INTEGRATED WATER VAPOUR MEASURE-MENT OVER DEHRADUN USING GROUND-BASED GPS AND COMPARISON WITH VALUES OBTAINED FROM NCEP REANALYSIS AND MODIS DATA

This paper presents the development of TM model by using the radiosonde stations from Peninsular Malaysia. Two types of TM model were developed; site-specific and regional models. The result revealed that the estimation from site-specific model has small improvement compared to the regional model, indicating that the regional model is adequately to use in estimation of GPS-derived IWV over Peninsular Malaysia. Meanwhile, this study found that the diurnal cycle of TS has influenced the TM&ndash;TS relationship. The separation between daytime and nighttime observation can improve the relationship of TM&ndash;TS. However, the impact of diurnal cycle to IWV estimation is less than 1&thinsp;%. The TM model from Global and Tropic also been evaluated. The Tropic TM model is superior to be utilized as compared to the Global TM model.

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SPATIO-TEMPORAL ESTIMATION OF INTEGRATED WATER VAPOUR OVER THE MALAYSIAN PENINSULA DURING MONSOON SEASON

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-4-w5-165-2017 ◽

2017 ◽

Vol XLII-4/W5 ◽

pp. 165-175

Author(s):

S. Salihin ◽

T. A. Musa ◽

Z. Mohd Radzi

Keyword(s):

Water Vapour ◽

Monsoon Season ◽

Temporal Distribution ◽

Southwest Monsoon ◽

Northeast Monsoon ◽

Path Delay ◽

Zenith Path Delay ◽

Temporal Estimation ◽

Integrated Water Vapour ◽

Spatio Temporal

This paper provides the precise information on spatial-temporal distribution of water vapour that was retrieved from Zenith Path Delay (ZPD) which was estimated by Global Positioning System (GPS) processing over the Malaysian Peninsular. A time series analysis of these ZPD and Integrated Water Vapor (IWV) values was done to capture the characteristic on their seasonal variation during monsoon seasons. This study was found that the pattern and distribution of atmospheric water vapour over Malaysian Peninsular in whole four years periods were influenced by two inter-monsoon and two monsoon seasons which are First Inter-monsoon, Second Inter-monsoon, Southwest monsoon and Northeast monsoon.

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Estimation of precipitable water vapour from GPS during winter season 2003

MAUSAM ◽

10.54302/mausam.v57i2.479 ◽

2021 ◽

Vol 57 (2) ◽

pp. 323-328

Author(s):

R. K. GIRI ◽

B. R. LOE ◽

N. PUVIARSON ◽

S. S. BHANDARI ◽

R. K. SHARMA

Keyword(s):

