• Abner Pinheiro de Matos
  • Júlia Clarinda Paiva Cohen




Micro line. Reflectivity. River breeze. BRAMS.


The precipitation in Belem region is mainly due the large atmospheric systems such as ITCZ and mesoscale systems like the Instability Lines. Beside these systems, there are convective systems forced locally which also promote precipitation in this region. This paper studies a convective system, observed for first time during the campaign of the RAIN project, which is called Micro Instability Line Fluvial (MLF) because its formation is associated with river breeze circulation. The GOES 12 satellite data, radar band X, anemometer, rain gauges, disdrometer, and NCEP reanalyzes were used to study this MLF. High-resolution numerical simulation with the BRAMS model was made for this MLF, using two grids with horizontal resolution of 3 km and 1 km. The simulation results showed that the MLF was formed by river breeze from the Marajo Bay, causing precipitation since the early stages in Belem area until this MLF was on the west bank of the Marajo bay. During its propagation westward, this MLF had increased its intensity, which was maximum over the Bay of Marajo, where there is intense transportation of cargo and passengers, and shipwrecks are the most frequent type of accidents.


Download data is not yet available.


Alcântara CR, Silva Dias MAF, Souza EP, Cohen JCP. Verification of the role of low level jets in Amazon squall lines. Atmospheric Research. 2011;100:36-44.

Cohen JCP, Silva Dias MAF, Nobre CA. Environmental conditions associated with amazonian squall lines: a case study. Mon. Wea. Rev. 1995;123:3163-3174.

Cohen JCP, Fitzjarrald DR, D’Oliveira FAF, Saraiva I, Barbosa IRS, Gandu AW, et al. Radar-observed spatial and temporal rainfall variability near the Tapajós-Amazon confluence. RBMET. 2014;29(n. esp.):23-30.

Cotton WR, Pielke RA, Walko RL, Liston GE, Tremback CJ, Jiang H. RAMS 2001: Current status and future directions. Meteorol. Atmos. Phys., Austria. 2003;82(1-4):5-29

Figueroa SN e Nobre CA. Precipitations distribution over central and western tropical South America. Climanálise – Boletim de Monitoramento e Análise Climática. 1990;5(6):36-45.

Fitzjarrald DR, Sakai RK, Moraes OLL, De Oliveira RC, Acevedo OC, Matthew J et al. Spatial and temporal rainfall variability near the Amazon-Tapajós confluence. JGR: Biogeosciences. 2008;113(G1):1-17.

Garstang M, Massie HL, Halverson J, Greco S. Amazon coastal squall lines. Part I: Structure and Kinematics. Mon. Wea. Rev. 1994;122:608-622.

Lu L, Denning AS, Silva Dias MAF, Silva Dias P, Longo M, Freitas SR, Saatchi S. Mesoscale circulations and atmospheric CO2 variations in the Tapajós region, Pará, Brazil. JGR. 2005;110(D21102):1-17.

Machado LAT, Silva Dias MAF, Morales C, Fisch G, Vila D, Albrecht R et al. The chuva project: How does convection vary across Brazil? Bull. Amer. Meteor. Soc. 2014;1365-1380.

Mesquita RLC e Silva RR. Insights of meso and micro-scale processes for the Caxiuanã forest region from high resolution simulation. RBMET. 2012;27(2): 253-261.

Molion LCB. Climatologia dinâmica da região amazônica: Mecanismos de prcipitação. RBMET. 1987;2:107-117.

Peel MC, Finlayson BL, McMahon TA. Updated world map of the Köppen-Geiger climate classification. HESS. 2007;11:1633-1644.

Pielke RA, Cotton WR, Walko RL, Tremback CJ, Lyons WA, Grasso LD et al. A comprehensive meteorological modeling system – RAMS. Meteorol. Atmos. Phys. 1992;49:69-91.

Santos SHM. Acidentes com transportes hidroviários e os extremos meteorológicos no nordeste da Amazônia [dissertação]. Belém: Universidade Federal do Pará; 2015. 92 p.

Sodré GRC. Estudo da convecção de mesoescala em diferentes superfícies na amazônia oriental [dissertação]. Belém: Universidade Federal do Pará; 2013. 65 p.

Silva Dias MAF, Silva Dias PL, Longo M, Fitzjarrald DR, Denning AS. River breeze circulation in eastern Amazonia: observations and modeling results. Theor. Appl. Climatol. 2004;78(1):111-121.



How to Cite

Matos, A. P. de, & Cohen, J. C. P. (2016). RIVER BREEZE CIRCULATION AND PRECIPITATION BAND ON THE EAST BANK OF THE MARAJÓ BAY. Ciência E Natura, 38, 21–27. https://doi.org/10.5902/2179460X19814