Summer Warmth Index Average from 1982-2003

The AVHRR data were compiled from 1982 to 2003, providing the longest satellite temperature record available. The length of this record, especially the inclusion of the earliest years, was important in producing a mean that characterized the conditions that created the present distribution of arctic vegetation.

Arctic vegetation communities are only beginning to respond to recent climate changes, and our goal was to minimize this effect in the temperature data. The AVHRR temperature data provide better spatial resolution than modeled data sets, which interpolate between climate stations. And arctic climate stations are few, unevenly distributed around the pole, and located mostly along coasts.