Observations of summertime NO fluxes and boundary-layer height at the South Pole during ISCAT 2000 using scalar similarity

Eddy-covariance heat flux as well as temperature and NO concentration gradients were measured during the ISCAT 2000 (Investigation of Sulfur Chemistry in the Antarctic Troposphere) field study at the South Pole (SP). These quantities allowed for the use of the modified Bowen ratio technique to estimate the surface flux of NO and, from photochemical considerations, the NO, flux. The meteorological measurement package employed in these experiments consisted of sonic anemometer/thermometers (ATI K-probes) and temperature/humidity sensors (NCAR). A chemiluminescent analyzer housed in an environmental enclosure was used to measure NO. All sampling took place on a 22 m meteorological tower. The time period over which flux measurements were recorded was 26 November through 30 November 2000. The average value of the NO flux was estimated to be 2.6+/-0.3 x 10(8) molec cm(-2) S-1; whereas, for NO, the average flux was 3.9+/-0.4 x 108 molec cm(-2) s(-1). To assist in the interpretation of these results, the height of the atmospheric boundary-layer at the SP from 23 November to 28 December 2000 was also estimated. (C) 2004 Elsevier Ltd. All rights reserved.