The Arctic is experiencing a significant warming trend as well as a decadal oscillation. The atmospheric circulation represented by the Polar Vortex and the sea ice cover show decadal variabilities, while it has been ...The Arctic is experiencing a significant warming trend as well as a decadal oscillation. The atmospheric circulation represented by the Polar Vortex and the sea ice cover show decadal variabilities, while it has been difficult to reveal the decadal oscillation from the ocean interior. The recent distribution of Russian hydrochemical data collected from the Arctic Basin provides useful information on ocean interior variabilities. Silicate is used to provide the most valuable data for showing the boundary between the silicate-rich Pacific Water and the opposite Atlantic Water. Here, it is assumed that the silicate distribution receives minor influence from seasonal biological productivity and Siberian Rivers outflow. It shows a clear maximum around 100m depth in the Canada Basin, along with a vertical gradient below 100 m, which provides information on the vertical motion of the upper boundary of the Atlantic Water at a decadal time scale. The boundary shifts upward (downward), as realized by the silicate reduction (increase) at a fixed depth, responding to a more intense (weaker) Polar Vortex or a positive (negative) phase of the Arctic Oscillation. A coupled ice-ocean model is employed to reconstruct this decadal oscillation.展开更多
Although the importance to global oceanography of ice shelf-oceaaa interactions has been recognized for many years, only more recently has its role in the control of ice flow- from the interior, grounded ice sheet int...Although the importance to global oceanography of ice shelf-oceaaa interactions has been recognized for many years, only more recently has its role in the control of ice flow- from the interior, grounded ice sheet into the ocean been more clearly understood. The consequences for global sea level of increasing ice loss from the Antarctic and Greenland ice sheets has prompted rapidly growing research efforts in this area. Here we describe the different techniques commonly employed in the field study of ice shelf-ocean interactions. We focus on techniques used by the British Antarctic Survey, primarily on Filchner-Ronne Ice Shelf, and describe some recent results from instruments deployed both beneath the ice shelf and on its upper surface, which demonstrate variability at a broad range of time scales.展开更多
基金The work was suppo rted financially thro ugh The Category 7 of MEXT(Ministry of Education,Culture,Sports,Science and Technology)RR2002(Research Revolution 2002)Project for Sustainable Coexistence of Human。Nature and the Earth,Frontier Rese arch System for Global Change.
文摘The Arctic is experiencing a significant warming trend as well as a decadal oscillation. The atmospheric circulation represented by the Polar Vortex and the sea ice cover show decadal variabilities, while it has been difficult to reveal the decadal oscillation from the ocean interior. The recent distribution of Russian hydrochemical data collected from the Arctic Basin provides useful information on ocean interior variabilities. Silicate is used to provide the most valuable data for showing the boundary between the silicate-rich Pacific Water and the opposite Atlantic Water. Here, it is assumed that the silicate distribution receives minor influence from seasonal biological productivity and Siberian Rivers outflow. It shows a clear maximum around 100m depth in the Canada Basin, along with a vertical gradient below 100 m, which provides information on the vertical motion of the upper boundary of the Atlantic Water at a decadal time scale. The boundary shifts upward (downward), as realized by the silicate reduction (increase) at a fixed depth, responding to a more intense (weaker) Polar Vortex or a positive (negative) phase of the Arctic Oscillation. A coupled ice-ocean model is employed to reconstruct this decadal oscillation.
文摘Although the importance to global oceanography of ice shelf-oceaaa interactions has been recognized for many years, only more recently has its role in the control of ice flow- from the interior, grounded ice sheet into the ocean been more clearly understood. The consequences for global sea level of increasing ice loss from the Antarctic and Greenland ice sheets has prompted rapidly growing research efforts in this area. Here we describe the different techniques commonly employed in the field study of ice shelf-ocean interactions. We focus on techniques used by the British Antarctic Survey, primarily on Filchner-Ronne Ice Shelf, and describe some recent results from instruments deployed both beneath the ice shelf and on its upper surface, which demonstrate variability at a broad range of time scales.
