Open AccessTemperature profile determination from microwave oxygen emissions in limb sounding geometry
Author(s) -
von Engeln Axel,
Bühler Stefan
Publication year - 2002
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2001jd001029
Subject(s) - stratosphere , microwave limb sounder , depth sounding , microwave , mesosphere , remote sensing , temperature measurement , antenna (radio) , noise (video) , environmental science , filter (signal processing) , millimeter , physics , optics , meteorology , geology , computer science , telecommunications , oceanography , quantum mechanics , artificial intelligence , image (mathematics) , computer vision
We present a theoretical investigation of the temperature profile retrieval capabilities of oxygen emission lines in the microwave. The main focus is on two strong lines, both allowing temperature retrieval throughout the mesosphere. One is within the oxygen cluster at 61.15 GHz, the other one is isolated at 118.75 GHz. A thorough comparison of these two lines is presented. Several instrumental parameters such as system noise temperature, antenna beam width, filter width, and coverage of the line are assessed, as well as the possible impact of an error in the spectroscopic parameters. The instrumental setup follows roughly the specifications for the Millimeter Wave Acquisitions for Stratosphere/Troposphere Exchange Research (MASTER) instrument, serving as a basis for a modern passive microwave instrument. The instrumental parameters have also been varied in order to allow comparisons with two instruments that use the 118.75‐GHz line for temperature profile determination, the Odin submillimeter radiameter (SMR) and the EOS microwave limb sounder (MLS). Simultaneous retrieval of temperature and pointing bias is performed with the Optimal Estimation Method. We find temperature retrieval errors of <5 K in the mesosphere, and at sub‐Kelvin level in the lower stratosphere. Good knowledge of spectroscopic parameters is required for accurate retrievals. The simultaneous retrieval of a pointing bias can reduce the impact of spectroscopic parameter errors on the temperature retrieval.