Regional dynamic and steric sea level change in response to the IPCC-A1B scenario
Regional dynamic and steric sea level change in response to the IPCC-A1B scenario
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DOI：
10.1175/jpo3013.1
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发表时间：
2007-02-01
影响因子：
3.5
通讯作者：
Marotzke, Jochem
中科院分区：
文献类型：
--
作者：
Landerer, Felix W.;Jungclaus, Johann H.;Marotzke, Jochem
本文利用马克斯·普朗克气象研究所(MPI)的大气-海洋耦合环流模式ECHAM5/MPI-OM，分析了气候变化模拟中的区域海平面变化。气候变化情景以1860年至2000年观测到的大气温室气体(GHG)浓度为基础，随后是国际气候变化专门委员会(IPCC)A1B气候变化情景，直至2100年；从2100年至2199年，温室气体浓度固定在2100水平。与未受扰动的控制气候相比，到2100年，全球海平面上升0.26m，通过空间膨胀，全球海平面上升0.56m；海平面变化不包括在本次模拟中。该模型的海平面在不同的海洋盆地中的演变有很大的不同。北冰洋的海平面上升最强，这是由于降水和大陆径流的淡水输入增加，而南大洋的海平面上升最弱，这是因为通过动态海面高度(SSH)调整补偿了空间变化。在北大西洋(NA)，副热带到副极地涡旋锋面上的一个复杂的三极SSH模式演变，这与NA海流的北移是一致的。在年际到年代际的时间尺度上，百慕大和拉布拉多海之间的SSH差异与北半球的斜压涡旋联合输送高度相关，但与经向翻转环流(MOC)的相关性很弱，因此不能在这些时间尺度上估计MOC。陆架区域的底部压力增加了0.45米(水柱当量)，南大洋大西洋部分的底部压力下降了0.20米。对温差和盐度海平面变化的单独评估表明，世界大洋大部分地区的温差异常为正。由于大气水汽从低纬向高纬度输送的增加，盐度异常在副热带地区为负，部分补偿了温差异常，而在北冰洋为正值，增加了温差异常。温度和盐度异常的垂直分布在各大洋盆地之间高度不均匀，到21世纪末，南大洋达到3000米深，北大西洋低至2200米，太平洋只有500米深。
This paper analyzes regional sea level changes in a climate change simulation using the Max Planck Institute for Meteorology ( MPI) coupled atmosphere - ocean general circulation model ECHAM5/MPI-OM. The climate change scenario builds on observed atmospheric greenhouse gas ( GHG) concentrations from 1860 to 2000, followed by the International Panel on Climate Change ( IPCC) A1B climate change scenario until 2100; from 2100 to 2199, GHG concentrations are fixed at the 2100 level. As compared with the unperturbed control climate, global sea level rises 0.26 m by 2100, and 0.56 m by 2199 through steric expansion; eustatic changes are not included in this simulation. The model's sea level evolves substantially differently among ocean basins. Sea level rise is strongest in the Arctic Ocean, from enhanced freshwater input from precipitation and continental runoff, and weakest in the Southern Ocean, because of compensation of steric changes through dynamic sea surface height ( SSH) adjustments. In the North Atlantic Ocean ( NA), a complex tripole SSH pattern across the subtropical to subpolar gyre front evolves, which is consistent with a northward shift of the NA current. On interannual to decadal time scales, the SSH difference between Bermuda and the Labrador Sea correlates highly with the combined baroclinic gyre transport in the NA but only weakly with the meridional overturning circulation ( MOC) and, thus, does not allow for estimates of the MOC on these time scales. Bottom pressure increases over shelf areas by up to 0.45 m ( water column equivalent) and decreases over the Atlantic section in the Southern Ocean by up to 0.20 m. The separate evaluation of thermosteric and halosteric sea level changes shows that thermosteric anomalies are positive over most of the World Ocean. Because of increased atmospheric moisture transport from low to high latitudes, halosteric anomalies are negative in the subtropical NA and partly compensate thermosteric anomalies, but are positive in the Arctic Ocean and add to thermosteric anomalies. The vertical distribution of thermosteric and halosteric anomalies is highly nonuniform among ocean basins, reaching deeper than 3000 m in the Southern Ocean, down to 2200 m in the North Atlantic, and only to depths of 500 m in the Pacific Ocean by the end of the twenty-first century.