Atmosphere/vegetation feedbacks: A mechanism for abrupt climate change over northern Africa

被引:40
|
作者
Patricola, C. M. [1 ]
Cook, K. H. [1 ]
机构
[1] Cornell Univ, Dept Earth & Atmospher Sci, Ithaca, NY 14853 USA
关键词
D O I
10.1029/2007JD009608
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
Modeling studies and paleoclimate data of the mid- Holocene provide strong evidence of abrupt climate change over northern Africa. Regional climate model simulations are used to isolate and diagnose the role of interactions between vegetation and the dynamics of the West African summer monsoon in generating abrupt climate change. Simulations with both fixed and interactive vegetation distributions are included. The modeled climate is largely insensitive to the latitude of the desert border when the border is located south of 17.9 degrees N. But when the desert border is located only 180 km north of 17.9 degrees N, the climate is quite sensitive, with summer precipitation rates a factor of 5 greater over the Sahara desert and an African easterly jet that is 50% weaker. Prescribing vegetation north of the threshold latitude places moist soil beneath the thermal low, increasing the low-level moist static energy and convective instability. The atmospheric model is asynchronously coupled with a simple vegetation model that allows the vegetation to respond to and influence climate. When the model is initialized with the desert border at 10.0 degrees N, the resulting equilibrium vegetation distribution is similar to that of the present day. In contrast, when the model is initialized with the desert border at 20.9 degrees N, a new equilibrium vegetation distribution results in which the central Sahara is vegetated. The existence of these two stable climate and vegetation states and the threshold latitude indicates that interactions between vegetation (specifically through soil moisture) and the atmosphere (through the African easterly jet) can produce abrupt climate change.
引用
收藏
页数:18
相关论文
共 50 条
  • [1] Climate and abrupt vegetation change in Northern Europe since the last deglaciation
    Seddon, Alistair W. R.
    Macias-Fauria, Marc
    Willis, Kathy J.
    [J]. HOLOCENE, 2015, 25 (01): : 25 - 36
  • [2] Vegetation-climate feedbacks modulate rainfall patterns in Africa under future climate change
    Wu, Minchao
    Schurgers, Guy
    Rummukainen, Markku
    Smith, Benjamin
    Samuelsson, Patrick
    Jansson, Christer
    Siltberg, Joe
    May, Wilhelm
    [J]. EARTH SYSTEM DYNAMICS, 2016, 7 (03) : 627 - 647
  • [3] Modelling carbon cycle feedbacks during abrupt climate change
    Ewen, TL
    Weaver, AJ
    Schmittner, A
    [J]. QUATERNARY SCIENCE REVIEWS, 2004, 23 (3-4) : 431 - 448
  • [4] Atmosphere-land surface interactions and their influence on extreme rainfall and potential abrupt climate change over southern Africa
    C. J. R. Williams
    D. R. Kniveton
    [J]. Climatic Change, 2012, 112 : 981 - 996
  • [5] Atmosphere-land surface interactions and their influence on extreme rainfall and potential abrupt climate change over southern Africa
    Williams, C. J. R.
    Kniveton, D. R.
    [J]. CLIMATIC CHANGE, 2012, 112 (3-4) : 981 - 996
  • [6] Changes in vegetation in northern Alaska under scenarios of climate change, 2003-2100: implications for climate feedbacks
    Euskirchen, E. S.
    McGuire, A. D.
    Chapin, F. S., III
    Yi, S.
    Thompson, C. C.
    [J]. ECOLOGICAL APPLICATIONS, 2009, 19 (04) : 1022 - 1043
  • [7] Climate change, phenology, and phenological control of vegetation feedbacks to the climate system
    Richardson, Andrew D.
    Keenan, Trevor F.
    Migliavacca, Mirco
    Ryu, Youngryel
    Sonnentag, Oliver
    Toomey, Michael
    [J]. AGRICULTURAL AND FOREST METEOROLOGY, 2013, 169 : 156 - 173
  • [8] Quantifying the role of biosphere-atmosphere feedbacks in climate change: coupled model simulations for 6000 years BP and comparison with palaeodata for northern Eurasia and northern Africa
    Texier, D
    de Noblet, N
    Harrison, SP
    Haxeltine, A
    Jolly, D
    Joussaume, S
    Laarif, F
    Prentice, IC
    Tarasov, P
    [J]. CLIMATE DYNAMICS, 1997, 13 (12) : 865 - 882
  • [9] Quantifying the role of biosphere-atmosphere feedbacks in climate change: coupled model simulations for 6000 years BP and comparison with palaeodata for northern Eurasia and northern Africa
    D. Texier
    N. de Noblet
    S. P. Harrison
    A. Haxeltine
    D. Jolly
    S. Joussaume
    F. Laarif
    I. C. Prentice
    P. Tarasov
    [J]. Climate Dynamics, 1997, 13 : 865 - 881
  • [10] Effects of vegetation feedback on future climate change over West Africa
    Yu, Miao
    Wang, Guiling
    Pal, Jeremy S.
    [J]. CLIMATE DYNAMICS, 2016, 46 (11-12) : 3669 - 3688