[1] UNIV COLORADO, NBS, JOINT INST LAB ASTROPHYS, BOULDER, CO 80302 USA
[2] SACRAMENTO PEAK OBSERV, SUNSPOT, NM 88349 USA
[3] NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA
[4] NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, BOULDER, CO 80307 USA
[5] LOCKHEED PALO ALTO RES LAB, PALO ALTO, CA 94304 USA