scholarly journals A comparison of Global Positioning System retrieved precipitable water vapor with the numerical weather prediction analysis data over the Japanese Islands

2000 ◽  
Vol 105 (D4) ◽  
pp. 4573-4585 ◽  
Author(s):  
Tetsuya Iwabuchi ◽  
Isao Naito ◽  
Nobutaka Mannoji
Keyword(s):  
Water Vapor ◽  
Global Positioning System ◽  
Numerical Weather Prediction ◽  
Weather Prediction ◽  
Precipitable Water ◽  
Analysis Data ◽  
Positioning System ◽  
Numerical Weather ◽  
Global Positioning ◽  
Japanese Islands

Variability of GPS water vapor associated with warming activity in Peninsular Malaysia during the period of 2008–2011

2015 ◽  
Vol 7 (1) ◽  
pp. 240-250 ◽  
Author(s):  
Wayan Suparta ◽  
Maszidah Muhammad ◽  
Mandeep Singh Jit Singh ◽  
Fredolin T. Tangang ◽  
Mardina Abdullah ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Positioning System ◽  
Positive Relationship ◽  
Precipitable Water ◽  
Peninsular Malaysia ◽  
Positioning System ◽  
Dry Spells ◽  
Global Positioning ◽  
Semiannual Variation ◽  
Monthly Variations

This study utilizes the precipitable water vapor (PWV) parameter retrieved from ground-based global positioning system (GPS) to detect warming activity in Peninsular Malaysia from 2008 to 2011. Daily average of GPS PWV and surface meteorology data taken from six selected stations over Peninsular Malaysia are analyzed. Prior to warming detection, GPS PWV results are compared with PWV obtained from Radiosonde and found a positive relationship. The daily GPS PWV variability was characterized as high during the inter-monsoon seasons (April-May and October-November) and lower at the beginning, middle and the end of the year. For the monthly variations, GPS PWV increased by about 2.40 mm, which is correlated with an increase in surface temperature of 0.20 °C. We detected variability of PWV with a semiannual variation and the pattern is opposite to the accumulated precipitation, indicating that wet and dry spells coincide with local monsoon and intermonsoon periods. The warming effect in this study was felt over all selected stations with northern parts of Peninsular Malaysia affected significantly. The results imply that GPS is a powerful tool for analysis of warming effects and the mechanism of how it affects the circulation of water vapor is discussed in this study.

scholarly journals Column water vapor determination in night period with a lunar photometer prototype

2013 ◽  
Vol 6 (8) ◽  
pp. 2159-2167 ◽  
Author(s):  
A. Barreto ◽  
E. Cuevas ◽  
B. Damiri ◽  
P. M. Romero ◽  
F. Almansa
Keyword(s):  
Water Vapor ◽  
Global Positioning System ◽  
Precipitable Water ◽  
High Mountain ◽  
Positioning System ◽  
Gps Receiver ◽  
Global Positioning ◽  
Lc Filter ◽  
Mean Square Errors ◽  
Night Period

Abstract. In this paper we present the preliminary results of atmospheric column-integrated precipitable water vapor (PWV) obtained with a new Lunar Cimel photometer (LC) at the high mountain Izaña Observatory in the period July–August 2011. We have compared quasi-simultaneous nocturnal PWV from LC with PWV from a Global Positioning System (GPS) receiver and nighttime radiosondes (RS92). LC data have been calibrated using the Lunar Langley method (LLM). We complemented this comparative study using quasi-simultaneous daytime PWV from Cimel AERONET (CA), GPS and RS92. Comparison of daytime PWV from CA shows differences between GPS and RS92 up to 0.18 cm. Two different filters, with and approximate bandwidth of 10 nm and central wavelengths at 938 nm (Filter#1) and 937 nm (Filter#2), were mounted onto the LC. Filter#1 is currently used in operational AERONET sun photometers. PWV obtained with LC-Filter#1 showed an overestimation above 0.18 and 0.25 cm compared to GPS and RS92, respectively, and root-mean-square errors (RMSEs) up to 0.27 cm and 0.24 cm, respectively. Filter#2, with a reduced out-of-band radiation, showed very low differences compared with the same references (≤ 0.05 cm) and RMSE values ≤ 0.08 cm in the case of GPS precise orbits. These results demonstrate the ability of the new lunar photometer to obtain accurate and continuous PWV measurements at night, and the remarkable influence of the filter's transmissivity response to PWV determination at nighttime. The use of enhanced bandpass filters in lunar photometry, which is affected by more important inaccuracies than sun photometry, is necessary to infer PWV with similar precision to AERONET.

Sign in / Sign up

Export Citation Format

Share Document