[1] MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02139 USA
[2] OREGON GRAD CTR, DEPT ENVIRONM SCI, BEAVERTON, OR 97006 USA
[3] UNIV BRISTOL, DEPT GEOCHEM, BRISTOL BS8 1TH, AVON, ENGLAND
[4] CAP INC, ATLANTA, GA USA
[5] SIRO, DIV ATMOSPHER PHYS, ASPENDALE, VIC, AUSTRALIA
[6] ATMOSPHER & ENVIRONM RES INC, CAMBRIDGE, MA USA