Greenland Dry Snow Zone Accumulation Rate Field from SMMR 6.6 GHz Data

The derived data are estimates from the accumulation rate (in kg/m²/year) on the Greenland ice sheet. The validity of the estimation method is limited to the dry snow zone. The data are derived from dual-polarized observations of microwave emission at 6.6 GHz made by the Scanning Microwave Multichannel Microwave Radiometer between 1979 and 1985 — specifically, we have averaged brightness temperatures for each 25 km pixel on the SSM/I grid (as provided in the NASA Goddard Space Flight Center SMMR Polar Data collection on CD- over the entire period between the start of data collection in 1979 and the end of the calendar year 1985, excluding only brief periods during some summers when brightness temperatures jumped anomalously 5k. (The latter events are likely to have been surface hoar formation events.)

We have added 6K to the resulting average vertically polarized brightness temperatures for the reason discussed by Winebrenner et al. (JGR 2001), formed a polarization ratio, and used a relationship between polarization and accumulation rate to derive this data set.

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The files that can be downloaded here provide the underlying data for the map of accumulation rates on Greenland discussed in the JGR paper.
To access the data as of this moment, you will need to have the commercial program MATLAB. (Files to provide the data
without the need for MATLAB will be provided in the future.) Download the 6 .mat and 1 .m files you see here into a single directory, and
run MATLAB in that directory. Then simply type the command show_accum_gr, and plate 1 of the JGR paper will appear on your screen. Hit return to get back to the MATLAB command prompt, and type the command who. You will see an array ACCUM — this
contains the accumulation rate values shown in floating point array form. The array locations coincide with a subset of the northern hemisphere SSM/I grid.