Articles | Volume 8, issue 1
08 Jan 2008
08 Jan 2008

Validation of the Atmospheric Chemistry Experiment (ACE) version 2.2 temperature using ground-based and space-borne measurements

R. J. Sica, M. R. M. Izawa, K. A. Walker, C. Boone, S. V. Petelina, P. S. Argall, P. Bernath, G. B. Burns, V. Catoire, R. L. Collins, W. H. Daffer, C. De Clercq, Z. Y. Fan, B. J. Firanski, W. J. R. French, P. Gerard, M. Gerding, J. Granville, J. L. Innis, P. Keckhut, T. Kerzenmacher, A. R. Klekociuk, E. Kyrö, J. C. Lambert, E. J. Llewellyn, G. L. Manney, I. S. McDermid, K. Mizutani, Y. Murayama, C. Piccolo, P. Raspollini, M. Ridolfi, C. Robert, W. Steinbrecht, K. B. Strawbridge, K. Strong, R. Stübi, and B. Thurairajah

Abstract. An ensemble of space-borne and ground-based instruments has been used to evaluate the quality of the version 2.2 temperature retrievals from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The agreement of ACE-FTS temperatures with other sensors is typically better than 2 K in the stratosphere and upper troposphere and 5 K in the lower mesosphere. There is evidence of a systematic high bias (roughly 3–6 K) in the ACE-FTS temperatures in the mesosphere, and a possible systematic low bias (roughly 2 K) in ACE-FTS temperatures near 23 km. Some ACE-FTS temperature profiles exhibit unphysical oscillations, a problem fixed in preliminary comparisons with temperatures derived using the next version of the ACE-FTS retrieval software. Though these relatively large oscillations in temperature can be on the order of 10 K in the mesosphere, retrieved volume mixing ratio profiles typically vary by less than a percent or so. Statistical comparisons suggest these oscillations occur in about 10% of the retrieved profiles. Analysis from a set of coincident lidar measurements suggests that the random error in ACE-FTS version 2.2 temperatures has a lower limit of about ±2 K.

Final-revised paper