Investigation of the thermodynamic processes of a floe-lead system in the central Arctic during later summer  

作　　者：LEI RuiBo LI ZhiJun CHENG Bin YANG QingHua LI Na 

机构地区：[1]Polar Research Institute of China, Shanghai 200136, China [2]State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Daliah 116024, China [3]Finnish Meteorology Institute, EO.Box33, Helsinki, H-00931, Finland [4]National Marine Environmental Forecasting Center, Beijing 100081, China

出　　处：《Chinese Journal of Polar Science》2011年第1期10-16,共7页极地研究（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant no. 40930848);the Norwegian Research Council (AMORA, 193592/S30);the China Postdoctoral Science Foundation (Grant no. 20100470400);the International Cooperation Project of the Chinese Arctic and Antarctic Administration, SOA (Grant no. IC2010007)

摘　　要：Thermodynamic processes of a system involving a floe and a small lead in the central Arctic were investigated during the ice-camp period of the third Chinese National Arctic Research Expedition from 20 to 28 August, 2008. The measurements included surface air temperatures above the floe, spectral albedo of the lead, seawater temperatures in the lead and under the ice cover, and the lateral and bottom mass balance of the floe. The surface air temperature at 1.15 m remained below 0~Cthroughout the observation period and sea ice had commenced its annual cycle of growth in response to autumn cooling during the study. The surface of the lead was frozen by 23 August, after which the spectral albedo of the thin-ice-covered lead in the band of 320-950 nm was 0.46 -0.03, the seawater temperatures both in the lead and under the ice cover, as well as the vertical seawater-temperature gradient in the lead decreased gradually, and the oceanic heat under the ice was maintained at a low level approaching 0 W/m2. By the end of the measurement, the thickness of the investigated floe had reached its annual minimum, while the lateral of the floe was still in the melting phase, with a mean melting rate of 1.0±0.3 cm/d during the measurement, responding to an equivalent latent heat flux of 21 ±6 W/m2. The lateral melting of the floe had made a more significant contribution to the sea-ice mass balance than the surface and bottom melting in the end of August.Thermodynamic processes of a system involving a floe and a small lead in the central Arctic were investigated during the ice-camp period of the third Chinese National Arctic Research Expedition from 20 to 28 August, 2008. The measurements included surface air temperatures above the floe, spectral albedo of the lead, seawater temperatures in the lead and under the ice cover, and the lateral and bottom mass balance of the floe. The surface air temperature at 1.15 m remained below 0~Cthroughout the observation period and sea ice had commenced its annual cycle of growth in response to autumn cooling during the study. The surface of the lead was frozen by 23 August, after which the spectral albedo of the thin-ice-covered lead in the band of 320-950 nm was 0.46 -0.03, the seawater temperatures both in the lead and under the ice cover, as well as the vertical seawater-temperature gradient in the lead decreased gradually, and the oceanic heat under the ice was maintained at a low level approaching 0 W/m2. By the end of the measurement, the thickness of the investigated floe had reached its annual minimum, while the lateral of the floe was still in the melting phase, with a mean melting rate of 1.0±0.3 cm/d during the measurement, responding to an equivalent latent heat flux of 21 ±6 W/m2. The lateral melting of the floe had made a more significant contribution to the sea-ice mass balance than the surface and bottom melting in the end of August.

关 键 词：Sea ice LEAD thermodynamic process TEMPERATURE thickness ARCTIC 

分 类 号：P715.2[天文地球—海洋科学] O414.1[理学—理论物理]