This paper reports the experimental fusion of ground based radar and satellite radiometer data in order to analyse cloud vertical profile structures, and their influence on passive microwave signature. Satellite passive microwave measurements of precipitation are characterised by the presence of large hydrometeors within clouds, they view the atmosphere from the top downwards and the spatial resolution is very poor. Surface-based radar measurements of precipitation are based on the estimation of hydrometeors falling from the basis of clouds; they view the atmosphere from the bottom upwards. The temporal and spatial resolution is very good. Vertical profiles obtained through polarimetric radar measurements carries a more complete information; such profiles provides useful clues to understand the vertical structure of observed phenomena and to aid the comprehension of the inversion topic passive microwave measurements. A research project is undertaken between active and passive microwave observation of precipitating clouds over land. In particular, the active microwave source is a weather radar (Montagnana or Chilbolton radar), whilst the passive microwave source is the DMSP SSM/I instrument. The two microwave data type have been processed in order to be overlayable in time and space. Passive microwave data were processed in order to estimate several parameters related to cloud hydrometeors over land. Meanwhile, vertical profile radar data were processed in order to classify cloud hydrometeors types according to horizontal and the differential reflectivity values. A classification schema derived from Zrnic and Doviak was empirically calibrated and used to obtain cloud vertical profile structure. Two different processing algorithms were used for Montagnana and Chilbolton radar due to their different features and to the diverse characteristics of the event observed by them. These processing schemas allowed to outline several cloud layers. For each layer the correlation betwwen radar and satellite deirved parameters was analysed and scatterplots were worked out with SSM/I derived parameters along the Y axis and the radar derived cloud parameter along the X axis. The achieved analysis were numerous and complex. The developed research shows that radar vertical multiparameters profiles may be successfully utilised in order to estimate some cloud characteristics which are very important in order to better understand passive microwave brightness temperature behaviour. In particular, for rainfall monitoring over land, it is possible to notice the correlation between the high frequency brightness temperature range of values and the height of the top of the cloud. Furthermore, it is possible to appreciate the contribution of the wet particles belonging to the high layers of the cloud, to the brightness temperature at the high frequencies. Future work is including the assessment of the present results utilising a wider number of events and the introduction of parameters considering ground conditions.

Preliminary Results of Cloud Vertical Profile Observations in Tuscany Using Meteorological Radar and Satellite-based Microwave Radiometer

S Nativi;LBaldini;
1998

Abstract

This paper reports the experimental fusion of ground based radar and satellite radiometer data in order to analyse cloud vertical profile structures, and their influence on passive microwave signature. Satellite passive microwave measurements of precipitation are characterised by the presence of large hydrometeors within clouds, they view the atmosphere from the top downwards and the spatial resolution is very poor. Surface-based radar measurements of precipitation are based on the estimation of hydrometeors falling from the basis of clouds; they view the atmosphere from the bottom upwards. The temporal and spatial resolution is very good. Vertical profiles obtained through polarimetric radar measurements carries a more complete information; such profiles provides useful clues to understand the vertical structure of observed phenomena and to aid the comprehension of the inversion topic passive microwave measurements. A research project is undertaken between active and passive microwave observation of precipitating clouds over land. In particular, the active microwave source is a weather radar (Montagnana or Chilbolton radar), whilst the passive microwave source is the DMSP SSM/I instrument. The two microwave data type have been processed in order to be overlayable in time and space. Passive microwave data were processed in order to estimate several parameters related to cloud hydrometeors over land. Meanwhile, vertical profile radar data were processed in order to classify cloud hydrometeors types according to horizontal and the differential reflectivity values. A classification schema derived from Zrnic and Doviak was empirically calibrated and used to obtain cloud vertical profile structure. Two different processing algorithms were used for Montagnana and Chilbolton radar due to their different features and to the diverse characteristics of the event observed by them. These processing schemas allowed to outline several cloud layers. For each layer the correlation betwwen radar and satellite deirved parameters was analysed and scatterplots were worked out with SSM/I derived parameters along the Y axis and the radar derived cloud parameter along the X axis. The achieved analysis were numerous and complex. The developed research shows that radar vertical multiparameters profiles may be successfully utilised in order to estimate some cloud characteristics which are very important in order to better understand passive microwave brightness temperature behaviour. In particular, for rainfall monitoring over land, it is possible to notice the correlation between the high frequency brightness temperature range of values and the height of the top of the cloud. Furthermore, it is possible to appreciate the contribution of the wet particles belonging to the high layers of the cloud, to the brightness temperature at the high frequencies. Future work is including the assessment of the present results utilising a wider number of events and the introduction of parameters considering ground conditions.
1998
Remote sensing; radara; informatics applications
Meteorology & Atmospheric Sciences;
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/243038
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