DOI: 10.5194/cp-10-523-2014
Scopus记录号: 2-s2.0-84896283739
论文题名: The challenge of simulating the warmth of the mid-Miocene climatic optimum in CESM1
作者: Goldner A. ; Herold N. ; Huber M.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 2 起始页码: 523
结束页码: 536
语种: 英语
Scopus关键词: climate effect
; climate modeling
; dating method
; latitude
; Miocene
; paleoclimate
; proxy climate record
; simulation
英文摘要: The mid-Miocene climatic optimum (MMCO) is an intriguing climatic period due to its above-modern temperatures in mid-to-high latitudes in the presence of close-to-modern CO2 concentrations. We use the recently released Community Earth System Model (CESM1.0) with a slab ocean to simulate this warm period, incorporating recent Miocene CO2 reconstructions of 400 ppm (parts per million). We simulate a global mean annual temperature (MAT) of 18 C, ∼4 C above the preindustrial value, but 4 C colder than the global Miocene MAT we calculate from climate proxies. Sensitivity tests reveal that the inclusion of a reduced Antarctic ice sheet, an equatorial Pacific temperature gradient characteristic of a permanent El Niño, increased CO2 to 560 ppm, and variations in obliquity only marginally improve model-data agreement. All MMCO simulations have an Equator to pole temperature gradient that is at least ∼10 C larger than that reconstructed from proxies. The MMCO simulation most comparable to the proxy records requires a CO2 concentration of 800 ppm. Our results illustrate that MMCO warmth is not reproducible using the CESM1.0 forced with CO2 concentrations reconstructed for the Miocene or including various proposed Earth system feedbacks; the remaining discrepancy in the MAT is comparable to that introduced by a CO2 doubling. The model's tendency to underestimate proxy derived global MAT and overestimate the Equator to pole temperature gradient suggests a major climate problem in the MMCO akin to those in the Eocene. Our results imply that this latest model, as with previous generations of climate models, is either not sensitive enough or additional forcings remain missing that explain half of the anomalous warmth and pronounced polar amplification of the MMCO. © 2014 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49300
Appears in Collections: 气候变化与战略
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Recommended Citation:
Goldner A.,Herold N.,Huber M.. The challenge of simulating the warmth of the mid-Miocene climatic optimum in CESM1[J]. Climate of the Past,2014-01-01,10(2)