Abstract
Global spatial and annual distribution of surface water vapour density were estimated using 2005 -2016 monthly air temperature and relative humidity at 1° ×1° resolution obtained from Era interim and NCEP/NCAR database products. Obtained results from reanalysis were statistically tested using in situ data from Tropospheric Data Acquisition Network (TRODAN) of The Center for Atmospheric Research (CAR). Four seasonal variations of surface water vapour density (winter (DJF), spring (MAM), summer (JJA) and autumn (SON)) was examined. Observed result from the two reanalysis follow similar trends with value from Era interim leading. High values ranges between 50 g/m2 and 68 g/m2 were observed in tropical regions and humid sub-tropical regions. Low values ranges between 8 g/m2 and 38 g/m2 were observed in Ice cap, Tundra and arid regions. High warming may be experienced in tropical and sub-tropical regions, similarly, climate change with alarming rate may be experienced in locations with low values. The annual cycle of surface water vapor density is clearly established from two reanalysis across world classified into twelve regions. The statistical test for the reanalysis present good result with a mean bias error, MBE, root mean square error, RMSE and R square of 20.56, 18.29, 0.87 and 5.87, 0.98, 0.93 for Era interim and NCEP/NCAR respectively.
Highlights
Water is the central of the hydrological cycle, which is inter or intra movement of water, in the Earth's atmosphere, oceans, and continents
Values of Surface water vapour density (SWVD) obtained from reanalysis data at 1.0° grid were compared with in situ data obtained from the Tropospheric Data Acquisition Network (TRODAN) of The Center for Atmospheric Research (CAR)
Seasonal and internannual global variations and changes of surface water vapour density (SWVD) derived from two reanalysis products (i.e NCEP/NCAR, ERA-Interim) are evaluated against in situ data obtained from the Tropospheric Data Acquisition Network (TRODAN) of The Center for Atmospheric Research (CAR)
Summary
Water is the central of the hydrological cycle, which is inter or intra movement of water, in the Earth's atmosphere, oceans, and continents. The primary and most effective greenhouse gas in the atmosphere is water vapour, because it absorbs longwave radiation and radiates it back to the surface, which contributing to warming [1,2,3,4,5]. The atmosphere holds more water vapour as the temperature of the Earth's surface and atmosphere increases [1]. Water vapour molecules absorbed heat energy radiated from the Earth's surface. Distribution and productivity of ecosystem depend on the dynamics of the water cycle [8]. As a result of climate change, hydrological and thermal regimes of rivers are expected to change and affect freshwater ecosystems, water quality and human water use [9].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call