Dr. Juanxiong He, a researcher at IAP/ICCES, has recently published a paper in Nature Climate Change, under the international collaboration with Dr. Xiangdong Zhang and his group at IARC/UAF, titled “Enhanced poleward moisture transport and amplified northern high-latitude wetting trend”. In this study, they found that the poleward atmospheric moisture transport has dramatically enhanced during the last 60 years and a record high occurred in 2006. This enhanced transport has played a decisively driving role in the increased Eurasian river discharges into the Arctic Ocean.
As the earth’s climate continues to change, the high-latitude North is becoming even wetter than before. In particular, air moisture, precipitation, and river discharge have increased, leading to a stronger hydrological cycle. These changes may intensify climate system interactions and further advance climate change. This may involve a warmer Arctic surface, a fresher Arctic Ocean and a larger Arctic Ocean freshwater export. The latter has significant implications for the Arctic sea ice mass balance and the North Atlantic thermohaline circulation and broader scale global climate variability.
However, specific reasons for the accelerated water cycle have remained unclear. The increased Eurasian river discharge has been attributed to various global warming caused changes in local thermodynamic processes such as thawing permafrost, decreasing transpiration by plants, and local water recycling. This new study suggests that changes in the hemispheric scale atmospheric circulation patterns and the resultant increase in poleward moisture transport have clearly contributed to a boost in hydrologic processes in the Eurasian Arctic. The high-latitude hydrological cycle is an integral part of the dynamically changing global climate system.
More information about this study can be found at:
Citation: Zhang X.D. et al. Nature Climate Change. doi:10.1038/nclimate1631 (2012)
Annual net AMT converged into the Ob, Yenisei and Lena river basins (red solid line) and annual discharge from these three rivers (blue solid line) from 1948 to 2008. The five-year running means were applied to detect QDV of net AMT (red dashed line) and discharge (blue dashed line). The linear trends are derived from the linear regression