scholarly journals Interannual variability of the GNSS derived precipitable water vapour in the light of tropical climate patterns

2021 ◽  
Author(s):  
Grzegorz Nykiel ◽  
Zofia Baldysz ◽  
Beata Latos ◽  
Mariusz Figurski
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Interannual Variability ◽  
Water Vapour ◽  
Precipitable Water ◽  
Precipitable Water Vapour ◽  
Climate Patterns ◽  
Non Linear ◽  
Linear Trends

<p>Among various greenhouse gases, water vapour is characterized by the single highest positive feedback on the surface temperature and dominates increasing of the Earth’s surface temperature. Hence, long-term changes in its concentration in the atmosphere are one of the indicators for the assessment of the global warming rate. Consequently, monitoring of water vapour interannual variability is an important element in climate observing system, especially considering limitations of the surface technology that is traditionally used for this purpose. In this work, we have used 18 years of global navigation satellite system (GNSS) observations derived from 43 International GNSS Service (IGS) stations located across the global tropics. Based on them, we have estimated zenith tropospheric delay (ZTD) time series by precise point positioning (PPP) approach, and in next step converted them to long-term and homogenous precipitable water vapour (PWV) time series. We have investigated their interannual variability through estimation of non-linear trends and assessment which climate phenomena affect GNSS PWV long-term variability the most. Results have shown that for most of the analysed stations, GNSS PWV time series present distinct analogies to the global and regional climate phenomena such as El Nino Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) or North Pacific Gyro Oscillation (NPGO). Comparative analysis between GNSS PWV non-linear trends and selected climate indices showed strong cross-correlation, that amounted to 0.78. Moreover small-scale weather phenomena, such as local droughts, were clearly distinguishable, thus showing how GNSS PWV time series are sensitive to the combined effect of various weather and climate patterns. </p>

On the importance of proper noise modelling for long-term precipitable water vapour trend estimations

2007 ◽  
Vol 110 (2-3) ◽  
pp. 211-218 ◽  
Author(s):  
A. Z.A. Combrink ◽  
M. S. Bos ◽  
R. M.S. Fernandes ◽  
W. L. Combrinck ◽  
C. L. Merry
Keyword(s):  
Water Vapour ◽  
Precipitable Water ◽  
Precipitable Water Vapour

scholarly journals Water Vapour Assessment Using GNSS and Radiosondes over Polar Regions and Estimation of Climatological Trends from Long-Term Time Series Analysis

2021 ◽  
Vol 13 (23) ◽  
pp. 4871
Author(s):  
Monia Negusini ◽  
Boyan H. Petkov ◽  
Vincenza Tornatore ◽  
Stefano Barindelli ◽  
Leonardo Martelli ◽  
...  
Keyword(s):  
Water Vapour ◽  
Correlation Coefficients ◽  
Arctic Region ◽  
Precipitable Water ◽  
Satellite System ◽  
The Arctic ◽  
Polar Regions ◽  
Precipitable Water Vapour ◽  
Water Vapour Content

The atmospheric humidity in the Polar Regions is an important factor for the global budget of water vapour, which is a significant indicator of Earth’s climate state and evolution. The Global Navigation Satellite System (GNSS) can make a valuable contribution in the calculation of the amount of Precipitable Water Vapour (PW). The PW values retrieved from Global Positioning System (GPS), hereafter PWGPS, refer to 20-year observations acquired by more than 40 GNSS geodetic stations located in the polar regions. For GNSS stations co-located with radio-sounding stations (RS), which operate Vaisala radiosondes, we estimated the PW from RS observations (PWRS). The PW values from the ERA-Interim global atmospheric reanalysis were used for validation and comparison of the results for all the selected GPS and RS stations. The correlation coefficients between times series are very high: 0.96 for RS and GPS, 0.98 for RS and ERA in the Arctic; 0.89 for RS and GPS, 0.97 for RS and ERA in Antarctica. The Root-Mean-Square of the Error (RMSE) is 0.9 mm on average for both RS vs. GPS and RS vs. ERA in the Arctic, and 0.6 mm for RS vs. GPS and 0.4 mm for RS vs. ERA in Antarctica. After validation, long-term trends, both for Arctic and Antarctic regions, were estimated using Hector scientific software. Positive PWGPS trends dominate at Arctic sites near the borders of the Atlantic Ocean. Sites located at higher latitudes show no significant values (at 1σ level). Negative PWGPS trends were observed in the Arctic region of Greenland and North America. A similar behaviour was found in the Arctic for PWRS trends. The stations in the West Antarctic sector show a general positive PWGPS trend, while the sites on the coastal area of East Antarctica exhibit some significant negative PWGPS trends, but in most cases, no significant PWRS trends were found. The present work confirms that GPS is able to provide reliable estimates of water vapour content in Arctic and Antarctic regions too, where data are sparse and not easy to collect. These preliminary results can give a valid contribution to climate change studies.

scholarly journals Inter-annual and seasonal patterns of precipitable water vapour over Malaysia from 1990–2019 based on MERRA-2 reanalysis

