Reply on RC2

Abstract

New global nitric oxide (NO) volume mixing ratio and lower thermospheric temperature data products, retrieved from Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) spectra with the IMK-IAA MIPAS data processor, have been released. The dataset covers the entire Envisat mission lifetime and includes retrieval results from all MIPAS observation modes. The data are based on ESA version 8 calibration and were processed using an improved retrieval approach compared to previous versions, specifically regarding the choice and construction of the a priori and atmospheric parameter profiles, the treatment of horizontal inhomogeneities, the treatment of the radiance offset correction, and the selection of optimized numerical settings. NO retrieval errors of individual observations are dominated by measurement noise and range from 5 % to 50 % in the stratosphere and thermosphere, and reach 40 % to 90 % in the mesosphere. Systematic errors are typically within 10–30 %. Lower thermospheric temperature errors are 5 K to 50 K with a systematic component of around 10K, the latter being dominated by non-LTE related uncertainties. NO data from different observation modes are consistent within 5–10 %. MIPAS version 8 temperatures have a better representation of the diurnal tide in the lower thermosphere compared to previous data versions. The new MIPAS temperatures are systematically warmer than results from the empirical NLRMSIS2.0 model by 30 K to 80 K in the 100–120 km region, and are colder above.