Climate change projections over three metropolitan regions in Southeast Brazil using the non-hydrostatic Eta regional climate model at 5-km resolution

Author(s)

Lyra, Andre ^[1] ; Tavares, Priscila ^[1] ; Chou, Sin Chan ^[1] ; Sueiro, Gustavo ^[1] ; Dereczynski, Claudine ^[2] ; Sondermann, Marcely ^[2] ; Silva, Adan ^[1] ; Marengo, Jose ^[3] ; Giarolla, Angelica ^[1]

Affiliation

^[1] Natl Inst Space Res INPE, Rod Pres Dutra Km 39, Cachoeira Paulista, SP - Brazil

^[2] Univ Fed Rio de Janeiro, Ilha Fundao, Av Athos da Silveira Ramos 274, Rio de Janeiro, RJ - Brazil

^[3] Natl Ctr Monitoring & Early Warning Nat Disasters, Rod Pres Dutra Km 39, Cachoeira Paulista, SP - Brazil

• Document type: Journal article
• Source: THEORETICAL AND APPLIED CLIMATOLOGY; v. 132, n. 1-2, p. 663-682, APR 2018.
• Web of Science Citations: 5

Abstract

The objective of this work is to assess changes in three metropolitan regions of Southeast Brazil (Rio de Janeiro, So Paulo, and Santos) based on the projections produced by the Eta Regional Climate Model (RCM) at very high spatial resolution, 5 km. The region, which is densely populated and extremely active economically, is frequently affected by intense rainfall events that trigger floods and landslides during the austral summer. The analyses are carried out for the period between 1961 and 2100. The 5-km simulations are results from a second downscaling nesting in the HadGEM2-ES RCP4.5 and RCP8.5 simulations. Prior to the assessment of the projections, the higher resolution simulations were evaluated for the historical period (1961-1990). The comparison between the 5-km and the coarser driver model simulations shows that the spatial patterns of precipitation and temperature of the 5-km Eta simulations are in good agreement with the observations. The simulated frequency distribution of the precipitation and temperature extremes from the 5-km Eta RCM is consistent with the observed structure and extreme values. Projections of future climate change using the 5-km Eta runs show stronger warming in the region, primarily during the summer season, while precipitation is strongly reduced. Projected temperature extremes show widespread heating with maximum temperatures increasing by approximately 9 A degrees C in the three metropolitan regions by the end of the century in the RCP8.5 scenario. A trend of drier climate is also projected using indices based on daily precipitation, which reaches annual rainfall reductions of more than 50 % in the state of Rio de Janeiro and between 40 and 45 % in So Paulo and Santos. The magnitude of these changes has negative implications to the population health conditions, energy security, and economy. (AU)

• FAPESP's process: 12/51876-0 - An integrated framework to analyze local decision-making and adaptive capacity to large-scale environmental change: community case studies in Brazil, the UK and the US
• Grantee: Jose Antonio Marengo Orsini
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 14/00192-0 - IMPACTS OF CLIMATE CHANGE ON THE PRODUCTIVITY OF COFFEE TREES IN SOUTHEASTERN AREAS OF BRAZIL
• Grantee: Priscila da Silva Tavares
• Support type: Scholarships in Brazil - Doctorate