Ground Based Infrared Measurements in the Arctic

点击翻译按钮获取中文摘要

Infrared observations of the atmosphere from to sites in the Arctic are proposed: Fairbanks, Alaska and Eureka, NWT, Canada. The instrument at Fairbanks will be a very high spectral resolution solar absorption spectrometer. This instrument covers the range 2.5 to 15 (m. At least 30 chemical compounds have absorptions in the instrument bandpass. This permits the derivation of total atmospheric quantities of those gases. The very high spectral resolution permits recovery of altitude profile information for at least half a dozen gases, including ozone, HCI, HF, and N2O. This information will be used to study stratospheric chemistry and dynamics, and will be compared with data from McMurdo Station, Antarctic and other northern hemisphere sites. Fairbanks is usually outside of the stratospheric polar vortex, but is in the area where maximum leakage of vortex air occurs. This allows the study of filaments of materials with different temperature, sunlight, and chemical conditioning. The Eureka, NWT, Canada (80(N, 86(W) instrument is a medium spectral resolution system designed to measure the infrared thermal emission of the atmosphere. This instrument covers 6 to 15(m. The atmosphere is very cold, and the signal is small, but measurements can be made in the absence of sunlight. Eureka is usually on the edge of the polar vortex, allowing observations in and out of vortex conditions within a few days. The amounts of several gases can be determined from the observations, particularly HNO3, which is directly involved in the formation of polar stratospheric clouds (PSC) and the chemical processing that occurs in ozone destroying conditions. The spectral data also relate directly to the greenhouse effect, and will be used to study the effect of chemistry, clouds, and snow on the radiation balance. Both instruments will be used for the study of chemical processes that occur in the Arctic during the winter. The multiyear data set will be important in the study of seasonal cycles, and in the study of global change.