1. University of Alaska/Geophysical Institute, Fairbanks, Alaska 99775-7320
2. Dartmouth College, Hanover, New Hampshire 03755
3. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771
4. University of Colorado, Boulder, Colorado 80309
5. University of Iowa, Iowa City, Iowa 52242
6. Worcester Polytechnic Institute, Worcester, Massachusetts 01609