Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7846139 | Journal of Quantitative Spectroscopy and Radiative Transfer | 2018 | 13 Pages |
Abstract
A spatial heterodyne spectrometer (SHS) has been developed to measure the vertical distribution of water vapour in the upper troposphere and the lower stratosphere with a high vertical resolution (â¼500â¯m). The Spatial Heterodyne Observations of Water (SHOW) instrument combines an imaging system with a monolithic field-widened SHS to observe limb scattered sunlight in a vibrational band of water (1363â¯nm-1366â¯nm). The instrument has been optimized for observations from NASA's ER-2 aircraft as a proof-of-concept for a future low earth orbit satellite deployment. A robust model has been developed to simulate SHOW ER-2 limb measurements and retrievals. This paper presents the simulation of the SHOW ER-2 limb measurements along a hypothetical flight track and examines the sensitivity of the measurement and retrieval approach. Water vapour fields from an Environment and Climate Change Canada forecast model are used to represent realistic spatial variability along the flight path. High spectral resolution limb scattered radiances are simulated using the SASKTRAN radiative transfer model. It is shown that the SHOW instrument onboard the ER-2 is capable of resolving the water vapour variability in the UTLS from approximately 12â¯km - 18â¯km with ±1â¯ppm accuracy. Vertical resolutions between 500â¯m and 1â¯km are feasible. The along track sampling capability of the instrument is also discussed.
Related Topics
Physical Sciences and Engineering
Chemistry
Spectroscopy
Authors
J.A. Langille, D. Letros, D. Zawada, A. Bourassa, D. Degenstein, B Solheim,