GPS-Based Multi-Temporal Variation in Precipitable Water over the Territory of Poland

An increase in temperature causes higher evaporation of water from water bodies; consequently, the water content in the atmosphere also increases. The precipitable water (PW), as the water content in the atmospheric air column, is therefore an important parameter to consider when studying climate change. The aim of this study was to analyse multi-annual precipitable water data derived from a dense Global Navigational Satellite Systems (GNSS) network. Twelve years of observations from over a hundred ASG-EUPOS stations were used to estimate changes in precipitation water values over Poland. The data were validated by comparison with the available radio-sounding data. The analysis of the GPS-based PW values showed an upward trend in the PW value of 0.078 mm/year. The spatio-temporal distribution of the mean PW values and their fluctuations over the years were studied and visualised in the form of maps. The results are congruent with the fact that Poland lies on the border of influence of both continental and oceanic climates. Our results are also consistent with other climate research concerning this region.

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Diagnosing the average spatio-temporal impact of convective systems – Part 1: A methodology for evaluating climate models

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-12043-2013 ◽

2013 ◽

Vol 13 (23) ◽

pp. 12043-12058 ◽

Cited By ~ 2

Author(s):

M. S. Johnston ◽

S. Eliasson ◽

P. Eriksson ◽

R. M. Forbes ◽

K. Wyser ◽

...

Keyword(s):

Water Content ◽

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Cloud Fraction ◽

Convective Systems ◽

Ice Water Content ◽

The Mean ◽

Spatio Temporal ◽

Cloud Ice ◽

Ice Water

Abstract. An earlier method to determine the mean response of upper-tropospheric water to localised deep convective systems (DC systems) is improved and applied to the EC-Earth climate model. Following Zelinka and Hartmann (2009), several fields related to moist processes and radiation from various satellites are composited with respect to the local maxima in rain rate to determine their spatio-temporal evolution with deep convection in the central Pacific Ocean. Major improvements to the earlier study are the isolation of DC systems in time so as to prevent multiple sampling of the same event, and a revised definition of the mean background state that allows for better characterisation of the DC-system-induced anomalies. The observed DC systems in this study propagate westward at ~4 m s−1. Both the upper-tropospheric relative humidity and the outgoing longwave radiation are substantially perturbed over a broad horizontal extent and for periods >30 h. The cloud fraction anomaly is fairly constant with height but small maximum can be seen around 200 hPa. The cloud ice water content anomaly is mostly confined to pressures greater than 150 hPa and reaches its maximum around 450 hPa, a few hours after the peak convection. Consistent with the large increase in upper-tropospheric cloud ice water content, albedo increases dramatically and persists about 30 h after peak convection. Applying the compositing technique to EC-Earth allows an assessment of the model representation of DC systems. The model captures the large-scale responses, most notably for outgoing longwave radiation, but there are a number of important differences. DC systems appear to propagate eastward in the model, suggesting a strong link to Kelvin waves instead of equatorial Rossby waves. The diurnal cycle in the model is more pronounced and appears to trigger new convection further to the west each time. Finally, the modelled ice water content anomaly peaks at pressures greater than 500 hPa and in the upper troposphere between 250 hPa and 500 hPa, there is less ice than the observations and it does not persist as long after peak convection. The modelled upper-tropospheric cloud fraction anomaly, however, is of a comparable magnitude and exhibits a similar longevity as the observations.

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Estimation of spatio-temporal distribution of precipitable water using MODIS and AVHRR data: a case study for Cyprus

Advances in Geosciences ◽

10.5194/adgeo-30-23-2011 ◽

2011 ◽

Vol 30 ◽

pp. 23-29 ◽

Cited By ~ 3

Author(s):

D. Hadjimitsis ◽

Z. Mitraka ◽

I. Gazani ◽

A. Retalis ◽

N. Chrysoulakis ◽

...

Keyword(s):

Near Infrared ◽

Temporal Distribution ◽

Grid Cell ◽

Precipitable Water ◽

Avhrr Data ◽

Moderate Resolution ◽

Resolution Imaging ◽

Spatio Temporal ◽

Moderate Resolution Imaging Spectroradiometer

Abstract. In this paper, the atmospheric precipitable water (PW) over the area of Cyprus was estimated by means of Advanced Very High Resolution Radiometer (AVHRR) thermal channels brightness temperature difference (ΔT). The AVHRR derived ΔT was calculated in a grid of 5 × 5 km cells; the corresponding PW value in each grid cell was extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) Level 2 product (near-infrared algorithm). Once the PW – ΔT relationship coefficients corresponding to the area of Cyprus were calculated, the relationship was applied to AVHRR data for one month period. Radiosonde derived PW values, as well as MODIS independent PW values were used to validate the estimations and a good agreement was noted.

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Diagnosing the average spatio-temporal impact of convective systems – Part 1: A methodology for evaluating climate models

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-13653-2013 ◽

2013 ◽

Vol 13 (5) ◽

pp. 13653-13684

Author(s):

M. S. Johnston ◽

P. Eriksson ◽

S. Eliasson ◽

M. D. Zelinka ◽

R. M. Forbes ◽

...

