Ocean Heat Uptake Efficiency Increase Since 1970
Ocean Heat Uptake Efficiency Increase Since 1970
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DOI：
10.1029/2022gl100215
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发表时间：
2022-10-16
影响因子：
5.2
通讯作者：
Cael, B. B.
中科院分区：
文献类型：
--
作者：
Cael, B. B.
海洋储存了地球系统中大部分人为产生的热量。因此，海洋热吸收效率（OHUE）——每一度全球变暖进入海洋的热量——是决定未来几十年全球变暖程度的关键因素。在气候模式中，OHUE具有很好的特征，在百年时间尺度上呈下降趋势；相比之下，OHUE并没有很好地受到地球观测的限制。在这里，OHUE及其变化率是根据全球温度和海洋热含量记录诊断的。在过去的50年里，OHUE增加了0.19 +/- 0.04 W/m(2)K，在此期间平均增加了0.58 +/- 0.08 W/m(2)K。这种增加归因于海洋中人为热梯度的变陡，并且对应于超过1.5或2摄氏度等温度目标的几年差异。人类活动导致额外的能量被辐射回地球表面。这些额外的能量大部分以热量的形式在海洋中积累。根据全球变暖和海洋热含量的记录，这里显示了近几十年来将这种能量转移到海洋的效率有所提高。这种“海洋热吸收效率”是指每一度全球变暖转移到海洋中的能量，在过去50年里增加了大约三分之一。这意味着，在超过全球变暖目标（如2摄氏度）之前，要推迟数年时间。
The ocean stores the bulk of anthropogenic heat in the Earth system. The ocean heat uptake efficiency (OHUE)-the flux of heat into the ocean per degree of global warming-is therefore a key factor in how much warming will occur in the coming decades. In climate models, OHUE is well-characterized, tending to decrease on centennial timescales; in contrast, OHUE is not well-constrained from Earth observations. Here OHUE and its rate of change are diagnosed from global temperature and ocean heat content records. OHUE increased over the past five decades by 0.19 +/- 0.04 W/m(2)K, and was on average 0.58 +/- 0.08 W/m(2)K during this period. This increase is attributed to steepening anthropogenic heat gradients in the ocean, and corresponds to several years' difference in when temperature targets such as 1.5 or 2 degrees C are exceeded.Plain Language Summary Human activity causes extra energy to be radiated back onto Earth's surface. Much of this extra energy accumulates in the ocean as heat. Based on records of global warming and the ocean's heat content, here it is shown that the efficiency of the transfer of this energy into the ocean has increased in recent decades. This "ocean heat uptake efficiency" is the amount of energy transferred into the ocean per degree of global warming, and has increased by roughly a third over the past five decades. This translates into several years' delay until global warming temperature targets, such as 2 degrees C warming, are exceeded.