c. champollion (1,2), c. flamant (2), f. masson (3), p. gégout (3), p. brousseau (4), g. dick (5),...
TRANSCRIPT
C. Champollion (1,2), C. Flamant (2), F. Masson (3), P. Gégout (3), P. Brousseau (4), G. Dick (5), J-Van Baelen (6) and E. Richard (7)
(1) Géosciences Montpellier UM2/CNRS, (2) Service d'Aéronomie UPMC/IPSL, (3) Institut de Physique du Globe de Strasbourg EOST/CNRS, (4) Centre National de Recherches Météorologiques Météo-France/CNRS, (5) GeoForschungsZentrum Potsdam, (6) Laboratoire de Météorologie Dynamique OPGC/CNRS, (7) Laboratoire d'Aérologie OMP/CNRS
COPS 6th Workshop., Hohenheim, Feb. 2007
AANNRR
First results from GPS tomography during the COPS field experiment
Why GPS measurements ?
1- Additional data with good temporal sampling for CI case studies
2- Impact of GPS data assimilation in numerical modeling: need to determine the best GPS network configuration for future operational applications
3- Synergy between the GPS tomography and the profiling instruments (RS, LIDAR,IASI)
4- Real interest of the GPS tomography: - Quantitative evaluation of the GPS tomography accuracy - Are they new information in GPS tomography inversion
compared to numerical simulation with GPS data assimilated?
The COSP GPS Network
A few numbers:
- 25 GPS (20 Fr. et 5 All.) installed during COPS
- ~80 GPS on a large COPS area
- A regional network (50 km)
- A E-W dense profil (10 km)
- 3 months of continuous measurements
- About 15 people participated to the field experiment
What has been done
- A complete raw data base have done. Concerning the French GPS stations, only 3 have experienced technical problems (power supply).
- A near real time (H+90) GPS data processing (ZTD) have been done and published on the web (P. Gégout; EOST / IPGS): eost.u-strasbg.fr/COPS (web site still active with new reprocessed data).
- A rapid post-processing have been done to provide quicklooks of non real-time data.
- Definitive GPS data post-processing (ZTD and IWV) available at [email protected].
What will be done (and when?)
- Slant delay processing and Tomographic inversion (until the end of March)
- Slant delay processing and cross-validation with GFZ results.
- Validation of the IWV and the tomographic inversion with the help of RS and LIDAR measurements (IPSL / GM)
- Studies of the water vapour temporal variability near the Bruche Valley (and diurnal cycle) (IPGS / IPSL / GM)
- Participation in CI case studies (IPSL / MF)
- Assimilation of ZTD (IPSL / MF)
- Evaluation of the accuracy of NRT GPS data processing (IPGS / GM)
Exemple of Quicklooks available on the web site- IWV maps- IWV Time series
Meteorological GPS Measurements:
The troposphere is modelled by two variables:- Integrated Water Vapour- Gradients NS and EW: azimuthal water vapour
variations
Meteorological GPS Measurements:
The troposphere is modelled by two variables:- Integrated Water Vapour- Gradients NS and EW: azimuthal water vapour
variations
Three months of continuous water vapour measurements in Strasburg
The good day
First IASI / GPS Integrated water vapour inter comparison
Meteorological GPS Measurements:
The troposphere is modelled by two variables:- Integrated Water Vapour- Gradients NS and EW: azimuthal water vapour
variations
Meteorological GPS Measurements:
The troposphere is modelled by two variables:- Integrated Water Vapour- Gradients NS and EW: azimuthal water vapour
variations
The Gradients
The GPS tomography validation
What we to see:The famous dry air intrusions
P. Brosser
AVIONGPS
VOSGES
What we to see:Orographic circulations
Thanks to the:
GPS INSU division Secretaries of SA and IPGS Field participants (Diana, Sophie, Myrto,
Karen, Frederic, Phillipe, Joel, Pascal, Cécile, Caroline, Bernard, ...).
GPS data providers: Orphéon, RGP, GFZ, Engref de Nancy, SwissTopo
Meteorological data providers: Météo-France, SwissMeteo, DWD, SAFIRE
GM and GA for free GPS rent.
Solution:
assimilation de radiosondages
Solution:
assimilation de radiosondages
- Taille de la cellule horizontale et verticale imposée par la densité du réseau GPS
- Résolution verticale limitée par la géométrie du problème
Limites de la tomographieLimites de la tomographie