Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale
International audience Cirrus clouds not only play a major role in the energy budget of the Earth-Atmosphere system, but are also important in the hydrological cycle. According to satellite passive remote sensing high-altitude clouds cover as much as 40% of the earth's surface on average and ca...
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ftsorbonneuniv:oai:HAL:hal-04113712v1 2024-09-09T19:28:11+00:00 Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale Dupont, J. C. Haeffelin, M. Long, C. N. Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) à renseigner, Unknown Region 2009 https://hal.science/hal-04113712 en eng HAL CCSD hal-04113712 https://hal.science/hal-04113712 BIBCODE: 2009EGUGA.11.4709D EGU General Assembly 2009 https://hal.science/hal-04113712 EGU General Assembly 2009, 2009, à renseigner, Unknown Region. pp.4709 [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/conferenceObject Conference papers 2009 ftsorbonneuniv 2024-08-01T23:46:51Z International audience Cirrus clouds not only play a major role in the energy budget of the Earth-Atmosphere system, but are also important in the hydrological cycle. According to satellite passive remote sensing high-altitude clouds cover as much as 40% of the earth's surface on average and can reach 70% of cloud cover over the Tropics. Hence, given their very large cloud cover, the relatively small instantaneous radiative effects of these cirrus clouds can engender a significant cumulative radiative forcing at the surface. Precise calculations of the cirrus cloud radiative forcing are obtained from the difference between measured radiative fluxes downwelling at the surface in the presence of cirrus clouds (broadband flux measurements) and computed clear sky references (parametric models with RMS error < 5 W m-2). Overcast and clear sky period identification is obtained from a combined analysis of lidar and broadband flux measurements. In this study, we analyze two datasets: ground-based and satellite measurements. The firsts corresponds to solar and infrared irradiance measurements, cloud and aerosol Lidar backscattering profiles, microwave radiometer brightness temperatures, radiosonde profiles, and sun-photometer extinctions monitored at four observatories located in the midlatitudes (SIRTA Observatory and ARM SGP Lamont), the Tropics (ARM TWP Nauru) and the Arctic (ARM NSA Barrow). This dataset permits us to estimate the Cirrus cloud Radiative Forcing (cloud base altitude above 7 km) on surface-level shortwave (CRFSW) and longwave (CRFLW) irradiances. The sensitivity of CRFSW to Cloud Optical Thickness (noted CRFSW*) is established and ranges from 100 W m-2 to 200 W m-2 per unit of cloud optical thickness. The important variability of aerosols and water vapor content obtained in studying the 4 observatories allows us to quantify the combined influence of aerosol optical thickness and integrated water vapor on CRFSW* : 10 to 20 % CRFSW* range for turbid and pristine atmosphere. Moreover, the sensitivity ... Conference Object Arctic HAL Sorbonne Université Arctic |
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Open Polar |
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HAL Sorbonne Université |
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ftsorbonneuniv |
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English |
topic |
[SDU]Sciences of the Universe [physics] |
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[SDU]Sciences of the Universe [physics] Dupont, J. C. Haeffelin, M. Long, C. N. Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Cirrus clouds not only play a major role in the energy budget of the Earth-Atmosphere system, but are also important in the hydrological cycle. According to satellite passive remote sensing high-altitude clouds cover as much as 40% of the earth's surface on average and can reach 70% of cloud cover over the Tropics. Hence, given their very large cloud cover, the relatively small instantaneous radiative effects of these cirrus clouds can engender a significant cumulative radiative forcing at the surface. Precise calculations of the cirrus cloud radiative forcing are obtained from the difference between measured radiative fluxes downwelling at the surface in the presence of cirrus clouds (broadband flux measurements) and computed clear sky references (parametric models with RMS error < 5 W m-2). Overcast and clear sky period identification is obtained from a combined analysis of lidar and broadband flux measurements. In this study, we analyze two datasets: ground-based and satellite measurements. The firsts corresponds to solar and infrared irradiance measurements, cloud and aerosol Lidar backscattering profiles, microwave radiometer brightness temperatures, radiosonde profiles, and sun-photometer extinctions monitored at four observatories located in the midlatitudes (SIRTA Observatory and ARM SGP Lamont), the Tropics (ARM TWP Nauru) and the Arctic (ARM NSA Barrow). This dataset permits us to estimate the Cirrus cloud Radiative Forcing (cloud base altitude above 7 km) on surface-level shortwave (CRFSW) and longwave (CRFLW) irradiances. The sensitivity of CRFSW to Cloud Optical Thickness (noted CRFSW*) is established and ranges from 100 W m-2 to 200 W m-2 per unit of cloud optical thickness. The important variability of aerosols and water vapor content obtained in studying the 4 observatories allows us to quantify the combined influence of aerosol optical thickness and integrated water vapor on CRFSW* : 10 to 20 % CRFSW* range for turbid and pristine atmosphere. Moreover, the sensitivity ... |
author2 |
Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL) |
format |
Conference Object |
author |
Dupont, J. C. Haeffelin, M. Long, C. N. |
author_facet |
Dupont, J. C. Haeffelin, M. Long, C. N. |
author_sort |
Dupont, J. C. |
title |
Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
title_short |
Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
title_full |
Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
title_fullStr |
Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
title_full_unstemmed |
Cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
title_sort |
cirrus cloud radiative forcing on surface-level shortwave and longwave irradiances at regional and global scale |
publisher |
HAL CCSD |
publishDate |
2009 |
url |
https://hal.science/hal-04113712 |
op_coverage |
à renseigner, Unknown Region |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
EGU General Assembly 2009 https://hal.science/hal-04113712 EGU General Assembly 2009, 2009, à renseigner, Unknown Region. pp.4709 |
op_relation |
hal-04113712 https://hal.science/hal-04113712 BIBCODE: 2009EGUGA.11.4709D |
_version_ |
1809897452599246848 |