Effects of Explicit Urban-Canopy Representation on Local Circulations Above a Tropical Mega-City     

José L. Flores Rojas  Augusto J. Pereira Filho  Hugo A. Karam  Felipe Vemado  Valéry Masson 《Boundary-Layer Meteorology》2018,166(1):83-111

The Advanced Regional Prediction System (ARPS) is coupled with the tropical town energy budget (tTEB) scheme to analyze the effects of the urban canopy circulation over the metropolitan area of São Paulo and its interactions with the sea breeze and mountain-valley circulation in the eastern state of São Paulo, Brazil. Two experiments are carried out for the typical sea-breeze event occurring on 22 August 2014 under weak synoptic forcing and clear-sky conditions: (a) a control run with the default semi-desert surface parametrization and; (b) a tTEB run for the urban canopy of São Paulo. A realistic land-use database over the south-eastern domain of Brazil is used in the downscaling simulation to a horizontal grid resolution of 3 km. Our results indicate that ARPS effectively simulates features of the nighttime and early morning land-breeze circulation, which is affected by the surrounding hills and the nocturnal heat island of São Paulo. By early afternoon, the south-eastern sea-breeze circulation moves inland perpendicular to the upslope of the Serra do Mar scarp, which generates a line of moisture convergence and updrafts further inland. Later, the convergence line reaches São Paulo and interacts with the circulation arising from the urban heat island (UHI), which increases the moisture convergence and strength of updrafts. The surface energy balance indicates that the UHI is caused by large sensible heat storage within the urban canopy during the day, which is later released in the afternoon and at night. The simulations are verified with available radiosonde and surface weather station data, land-surface-temperature estimates from the moderate resolution imaging spectroradiometer, as well as the National Center for Atmospheric Research reanalysis databases. The three-dimensional geometry of the urban canyons within the tTEB scheme consistently improves the thermodynamically-induced circulation over São Paulo.  相似文献   

Characterization of a landslide-triggered debris flow at a rainforest-covered mountain region in Brazil     

Cabral  Victor Carvalho  Reis  Fábio Augusto Gomes Vieira  D’Affonseca  Fernando Mazo  Lucía  Ana  dos Santos Corrêa  Claudia Vanessa  Veloso  Vinicius  Gramani  Marcelo Fischer  Ogura  Agostinho Tadashi  Lazaretti  Andrea Fregolente  Vemado  Felipe  Pereira Filho  Augusto José  dos Santos  Claudia Cristina  Lopes  Eymar Silva Sampaio  Rabaco  Lis Maria Reoni  do Carmo Giordano  Lucilia  Zarfl  Christiane 《Natural Hazards》2021,108(3):3021-3043

Natural Hazards - Debris flows represent great hazard to humans due to their high destructive power. Understanding their hydrogeomorphic dynamics is fundamental in hazard assessment studies,...  相似文献