Chapter 17 - Measurements of carbon monoxide at Polar regions

Abstract

Measurement of boundary-layer carbon monoxide (CO) concentration at Maitri (70.46S, 11.44E, 140masl), Schirmacher region of east Antarctica was conducted over a 6-week period during February 1–March 14, 2003 (austral summer). A systematical diurnal cycle of CO concentration coinciding with the diurnal cycle of solar actinic radiation at a snow-covered region of Antarctica has been observed. A rapid increase in CO concentration between 06 and 13hours has been observed on the clear sky days. On the cloudy days however, CO concentration decreased during the daytime, and cloudy condition and no diurnal variation like sunny days were observed. To study the snow-pack production of carbon monoxide and its diurnal variability, CO measurements were also carried out at Indian Arctic station “Himadri,” Ny-Ålesund, Svalbard (78°54′N, 11°53′E), during the first Indian Arctic winter phase expedition (March 3–31, 2008). A positive correlation was observed between ambient CO concentration and UV radiation when the atmospheric conditions of days were clear sunny and calm winds. This correlation indicates that direct photoreactions of organic compounds and indirect photoreaction involving other oxidants may probably be responsible for CO production and diurnal variability in Polar regions. The measurements of CO and surface ozone were also carried out at Indian Arctic station “Himadri,” Ny-Ålesund, Svalbard from March 20 to April 19, 2010, which coincide with the episode of tropospheric ozone depletion that occurred from March 29, 2010, 2200 hours to April 01, 2010, 1700 hours. A signature of slightly gradual increase of CO levels was observed during depletion event. This may be significant for the local CO budget and oxidizing capacity of the atmosphere but not on a global scale. The results from this study suggest that substantial photooxidation of organic matter occurs in sea ice and photochemistry in cold ecosystems might play an important role in the chemical transformation of various chemical compounds.