Clouds and their effects on solar radiation in São Paulo
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da USP |
Texto Completo: | http://www.teses.usp.br/teses/disponiveis/14/14133/tde-06092018-123251/ |
Resumo: | Clouds and their instantaneous effects on downward solar radiation were studied at the Metropolitan Area of São Paulo. For this purpose, visual observations of clouds, ground-based measurements performed by different radiometers, products from the polar orbiting satellites CALIPSO and CloudSat and 1-D Radiative Transfer Model (RTM) LibRadtran were used. Daytime climatology of cloud cover fraction (1958-2016) using data of hourly visual observations was carried out. The diurnal cycle of cloud cover fraction was dominated by low clouds especially by stratiform clouds. Remarkable differences in the diurnal cycles of low cumuliform and stratiform clouds were also observed. During the time period, positive trends for low cloud cover (1.6 %/decade), especially stratiform (3.1 %/decade), and cirriform cloud (0.8 %/decade) were observed, while a decreasing trend of mid-level cloud cover (-2.4%/decade) was found. Seasonal and diurnal variability of vertical profile of cloud was observed, with cloud extending to higher altitudes at night and with maximum frequency of occurrence observed in summer. In winter, low clouds prevailed. Effective cloud optical depth (ECOD), using the total transmittance at 415 nm, and instantaneous cloud effects on solar radiation at the surface, using global irradiance measurements, were estimated in synergy with LibRadtran computations. ECOD presented seasonal and diurnal variability, with maximum of mean in spring (34.4) and in the afternoon (34.2), and minimum at sunrise (25.5) and winter (26.9) for low clouds. The shortwave effects of clouds depended on solar disk condition, cloud type and cloud cover. Maximum of shortwave radiative attenuation was observed for low clouds in total overcast conditions with a median reduction of 72 % of global irradiance compared to clear sky. Median reduction of mid and high clouds was 57 % and 33 %, respectively. Enhancement effects with duration as long as 20 minutes, caused by lateral scattering, were observed in the presence of all analyzed cloud types, when the solar disk was not blocked by clouds, increasing global solar irradiance around 10% at the surface. Maximum enhancement could reach 50 % for low clouds. |
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Clouds and their effects on solar radiation in São PauloNuvens e seus efeitos na radiação solar em São PauloCALIPSO-CloudSatCALIPSO-CloudSatcloudsCODCODLibRadtranLibRadtran.MFRSRMFRSRNuvensClouds and their instantaneous effects on downward solar radiation were studied at the Metropolitan Area of São Paulo. For this purpose, visual observations of clouds, ground-based measurements performed by different radiometers, products from the polar orbiting satellites CALIPSO and CloudSat and 1-D Radiative Transfer Model (RTM) LibRadtran were used. Daytime climatology of cloud cover fraction (1958-2016) using data of hourly visual observations was carried out. The diurnal cycle of cloud cover fraction was dominated by low clouds especially by stratiform clouds. Remarkable differences in the diurnal cycles of low cumuliform and stratiform clouds were also observed. During the time period, positive trends for low cloud cover (1.6 %/decade), especially stratiform (3.1 %/decade), and cirriform cloud (0.8 %/decade) were observed, while a decreasing trend of mid-level cloud cover (-2.4%/decade) was found. Seasonal and diurnal variability of vertical profile of cloud was observed, with cloud extending to higher altitudes at night and with maximum frequency of occurrence observed in summer. In winter, low clouds prevailed. Effective cloud optical depth (ECOD), using the total transmittance at 415 nm, and instantaneous cloud effects on solar radiation at the surface, using global irradiance measurements, were estimated in synergy with LibRadtran computations. ECOD presented seasonal and diurnal variability, with maximum of mean in spring (34.4) and in the afternoon (34.2), and minimum at sunrise (25.5) and winter (26.9) for low clouds. The