The Relationship Between the Global Mean Deep-Sea and Surface Temperature During the Early Eocene
The Relationship Between the Global Mean Deep-Sea and Surface Temperature During the Early Eocene
复制标题
始新世早期全球平均深海温度与表面温度的关系
DOI：
10.1029/2022pa004532
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发表时间：
2023
影响因子：
3.5
通讯作者：
Goudsmit-Harzevoort B
中科院分区：
文献类型：
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作者：
Goudsmit-Harzevoort B
新生代全球平均近地表气温（global SAT）的估算很大程度上依赖于深海温度（DST）的古代数据，并假设全球SAT的变化与全球平均深海温度（global DST）和全球平均海表温度（global SST）的变化相关。我们利用深时模式比对项目模拟始新世早期气候最佳（EECO）的25个不同模式，分析了全球海表温度、SAT和DST之间的关系，验证了这一假设的有效性。与现代情况类似，我们发现夏令时的空间变异性有限，表明局部夏令时估计值可以被视为全球夏令时的一阶代表。线性回归分析表明，全球DST和SAT对大气co2变化的响应都强于全球海表温度，其响应因子相似。因此，这一基于模型的分析验证了全球DST变化可以用来估计早期新生代全球SAT变化的假设。EECO期间全球DST、SST和SAT的古代估计值与大气co2水平为1,680 ppm的模式模拟结果最吻合。这与EECO大气CO2的古代用物相匹配，表明模型与代用物之间的拟合良好。
Estimates of global mean near‐surface air temperature (global SAT) for the Cenozoic era rely largely on paleo‐proxy data of deep‐sea temperature (DST), with the assumption that changes in global SAT covary with changes in the global mean deep‐sea temperature (global DST) and global mean sea‐surface temperature (global SST). We tested the validity of this assumption by analyzing the relationship between global SST, SAT, and DST using 25 different model simulations from the Deep‐Time Model Intercomparison Project simulating the early Eocene Climatic Optimum (EECO) with varying CO2levels. Similar to the modern situation, we find limited spatial variability in DST, indicating that local DST estimates can be regarded as a first order representative of global DST. In line with previously assumed relationships, linear regression analysis indicates that both global DST and SAT respond stronger to changes in atmospheric CO2than global SST by a similar factor. Consequently, this model‐based analysis validates the assumption that changes in global DST can be used to estimate changes in global SAT during the early Cenozoic. Paleo‐proxy estimates of global DST, SST, and SAT during EECO show the best fit with model simulations with a 1,680 ppm atmospheric CO2level. This matches paleo‐proxies of EECO atmospheric CO2, indicating a good fit between models and proxy‐data.