Uptake of reactive nitrogen on cirrus cloud particles in the upper troposphere and lowermost stratosphere

Abstract

NOy (total reactive nitrogen) contained in ice particles was measured on board the NASA DC-8 aircraft in the Arctic in January and March 2000. During some of the flights, the DC-8 encountered widespread cirrus clouds. Large quantities of ice particles were observed at 8-12 km and particulate NOy showed large increases. The data indicate that the amount of NOy covering the cirrus ice particles strongly depended on temperature. Similar measurements were made in the upper troposphere over the tropical Pacific Ocean in August-September 1998 and 1999. The data obtained in the Arctic and tropics show very limited uptake of NOy on ice at temperatures above 215 K.