HR: 1340h
AN: A33D-0109    [Abstracts]
TI: IMAA-CNR Campaign for the Validation of MIPAS Water Vapor and Temperature Products
AU: * Pappalardo, G
EM: pappalardo@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AU: Amodeo, A
EM: amodeo@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AU: Cornacchia, C
EM: cornacchia@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AU: Mona, L
EM: mona@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AU: Pandolfi, M
EM: pandolfi@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AU: Cuomo, V
EM: cuomo@imaa.cnr.it
AF: Istituto di Metodologie per l'Analisi Ambientale, IMAA-CNR, Contrada S. Loja, Tito Scalo, PZ I-85050 Italy
AB: An intensive measurement campaign, has been performed at IMAA in Tito Scalo (PZ) (Southern Italy, 40ø36'N, 15ø44'E, 820 m above sea level) in the framework of the validation program of ENVISAT. This campaign has been carried out by using a Raman lidar system, able to perform measurements of water vapor mixing ratio vertical profiles with high vertical and temporal resolution, and a radiosounding station for PTU measurements. These data have been used to validate MIPAS water vapor and temperature products. In the period July 2002 - December 2002, 2 radiosoundings and 2 lidar measurements of water vapor mixing ratio per week in coincidence with satellite overpasses have been performed. In the period January 2003 - July 2003, 1 radiosounding and 1 lidar measurement per week have been performed. Moreover, after the validation campaign, systematic measurements are still in progress. A set of criteria was defined to select the overpasses and to decide when MIPAS, lidar and radiosounding measurements can be considered as coincident and used for the validation: a) the maximum spatial distance between MIPAS overpass and IMAA station has to be lower than 1000 km; b) the maximum temporal distance between MIPAS overpass time and the radiosonde launch time has to be lower than 2h30min; c) the lidar water vapor vertical profile is retrieved by integrating measurements over 10 minutes, with this time interval centered on the overpass time. An analysis of the comparison between MIPAS, lidar and radiosonde for H2O measurements has been performed in terms of water vapor mixing ratio. This is directly measured by Raman lidar, while for MIPAS it is easily obtained converting the ppm unit and for radiosonde is obtained by using relative humidity and simultaneous pressure and temperature profiles. Starting from the available MIPAS data processed with IPF 4.61, used for the validation purposes, a mean underestimation of MIPAS of 0.016 g/kg has been observed in the altitude range of 10-13 km above sea level. It is evident that MIPAS presents several problems in performing water vapor measurements in the tropopause because of the sharp gradient in water vapor content typical at these heights. MIPAS temperature data have been validated by means of a radiosounding system located at IMAA-CNR. A total number of 12 coincidences with a 98 temperature compared points has been studied. The agreement is quite good. However, it is not possible to verify and quantify the presence of any temperature bias, because of the large MIPAS temperature error. In the near future, the availability of more reprocessed MIPAS data will improve validation activity. ACKNOWLEDGMENTS The financial support of this work by the European Space Agency under grant ESA-ESTEC Contract No. 16040/02/NL/SF, "Ground based observations of water vapour and aerosol for the validation of ENVISAT products", is gratefully acknowledged.
DE: 0350 Pressure, density, and temperature
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting