Read me file for RSS MSU data, Version v01_3 Channel 2: There are two small changes for the ch2 v01_3 dataset relative to the ch2 v01_2 dataset. First, we relaxed the outlier trimming procedure to allow more data to be kept. This allows apparently real tropospheric polar events to be included that were previously being excluded. In many months, there are a number of pixels (0 - 5%) that have changed a little (0.0K - 1.0K), with most remaining the same. No significant change in long-term behavior results from this change. This change is minor compared to the change in Channels 3 and 4. Second, in version v01_2, a number of orbits were missing from late 2001 and 2002. We have found the data for these orbits and included it in this version. Channels 3 and 4: There is a significant change for the ch3,4 v01_3 dataset relative to the ch3,4 v01 dataset. We discovered that the outlier trimming procedure we were using to remove occasional erroneous data was also removing some valid data for channels 3 and 4. Pronounced stratospheric warming events in the polar regions were being completely edited out. We no longer perform outlier trimming on channel 3 or channel 4 data. Specific warming events are now included. We did not see much effect on the long-term trends, but the inclusion of these events within this data set should result in increased variability in the polar regions.