Keyword(s):

Water Content ◽

Outgoing Longwave Radiation ◽

Deep Convection ◽

Longwave Radiation ◽

Cloud Fraction ◽

Ice Water Content ◽

The Mean ◽

Spatio Temporal ◽

Cloud Ice ◽

Ice Water

Abstract. A~method to determine the mean response of upper tropospheric water to localised deep convective (DC) events is improved and applied to the EC-Earth climate model. Following Zelinka and Hartmann (2009), several fields related to moist processes and radiation are composited with respect to local maxima in rain rate to determine their spatio-temporal evolution with deep convection in the central Pacific Ocean. Major improvements to the above study are the isolation of DC events in time so as to prevent multiple sampling of the same event, and a revised definition of the mean background state that allows for better characterization of the DC-induced anomalies. The DC events observed in this study propagate westward at ~ 4 m s−1. Both the upper tropospheric relative humidity and outgoing longwave radiation are substantially perturbed over a broad horizontal extent during peak convection and for long periods of time. Cloud fraction anomaly increases throughout the upper troposphere, especially in the 200–250 hPa layer, reaching peak coverage following deep convection. Cloud ice water content anomaly confined to pressures greater than about 250 hPa and peaks near 450 hPa within a few hours of the DC event but remain enhanced following the DC event. Consistent with the large increase in upper tropospheric cloud ice, albedo increases dramatically and persists for sometime following the DC event. Applying the method to the model demonstrates that it is able to capture the large-scale responses to DC events, most notably for outgoing longwave radiation, but there are a number of important differences. For example, the DC signature of upper tropospheric humidity consistently covers a broader horizontal area than what is observed. In addition, the DC events move eastward in the model, but westward in the observations, and exhibit an unrealistic 24 h repeat cycle. Moreover, the modeled upper tropospheric cloud fraction anomalies – despite being of comparable magnitude and exhibiting similar longevity – are confined to a thinner layer that is closer to the tropopause and peak earlier than in observations. Finally, the modeled ice water content anomalies at pressures greater than about 350 hPa are about twice as large as in the observations and do not persist as long after peak convection.

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Variability in atmospheric circulation and moisture flux over the Arctic

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1995.0065 ◽

1995 ◽

Vol 352 (1699) ◽

pp. 215-225 ◽

Cited By ~ 16

Keyword(s):

Water Vapour ◽

North Atlantic ◽

Temporal Distribution ◽

Local Maximum ◽

Precipitable Water ◽

Moisture Flux ◽

The Arctic ◽

Polar Cap ◽

Arctic Water ◽

Spatio Temporal

Mean characteristics and variability in the spatio-temporal distribution of Arctic water vapour and vapour fluxes are examined using several different rawinsondederived databases. Precipitable water averaged over the polar cap, 70-90° N, peaks in July at 14.0 mm. Large poleward fluxes near the prime meridian reflect transport associated with north Atlantic cyclones and, for most months, a local maximum in available water vapour. The mean vapour flux convergence averaged for the polar cap peaks in September. There is a mean annual excess of precipitation minus evaporation ( P — E ) of 163 mm, with a 78 mm range between extreme years. High P — E is favoured by a meridional circulation accompanied by a more dominant North Atlantic cyclone track. No trend in annual P — E is apparent over the 1974-1991 period.

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STUDIES ON THE TOTAL COLUMN ATMOSPHERIC AEROSOL OPTICAL DEPTH, OZONE AND PRECIPITABLE WATER CONTENT IN THE TROPICS: A CASE STUDY OF MALAYSIA

Photon: Jurnal Sain dan Kesehatan ◽

10.37859/jp.v1i2.117 ◽

2011 ◽

Vol 1 (2) ◽

pp. 55-62

Author(s):

Said Fhazli

Keyword(s):

Water Vapor ◽

Water Content ◽

Aerosol Optical Depth ◽

Optical Depth ◽

Precipitable Water ◽

Mean Value ◽

Total Column Ozone ◽

Precipitable Water Content ◽

The Mean ◽

Total Column

A Multifilter Rotating Shadowband Radiometer has been used to monitor the directly transmitted solar irradiance at six wavelength regions (413.9 nm, 494.6 nm, 612.7 nm, 670.8 nm, 868.0 nm and 939.1 nm) for three clear stable days at Bangi. Extensive observations of the columnar aerosol optical depth (AOD), total column ozone (TCO) and precipitable water content (PWC) have been carried out using this instrument. The result shows that the maximum optical depth of aerosol at the shorter wavelength, especially on 24th February 2002 with mean value of 0.254 (24th February 2002), 0.095 (25th February 2002), and 0.072 (26th February 2002) while the ozone optical depth shows the mean value 0.0153 on 24th February 2002, 0.0174 on 25thFebruary 2002 and 0.0175 on 26th February 2002 with the avarage absorption coefficient (a), 0.2 (24th and 26th February 2002) and 0.1 (25th February 2002). The mean value of water vapor content shows that  = 0.356 cm and k = 0.301 cm for wavelength 939.1 nm. From the aerosol optical depth, it shows the existence of smoke type of aerosol on February, 24th to 25th 2002 with Ångström coefficient, , is 1.534 and 1.5513, respectively, and sea water vapor is 0.9889 on 26thFebruary 2002. From the Ångström coefficient, it shows that atmosphere layer of Bangi at that moment is similar to U.S. Standard Atmosphere, with maximum spectral irradiance on black body temperature is 5860 oK.

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