TY - GEN
T1 - Shortwave and longwave radiative forcings of aerosols depending on the vertical stratification of aerosols and clouds
AU - Oikawa, Eiji
AU - Suzuki, Kentaroh
AU - Nakajima, Teruyuki
AU - Nishizawa, Tomoaki
N1 - Funding Information:
This study was partly supported by Earth, Cloud, Aerosol, Radiation Explorer (EarthCARE): 1st research announcement from the Japan Aerospace Exploration Agency (JAXA).
Publisher Copyright:
© 2017 Author(s).
PY - 2017/2/22
Y1 - 2017/2/22
N2 - We investigate four scenarios for estimating shortwave (SW) and longwave (LW) direct aerosol radiative forcing (DARF) at the top of atmosphere (TOA) using the global data set of the vertical distributions for aerosols and clouds of CALIPSO and CloudSat Level 2 products. One scenario is clear-sky (cloud-free) condition and three scenarios are cloudy-sky condition: the case that aerosols exists above clouds (AAC case), and the case that aerosols exist below high clouds such as cirrus, but without clouds below the aerosol layers (ABC case), and the case that aerosols are not observed in cloudy-sky condition. In clear-sky and ABC cases, aerosols mainly scatter sunlight and SWDARFs show negative values, except for bright surfaces, such as desert regions and the North and South Poles. In AAC case, aerosols absorb the reflected light from underlying low-level clouds to TOA, so that SWDARF at TOA shows positive value. Mineral dust absorbs the Earth's radiation and LWDARF indicates strong positive over Saharan and Arabian deserts. The global mean values of SW plus LW DARFs are -2.77, -0.77, and -1.40 Wm-2 under clear-sky, cloudy-sky, and all-sky conditions.
AB - We investigate four scenarios for estimating shortwave (SW) and longwave (LW) direct aerosol radiative forcing (DARF) at the top of atmosphere (TOA) using the global data set of the vertical distributions for aerosols and clouds of CALIPSO and CloudSat Level 2 products. One scenario is clear-sky (cloud-free) condition and three scenarios are cloudy-sky condition: the case that aerosols exists above clouds (AAC case), and the case that aerosols exist below high clouds such as cirrus, but without clouds below the aerosol layers (ABC case), and the case that aerosols are not observed in cloudy-sky condition. In clear-sky and ABC cases, aerosols mainly scatter sunlight and SWDARFs show negative values, except for bright surfaces, such as desert regions and the North and South Poles. In AAC case, aerosols absorb the reflected light from underlying low-level clouds to TOA, so that SWDARF at TOA shows positive value. Mineral dust absorbs the Earth's radiation and LWDARF indicates strong positive over Saharan and Arabian deserts. The global mean values of SW plus LW DARFs are -2.77, -0.77, and -1.40 Wm-2 under clear-sky, cloudy-sky, and all-sky conditions.
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U2 - 10.1063/1.4975547
DO - 10.1063/1.4975547
M3 - Conference contribution
AN - SCOPUS:85015952865
T3 - AIP Conference Proceedings
BT - Radiation Processes in the Atmosphere and Ocean, IRS 2016
A2 - Schmutz, Werner
A2 - Davies, Roger
A2 - Egli, Luca
PB - American Institute of Physics Inc.
T2 - International Radiation Symposium 2016: Radiation Processes in the Atmosphere and Ocean, IRS 2016
Y2 - 16 April 2016 through 22 April 2016
ER -