Land-sea thermal contrast and intensity of the North American monsoon under climate change conditions

Abraham Torres-Alavez, Tereza Cavazos, Cuauhtemoc Turrent

Resultado de la investigación: Contribución a una revistaArtículo

10 Citas (Scopus)

Resumen

The hypothesis that global warming during the twenty-first century will increase the land-sea thermal contrast (LSTC) and therefore the intensity of early season precipitation of the North American monsoon (NAM) is examined. To test this hypothesis, future changes (2075-99 minus 1979-2004 means) in LSTC, moisture flux convergence (MFC), vertical velocity, and precipitation in the region are analyzed using six global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) under the representative concentration pathway 8.5 (RCP8.5) emission scenario. A surface LSTC index shows that the continent becomes warmer than the ocean in May in the North American Regional Reanalysis (NARR) and ECMWF Interim Re-Analysis (ERA-Interim) and in June in the mean ensemble of the GCMs (ens_GCMs), and the magnitude of the positive LSTC is greater in the reanalyses than in the ens_GCMs during the historic period. However, the reanalyses underestimate July-August precipitation in the NAM region, while the ens_GCMs reproduces the peak season surprisingly well but overestimates it the rest of the year. The future ens_GCMs projects a doubling of the magnitude of the positive surface LSTC and an earlier start of the continental summer warming in mid-May. Contrary to the stated hypothesis, however, the mean projection suggests a slight decrease of monsoon coastal precipitation during June-August (JJA), which is attributed to increased midtropospheric subsidence, a reduced midtropospheric LSTC, and reduced MFC in the NAM coastal region. In contrast, the future ens_GCMs produces increased MFC and precipitation over the adjacent mountains during JJA and significantly more rainfall over the entire NAM region during September-October, weakening the monsoon retreat.

Idioma originalInglés
Páginas (desde-hasta)4566-4580
Número de páginas15
PublicaciónJournal of Climate
Volumen27
N.º12
DOI
EstadoPublicada - 2014

Huella dactilar

monsoon
climate change
moisture flux
general circulation model
global climate
land surface
climate modeling
twenty first century
sea
land
global warming
subsidence
warming
rainfall
mountain
ocean
summer
CMIP

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Torres-Alavez, Abraham ; Cavazos, Tereza ; Turrent, Cuauhtemoc. / Land-sea thermal contrast and intensity of the North American monsoon under climate change conditions. En: Journal of Climate. 2014 ; Vol. 27, N.º 12. pp. 4566-4580.
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abstract = "The hypothesis that global warming during the twenty-first century will increase the land-sea thermal contrast (LSTC) and therefore the intensity of early season precipitation of the North American monsoon (NAM) is examined. To test this hypothesis, future changes (2075-99 minus 1979-2004 means) in LSTC, moisture flux convergence (MFC), vertical velocity, and precipitation in the region are analyzed using six global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) under the representative concentration pathway 8.5 (RCP8.5) emission scenario. A surface LSTC index shows that the continent becomes warmer than the ocean in May in the North American Regional Reanalysis (NARR) and ECMWF Interim Re-Analysis (ERA-Interim) and in June in the mean ensemble of the GCMs (ens_GCMs), and the magnitude of the positive LSTC is greater in the reanalyses than in the ens_GCMs during the historic period. However, the reanalyses underestimate July-August precipitation in the NAM region, while the ens_GCMs reproduces the peak season surprisingly well but overestimates it the rest of the year. The future ens_GCMs projects a doubling of the magnitude of the positive surface LSTC and an earlier start of the continental summer warming in mid-May. Contrary to the stated hypothesis, however, the mean projection suggests a slight decrease of monsoon coastal precipitation during June-August (JJA), which is attributed to increased midtropospheric subsidence, a reduced midtropospheric LSTC, and reduced MFC in the NAM coastal region. In contrast, the future ens_GCMs produces increased MFC and precipitation over the adjacent mountains during JJA and significantly more rainfall over the entire NAM region during September-October, weakening the monsoon retreat.",
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Land-sea thermal contrast and intensity of the North American monsoon under climate change conditions. / Torres-Alavez, Abraham; Cavazos, Tereza; Turrent, Cuauhtemoc.