shortwave effects of clouds depended on solar disk condition, cloud type and cloud cover. Maximum of shortwave radiative attenuation was observed for low clouds in total overcast conditions with a median reduction of 72 % of global irradiance compared to clear sky. Median reduction of mid and high clouds was 57 % and 33 %, respectively. Enhancement effects with duration as long as 20 minutes, caused by lateral scattering, were observed in the presence of all analyzed cloud types, when the solar disk was not blocked by clouds, increasing global solar irradiance around 10% at the surface. Maximum enhancement could reach 50 % for low clouds.Na Região Metropolitana de São Paulo, foram estudadas as nuvens e seus efeitos na radiação solar. Para tanto, foram usadas observações visuais de nuvens, medições desde a superfície efetuadas por diferentes radiômetros, produtos dos satélites de órbita polar CALIPSO e CloudSat e o modelo de transferência radiativa 1-D LibRadtran. Foi desenvolvida uma climatologia para o ciclo diurno da fração de cobertura de nuvens (1958-2016) usando dados de observações visuais. O ciclo diurno da cobertura de nuvens foi dominado por nuvens baixas, especialmente as estratiformes. Observaram-se diferenças entre o ciclo diurno das nuvens baixas cumuliformes e estratiformes. Além disso, houve uma tendência de aumento da fração de cobertura de nuvens baixas (1,6 %/década), especificamente das estratiformes (3,1 %/década), e das nuvens cirriformes (0,8%/década). Por outro lado, observou-se tendência de diminuição da fração de cobertura de nuvens médias (-2,4%/década). A variabilidade sazonal e diurna do perfil vertical de nuvens foi analisada, com as nuvens atingindo maiores altitudes à noite e no verão. No inverno, as nuvens baixas predominaram. A profundidade óptica efetiva da nuvem (ECOD), usando a transmitância total em 415 nm, e os efeitos instantâneos das nuvens sobre a radiação solar, de medições de irradiância solar global, foram estimados em sinergia com cálculos feitos com o LibRadtran. ECOD apresentou variabilidade diurna e sazonal com máximo na primavera (34,4) e no período da tarde (34,2) e mínimo pela manhã, próximo ao nascer do sol (25,5) e no inverno (26,9) para nuvens baixas. O efeito radiativo de onda curta apresentou dependência com relação à obstrução do disco solar pelas nuvens, o tipo de nuvem e fração de cobertura. A atenuação máxima foi observada para nuvens baixas com o céu totalmente nublado, com valor médio de redução de 72 % da irradiância global, comparada com condições de céu claro. Medianas de redução de nuvens médias e altas foram de 57 % e 33 %, respectivamente. Foram observados efeitos de incrementos da radiação solar (enhancement) de cerca de 10 % com duração de até 20 minutos, devido ao espalhamento pelas laterais das nuvens, em presença de todos os tipos de nuvens analisados, quando o disco solar não estava obstruído. O máximo de enhancement chegou até 50 % na presença de nuvens baixas.Biblioteca Digitais de Teses e Dissertações da USPYamasoe, Márcia AkemiSantana, Jorge Rosas2018-07-03info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://www.teses.usp.br/teses/disponiveis/14/14133/tde-06092018-123251/reponame:Biblioteca Digital de Teses e Dissertações da USPinstname:Universidade de São Paulo (USP)instacron:USPLiberar o conteúdo para acesso público.info:eu-repo/semantics/openAccesseng2019-04-09T23:21:59Zoai:teses.usp.br:tde-06092018-123251Biblioteca Digital de Teses e Dissertaçõeshttp://www.teses.usp.br/PUBhttp://www.teses.usp.br/cgi-bin/mtd2br.plvirginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.bropendoar:27212019-04-09T23:21:59Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP)false |
dc.title.none.fl_str_mv |
Clouds and their effects on solar radiation in São Paulo Nuvens e seus efeitos na radiação solar em São Paulo |
title |
Clouds and their effects on solar radiation in São Paulo |
spellingShingle |
Clouds and their effects on solar radiation in São Paulo Santana, Jorge Rosas CALIPSO-CloudSat CALIPSO-CloudSat clouds COD COD LibRadtran LibRadtran. MFRSR MFRSR Nuvens |
title_short |
Clouds and their effects on solar radiation in São Paulo |
title_full |
Clouds and their effects on solar radiation in São Paulo |
