| DOI: | 10.5194/cp-10-41-2014
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| Scopus记录号: | 2-s2.0-84892427978
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| 论文题名: | Mending Milankovitch's theory: Obliquity amplification by surface feedbacks |
| 作者: | Tabor C.R.; Poulsen C.J.; Pollard D.
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| 刊名: | Climate of the Past
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| ISSN: | 18149324
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| 出版年: | 2014
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| 卷: | 10, 期:1 | | 起始页码: | 41
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| 结束页码: | 50
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| 语种: | 英语
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| Scopus关键词: | albedo
; annual variation
; dominance
; environmental response
; global perspective
; ice sheet
; insolation
; latitude
; obliquity
; optimization
; Pleistocene
; proxy climate record
; seasonal variation
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| 英文摘要: | Milankovitch's theory states that orbitally induced changes in high-latitude summer insolation dictate the waxing and waning of ice sheets. Accordingly, precession should dominate the ice-volume response because it most strongly modulates summer insolation. However, early Pleistocene (2.588-0.781 Ma) ice-volume proxy records vary almost exclusively at the frequency of the obliquity cycle. To explore this paradox, we use an Earth system model coupled with a dynamic ice sheet to separate the climate responses to idealized transient orbits of obliquity and precession that maximize insolation changes. Our results show that positive surface albedo feedbacks between high-latitude annual-mean insolation, ocean heat flux and sea-ice coverage, and boreal forest/tundra exchange enhance the ice-volume response to obliquity forcing relative to precession forcing. These surface feedbacks, in combination with modulation of the precession cycle power by eccentricity, help explain the dominantly 41 kyr cycles in global ice volume of the early Pleistocene. © Author(s) 2014. |
| 资助项目: | NSF, National Science Foundation
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/49328
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| Appears in Collections: | 气候变化与战略
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| Recommended Citation: | |
Tabor C.R.,Poulsen C.J.,Pollard D.. Mending Milankovitch's theory: Obliquity amplification by surface feedbacks[J]. Climate of the Past,2014-01-01,10(1)
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