FY 1998

Carbon monoxide measurements from 76°N to 59°S and over the South Tasman Sea

Kok, G.L., A.S.H. Prevot, R.D. Schillawski, and J.E. Johnson

J. Geophys. Res., 103(D13), 16,731–16,736 (1998)

In November and December of 1995, carbon monoxide (CO) measurements were made in a Pacific transect and over the South Tasman Sea as part of the First Aerosol Characterization Experiment (ACE 1) program. Airborne CO measurements were made from 76°N to 59°S. A clear latitudinal gradient in CO concentrations was measured, with the southern hemisphere average about 80 parts per billion by volume (ppbv), and increasing to 120-130 ppbv at the most northern latitudes. Plumes of CO with a 30-40 ppbv concentration increase over the general background concentrations could be seen at several latitudes. The National Oceanic and Atmospheric Administration R/V Discoverer made CO measurements over the South Tasman Sea from November 15 to December 9, 1995. A systematic decrease of 0.31 ppbv/d CO was observed. Vertical profile measurements of CO from near the ocean surface to 2500 m altitude during the Lagrangian B intensive of ACE 1 suggested the mixing of stratospheric air with reduced CO concentrations.