Cluster analysis applied to the spatial and temporal variability of monthly rainfall in Alagoas state, Northeast of Brazil

Autor(es)

Lyra, Gustavo B. ^[1] ; Oliveira-Junior, Jose F. ^[1] ; Zeri, Marcelo ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Rio de Janeiro, Inst Florestas, Dept Ciencias Ambientais, BR-23890000 Rio De Janeiro - Brazil

^[2] Inst Nacl Pesquisas Espaciais, Ctr Ciencia Sistema Terrestre, BR-12630000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF CLIMATOLOGY; v. 34, n. 13, p. 3546-3558, NOV 15 2014.
• Citações Web of Science: 22

Resumo

Rainfall over the northeast part of Brazil is highly influenced by several weather systems such as trade winds, the Intertropical Convergence Zone, Easterly Wave Disturbances, Bolivia High and Atlantic Sub-tropical Anticyclone. The objectives of this work were to identify, using cluster analysis, spatial and temporal rainfall patterns for the northeastern Brazilian state of Alagoas, and to relate those patterns with the weather systems that occur over that region, which is the most populated area of semiarid climate in the world. The dataset consists of 30-years long time series of rainfall from 36 stations located on the state. Hierarchical clustering using Ward's algorithm was used to classify the sites into five groups. The stations were grouped according to the distance to the coast and orography. Rainfall is not uniformly distributed in space and time in all regions, such as in two groups within the arid zone, where more than 60% of annual precipitation occurs in a period of 5 months (March to July). Rainfall was highest in the coastal regions and over areas of the state with high altitude, due to orographic rainfall. Overall, rainfall over the state of Alagoas is characterized by strong gradients from the coast to the continent and from north to south due to the physiography of the region and the influence of weather systems with different time scales. (AU)

• Processo FAPESP: 11/04101-0 - Fluxos verticais de energia, escalares e momentum sobre superfícies vegetadas calculados pela técnica surface renewal
• Beneficiário: Luis Marcelo de Mattos Zeri
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado