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In a paper just published in the journal Science, Australian scientists from the Commonwealth Scientific andIndustrial Research Organisation (CSIRO) and the Lawrence LivermoreNational Laboratory, California, reported changing patterns ofsalinity in the global ocean during the past 50 years, marking aclear fingerprint of climate change. Lead author, Dr Paul Durack, said that by looking at observed oceansalinity changes and the relationship between salinity, rainfalland evaporation in climate models, they determined the water cyclehas strengthened by four per cent from 1950-2000. This is twice theresponse projected by current generation global climate models. "Salinity shifts in the ocean confirm climate and the globalwater cycle have changed. "These changes suggest that arid regions have become drier andhigh rainfall regions have become wetter in response to observedglobal warming," said Dr Durack, a post-doctoral fellow at theLawrence Livermore National Laboratory. With a projected temperature rise of 3ºC by the end of thecentury, the researchers estimate a 24 per cent acceleration of thewater cycle is possible. Scientists have struggled to determine coherent estimates of watercycle changes from land-based data because surface observations ofrainfall and evaporation are sparse. However, according to theteam, global oceans provide a much clearer picture. "The ocean matters to climate -- it stores 97 per cent of theworld's water; receives 80 per cent of the all surface rainfalland; it has absorbed 90 per cent of the Earth's energy increaseassociated with past atmospheric warming," said co-author, DrRichard Matear of CSIRO's Wealth from Oceans Flagship. "Warming of the Earth's surface and lower atmosphere isexpected to strengthen the water cycle largely driven by theability of warmer air to hold and redistribute more moisture." He said the intensification is an enhancement in the patterns ofexchange between evaporation and rainfall and with oceansaccounting for 71 percent of the global surface area the change isclearly represented in ocean surface salinity patterns. In the study, the scientists combined 50-year observed globalsurface salinity changes with changes from global climate modelsand found "robust evidence of an intensified global watercycle at a rate of about eight per cent per degree of surfacewarming," Dr Durack said. Dr Durack said the patterns are not uniform, with regionalvariations agreeing with the 'rich get richer' mechanism, where wetregions get wetter and dry regions drier. He said a change in freshwater availability in response to climatechange poses a more significant risk to human societies andecosystems than warming alone. "Changes to the global water cycle and the correspondingredistribution of rainfall will affect food availability,stability, access and utilization," Dr Durack said. Dr Susan Wijffels, co-Chair of the global Argo project and aco-author on the study, said maintenance of the present fleet ofaround 3,500 profilers is critical to observing continuing changesto salinity in the upper oceans. The work was funded through the Australian Climate Change ScienceProgram, a joint initiative of the Department of Climate Change andEnergy Efficiency, the Bureau of Meteorology and CSIRO. I am an expert from medicalgradetape.com, while we provides the quality product, such as Rigid Tapes , Surgical Paper Tape, Fabric Medical Tape,and more.
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