2021 ◽  
Vol 30 (1) ◽  
pp. 208-218
Author(s):  
Ezekiel Makama ◽  
Hwee Lim
Keyword(s):  
Water Vapour ◽  
Precipitable Water ◽  
Regression Method ◽  
Least Square ◽  
Seasonal Patterns ◽  
Positive Trend ◽  
Precipitable Water Vapour ◽  
Significant Positive Trend ◽  
East Malaysia

In this study seasonal and inter-annual patterns as well as trend in the total precipitable water vapour (TPW) over Malaysia, based on a 30-year data from MERRA-2, have been evaluated using least square regression method. Indicator TPW revealed a pair of minima in February/August and maxima in May/November with highest and lowest long-term means found in East Malaysia. Long-term seasonal variability of TPW exhibited latitudinal dependency in both the NEM and SWM seasons. Indicator TPW showed respective southeast-northwest and southwest-northeast spatial distribution in West and East Malaysia, with the highest statistically significant positive trend found in the former.

scholarly journals Continuous quality assessment of atmospheric water vapour measurement techniques: FTIR, Cimel, MFRSR, GPS, and Vaisala RS92

2010 ◽  
Vol 3 (2) ◽  
pp. 323-338 ◽  
Author(s):  
M. Schneider ◽  
P. M. Romero ◽  
F. Hase ◽  
T. Blumenstock ◽  
E. Cuevas ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Water Vapour ◽  
Measurement Techniques ◽  
Precipitable Water ◽  
Atmospheric Conditions ◽  
Constrained Estimation ◽  
Precipitable Water Vapour ◽  
Mixing Ratios ◽  
Better Than

Abstract. At the Izaña Observatory, water vapour amounts have been measured routinely by different techniques for many years. We intercompare the total precipitable water vapour (PWV) amounts measured between 2005 and 2009 by a Fourier Transform Infrared (FTIR) spectrometer, a Multifilter Rotating Shadow-band Radiometer (MFRSR), a Cimel sunphotometer, a Global Positioning System (GPS) receiver, and daily radiosondes (Vaisala RS92). The long-term characteristics of our study allows a reliable and extensive empirical quality assessment of long-term validity, which is an important prerequisite when applying the data to climate research. We estimate a PWV precision of 1% for the FTIR, about 10% for the MFRSR, Cimel, and GPS (when excluding rather dry conditions), and significantly better than 15% for the RS92 (the detection of different airmasses avoids a better constrained estimation). We show that the MFRSR, Cimel and GPS data quality depends on the atmospheric conditions (humid or dry) and that the restriction to clear-sky observations introduces a significant dry bias in the FTIR and Cimel data. In addition, we intercompare the water vapour profiles measured by the FTIR and the Vaisala RS92, which allows the conclusion that both experiments are able to detect lower to upper tropospheric water vapour mixing ratios with a precision of better than 15%.

scholarly journals Quality assessment of Izaña's upper-air water vapour measurement techniques: FTIR, Cimel, MFRSR, GPS, and Vaisala RS92

2009 ◽  
Vol 2 (4) ◽  
pp. 1625-1662 ◽  
Author(s):  
M. Schneider ◽  
P. M. Romero ◽  
F. Hase ◽  
T. Blumenstock ◽  
E. Cuevas ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Water Vapour ◽  
Measurement Techniques ◽  
Precipitable Water ◽  
Research Centre ◽  
Atmospheric Conditions ◽  
Precipitable Water Vapour ◽  
Clear Sky ◽  
Large Water

Abstract. At the Izaña Atmospheric Research Centre water vapour amounts are measured routinely by different techniques since many years. We intercompare the total precipitable water vapour amounts measured between 2005 and 2009 by a Fourier Transform Infrared (FTIR) spectrometer, a Multifilter rotating shadow-band radiometer (MFRSR), a Cimel sunphotometer, a Global Positioning System (GPS) receiver, and daily radiosondes (Vaisala RS92). In addition we intercompare the water vapor profiles measured by the FTIR and the radiosondes. The long-term intercomparison assures that our study well represents the large water vapour variabilities that occur in the troposphere and allows a reliable empirical quality assessment for the different water vapour dataset. We examine how the data quality of the different techniques depends on atmospheric conditions and estimate the dry bias of the techniques which are restricted to clear sky observations.

scholarly journals Interannual variability of precipitable water

1996 ◽  
Vol 14 (4) ◽  
pp. 464-467 ◽  
Author(s):  
R. P. Kane
Keyword(s):  
Interannual Variability ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Precipitable Water ◽  
Radiosonde Data ◽  
High Latitudes ◽  
Zonal Winds ◽  
Low Latitudes ◽  
Linear Trends

Abstract. The 12-month running means of the surface-to-500 mb precipitable water obtained from analysis of radiosonde data at seven selected locations showed three types of variability viz: (1) quasi-biennial oscillations; these were different in nature at different latitudes and also different from the QBO of the stratospheric tropical zonal winds; (2) decadal effects; these were prominent at middle and high latitudes and (3) linear trends; these were prominent at low latitudes, up trends in the Northern Hemisphere and downtrends in the Southern Hemisphere.

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