Patterns and Mechanisms of Northeast Pacific Temperature Response to Pliocene Boundary Conditions
Patterns and Mechanisms of Northeast Pacific Temperature Response to Pliocene Boundary Conditions
复制标题
DOI：
10.1029/2021pa004370
复制
发表时间：
2022-06
影响因子：
3.5
通讯作者：
P. Brennan;Tripti Bhattacharya;R. Feng;J. Tierney;E. Jorgensen
中科院分区：
文献类型：
--
作者：
P. Brennan;Tripti Bhattacharya;R. Feng;J. Tierney;E. Jorgensen
北太平洋的海洋-大气动力学在全球气候系统中起着重要作用，并影响着北美西部的水文气候。然而，在大气温室气体浓度增加的情况下，该地区平均气候的变化还没有得到很好的理解。在这里，我们提出了新的基于烯酮的记录海表面温度（SST）东北太平洋从中期Piacenzian温暖期（约3.3-3.0 Ma），一个时间间隔被认为是一个模拟不久的未来气候下中间的道路人为排放。我们将这些和其他基于烯酮的北太平洋SST记录与完全耦合的气候模式模拟进行比较，以研究上新世中期CO2和其他边界条件对区域气候动力学的影响，并探索控制区域温度模式差异的因素。模型的性能因地区而异，社区地球系统模型1.2（CESM 1.2）和CESM 2在加州边缘等变暖较大的地区表现最好，尽管这些模型低估了我们新的代理记录和该地区其他地区的变暖。单一强迫模拟揭示了强烈的影响，规定的陆地表面的变化和较高的CO2水平沿海变暖模式沿CESM 2加州边缘。此外，模型之间短波和长波辐射和环流的差异，可能与模型大气成分的变化有关，可能在模型捕捉上新世温暖的区域变化模式的能力中发挥关键作用。因此，从地球化学记录推断的区域温度变化模式有助于了解不同模式参数化方案对区域气候模式的影响。
Ocean‐atmosphere dynamics in the north Pacific play an important role in the global climate system and influence hydroclimate in western North America. However, changes to this region's mean climate under increased atmospheric greenhouse gas concentrations are not well understood. Here we present new alkenone‐based records of sea surface temperature (SST) from the northeast Pacific from the mid‐Piacenzian warm period (approximately 3.3–3.0 Ma), an interval considered to be an analog for near‐future climate under middle‐of‐the‐road anthropogenic emissions. We compare these and other alkenone‐based SST records from the north Pacific to fully‐coupled climate model simulations to examine the impact of mid‐Pliocene CO2 and other boundary conditions on regional climate dynamics and to explore factors governing model disagreement about regional temperature patterns. Model performance varies regionally, with Community Earth System Model 1.2 (CESM 1.2) and CESM2 performing best in regions with greater warming like the California Margin, though these models underestimate the warming evidenced in our new proxy record and others from the region. Single forcing simulations reveal a strong influence for prescribed land surface changes and higher CO2 levels on coastal warming patterns along the California Margin in CESM2. Furthermore, differences in shortwave and longwave radiation and circulation between the models, likely related to changes in the atmospheric component of the model, may play a key role in the ability of models to capture regionally‐varying patterns of Pliocene warmth. Regional patterns of temperature change inferred from geochemical records could therefore help to understand the impacts of different model parameterization schemes on regional climate patterns.