Ice and brine production in Storfjorden from four winters of satellite and in situ observations and modeling
Ice and brine production in Storfjorden from four winters of satellite and in situ observations and modeling
复制标题
Storfjorden 四个冬天的冰和盐水产量的卫星以及现场观测和建模
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
J. Haarpaintner
中科院分区：
文献类型：
--
作者：
R. Skogseth;P. Haugan;J. Haarpaintner
[1]1998年至2001年冬季，ERS-2 SAR图像中Storfjorden的固定冰、浮冰和冰间湖（开阔水域和薄冰）的人工分类被用来确定风驱动冰间湖宽度模型中的模型参数。然后根据表面热平衡计算分类区域的冰产量。模拟的开放水域面积平均占总面积的10%，并产生了58%的总冰（Tice）。富盐水陆架水的体积（BSW; Vbsw）估计在0.9-1.1 × 1012 m3或0.06-0.07 Sv（冻结期平均）和0.03-0.04 Sv（年平均）之间。偏北风分量的强度似乎占主导地位的净热通量的变化在TICE的原因。研究发现BSW（Sbsw）的盐度主要取决于冰碴冰的产生，而Vbsw主要取决于Tice和表面盐度（初始和冬季变化）。对1970 ~ 2001年冬季冰间湖平均面积和Tice的模拟时间序列的相关性研究表明，年际变化部分可以用区域冰和海洋条件的变化来解释，部分可以用北大西洋或北大西洋涛动（NAO）的西南风强度来解释。强烈的南风（高NAO）可能会减少巴伦支海西部的北极冰进口和冰生产，导致秋季Storfjorden的表面盐度较高。由此产生的弱稳定性的水柱可能会产生大Vbsw下一个冬天的有利条件。如果Storfjorden上空的强北风与低NAO相关，则从高NAO到低NAO的快速转换将产生高Vbsw和Sbsw。与NAO的联系似乎随时间而变化。然而，从弱偏北风在1999年冬季强偏北风在2000年冬季的过渡是伴随着高观测到的Sbsw 2000年冬季与预期一致。
[1] Manual classification of fast ice, pack ice, and polynya (open water and thin ice) in Storfjorden from ERS-2 SAR images during winters 1998 to 2001 was used to determine model parameters in a wind-driven polynya width model. Production of ice in the classified areas was then calculated from surface heat balance. The modeled open water area occupied on average 10% of the total area and produced 58% of the total ice (Tice). The volume of brine-enriched shelf water (BSW; Vbsw) was estimated to be in the range 0.9–1.1 × 1012 m3 or 0.06–0.07 Sv (freezing period average) and 0.03–0.04 Sv (annual average). The strength of the northerly wind component seemed to dominate over net heat flux as cause of variability in Tice. Salinity of BSW (Sbsw) was found to be primarily governed by frazil ice production, whereas Vbsw was mostly determined from Tice and surface salinity (initial and change during winter). Correlation studies of modeled time series of winter mean polynya area and Tice in winters 1970 to 2001 showed that interannual variability could partly be explained by variability in regional ice and ocean conditions, and partly by the strength of the southwesterlies from the North Atlantic or the North Atlantic Oscillation (NAO). Strong southerly winds (high NAO) may give less Arctic ice import and ice production in the western Barents Sea, resulting in a higher surface salinity in Storfjorden in fall. The resulting weak stability in the water column may give favorable conditions for producing large Vbsw the following winter. If strong northerly winds over Storfjorden are associated with low NAO, rapid transitions from high to low NAO would give high Vbsw and Sbsw. The link to NAO seems to vary in time. However, the transition from weak northerly winds in winter 1999 to strong northerly winds in winter 2000 was accompanied by high observed Sbsw winter 2000 in agreement with expectations.