Measurement of the isotopic ratio distribution of HD(16)O and H(2)(16)O in the 20-38 km altitude range from far-infrared spectra

The altitude distribution of the isotopic ratio between HD(16)O and H(2) (16)O in the stratosphere is derived by retrieving the mixing ratio profiles (from 20 km to 38 km of altitude) of the two isotopic species from far‐infrared emission spectra. The measurements were made with a balloon‐borne Fourier Transform Spectrometer capable of 0.0025 cm(−1) spectral resolution during the IBEX 92 campaign. The retrievals were carried out using the global‐fit procedure on a statistically significant number of spectra for each isotope, in the 40–75 cm(−1) spectral region. This measurement determines the D/H ratio in stratospheric water over an altitude range larger than that of previous measurements. The value of the HD(16)O/H(2) (16)O ratio, normalized to the standard value, ranges from 0.4 to 0.5 (with a 10% random error) in the altitude range studied and is in good agreement with the values previously measured

SIUBEX (Submillimeter Infrared Ultraviolet Balloon Experiment) project. Report activity, May 1992 - September 1992 Italian Groups

SIGLEITItal

Infrared Balloon EXperiment (IBEX. An interim report

SIGLEITItal

Coordinated activity for the geophysical validation of MIPAS-ENVISAT v4.61/ v4.62 Ozone data

International audienceLaunched on March 1st, 2002 on-board the polar orbiting ENVISAT satellite, the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) mid-infrared FT spectrometer performed limb emission measurements at high spectral resolution (0.025 cm-1) for about two years. Due to too frequent anomalies observed in the Interferometer Drive Unit, operations were suspended in March 2004 and finally resumed, in January 2005, in a new reduced resolution (0.01 cm-1) mode. Operational level 2 products for the complete set of target species (i.e. geo-located vertical profiles of Temperature and volume mixing ratio of H2O, O3, HNO3, CH4, N2O and NO2) were obtained during MIPAS full resolution mission, from July 6th, 2002 to March 26th, 2004. In this timeframe, several research groups involved in the ESA programme for geophysical validation of the ENVISAT Atmospheric Chemistry Instruments and in related national activities, carried out a variety of ground-based observations (ozone soundings, FT-IR, microwave radiometers, lidars) of the ozone vertical distribution and of in situ and remote sensing measurements from high altitude platforms, in close spatial and temporal coincidence with MIPAS overpasses. As a result, a comprehensive database of correlative measurements became available for a first inter-comparison of MIPAS O3 profiles with various datasets from coincident observations. A co-ordinated effort was finally conducted to bring together the individual outcomes of the different validation activities and to better exploit their redundant and complementary information. In the latter phase, special attention was paid to rigorous selection and use of correlative data, by adopting stringent coincidence criteria and by giving top priority to homogeneous and reliable validation data sources. Here we report a brief overview of the validation of MIPAS O3 data versions 4.61 and 4.62 (fully equivalent for validation purposes) by ground-based, balloon/aircraft and satellite measurements and discuss in details the resulting quality assessment of MIPAS O3 retrieved profiles