title_fullStr |
Clouds and their effects on solar radiation in São Paulo |
title_full_unstemmed |
Clouds and their effects on solar radiation in São Paulo |
title_sort |
Clouds and their effects on solar radiation in São Paulo |
author |
Santana, Jorge Rosas |
author_facet |
Santana, Jorge Rosas |
author_role |
author |
dc.contributor.none.fl_str_mv |
Yamasoe, Márcia Akemi |
dc.contributor.author.fl_str_mv |
Santana, Jorge Rosas |
dc.subject.por.fl_str_mv |
CALIPSO-CloudSat CALIPSO-CloudSat clouds COD COD LibRadtran LibRadtran. MFRSR MFRSR Nuvens |
topic |
CALIPSO-CloudSat CALIPSO-CloudSat clouds COD COD LibRadtran LibRadtran. MFRSR MFRSR Nuvens |
description |
Clouds and their instantaneous effects on downward solar radiation were studied at the Metropolitan Area of São Paulo. For this purpose, visual observations of clouds, ground-based measurements performed by different radiometers, products from the polar orbiting satellites CALIPSO and CloudSat and 1-D Radiative Transfer Model (RTM) LibRadtran were used. Daytime climatology of cloud cover fraction (1958-2016) using data of hourly visual observations was carried out. The diurnal cycle of cloud cover fraction was dominated by low clouds especially by stratiform clouds. Remarkable differences in the diurnal cycles of low cumuliform and stratiform clouds were also observed. During the time period, positive trends for low cloud cover (1.6 %/decade), especially stratiform (3.1 %/decade), and cirriform cloud (0.8 %/decade) were observed, while a decreasing trend of mid-level cloud cover (-2.4%/decade) was found. Seasonal and diurnal variability of vertical profile of cloud was observed, with cloud extending to higher altitudes at night and with maximum frequency of occurrence observed in summer. In winter, low clouds prevailed. Effective cloud optical depth (ECOD), using the total transmittance at 415 nm, and instantaneous cloud effects on solar radiation at the surface, using global irradiance measurements, were estimated in synergy with LibRadtran computations. ECOD presented seasonal and diurnal variability, with maximum of mean in spring (34.4) and in the afternoon (34.2), and minimum at sunrise (25.5) and winter (26.9) for low clouds. The shortwave effects of clouds depended on solar disk condition, cloud type and cloud cover. Maximum of shortwave radiative attenuation was observed for low clouds in total overcast conditions with a median reduction of 72 % of global irradiance compared to clear sky. Median reduction of mid and high clouds was 57 % and 33 %, respectively. Enhancement effects with duration as long as 20 minutes, caused by lateral scattering, were observed in the presence of all analyzed cloud types, when the solar disk was not blocked by clouds, increasing global solar irradiance around 10% at the surface. Maximum enhancement could reach 50 % for low clouds. |
publishDate |
2018 |
dc.date.none.fl_str_mv |
2018-07-03 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://www.teses.usp.br/teses/disponiveis/14/14133/tde-06092018-123251/ |
url |
http://www.teses.usp.br/teses/disponiveis/14/14133/tde-06092018-123251/ |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
|
dc.rights.driver.fl_str_mv |
Liberar o conteúdo para acesso público. info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Liberar o conteúdo para acesso público. |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.coverage.none.fl_str_mv |
|
dc.publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
publisher.none.fl_str_mv |
Biblioteca Digitais de Teses e Dissertações da USP |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da USP instname:Universidade de São Paulo (USP) instacron:USP |
instname_str |
Universidade de São Paulo (USP) |
instacron_str |
USP |
institution |
USP |
reponame_str |
Biblioteca Digital de Teses e Dissertações da USP |
collection |
Biblioteca Digital de Teses e Dissertações da USP |
repository.name.fl_str_mv |
Biblioteca Digital de Teses e Dissertações da USP - Universidade de São Paulo (USP) |
repository.mail.fl_str_mv |
virginia@if.usp.br|| atendimento@aguia.usp.br||virginia@if.usp.br |
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1815256725594308608 |