GPS-based atmospheric precipitable water vapor estimation using meteorological parameters interpolated from NCEP global reanalysis data
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
GPS-based atmospheric precipitable water vapor estimation
using meteorological parameters interpolated from
NCEP global reanalysis data
|
|
| Creator |
Jade, Sridevi
M S M, Vijayan |
|
| Subject |
Global Positioning System
|
|
| Description |
This study for the first time used the Indian GPS network data along with the
interpolated National Centers for Environmental Prediction (NCEP)/National Center for
Atmospheric Research (NCAR) reanalysis meteorological data to estimate the precipitable
water vapor (PWV) over the Indian atmosphere for a 4 year period (2001–2004) at 21
Indian GPS and 7 International GNSS Service stations. The site-specific daily average
meteorological data required for water vapor estimation at these sites is obtained by
performing vertical interpolation on 2.5 _ 2.5_ gridded NCEP/NCAR global reanalysis
data set available at 17 pressure levels and horizontal interpolation on similarly gridded
NCEP/NCAR data set available at the surface. The comparison of the site-specific
interpolated surface pressure and temperature thus obtained from NCEP/NCAR data with
the measured pressure and temperature profiles available at six GPS sites gives biases of
<1 mbar and <3_C which exhibits the robustness of the interpolation schemes. The water
vapor estimated at these six sites located in different geographical regions using
interpolated surface pressure and weighted mean temperature values from NCEP data
compare well (bias < 0.5 mm and standard deviation < 0.6 mm) with water vapor
estimated using measured surface pressure and temperature values. GPS PWV estimates
also compare well (bias < 3 mm) with the PWV estimates from the nearby radiosonde
sites. GPS PWV values at all the sites compare well (bias < 5 mm) with the horizontally
interpolated NCEP PWV values except for few sites located in the highly undulated
terrain. These GPS PWV values of the Indian network (4–35_N) are then used to model
the spatial variability of PWV over the Indian subcontinent as a function of zenith wet
delay (ZWD). The modeled spatial variability function gives a quick and reliable estimate
of near real-time GPS PWV in Indian subcontinent directly from ZWD thus eliminating
the need of site-specific weighted mean temperature values.
|
|
| Publisher |
American Geophysical Union
|
|
| Date |
2008-02-08
|
|
| Type |
Article
PeerReviewed |
|
| Format |
application/pdf
|
|
| Identifier |
http://cir.cmmacs.ernet.in/139/1/jade_vijayanJGR.pdf
Jade, Sridevi and M S M, Vijayan (2008) GPS-based atmospheric precipitable water vapor estimation using meteorological parameters interpolated from NCEP global reanalysis data. JOURNAL OF GEOPHYSICAL RESEARCH, 113 (D03106). pp. 1-12. |
|
| Relation |
http://www.agu.org/pubs
http://cir.cmmacs.ernet.in/139/ |
|