Short wave versus long wave radiative forcing by Indian Ocean aerosols: Role of sea-surface winds

Abstract. Collocated measurements of spectral aerosol optical depths (AODs), total and BC mass concentrations, and number size distributions of near surface aerosols, along with sea surface winds, made onboard a scientific cruise over southeastern Arabian Sea, are used to delineate the effects of changes in the wind speed on aerosol properties and its implication on the shortwave and longwave radiative forcing. The results indicated that an increase in the sea-surface wind speed from calm to moderate (<1 to 8 m s−1) values results in a selective increase of the particle concentrations in the size range 0.5 to 5 μm, leading to significant changes in the size distribution, increase in the mass concentration, decrease in the BC mass fraction, a remarkable increase in AODs in the near infrared and a flattening of the AOD spectrum. The consequent increase in the longwave direct radiative forcing almost entirely offsets the corresponding increase in the short wave direct radiative forcing (or even overcompensates) at the top of the atmosphere; while the surface forcing is offset by about 50%.

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Role of Space-Borne Sea Surface Winds on the Simulation of Tropical Cyclones Over the Indian Seas

Pure and Applied Geophysics ◽

10.1007/s00024-021-02890-0 ◽

2021 ◽

Author(s):

M. T. Bushair ◽

S. Indira Rani ◽

Gibies George ◽

Sushant Kumar ◽

Sumit Kumar ◽

...

Keyword(s):

Tropical Cyclones ◽

Sea Surface ◽

Surface Winds ◽

Sea Surface Winds ◽

Indian Seas

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Evaluation of reanalysis and satellite-based sea surface winds using in situ measurements from Chinese Antarctic Expeditions

ADVANCES IN POLAR SCIENCE ◽

10.3724/sp.j.1085.2013.00147 ◽

2013 ◽

Vol 24 (3) ◽

pp. 147

Author(s):

Ming LI ◽

Qinghua YANG ◽

Jiechen ZHAO ◽

Lin ZHANG ◽

Chunhua LI ◽

...

Keyword(s):

In Situ Measurements ◽

Sea Surface ◽

Surface Winds ◽

Sea Surface Winds

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Role of sea surface temperature responses in simulation of the climatic effect of mineral dust aerosol

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-6049-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 6049-6062 ◽

Cited By ~ 30

Author(s):

X. Yue ◽

H. Liao ◽

H. J. Wang ◽

S. L. Li ◽

J. P. Tang

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Radiative Forcing ◽

Mineral Dust ◽

Dust Aerosol ◽

Sea Surface ◽

Climatic Effect ◽

Radiative Effects ◽

Climate Simulations

Abstract. Mineral dust aerosol can be transported over the nearby oceans and influence the energy balance at the sea surface. The role of dust-induced sea surface temperature (SST) responses in simulations of the climatic effect of dust is examined by using a general circulation model with online simulation of mineral dust and a coupled mixed-layer ocean model. Both the longwave and shortwave radiative effects of mineral dust aerosol are considered in climate simulations. The SST responses are found to be very influential on simulated dust-induced climate change, especially when climate simulations consider the two-way dust-climate coupling to account for the feedbacks. With prescribed SSTs and dust concentrations, we obtain an increase of 0.02 K in the global and annual mean surface air temperature (SAT) in response to dust radiative effects. In contrast, when SSTs are allowed to respond to radiative forcing of dust in the presence of the dust cycle-climate interactions, we obtain a global and annual mean cooling of 0.09 K in SAT by dust. The extra cooling simulated with the SST responses can be attributed to the following two factors: (1) The negative net (shortwave plus longwave) radiative forcing of dust at the surface reduces SST, which decreases latent heat fluxes and upward transport of water vapor, resulting in less warming in the atmosphere; (2) The positive feedback between SST responses and dust cycle. The dust-induced reductions in SST lead to reductions in precipitation (or wet deposition of dust) and hence increase the global burden of small dust particles. These small particles have strong scattering effects, which enhance the dust cooling at the surface and further reduce SSTs.

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Role of sea surface temperature and wind convergence in regulating convection over the tropical Indian Ocean

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jd016947 ◽

2012 ◽

Vol 117 (D14) ◽

pp. n/a-n/a ◽

Cited By ~ 9

Author(s):

S. Meenu ◽

K. Parameswaran ◽

K. Rajeev

Keyword(s):

Indian Ocean ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Tropical Indian Ocean ◽

Sea Surface

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Is the ultraviolet waveband a special communication channel in avian mate choice?

Journal of Experimental Biology ◽

10.1242/jeb.204.14.2499 ◽

2001 ◽

Vol 204 (14) ◽

pp. 2499-2507 ◽

Cited By ~ 9

Author(s):

Sarah Hunt ◽

Innes C. Cuthill ◽

Andrew T. D. Bennett ◽

Stuart C. Church ◽

Julian C. Partridge

Keyword(s):

Mate Choice ◽

Communication Channel ◽

Visible Spectrum ◽

Short Wave ◽

Zebra Finches ◽

Long Wave ◽

Single Cone ◽

Coloured Filters ◽

Uv Reflection

SUMMARYThere is growing evidence that ultraviolet (UV) wavelengths play an important role in avian mate choice. One of the first experiments to support this idea showed that female zebra finches (Taeniopygia guttata) prefer UV-reflecting males to males whose ultraviolet reflection has been removed. The effect was very strong despite little or no UV reflection from several plumage areas. However, it is not clear how the importance of the UV waveband compares to other regions of the bird-visible spectrum. We tested whether the response of female zebra finches to the removal of male UV reflection is greater than to the removal of other wavebands. We presented females with a choice of males whose appearance was manipulated using coloured filters. The filters removed single blocks of the avian visible spectrum corresponding closely to the spectral sensitivities of each of the zebra finch’s single cone classes. This resulted in males that effectively had no UV (UV−), no short-wave (SW−), no medium-wave (MW−) or no long-wave (LW−) plumage reflection. Females preferred UV− and SW− males. LW− and MW− males were least preferred, suggesting that female zebra finches show the greatest response to the removal of longer wavelengths. Quantal catches of the single cone types viewing body areas of the male zebra finch are presented for each treatment. Our study suggests it is important to consider the role of the UV waveband in avian mate choice in conjunction with the rest of the avian visible spectrum.

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