1. Observation and numerical simulation of the river breeze circulation in the vicinity of the Tapajós and Amazon rivers Maria A. F. Silva Dias (1) Marcos Longo(1) Pedro L. Silva Dias(1) David R. Fitzjarrald (2) A. Scott Denning(3) Priscila Brier D'Auria(1) (1) Departamento de Ciências Atmosféricas, Universidade de São Paulo (2) Atmospheric Science Research Center, State University of New York at Albany (3) Department of Atmospheric Sciences, Colorado State University

5. 23 July 2001 Tapajós (from Pindobal to Boim and back) 28 July 2001 Tapajós & Amazonas (red line: temperature where the two rivers merge)

6. Sea level pressure and 925 hPa winds from CPTEC analysis July 29, 2001, 06 UTC

7. Difference in pressure reduced to sea level between Manaus and Santarem, from CPTEC analysis

8. East-West wind component from Belterra Sounding at 950 hPa (~ 500 m)

9. Pibal balloon data

10. AWS Jamaraquá 24 July / 1 August 2001 West East South North

12. Fitzjarrald et al, 2000

14. Winds at Belterra radiosonde Pressure (mb)

15. Winds and potential temperature Belterra radiosonde

16. RAMS numerical simulation 2 grids higher resolution 2 km no clouds different temperatures in Tapajós and Amazon rivers boundary conditions from CPTEC analysis

18. Wind vector 23 M ABOVE THE SURFACE

23. wind – streamlines perpendicular to the Tapajós river

34. Potencial temperature

35. RAMS numerical simulation 3 grids higher resolution 2 km clouds from microphysics parameterization different temperatures in Tapajós and Amazon rivers boundary conditions from CPTEC analysis

49. Fitzjarrald et al, 2002

50. Conclusion River induced local circulation is important in the Amazon region. –local cloudiness - impact in surface radiation –modulation of rainfall –local transports - impact on trace gas budgets