Impact of precession on the climate, vegetation and fire activity in southern Africa during MIS4 - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Climate of the Past Année : 2014

Impact of precession on the climate, vegetation and fire activity in southern Africa during MIS4

Résumé

The relationships between climate, vegetation and fires are a major subject of investigation in the context of climate change. In southern Africa, fire is known to play a crucial role in the existence of grasslands and Mediterranean-type biomes. Microcharcoal-based reconstructions of past fire activity in that region have shown a tight correlation between grass-fueled fires and the precessional cycle, with maximum fire activity during maxima of the climatic preces-sion index. These changes have been interpreted as the result of changes in fuel load in response to precipitation changes in eastern southern Africa. Here we use the general circulation model IPSL_CM5A (Institut Pierre Simon Laplace Climate Model version 5A) and the dynamic vegetation model LPJ-LMfire to investigate the response of climate, vegetation and fire activity to precession changes in southern Africa during marine isotopic stage 4 (74–59 kyr BP). We perform two climatic simulations, for a maximum and minimum of the pre-cession index, and use a statistical downscaling method to increase the spatial resolution of the IPSL_CM5A outputs over southern Africa and perform high-resolution simulations of the vegetation and fire activity. Our results show an anticorre-lation between the northern and southern African monsoons in response to precession changes. A decrease of the preces-sion climatic index leads to a precipitation decrease in the summer rainfall area of southern Africa. The drying of climate leads to a decrease of vegetation cover and fire activity. Our results are in qualitative agreement with data and confirm that fire activity in southern Africa during MIS4 is mainly driven by vegetation cover.

Domaines

Climatologie
Fichier principal
Vignette du fichier
cp-10-1165-2014.pdf (4.33 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Loading...

Dates et versions

hal-01312984 , version 1 (09-05-2016)

Licence

Paternité

Identifiants

Citer

M.-N Woillez, G Levavasseur, A.-L Daniau, M Kageyama, D.H. Urrego, et al.. Impact of precession on the climate, vegetation and fire activity in southern Africa during MIS4. Climate of the Past, 2014, 10 (3), pp.1165-1182. ⟨10.5194/cp-10-1165-2014⟩. ⟨hal-01312984⟩
445 Consultations
200 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More