Light backscattering and scattering by nonspherical sea-salt aerosols

Chamaillard, Karine; Jennings, S. G.; Kleefeld, Christoph; Čeburnis, Darius; Yoon, Young Jun

doi:10.1016/s0022-4073(02)00309-6

Cited by 44 publications

(19 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, to calculate the effect of aerosols on the polarization state of reflected light at TOA, we chose an example of a US STD atmosphere with sea salt aerosols. The calculation is conducted at the visible wavelength of 550 nm, where the refractive index of sea salt is given as 1.5 + i10 −8 (Chamaillard et al, 2003). The sea salt aerosol particle shapes are assumed to be the agglomerated debris as shown in Fig.…”

Section: Numerical Resultsmentioning

confidence: 99%

Modeling polarized solar radiation from the ocean–atmosphere system for CLARREO inter-calibration applications

Sun

Lukashin

2013

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Reflected solar radiance from the Earthatmosphere system is polarized. Radiance measurements can be affected by light's state of polarization if the radiometric sensor has polarization dependence. To enable the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission for inter-calibration of the imagers with polarization dependence, such as the MODIS, the polarization state of the light must be known with sufficient accuracy. For this purpose, the polarized solar radiation from the ocean-atmosphere system is studied with an adding-doubling radiative transfer model (ADRTM). The Cox-Munk ocean wave slope distribution model is used in calculation of the reflection matrix of a wind-ruffled ocean surface. An empirical foam spectral reflectance model and an empirical spectral reflectance model for water volume below the surface are integrated in the ocean-surface model. Solar reflectance from the ADRTM is compared with that from the discrete-ordinate radiative transfer (DISORT) model. Sensitivity studies are conducted for various ocean-surface and atmospheric conditions for the stratification of polarization distribution models (PDMs), which are to be used in the inter-calibration of the polarization-sensitive imager measurements with the CLARREO data. This report presents the first accurate approach for making the spectral PDMs over broad solar spectra, which cannot be achieved by empirical PDMs based on the data from polarimetric sensors.

show abstract

Section: Numerical Resultsmentioning

confidence: 99%

Modeling polarized solar radiation from the ocean–atmosphere system for CLARREO inter-calibration applications

Sun

Lukashin

2013

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Sea salt and mineral dust, however, are not spherical and therefore Mie theory cannot be used (Nousiainen, 2009). Nevertheless, for measurements with an integrating nephelometer, the error in s sp is assumed to be B5% for particles with D p B1 mm, but up to 30% for cubic particles !1 mm (Chamaillard et al, 2003).…”

Section: Optical Closure Studymentioning

confidence: 99%

Influence of water uptake on the aerosol particle light scattering coefficients of the Central European aerosol

Zieger

Fierz-Schmidhauser

Poulain

et al. 2014

Tellus B: Chemical and Physical Meteorology

View full text Add to dashboard Cite

A B S T R A C TThe influence of aerosol water uptake on the aerosol particle light scattering was examined at the regional continental research site Melpitz, Germany. The scattering enhancement factor f(RH), defined as the aerosol particle scattering coefficient at a certain relative humidity (RH) divided by its dry value, was measured using a humidified nephelometer. The chemical composition and other microphysical properties were measured in parallel. f(RH) showed a strong variation, e.g. with values between 1.2 and 3.6 at RH 085% and l0550 nm. The chemical composition was found to be the main factor determining the magnitude of f(RH), since the magnitude of f(RH) clearly correlated with the inorganic mass fraction measured by an aerosol mass spectrometer (AMS). Hysteresis within the recorded humidograms was observed and explained by long-range transported sea salt. A closure study using Mie theory showed the consistency of the measured parameters.

show abstract

“…Sea salt aerosols have been observed to crystallise at very low humidities (e.g. Chamaillard et al, 2003), but this was in heated dryers, and for conditions outside the range found by Sayer et al (2012b). Thus, for the maritime subset the assumption of sphericity is likely to introduce negligible additional uncertainty.…”

Section: Assumption Of Aerosol Sphericitymentioning

confidence: 99%

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

et al. 2012

View full text Add to dashboard Cite

Abstract. As well as spectral aerosol optical depth (AOD), aerosol composition and concentration (number, volume, or mass) are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN) cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET) inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of microphysical properties, such attempts are fraught with high uncertainties.

show abstract

Light backscattering and scattering by nonspherical sea-salt aerosols

Cited by 44 publications

References 25 publications

Modeling polarized solar radiation from the ocean–atmosphere system for CLARREO inter-calibration applications

Modeling polarized solar radiation from the ocean–atmosphere system for CLARREO inter-calibration applications

Influence of water uptake on the aerosol particle light scattering coefficients of the Central European aerosol

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

Contact Info

Product

Resources

About