DOI: 10.5194/cp-11-1575-2015
Scopus记录号: 2-s2.0-84948461078
论文题名: Modelled glacier equilibrium line altitudes during the mid-Holocene in the southern mid-latitudes
作者: Bravo C. ; Rojas M. ; Anderson B.M. ; Mackintosh A.N. ; Sagredo E. ; Moreno P.I.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2015
卷: 11, 期: 11 起始页码: 1575
结束页码: 1586
语种: 英语
Scopus关键词: ablation
; climate conditions
; climate forcing
; glacier dynamics
; glacier mass balance
; Holocene
; latitude
; numerical model
; paleoclimate
; precipitation assessment
; seasonality
; soil-vegetation interaction
; Southern Hemisphere
; temperature anomaly
; New Zealand
; Patagonia
; South Island
英文摘要: Glacier behaviour during the mid-Holocene (MH, 6000 years BP) in the Southern Hemisphere provides observational data to constrain our understanding of the origin and propagation of palaeoclimate signals. In this study we examine the climatic forcing of glacier response in the MH by evaluating modelled glacier equilibrium line altitudes (ELAs) and climatic conditions during the MH compared with pre-industrial time (PI, year 1750). We focus on the middle latitudes of the Southern Hemisphere, specifically Patagonia and the South Island of New Zealand. Climate conditions for the MH were obtained from PMIP2 model simulations, which in turn were used to force a simple glacier mass balance model to simulate changes in ELA. In Patagonia, the models simulate colder conditions during the MH in austral summer (-0.2 °C), autumn (-0.5 °C), and winter (-0.4), and warmer temperatures (0.2 °C) during spring. In the Southern Alps the models show colder MH conditions in autumn (-0.7 °C) and winter (-0.4 °C), warmer conditions in spring (0.3 °C), and no significant change in summer temperature. Precipitation does not show significant changes but exhibits a seasonal shift, with less precipitation from April to September and more precipitation from October to April during the MH in both regions. The mass balance model simulates a climatic ELA that is 15-33 m lower during the MH compared with PI conditions. We suggest that the main causes of this difference are driven mainly by colder temperatures associated with the MH simulation. Differences in temperature have a dual effect on glacier mass balance: (i) less energy is available for ablation during summer and early autumn and (ii) lower temperatures cause more precipitation to fall as snow rather than rain in late autumn and winter, resulting in more accumulation and higher surface albedo. For these reasons, we postulate that the modelled ELA changes, although small, may help to explain larger glacier extents observed by 6000 years BP in South America and New Zealand. © 2015 Author(s). 资助项目: CONICYT, Comisión Nacional de Investigación Científica y Tecnológica
; FONDECYT, Comisión Nacional de Investigación Científica y Tecnológica
; FONDECYT, Comisión Nacional de Investigación Científica y Tecnológica
; CONICYT, Comisión Nacional de Investigación Científica y Tecnológica
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49094
Appears in Collections: 气候变化与战略
There are no files associated with this item.
Recommended Citation:
Bravo C.,Rojas M.,Anderson B.M.,et al. Modelled glacier equilibrium line altitudes during the mid-Holocene in the southern mid-latitudes[J]. Climate of the Past,2015-01-01,11(11)