Impact of temperature field inhomogeneities on the retrieval of atmospheric species from MIPAS IR limb emission spectra
ATMOSPHERIC MEASUREMENT TECHNIQUES 3:5 (2010) 1487-1507
Measurement from sun-synchronous orbit of a reaction rate controlling the diurnal NOx cycle in the stratosphere
Atmospheric Chemistry and Physics Discussions 10:10 (2010) 24595-24620
Cloud detection for MIPAS using singular vector decomposition
Atmospheric Measurement Techniques 2:2 (2009) 533-547
Abstract:
Satellite-borne high-spectral-resolution limb sounders, such as the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard ENVISAT, provide information on clouds, especially optically thin clouds, which have been difficult to observe in the past. The aim of this work is to develop, implement and test a reliable cloud detection method for infrared spectra measured by MIPAS. Current MIPAS cloud detection methods used operationally have been developed to detect cloud effective filling more than 30% of the measurement field-of-view (FOV), under geometric and optical considerations - and hence are limited to detecting fairly thick cloud, or large physical extents of thin cloud. In order to resolve thin clouds, a new detection method using Singular Vector Decomposition (SVD) is formulated and tested. This new SVD detection method has been applied to a year's worth of MIPAS data, and qualitatively appears to be more sensitive to thin cloud than the current operational method.NASA HIRDLS and ESA MIPAS data product comparison (And other ground data)
Proceedings of SPIE - The International Society for Optical Engineering 7082 (2008)
Abstract:
The HIRDLS instrument is a limb viewing infra-red radiometer on the NASA Aura spacecraft in a sun synchronous low earth orbit and obtains measurements of the composition of the atmosphere covering the whole Earth each day. The MIPAS instrument is a limb viewing infra-red interferometer on board the European Envisat satellite in a very similar orbit to Aura except that the local solar time is different. The complement of geophysical data products of both instruments is very similar, and because of similar observation strategies their two data sets can be usefully compared. The comparison provides the means to support validation in order to obtain statistics such as systematic differences and variance. This is performed over the full latitude range of HIRDLS and height range of MIPAS and thereby helps to identify sources of errors. The identification of known atmospheric features is a useful diagnostic, and includes such things as regions of upwelling of tracer gases, or the propagation of coherent structures as with mid-latitude waves and we can test whether these structures are consistently represented in both data sets. HIRDLS version 2.04.19 (v004) temperature, ozone and nitric acid show very low systematic 'errors' compared to MIPAS over most of the spatial range. Currently pre-released water vapour, nitrous oxide and F-11 are reasonably similar, CH4 somewhat more restricted, and nitrogen dioxide, N2O5, chlorine nitrate and F-12 as yet susceptible to complications from the obstructed telescope. Further details are discussed in the paper.MIPAS: An instrument for atmospheric and climate research
Atmospheric Chemistry and Physics 8:8 (2008) 2151-2188