Water Vapour ◽

Winter Season ◽

Precipitable Water ◽

New Delhi ◽

Total Delay ◽

Precipitable Water Vapour ◽

Integrated Water Vapour ◽

Zenith Hydrostatic Delay ◽

Indian Institute Of Science ◽

Good Agreement

Lkkj & ok;qeaMy esa ty ok"i dk forj.k LFkkfud :i ls vkSj dkfyd rkSj ij cgqr vf/kd ifjorZu’khy gksrk gSA ty ok"i dk forj.k vusdksa ok;qeaMyh; izfØ;kvksa esa izeq[k Hkwfedk fuHkkrk gSA dqy lekdfyr ty ok"i vFkok le:ih o"kkZ ty ok"i dk vkdyu Xykscy iksft’kfuax flLVe ¼th- ih- ,l-½ tsfuFk VksVy fMys ¼tsM- Vh- Mh-½ ds vk¡dM+ksa dh lgk;rk ls fd;k tk ldrk gSA blesa tsfuFk nzoLFkSfrd fMys ds eku dks funf’kZr fd;k x;k gS vkSj bls tsM- Vh- Mh- ls fudkyus ij tsfuFk vknzZ fMys ds vk¡dM+s izkIr gksaxsA vr% bl izdkj vkdfyr fd, x, tsM- MCY;w- Mh- ds eku ls izk;% yxkrkj ,e- ,e- esa o"kkZ ty ok"i dk irk pysxkA bl 'kks/k&i= esa th- ih- ,l- ds vk¡dM+ksa dk mi;ksx djrs gq, ubZ fnYyh ds fy, o"kZ 2003 ds 'khrdkyhu _rq vkSj Hkkjrh; foKku laLFkku ifj"kn] caxykSj ds dsanzksa ds fy, ,e- ,e- esa ih- MCY;w- oh- dk vkdyu djus dk iz;kl fd;k x;k gSA buls izkIr gq, ifj.kkeksa dk jsfM;kslkSUnsa vk¡dM+ksa ds lkFk lgh rkyesy ik;k x;k gSA The distribution of water vapour in atmosphere is highly spatial and temporal variable. It plays a key role in many atmospheric processes. The total integrated water vapour or equivalent precipitable water vapour (PWV) can be estimated with the help of Global Positioning System (GPS) Zenith Total Delay (ZTD) data. The value of Zenith Hydrostatic Delay (ZHD) is modeled and subtracting from ZTD will give Zenith wet delay (ZWD). Consequently, the estimated ZWD values will provide PWV in mm almost in a continuous manner. In this paper an attempt has been made for the estimation of PWV in mm during winter season 2003 for New Delhi and Indian Institute of Science (IISC), Bangalore stations using GPS data. The result shows fairly good agreement with the radio-sonde data.

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Surface temperature and water vapour retrieval from MODIS data

International Journal of Remote Sensing ◽

10.1080/0143116031000102502 ◽

2003 ◽

Vol 24 (24) ◽

pp. 5161-5182 ◽

Cited By ~ 127

Author(s):

J. A. Sobrino ◽

J. El Kharraz ◽

Z.-L. Li

Keyword(s):

Surface Temperature ◽

Water Vapour ◽

Modis Data

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Diagnostic study of errors in the simulation of tropical continental precipitation in general circulation models

Annales Geophysicae ◽

10.5194/angeo-21-1197-2003 ◽

2003 ◽

Vol 21 (5) ◽

pp. 1197-1207 ◽

Cited By ~ 6

Author(s):

J. Srinivasan

Keyword(s):

Water Vapour ◽

General Circulation ◽

Nonlinear Function ◽

General Circulation Models ◽

Atmospheric Model ◽

Large Error ◽

Tropical Meteorology ◽

Diagnostic Model ◽

Diagnostic Study ◽

Integrated Water Vapour

Abstract. A simple diagnostic model has been used to identify the parameters that induce large errors in the simulation of tropical precipitation in atmospheric General Circulation models (GCM). The GCM that have been considered are those developed by the National Center for Environmental Prediction (NCEP), the National Center for Atmospheric Research (NCAR) and the Japanese Meteorological Agency (JMA). These models participated in the phase II of the Atmospheric Model Inter-comparison Project (AMIP II) and simulated the climate for the period 1979 to 1995. The root mean-square error in the simulation of precipitation in tropical continents was larger in NCEP and NCAR simulations than in the JMA simulation. The large error in the simulation of precipitation in NCEP was due to errors in the vertical profile of water vapour. The large error in precipitation in NCAR in North Africa was due to an error in net radiation (at the top of the atmosphere). The simple diagnostic model predicts that the moisture converge is a nonlinear function of integrated water vapour. The large error in the interannual variance of rainfall in NCEP over India has been shown to be due to this nonlinearity.Key words. Meteorology and atmospheric dynamics (precipitation; tropical meteorology; convective processes)

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Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-9453-2019 ◽

2019 ◽

Vol 19 (14) ◽

pp. 9453-9468 ◽

Cited By ~ 4

Author(s):

Olivier Bock ◽

Ana C. Parracho

Keyword(s):

