Name: Snow Melt Onset Over Arctic Sea Ice from SMMR and SSM/I Brightness Temperatures, Version 2
Creator: National Snow and Ice Data Center
Keywords: SNOW MELT

Snow Melt Onset Over Arctic Sea Ice from SMMR and SSM/I Brightness Temperatures, Version 2

Data set id:

NSIDC-0105

DOI: 10.5067/EBW7NSR7V1V4

Data Citation and Acknowledgment
As a condition of using these data, you must cite the use of this data set. Such a practice gives credit to data set producers and advances principles of transparency and reproducibility.

Drobot, S. & Anderson, M. (2009). Snow Melt Onset Over Arctic Sea Ice from SMMR and SSM/I Brightness Temperatures. (NSIDC-0105, Version 2). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/EBW7NSR7V1V4. [describe subset used if applicable]. Date Accessed 09-24-2025.

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There is a more recent version of these data.
Version Summary

The processing steps for Version 02 snow melt onset data were the same as for Version 01 with the exception of step 6.

Regarding further differences between the two versions, V01 processing had several problems with spurious brightness temperature values resulting in erroneous melt dates. Because the algorithm uses a threshold, it is particularly susceptible to the effects of spurious brightness temperatures. In V01, these spurious dates were corrected using a 9-point median filter. The cause of the spurious brightness temperatures was traced to an error in the input brightness temperature fields where bad scanlines of data were not properly flagged. The input brightness temperatures were reprocessed with the proper bad-data flags. The V02 melt product uses these reprocessed brightness temperatures. Because the spurious brightness temperatures were eliminated, the 9-point median filter was not needed and thus not implemented for the V02 melt product.

Overview

Yearly snow melt onset dates over Arctic sea ice are derived from Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) brightness temperatures. The introduction of liquid water to snow results in a sharp increase in the emissivity and hence brightness temperature of the snowpack. Snow melt onset is defined as the point in time when microwave brightness temperatures increase sharply due to the presence of liquid water in the snowpack. Data cover the years 1979 through 2007, and are in a polar stereographic grid at 25 km resolution. Data files are tab-delimited ASCII files and GIF images.

Parameter(s):

SNOW MELT

Platform(s):

DMSP

DMSP 5D-2/F11

DMSP 5D-2/F13

DMSP 5D-2/F8

Nimbus-7

Sensor(s):

SMMR

SSM/I

Data Format(s):

GIF

Binary

Temporal Coverage:

1 January 1979 to 31 December 2007

Temporal Resolution:

1 year

Spatial Resolution:

Not Specified

Spatial Reference System(s):

Not Specified

Spatial Coverage:

N:
90
S:
30
E:
180
W:
-180

Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

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This data set has been retired. There is a more recent version of these data.

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