Water mass transformation in the Greenland Sea during the 1990s
Water mass transformation in the Greenland Sea during the 1990s
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DOI：
10.1029/2004jc002510
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发表时间：
2005-07
影响因子：
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通讯作者：
J. Karstensen;P. Schlosser;D. Wallace;J. L. Bullister;J. Blindheim
中科院分区：
文献类型：
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作者：
J. Karstensen;P. Schlosser;D. Wallace;J. L. Bullister;J. Blindheim
水文和瞬态示踪剂测量的时间序列被用来研究1991年和2000年之间的格陵兰海水质量转换的变化。示踪剂存量的增加表明，格陵兰海中层水以0.1至0.2 Sv（1 Sv = 1 × 106 m3 s-1）（10年平均）的速度活跃更新。温度最大值（Tmax）建立在上层（500米）的基础上，作为一个结果，在20世纪90年代初的近地层的异常强大的淡水输入。到1995年，Tmax迅速下降到1500米，然后下降速度慢得多。与20世纪80年代相比，GSIW变得更温暖，含盐量更少。在Tmax的加深阶段，大气数据显示高于平均水平的风应力旋度和海洋热损失。此外，在这一时期，北冰洋海冰大量输出，当地没有海冰形成。所有这些因素的结合可能引起了GSIW与上层的有害淡水的更新。Tmax层建立了一个稳定的最大值，抑制中间和较深的沃茨之间的垂直交换。深层沃茨的温度和盐度继续分别以0.01°C/年和0.001/年的速度增加。然而，自1993年以来，减少和均匀化的深水瞬态示踪剂浓度表明，更新发生主要是通过增加北冰洋沃茨。在2000年，水柱（500米至3400米）需要在年平均热损失的基础上再增加60 W m−2（110 W m−2）才能将其热含量恢复到1989年（1971年）的数值。
Time series of hydrographic and transient tracer measurements were used to study the variability of Greenland Sea water mass transformation between 1991 and 2000. Increases in tracer inventories indicate active renewal of Greenland Sea Intermediate Water (GSIW) at a rate of 0.1 to 0.2 Sv (1 Sv = 1 × 106 m3 s−1) (10-year average). A temperature maximum (Tmax) was established at the base of the upper layer (500 m) as a consequence of anomalously strong freshwater input into the near-surface layer at the beginning of the 1990s. Tmax rapidly descended to 1500 m by 1995 followed by a much slower rate of descent. GSIW became warmer and less saline compared to the 1980s. During the deepening phase of Tmax, atmospheric data revealed above-average wind stress curl and oceanic heat loss. In addition, high Arctic Ocean sea-ice export and lack of local sea-ice formation have been documented for that period. A combination of all these factors may have evoked the renewal of GSIW with anomalously freshwater from the upper layers. The Tmax layer established a stability maximum that inhibits vertical exchange between intermediate and deeper waters. Temperature and salinity of deep waters continued to increase at rates of 0.01°C yr−1 and 0.001 yr−1, respectively. However, since 1993, decrease in and homogenization of deep water transient tracer concentrations indicate that renewal occurred predominantly by addition of Arctic Ocean waters. In 2000 the water column (500 m to 3400 m) required an additional 60 W m−2 (110 W m−2) over the annual mean heat loss to restore its heat content to 1989 (1971) values.