Standard Deviation ◽

Water Vapour ◽

Spatiotemporal Variability ◽

Small Scale ◽

Comparison Results ◽

Integrated Water Vapour ◽

Grid Points ◽

Error Statistic ◽

Climatic Features ◽

Gps Observations

Abstract. This study examines the consistency and representativeness differences of daily integrated water vapour (IWV) data from ERA-Interim reanalysis and GPS observations at 120 global sites over a 16-year period (1995–2010). Various comparison statistics are analysed as a function of geographic, topographic, and climatic features. A small (±1 kg m−2) bias is found in the reanalysis across latitudes (moist in northern and southern midlatitudes and dry in the tropics). The standard deviation of daily IWV differences is generally below 2 kg m−2 but peaks in the northern and southern storm-track regions. In general, the larger IWV differences are explained by increased representativeness errors, when GPS observations capture some small-scale variability that is not resolved by the reanalysis. A representativeness error statistic is proposed which measures the spatiotemporal variability in the vicinity of the GPS sites, based on reanalysis data at the four surrounding grid points. It allows to predict the standard deviation of daily IWV differences with a correlation of 0.73. In general, representativeness differences can be reduced by temporal averaging and spatial interpolation from the four surrounding grid points. A small number of outlying cases (15 sites) which do not follow the general tendencies are further examined. It is found that their special topographic and climatic features strongly enhance the representativeness errors (e.g. steep topography, coastlines, and strong seasonal cycle in monsoon regions). Discarding these sites significantly improves the global ERA-Interim and GPS comparison results. The selection of sites a priori, based on the representativeness error statistic, is able to detect 11 out of the 15 sites and improve the comparison results by 20 % to 30 %.

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The airport-sCAle seveRe weather nowcastinG prOject (CARGO)

10.5194/egusphere-egu2020-15177 ◽

2020 ◽

Author(s):

Riccardo Biondi ◽

Pierre-Yves Tournigand ◽

Enrico Solazzo ◽

Eugenio Realini ◽

Corrado Cimarelli ◽

...

Keyword(s):

Water Vapour ◽

Heavy Rain ◽

Severe Weather ◽

Time Range ◽

Atmospheric Parameter ◽

Atmospheric Conditions ◽

Temporal Behaviour ◽

Convective Systems ◽

Integrated Water Vapour ◽

Deep Convective Systems

Monitoring and predicting extreme atmospheric events, such as deep convective systems, is very challenging especially when they develop locally in a short time range. Despite the great improvement in model parametrization and the use of satellite measurements, there are still large uncertainties on the knowledge of the dynamical processes of deep convective systems at local scale.We use an innovative approach integrating a dense network of in situ measurements and satellite-based observations/products for the improvement of meteorological nowcasting at airport spatial scale focusing on the Malpensa airport (Italy). We add to the standard atmospheric parameters analysis, the information of integrated water vapour and lightning spatio-temporal behaviour (potential heavy rain precursors) during heavy rain phenomena detected by meteorological radars. The study is based on the anomaly of each atmospheric parameter during a convective event in comparison to its climatology in non-pre-convective environment, so that we are able to detect the variation with respect to the &#8220;standard&#8221; conditions. The ground based GNSS receivers (allowing the determination of the integrated water vapour trend before and during the storm), together with the lightning detectors, the weather stations (providing the trend of temperature, humidity and wind fields), the radiosondes and the GNSS radio occultations (allowing the estimation of vertical profiles of temperature, pressure and humidity) provide information on the pre-convective and non-pre-convective environment as a 3D picture of the atmospheric conditions.The final goal is the test of a severe weather events nowcasting algorithm with high spatial resolution, and based on neural networks, for improving aviation safety. This is followed by the development of a user-friendly tailored final product, easily understandable by the Air Traffic Management stakeholder.We have collected more than 600 cases suitable to develop the neural network algorithm. We show here the algorithm implementation and the meteorological characterization of deep convection usually developing on the Malpensa airport area.

