Nevertheless, climate change is more than changing temperatures, and a strengthened greenhouse effect is also expected to change the hydrological cycle which can be described as a chain of processes connected in a closed-loop where H 2 O exists in various forms within the planetary system. One advantage of using the global mean sea level as a measure of the state of the climate system is that it is not biased by an irregular distribution of thermometers nor the urban heat island effect. The global mean sea level represents an indicator that integrates the total effect of global warming, and functions like the mercury in a thermometer, as the ocean volume expands with higher temperature, in addition to a contribution from melting glaciers and ice sheets. The global mean temperature has played a key role in determining the climate sensitivity and has been used as a yardstick for the Paris Agreement for limiting climate change to 1.5☌ or 2.0☌ warming from preindustrial times. The most common index for the state of Earth’s climate and global warming has traditionally been the global mean temperature or the global sea level. Hence, the wavelet results are in line with an acceleration of the rate of the global hydrological cycle, combined with a diminishing global area of rainfall. Our results suggest that individual precipitation systems over the globe have shrunk in terms of their spatial extent while becoming more intense throughout the period 1950–2020. To further investigate historical variations in the precipitation surface area, we carried out a wavelet analysis of 24-hr precipitation from the ERA5 reanalysis that indicated how the rainfall patterns have changed over time. However, the estimated 24-hr global precipitation surface area varies when estimated from different reanalyses and the estimates are still uncertain. Based on the ERA5 reanalysis, we find that the global area of daily precipitation decreased from 43 to 41% of the global area between 19, whereas the total daily global rainfall increased from 1440 Gt to 1510 Gt per day. With a recent progress in both global satellite observations and reanalyses, we can now estimate the global rainfall surface area to provide new insights into how rainfall intensity changes over time. They are: i) the 24-hr global total rainfall, ii) the global surface area with daily precipitation, and iii) the global mean precipitation intensity. Initial high readings may well be corrected at a later date.There are few commonly used indicators that describe the state of Earth’s global hydrological cycle and here we propose three indicators to capture how an increased greenhouse effect influences the global hydrological cycle and the associated rainfall patterns. Note 4: Rain rate records are manually checked, and changed if necessary, due to occasional lag in data transmission. Note 3: Figures in brackets refer to departure from average conditions Note 2: The minimum recordable rain (the rain gauge resolution) is 0.2 mm Note 1: Rain records began in February 2009 Browse at your peril!Īlso, consider upgrading. You are using a browser (Mozilla/4.0 (compatible MSIE 6.0 Windows NT 5.1 SV1)) that is not compatible with nw3weather.
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