En: Journal of Climate, Vol. 27, N.º 12, 2014, p. 4566-4580.

Resultado de la investigación: Contribución a una revistaArtículo

TY - JOUR

T1 - Land-sea thermal contrast and intensity of the North American monsoon under climate change conditions

AU - Torres-Alavez, Abraham

AU - Cavazos, Tereza

AU - Turrent, Cuauhtemoc

PY - 2014

Y1 - 2014

N2 - The hypothesis that global warming during the twenty-first century will increase the land-sea thermal contrast (LSTC) and therefore the intensity of early season precipitation of the North American monsoon (NAM) is examined. To test this hypothesis, future changes (2075-99 minus 1979-2004 means) in LSTC, moisture flux convergence (MFC), vertical velocity, and precipitation in the region are analyzed using six global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) under the representative concentration pathway 8.5 (RCP8.5) emission scenario. A surface LSTC index shows that the continent becomes warmer than the ocean in May in the North American Regional Reanalysis (NARR) and ECMWF Interim Re-Analysis (ERA-Interim) and in June in the mean ensemble of the GCMs (ens_GCMs), and the magnitude of the positive LSTC is greater in the reanalyses than in the ens_GCMs during the historic period. However, the reanalyses underestimate July-August precipitation in the NAM region, while the ens_GCMs reproduces the peak season surprisingly well but overestimates it the rest of the year. The future ens_GCMs projects a doubling of the magnitude of the positive surface LSTC and an earlier start of the continental summer warming in mid-May. Contrary to the stated hypothesis, however, the mean projection suggests a slight decrease of monsoon coastal precipitation during June-August (JJA), which is attributed to increased midtropospheric subsidence, a reduced midtropospheric LSTC, and reduced MFC in the NAM coastal region. In contrast, the future ens_GCMs produces increased MFC and precipitation over the adjacent mountains during JJA and significantly more rainfall over the entire NAM region during September-October, weakening the monsoon retreat.

AB - The hypothesis that global warming during the twenty-first century will increase the land-sea thermal contrast (LSTC) and therefore the intensity of early season precipitation of the North American monsoon (NAM) is examined. To test this hypothesis, future changes (2075-99 minus 1979-2004 means) in LSTC, moisture flux convergence (MFC), vertical velocity, and precipitation in the region are analyzed using six global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) under the representative concentration pathway 8.5 (RCP8.5) emission scenario. A surface LSTC index shows that the continent becomes warmer than the ocean in May in the North American Regional Reanalysis (NARR) and ECMWF Interim Re-Analysis (ERA-Interim) and in June in the mean ensemble of the GCMs (ens_GCMs), and the magnitude of the positive LSTC is greater in the reanalyses than in the ens_GCMs during the historic period. However, the reanalyses underestimate July-August precipitation in the NAM region, while the ens_GCMs reproduces the peak season surprisingly well but overestimates it the rest of the year. The future ens_GCMs projects a doubling of the magnitude of the positive surface LSTC and an earlier start of the continental summer warming in mid-May. Contrary to the stated hypothesis, however, the mean projection suggests a slight decrease of monsoon coastal precipitation during June-August (JJA), which is attributed to increased midtropospheric subsidence, a reduced midtropospheric LSTC, and reduced MFC in the NAM coastal region. In contrast, the future ens_GCMs produces increased MFC and precipitation over the adjacent mountains during JJA and significantly more rainfall over the entire NAM region during September-October, weakening the monsoon retreat.

KW - Atmosphere-ocean interaction, Atmospheric circulation, Convergence/divergence, General circulation models, Model evaluation/performance, Reanalysis data

UR - http://www.scopus.com/inward/record.url?scp=84902095897&partnerID=8YFLogxK

U2 - 10.1175/JCLI-D-13-00557.1

DO - 10.1175/JCLI-D-13-00557.1

M3 - Artículo

AN - SCOPUS:84902095897

VL - 27

SP - 4566

EP - 4580

JO - Journal of Climate

JF - Journal of Climate

SN - 0894-8755

IS - 12

ER -