A GPS network for tropospheric tomography in the framework of the Mediterranean hydrometeorological observatory Cévennes-Vivarais (southeastern France)
The Mediterranean hydrometeorological observatory Cévennes-Vivarais (OHM-CV) coordinates hydrometeorological observations (radars, rain gauges, water level stations) on a regional scale in southeastern France. In the framework of OHM-CV, temporary GPS measurements have been carried out for 2 months...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-02-01
|
| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/7/553/2014/amt-7-553-2014.pdf |
| Summary: | The Mediterranean hydrometeorological observatory Cévennes-Vivarais
(OHM-CV) coordinates hydrometeorological observations (radars, rain gauges,
water level stations) on a regional scale in southeastern France. In the
framework of OHM-CV, temporary GPS measurements have been carried out for 2
months in autumn 2002, when the heaviest rainfall are expected. These
measurements increase the spatial density of the existing permanent GPS
network, by adding three more receivers between the Mediterranean coast and
the Cévennes-Vivarais range to monitor maritime source of water vapour
flow feeding the precipitating systems over the Cévennes-Vivarais
region. In addition, a local network of 18 receivers covered an area of 30
by 30 km within the field of view of the meteorological radar. These
regional and local networks of permanent and temporary stations are used to
monitor the precipitable water vapour (PWV) with high temporal resolution
(15 min). Also, the dense local network provided data which have been
inverted using tomographic techniques to obtain the 3-D field of
tropospheric water vapour content. This study presents methodological tests
for retrieving GPS tropospheric observations from dense networks, with the
aim of assessing the uncertainties of GPS retrievals. Using optimal
tropospheric GPS retrieval methods, high resolution measurements of PWV on a
local scale (a few kilometres) are discussed for rain events. Finally, the
results of 3-D fields of water vapour densities from GPS tomography are
analysed with respect to precipitation fields derived from a meteorological
radar, showing a good correlation between precipitation and water vapour
depletion areas. |
|---|---|
| ISSN: | 1867-1381 1867-8548 |