Surface melt in Antarctica 1979 - 2015
A dataset of daily surface melt in Antarctica is distributed, along with derived higher-level indexes. Surface melting is retrieved from passive microwave radiometer data (SMMR and SSM/I) using the algorithm developed by Torinesi et al. 2003 and Picard and Fily 2006. The microwave data are provided by NSIDC in two datasets: SMMR and SSM/I. The surface melting is provided with a spatial resolution of 25 km but the underlying data are at about 60 km resolution. The temporal resolution is 1 day (2 days before 1988) and records are almost continuous since 1979.
Condition of use.
The dataset and other information on this page are provided "AS IS", without warranty of any kind. Ackownledgment in publications will be appreciated and the following citation is suggested:
The dataset and other information are freely available but consider to subscribe to the mailing list osug-melt mailing-list to be informed of the updates and mistakes. Updates of the datasets should be provided yearly depending on the availability of SSMI/I data from NSIDC.
Daily Surface Melting Dataset.
This dataset includes the melted/not melted status of every pixel on the reduced Southern stereographic polar grid for every day since 1st April 1979. This grid is a cropped version of the Southern stereographic polar grid used by NSIDC. The grid has a 25 x 25 kmē resolution (see NSIDC information). The reduced grid size is 231 x 201 pixels. The upper left pixel is at coordinate (40,70) in the NSIDC Polar grid and the lower right pixel at coordinate (271,271). For ease of use, latitude and longitude of each pixel are included in the dataset.
The pixels are classified as follow:
- 0 : not melted
- 1 : melted
- -10 : no available data or masked out .
The most up-to-date dataset:
Surface Melting 1979-2015 Dataset ver 1.0 [ DOWNLOAD (9.0Mb) ]. This archive includes two files, one with missing satellite data filled by interpolation and one without (called raw) if you need to implement your own gap filling method.
The original dataset used with the publication of Picard et al. 2006:
Surface Melting 1979-2006 Dataset ver 1.0 [ DOWNLOAD (437Mb !!!) ]
Note: The differences between the original and the up-to-date datasets for years in common are explained by improvements in SSM/I brightness temperature dataset (Version 2 released in July 2006, see http://nsidc.org/data/docs/daac/nsidc0001_ssmi_tbs.gd.html)
Cumulative Melting Surface.
The Cumulative Melting Surface (CMS) is defined as the number of melted pixels for an entire summer and an entire region multiplied by the surface of a pixel (25 x 25 kmē). Its unit is expressed in day kmē. The Antarctic regions used here were defined by Zwally et Fiegles, 1994. See figure:
The CMS for the different regions have been corrected from changes in acquisition hours due to satellite replacements with the method developed by Picard and Fily, 2006. Both corrected and uncorrected CMS are available for download. To our opinion, the correction efficiently reduces errors for some regions (Peninsula, DML, Amery, Wilkes, MBL), but is less efficient or may add new errors for other regions (Filchner, Ross). In the latter regions, we recommend to use both the corrected and uncorrected CMS.
The file is organized in two columns. The first is the year corresponding to the end of the summer (e.g. 1980 corresponds to summer 1979/1980) and the second the CMS expressed in 106 km2 day.
Corrected CMS ver 1.0 (1979/1980-2005/2006): [ DOWNLOAD]
Uncorrected CMS ver 1.0 (1979/1980-2005/2006): [ DOWNLOAD]
Surface melting maps.The maps represent the number of days with surface melt. During the SMMR period (1979-1987), the brightness temperature were linearly interpolated on every day before the application of the melt detection algorithm.
- G. Picard, M.Fily, 2006, Surface melting observations in Antarctica by microwave radiometers: correcting 26 year-long timeseries from changes in acquisition hours. Remote Sensing of Environment.
- G. Picard, M. Fily, H. Gallee, 2007 Surface melting derived from microwave radiometers: a climatic indicator in Antarctica. Annals of Glaciology, vol 46, pp 29-34.
- P. Kuipers Munneke, G. Picard, M. R. van den Broeke, J. T. M. Lenaerts, E. van Meijgaard, Insignificant change in Antarctic snowmelt volume since 1979, Geophysical Research Letter, vol. 39, L01501, 2012, doi:10.1029/2011GL050207
- Torinesi O., M. Fily, and C. Genthon, 2003, Interannual variability and trend of the Antarctic summer melting period from 20 years of spaceborne microwave data, J. of Climate, 16(7), 1047-1060.
- Zwally, H. J., Fiegles, S. (1994). Extent and duration of Antarctic surface 829 melting. Journal of Glaciology, 40(136), 463.
Last update: Feb 2016