气候变化领域集成服务门户(CCPortal): Sensitivity of mid-Pliocene climate to changes in orbital forcing and PlioMIP's boundary conditions

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DOI	10.5194/cp-16-1643-2020
	Sensitivity of mid-Pliocene climate to changes in orbital forcing and PlioMIP's boundary conditions
	Samakinwa E.; Stepanek C.; Lohmann G.
发表日期	2020
ISSN	1814-9324
起始页码	353
结束页码	367
卷号	16 期号:4
英文摘要	We compare results obtained from modeling the mid-Pliocene warm period using the Community Earth System Models (COSMOS, version: COSMOS-landveg r2413, 2009) with the two different modeling methodologies and sets of boundary conditions prescribed for the two phases of the Pliocene Model Intercomparison Project (PlioMIP), tagged PlioMIP1 and PlioMIP2. Here, we bridge the gap between our contributions to PlioMIP1 (Stepanek and Lohmann, 2012) and PlioMIP2 (Stepanek et al., 2020). We highlight some of the effects that differences in the chosen mid-Pliocene model setup (PlioMIP2 vs. PlioMIP1) have on the climate state as derived with COSMOS, as this information will be valuable in the framework of the model-model and model-data comparison within PlioMIP2. We evaluate the model sensitivity to improved mid-Pliocene boundary conditions using PlioMIP's core mid-Pliocene experiments for PlioMIP1 and PlioMIP2 and present further simulations in which we test model sensitivity to variations in paleogeography, orbit, and the concentration of CO2. Firstly, we highlight major changes in boundary conditions from PlioMIP1 to PlioMIP2 and also the challenges recorded from the initial effort. The results derived from our simulations show that COSMOS simulates a mid-Pliocene climate state that is 0.29 °C colder in PlioMIP2 if compared to PlioMIP1 (17.82 °C in PlioMIP1, 17.53 °C in PlioMIP2; values based on simulated surface skin temperature). On the one hand, high-latitude warming, which is supported by proxy evidence of the mid-Pliocene, is underestimated in simulations of both PlioMIP1 and PlioMIP2. On the other hand, spatial variations in surface air temperature (SAT), sea surface temperature (SST), and the distribution of sea ice suggest improvement of simulated SAT and SST in PlioMIP2 if employing the updated paleogeography. Our PlioMIP2 mid- Pliocene simulation produces warmer SSTs in the Arctic and North Atlantic Ocean than those derived from the respective PlioMIP1 climate state. The difference in prescribed CO2 accounts for 0.5 °C of temperature difference in the Arctic, leading to an ice-free summer in the PlioMIP1 simulation, and a quasi ice-free summer in PlioMIP2. Beyond the official set of PlioMIP2 simulations, we present further simulations and analyses that sample the phase space of potential alternative orbital forcings that have acted during the Pliocene and may have impacted geological records. Employing orbital forcing, which differs from that proposed for PlioMIP2 (i.e., corresponding to pre-industrial conditions) but falls into the mid-Pliocene time period targeted in PlioMIP, leads to pronounced annual and seasonal temperature variations. Our result identifies the changes in mid-Pliocene paleogeography from PRISM3 to PRISM4 as the major driver of the mid- Pliocene warmth within PlioMIP and not the minor differences in forcings. © Author(s) 2020.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183636
作者单位	Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Institute of Geography, University of Bern, Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland; Institute of Environmental Physics, University of Bremen, Bremen, Germany
推荐引用方式 GB/T 7714	Samakinwa E.,Stepanek C.,Lohmann G.. Sensitivity of mid-Pliocene climate to changes in orbital forcing and PlioMIP's boundary conditions[J],2020,16(4).
APA	Samakinwa E.,Stepanek C.,&Lohmann G..(2020).Sensitivity of mid-Pliocene climate to changes in orbital forcing and PlioMIP's boundary conditions.Climate of the Past,16(4).
MLA	Samakinwa E.,et al."Sensitivity of mid-Pliocene climate to changes in orbital forcing and PlioMIP's boundary conditions".Climate of the Past 16.4(2020).