The observational and numerical study on the impact of the Amur to the Okhotsk sea ice

鄂霍次克海（OK）位于西伯利亚大陆和北太平洋之间，从11月到6月都被冰覆盖，是北半球最南端的冰覆盖海洋之一。自20世纪80年代末以来，北冰洋海冰的年际变化很大，海冰覆盖面积急剧减少。此外，海冰影响大尺度气候，如阿留申低压的发展和Noiih太平洋中间水的形成8-10。与北冰洋类似，北冰洋的海冰被认为受到地面水文过程的影响。先前的研究表明，在OK中存在一个高盐度、低盐度的表层，它抑制了深层对流，促进了冻结。也有人推测，低盐度层的形成主要是由于阿穆尔河淡水的流入。尽管以前的研究试图通过数据分析来寻找河流对海冰影响更大的证据，但由于缺乏可靠的海冰年际数据，因此无法直接比较冰量数据和流量数据。由于可靠的卫星冰量数据的周期已经足够长，可以分析内部变率，我们现在能够直接比较两者。本研究的目的是收集阿穆尔河流量数据，并在年际和更长时间尺度上量化阿穆尔河流量对海冰的影响。结果地面水文对高纬度海洋的影响，如冰川融化和海洋中河流的流量，可以通过调节低密度淡水流入的流量来影响全球气候，从而加强海洋的分层。抑制温盐环流，也促进海冰的形成。我们基于海冰和河流流量数据的时间序列分析表明，这些淡水对鄂霍次克海海冰的影响相对较小，而第二大西伯利亚河阿穆尔河的流量相对较小。有证据表明，旺纳河水的流入会使海表温度升高，并抑制冬季海冰的形成。这些发现表明，在研究全球气候变化时，应重新考虑高纬度地区大河输送的感热。少

PurposesThe Sea of Okhotsk(OK), which is located between the Sibeiian continent and the North Pacific, is covered by ice from November through June, and is one of the southernmost ice-covered oceans in the Northern Hemisphere. The interannual variability of the sea-ice in the OK is large and sea-ice coverage has abniptly decreased since the end of the 1980's. Also, the sea-ice influences large scale climate such as the development of the Aleutian low and the formation of the Noiih Pacific intermediate waters 8-10. In analogy with the Arctic Ocean, sea-ice in the OK has been believed to be influenced by the ground hydrological processes. Previous studies suggest the existance of a highly siralilied, low-salinity surface layer in the OK, which suppresses deep convection and promotes freezing. It has also been speculated that the low-salinity layer is mainly due to the inflow of the fresh water from the Amur River. Although previous studies attempted to find evidence of the river-water in … More fluence on the sea-ice using data analyses, the lack of reliable interannual data for sea-ice precluded direct comparison between the ice-data and the discharge-data Because the period of reliable satellite-based ice-data has become long enough to analyze the inteninnual variability, we are now able to directly compare the two. The purpose of our study is to collect the Amur discharge data and to quantify the effects of the Amur discharge on the sea-ice on interannual and longer time scalesResultsThe impacts of ground hydrology on the high-latitude oceans, such as melting glaciers and discharge from rivers in the oceans, can affect global climate by mediating the flow of low-density, fresh water inflow that strengthens the ocean's stratification, suppresses the thermohaline circulation and also promotes sea-ice formation. Ourtime series analysis based on sea-ice and river-discharge data indicates that the effect of this fresh water on the sea-ice in the Sea of Okhotsk, into which the second largest Siberian River, the Amur, discharges, is relatively unimportant Interannual variations in the ice extent are negatively correlated with the amount of discharge. We find evidence that the inflow of wanner river water tends to the raise of the sea surface temperature, and that it suppresses ice formation in the following winter. These findings imply that sensible heat transported by large rivers in high latitudes should be reconsidered in studying global climate change. Less