The hydrological cycle and ocean circulation of the Maritime Continent in the Pliocene: results from PlioMIP2
The hydrological cycle and ocean circulation of the Maritime Continent in the Pliocene: results from PlioMIP2
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DOI：
10.5194/cp-19-2053-2023
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发表时间：
2023-10
影响因子：
4.3
通讯作者：
Xin Ren;D. Lunt;Erica Hendy;A. S. von der Heydt;A. Abe‐Ouchi;B. Otto‐Bliesner;C. Williams;C. Ste
中科院分区：
文献类型：
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作者：
Xin Ren;D. Lunt;Erica Hendy;A. S. von der Heydt;A. Abe‐Ouchi;B. Otto‐Bliesner;C. Williams;C. Ste
抽象。海洋大陆（MC）形成了热带太平洋的西部边界，该地区相对较小的变化可以影响局部和远程的气候。在上新世中期Piacenzian温暖期（mPWP; 3.264至3.025 Ma）大气CO2浓度为400 ppm，和陆上巽他和Sahul货架的陆地-海洋分布的MC不同的今天。因此，地形变化和CO2水平升高，加上其他强迫，预计在这个时候已经在MC地区驱动了一个重要的气候信号。通过使用上新世模型相互比较项目第2阶段（PlioMIP 2）的结果，我们研究的平均气候特征的MC在mPWP和印度尼西亚的CO2流量（ITF）的变化相对于前工业化。结果表明，一个温暖和潮湿的mPWP气候的MC和较低的海面盐度在周围的海洋相比，工业化前。此外，我们通过ITF量化的体积传输，虽然ITF可能会受到阻碍的陆上货架，10出15个模型显示出增加的体积运输相比，工业化前。为了避免PlioMIP 2集合中存在的密切相关的模型的不当影响，我们引入了一个新的度量，多聚类均值（MCM），它是基于对单个模型的聚类分析。我们研究了MCM的选择与更传统的多模型均值（MMM）和个体模型分析对模型结果与数据之间差异的影响。我们发现，模式，再现现代MC气候很好，并不总是很好地模拟的mPWP气候异常的MC。通过与单个模式的比较，MMM和MCM较好地再现了再分析的工业化前海表温度（SST），与MC中的大多数单个模式相比，与重建的海表温度距平（SSTA）的差异较小。此外，聚类揭示了MMM没有捕获的空间信号，因此MCM为我们提供了一种新的方法来探索包括相似模型的模型集合的结果。
Abstract. The Maritime Continent (MC) forms the western boundary of the tropical Pacific Ocean, and relatively small changes in this region can impact the climate locally and remotely. In the mid-Piacenzian warm period of the Pliocene (mPWP; 3.264 to 3.025 Ma) atmospheric CO2 concentrations were ∼ 400 ppm, and the subaerial Sunda and Sahul shelves made the land–sea distribution of the MC different to today. Topographic changes and elevated levels of CO2, combined with other forcings, are therefore expected to have driven a substantial climate signal in the MC region at this time. By using the results from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2), we study the mean climatic features of the MC in the mPWP and changes in Indonesian Throughflow (ITF) with respect to the preindustrial. Results show a warmer and wetter mPWP climate of the MC and lower sea surface salinity in the surrounding ocean compared with the preindustrial. Furthermore, we quantify the volume transfer through the ITF; although the ITF may be expected to be hindered by the subaerial shelves, 10 out of 15 models show an increased volume transport compared with the preindustrial. In order to avoid undue influence from closely related models that are present in the PlioMIP2 ensemble, we introduce a new metric, the multi-cluster mean (MCM), which is based on cluster analysis of the individual models. We study the effect that the choice of MCM versus the more traditional analysis of multi-model mean (MMM) and individual models has on the discrepancy between model results and data. We find that models, which reproduce modern MC climate well, are not always good at simulating the mPWP climate anomaly of the MC. By comparing with individual models, the MMM and MCM reproduce the preindustrial sea surface temperature (SST) of the reanalysis better than most individual models and produce less discrepancy with reconstructed sea surface temperature anomalies (SSTA) than most individual models in the MC. In addition, the clusters reveal spatial signals that are not captured by the MMM, so that the MCM provides us with a new way to explore the results from model ensembles that include similar models.