The phenology of Arctic Ocean surface warming.
The phenology of Arctic Ocean surface warming.
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DOI：
10.1002/2016jc012089
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发表时间：
2016-09
影响因子：
3.6
通讯作者：
Dickinson, Suzanne
中科院分区：
文献类型：
--
作者：
Steele, Michael;Dickinson, Suzanne
在这项工作中，我们利用卫星和再分析资料，探索了北冰洋太平洋部分海冰退缩、海表面温度(SST)和大气热通量之间的季节关系(即物候)。我们发现，在大多数年份冰消退较早的地方，相对于消退较晚的地区，夏季最大海温通常较暖。对于任何特定的年份，我们发现异常的早期冰川消退通常会导致异常温暖的海温。然而，这种关系在楚科奇海很弱，那里的海洋平流起着很大的作用。在特定年份，退缩发生得比往年早，但在季节中仍然相对较晚，这也是较弱的，主要是因为当时的大气热通量较弱。这一结果有助于解释近年来在2007年和2012年两次极端冰川消退中发现的截然不同的海洋变暖反应。我们还发现，由于海面浮力和动量强迫的变化发生在8月初，我们称之为夏末过渡(LST)，冰消退的时间影响了最大SST的日期。在LST之后，上层海洋的混合增强导致海洋表面的冷却，而大气热通量仍然弱向下。我们的结果表明，在短期内，更早的冰川消退可能会导致北冰洋大部分地区的海洋表面变暖，尽管那里的冰川消退在季节的后期仍然发生。北冰洋上层每年夏季变暖程度很大程度上取决于海冰消退与大气热输入之间的关系2007年北冰洋比2012年变暖，这是因为大气热流峰值附近大范围的海冰提前消退，在海面净通量由于垂直混合而由下向上转化之前，北冰洋上层海面温度在早期消退区达到峰值。
In this work, we explore the seasonal relationships (i.e., the phenology) between sea ice retreat, sea surface temperature (SST), and atmospheric heat fluxes in the Pacific Sector of the Arctic Ocean, using satellite and reanalysis data. We find that where ice retreats early in most years, maximum summertime SSTs are usually warmer, relative to areas with later retreat. For any particular year, we find that anomalously early ice retreat generally leads to anomalously warm SSTs. However, this relationship is weak in the Chukchi Sea, where ocean advection plays a large role. It is also weak where retreat in a particular year happens earlier than usual, but still relatively late in the season, primarily because atmospheric heat fluxes are weak at that time. This result helps to explain the very different ocean warming responses found in two recent years with extreme ice retreat, 2007 and 2012. We also find that the timing of ice retreat impacts the date of maximum SST, owing to a change in the ocean surface buoyancy and momentum forcing that occurs in early August that we term the Late Summer Transition (LST). After the LST, enhanced mixing of the upper ocean leads to cooling of the ocean surface even while atmospheric heat fluxes are still weakly downward. Our results indicate that in the near‐term, earlier ice retreat is likely to cause enhanced ocean surface warming in much of the Arctic Ocean, although not where ice retreat still occurs late in the season. How warm the upper Arctic Ocean gets each summer strongly depends on the relationship between sea ice retreat and atmospheric heat input 2007 was warmer than 2012 owing to earlier sea ice loss over a wide area near the peak of atmospheric heat flux Sea surface temperature peaks in areas of early retreat before the net surface flux turns from downward to upward owing to vertical mixing