Validation of nitric acid retrieved by the IMK-IAA processor from MIPAS/ENVISAT measurements

Abstract

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard the ENVISAT satellite provides profiles of temperature and various trace-gases from limb-viewing mid-infrared emission measurements. The stratospheric nitric acid (HNO 3 ) from September 2002 to March 2004 was retrieved from the MIPAS observations using the science-oriented data processor developed at the Institut für Meteorologie und Klimaforschung (IMK), which is complemented by the component of non-local thermodynamic equilibrium (non-LTE) treatment from the Instituto de Astrofísica de Andalucía (IAA). The IMK-IAA research product, different from the ESA operational product, is validated in this paper by comparison with a number of reference data sets. Individual HNO 3 profiles of the IMK-IAA MI-PAS show good agreement with those of the balloon-borne version of MIPAS (MIPAS-B) and the infrared spectrometer MkIV, with small differences of less than 0.5 ppbv throughout the entire altitude range up to about 38 km, and below 0.2 ppbv above 30 km. However, the degree of consistency is largely affected by their temporal and spatial coincidence, and differences of 1 to 2 ppbv may be observed between 22 and 26 km at high latitudes near the vortex boundary, due to large horizontal inhomogeneity of HNO 3 . Statistical comparisons of MIPAS IMK-IAA HNO 3 VMRs with respectCorrespondence to: D. Y. Wang (dwang@unb.ca) to those of satellite measurements of Odin/SMR, ILAS-II, ACE-FTS, as well as the MIPAS ESA product show good consistency. The mean differences are generally ±0.5 ppbv and standard deviations of the differences are of 0.5 to 1.5 ppbv. The maximum differences are 2.0 ppbv around 20 to 25 km. This gives confidence in the general reliability of MIPAS HNO 3 VMR data and the other three satellite data sets.

A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008

“…In the following sections we show that the near-simultaneous measurements (within 30 s and 10 km) by CALIOP and MLS from the A-train can provide important information on the characteristics of PSCs and the associated atmospheric composition. Microwave gas-phase measurements are insensitive to the presence of PSCs along the lineof-sight, unlike solar occultation and infrared measurements, e.g., MIPAS (Wang et al, 2007), which must attempt to separate the effects of aerosol and cloud contamination on the gas-phase measurements. Observations of PSCs by CALIOP have been reported by Noel et al (2008Noel et al ( , 2009 and Pitts et al (2007Pitts et al ( , 2009Pitts et al ( , 2011.…”

Comparison of ECHAM5/MESSy Atmospheric Chemistry (EMAC) simulations of the Arctic winter 2009/2010 and 2010/2011 with Envisat/MIPAS and Aura/MLS observations

“…Here, the Envisat/MIPAS HNO 3 and temperature data version V5H_HNO3_20 and V5H_T_20 and V5R_HNO3_224/225 and V5R_T_220/221 (nominal mode) derived with the IMK/IAA retrieval processor covering the periods July 2002-March 2003 and January 2005-April 2012, respectively, have been used (updated version of the retrieval as described in Milz et al, 2009, andvon Clarmann et al, 2009). Comparison of the MIPAS HNO 3 data product with satellite measurements from Odin/SMR (Odin/Sub-Millimetre Radiometer), ADEOS/ILAS-II (Advanced Earth Observing Satellite/Improved Limb Atmospheric Spectrometer), SCISAT/ACE-FTS (SCISAT/Atmospheric Chemistry Experiment-Fourier Transform Spectrometer), and the Envisat/MIPAS ESA (European Space Agency) product showed good agreement, and differences were generally within ±0.5 ppbv (Wang et al, 2007;Wolff et al, 2008). Differences between MIPAS HNO 3 and the balloon-borne version of MIPAS (MIPAS-B) and the infrared spectrometer MkIV were even smaller, generally less than 0.5 ppbv throughout the altitude range up to 38 km.…”

“…Differences between MIPAS HNO 3 and the balloon-borne version of MIPAS (MIPAS-B) and the infrared spectrometer MkIV were even smaller, generally less than 0.5 ppbv throughout the altitude range up to 38 km. However, at high latitudes differences can increase up to 1-2 ppbv between 22 and 26 km due to the large horizontal inhomogeneity of HNO 3 near the vortex boundary (Wang et al, 2007). Further et al (2005).…”

Validation of ACE-FTS version 3.5 NO<sub><i>y</i></sub> species profiles using correlative satellite measurements

“…In similar comparisons with correlative satellite-based solar occultation measurements, the MIPAS ESA profiles typically agreed within 10-30 %. Wang et al (2007a, b) assessed the quality of the MIPAS IMK-IAA version 3 and MIPAS ESA version 4.6 HNO 3 data sets, respectively. Comparing MIPAS ESA HNO 3 with correlative data sets from ground-based and balloon-borne instruments, both Wang et al (2007a, b) studies determined that relative differences were typically better than 10 %.…”

“…Wang et al (2007a, b) assessed the quality of the MIPAS IMK-IAA version 3 and MIPAS ESA version 4.6 HNO 3 data sets, respectively. Comparing MIPAS ESA HNO 3 with correlative data sets from ground-based and balloon-borne instruments, both Wang et al (2007a, b) studies determined that relative differences were typically better than 10 %. In their comparisons with ACE-FTS v2.2 HNO 3 , relative differences in the lower to mid-stratosphere were on the order of 5-15 %.…”