Bock O., Guichard F., Janicot Serge, Lafore J.P., Bouin M.N., Sultan Benjamin. (2007). Multiscale analysis of precipitable water vapor over Africa from GPS data and ECMWF analyses. Geophysical Research Letters, 34, art. L09705 [6 p. ]. ISSN 0094-8276.
Titre du document
Multiscale analysis of precipitable water vapor over Africa from GPS data and ECMWF analyses
Bock O., Guichard F., Janicot Serge, Lafore J.P., Bouin M.N., Sultan Benjamin
Source
Geophysical Research Letters, 2007,
34, art. L09705 [6 p. ] ISSN 0094-8276
This is the first climatological analysis of precipitable water vapor (PWV) from GPS data over Africa. The data reveal significant modulations and variability in PWV over a broad range of temporal scales. GPS PWV estimates are compared to ECMWF reanalysis ERA40. Both datasets show good agreement at the larger scales (seasonal cycle and inter-annual variability), driven by large scale moisture transport. At intra-seasonal (15–40 days) and synoptic (3–10 days) scales, strong PWV modulations are observed from GPS, consistently with ECMWF analysis. They are shown to be correlated with convection and the passage of equatorial waves and African Easterly waves. The high-frequency GPS observations also reveal a significant diurnal cycle in PWV, which magnitude and spectral content depends strongly on geographic location and shows a seasonal modulation. The diurnal cycle of PWV is poorly represented in ERA40 reflecting weaknesses in the water cycle of global circulation models at this timescale.
Plan de classement
Analyse de données [020STAT02]
;
Etude du bilan d'énergie des surfaces naturelles ou cultivées / mesure des flux de chaleur et de vapeur d'eau [072BCLIGE02]
Descripteurs
BIOCLIMATOLOGIE ; PRECIPITATION ; EVAPORATION ; VARIATION SAISONNIERE ; VARIATION PLURIANNUELLE ; ANALYSE MULTIVARIABLE ; GPS.SYSTEME DE POSITIONNEMENT GLOBAL
