Timing and regional patterns of snowmelt on Antarctic sea ice from passive microwave satellite observations


Contact
Stefanie.Arndt [ at ] awi.de

Abstract

An improved understanding of the temporal variability and the spatial distribution of snowmelt on Antarctic sea ice is crucial to better quantify atmosphere-ice-ocean interactions, in particular sea-ice mass and energy budgets. It is therefore important to understand the mechanisms that drive snowmelt, both at different times of the year and in different regions around Antarctica. In this study, we combine diurnal brightness temperature differences (dTB(37 GHz)) and ratios (TB(19 GHz)/TB(37 GHz)) to detect and classify snowmelt processes. We distinguish temporary snowmelt from continuous snowmelt to characterize dominant melt patterns for different Antarctic sea-ice regions from 1988/1989 to 2014/2015. Our results indicate four characteristic melt types. On average, 38.9 ± 6.0% of all detected melt events are diurnal freeze-thaw cycles in the surface snow layer, characteristic of temporary melt (Type A). Less than 2% reveal immediate continuous snowmelt throughout the snowpack, i.e., strong melt over a period of several days (Type B). In 11.7 ± 4.0%, Type A and B take place consecutively (Type C), and for 47.8 ± 6.8% no surface melt is observed at all (Type D). Continuous snowmelt is primarily observed in the outflow of the Weddell Gyre and in the northern Ross Sea, usually 17 days after the onset of temporary melt. Comparisons with Snow Buoy data suggest that also the onset of continuous snowmelt does not translate into changes in snow depth for a longer period but might rather affect the internal stratigraphy and density structure of the snowpack. Considering the entire data set, the timing of snowmelt processes does not show significant temporal trends.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
41442
DOI https://www.doi.org/10.1002/2015jc011504

Cite as
Arndt, S. , Willmes, S. , Dierking, W. and Nicolaus, M. (2016): Timing and regional patterns of snowmelt on Antarctic sea ice from passive microwave satellite observations , Journal of Geophysical Research: Oceans, 121 (8), pp. 5916-5930 . doi: https://www.doi.org/10.1002/2015jc011504


Download
[thumbnail of Arndt_et_al-2016-Journal_of_Geophysical_Research__Oceans.pdf]
Preview
PDF
Arndt_et_al-2016-Journal_of_Geophysical_Research__Oceans.pdf

Download (1MB) | Preview
Cite this document as:

Share


Citation

Geographical region

Research Platforms
N/A

Campaigns
N/A


Actions
Edit Item Edit Item