clearer than usual conditions are evident prior to melt. Hence, atmospheric processes are imperative for melt onset. It is also found that spring LWD increased during recent decades, consistent with trends toward an earlier melt onset. ©2016. American Geophysical Union. All Rights Reserved.