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Tropospheric water vapour above Switzerland over the last 12 years

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-5975-2009 ◽

2009 ◽

Vol 9 (16) ◽

pp. 5975-5988 ◽

Cited By ~ 28

Author(s):

J. Morland ◽

M. Collaud Coen ◽

K. Hocke ◽

P. Jeannet ◽

C. Mätzler

Keyword(s):

Time Series ◽

Water Vapour ◽

Grid Point ◽

Microwave Radiometer ◽

Regional Scale ◽

Seasonal Trends ◽

Climate Change Effects ◽

Integrated Water Vapour ◽

Mountain Weather

Abstract. Integrated Water vapour (IWV) has been measured since 1994 by the TROWARA microwave radiometer in Bern, Switzerland. Homogenization techniques were used to identify and correct step changes in IWV related to instrument problems. IWV from radiosonde, GPS and sun photometer (SPM) was used in the homogenisation process as well as partial IWV columns between valley and mountain weather stations. The average IWV of the homogenised TROWARA time series was 14.4 mm over the 1996–2007 period, with maximum and minimum monthly average values of 22.4 mm and 8 mm occurring in August and January, respectively. A weak diurnal cycle in TROWARA IWV was detected with an amplitude of 0.32 mm, a maximum at 21:00 UT and a minimum at 11:00 UT. For 1996–2007, TROWARA trends were compared with those calculated from the Payerne radiosonde and the closest ECMWF grid point to Bern. Using least squares analysis, the IWV time series of radiosondes at Payerne, ECMWF, and TROWARA showed consistent positive trends from 1996 to 2007. The radiosondes measured an IWV trend of 0.45±0.29%/y, the TROWARA radiometer observed a trend of 0.39±0.44%/y, and ECMWF operational analysis gave a trend of 0.25±0.34%/y. Since IWV has a strong and variable annual cycle, a seasonal trend analysis (Mann-Kendall analysis) was also performed. The seasonal trends are stronger by a factor 10 or so compared to the full year trends above. The positive IWV trends of the summer months are partly compensated by the negative trends of the winter months. The strong seasonal trends of IWV on regional scale underline the necessity of long-term monitoring of IWV for detection,understanding, and forecast of climate change effects in the Alpine region.

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Water vapour retrieval using the Precision Solar Spectroradiometer

Atmospheric Measurement Techniques ◽

10.5194/amt-11-1143-2018 ◽

2018 ◽

Vol 11 (2) ◽

pp. 1143-1157 ◽

Cited By ~ 4

Author(s):

Panagiotis-Ioannis Raptis ◽

Stelios Kazadzis ◽

Julian Gröbner ◽

Natalia Kouremeti ◽

Lionel Doppler ◽

...

Keyword(s):

Water Vapour ◽

Single Channel ◽

Microwave Radiometer ◽

Coefficient Of Determination ◽

High Temporal Resolution ◽

Spectral Approach ◽

Spectral Measurements ◽

Data Set ◽

Integrated Water Vapour ◽

Relative Differences

Abstract. The Precision Solar Spectroradiometer (PSR) is a new spectroradiometer developed at Physikalisch-Meteorologisches Observatorium Davos – World Radiation Center (PMOD–WRC), Davos, measuring direct solar irradiance at the surface, in the 300–1020 nm spectral range and at high temporal resolution. The purpose of this work is to investigate the instrument's potential to retrieve integrated water vapour (IWV) using its spectral measurements. Two different approaches were developed in order to retrieve IWV: the first one uses single-channel and wavelength measurements, following a theoretical water vapour high absorption wavelength, and the second one uses direct sun irradiance integrated at a certain spectral region. IWV results have been validated using a 2-year data set, consisting of an AERONET sun-photometer Cimel CE318, a Global Positioning System (GPS), a microwave radiometer profiler (MWP) and radiosonde retrievals recorded at Meteorological Observatorium Lindenberg, Germany. For the monochromatic approach, better agreement with retrievals from other methods and instruments was achieved using the 946 nm channel, while for the spectral approach the 934–948 nm window was used. Compared to other instruments' retrievals, the monochromatic approach leads to mean relative differences up to 3.3 % with the coefficient of determination (R2) being in the region of 0.87–0.95, while for the spectral approach mean relative differences up to 0.7 % were recorded with R2 in the region of 0.96–0.98. Uncertainties related to IWV retrieval methods were investigated and found to be less than 0.28 cm for both methods. Absolute IWV deviations of differences between PSR and other instruments were determined the range of 0.08–0.30 cm and only in extreme cases would reach up to 15 %.

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