| Texto completo | |
| Autor(es): |
Boers, Niklas
;
Marwan, Norbert
;
Barbosa, Henrique M. J.
;
Kurths, Juergen
Número total de Autores: 4
|
| Tipo de documento: | Artigo Científico |
| Fonte: | SCIENTIFIC REPORTS; v. 7, JAN 25 2017. |
| Citações Web of Science: | 23 |
| Resumo | |
The Amazon rainforest has been proposed as a tipping element of the earth system, with the possibility of a dieback of the entire ecosystem due to deforestation only of parts of the rainforest. Possible physical mechanisms behind such a transition are still subject to ongoing debates. Here, we use a specifically designed model to analyse the nonlinear couplings between the Amazon rainforest and the atmospheric moisture transport from the Atlantic to the South American continent. These couplings are associated with a westward cascade of precipitation and evapotranspiration across the Amazon. We investigate impacts of deforestation on the South American monsoonal circulation with particular focus on a previously neglected positive feedback related to condensational latent heating over the rainforest, which strongly enhances atmospheric moisture inflow from the Atlantic. Our results indicate the existence of a tipping point. In our model setup, crossing the tipping point causes precipitation reductions of up to 40% in non-deforested parts of the western Amazon and regions further downstream. The responsible mechanism is the breakdown of the aforementioned feedback, which occurs when deforestation reduces transpiration to a point where the available atmospheric moisture does not suffice anymore to release the latent heat needed to maintain the feedback. (AU) | |
| Processo FAPESP: | 11/50151-0 - Fenômenos dinâmicos em redes complexas: fundamentos e aplicações |
| Beneficiário: | Elbert Einstein Nehrer Macau |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 13/50510-5 - Pesquisa colaborativa Brasil-EUA: modificações causadas pela poluição antrópica na química da atmosfera e na microfísica de partículas da floresta tropical durante as campanhas intensivas do GoAmazon |
| Beneficiário: | Henrique de Melo Jorge Barbosa |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular |