English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Millions of tons of mineral dust are lifted by the wind fromarid surfaces and transported around the globe every year. The physical andchemical properties of the mineral dust are needed to better constrain remotesensing observations and are of fundamental importance for the understandingof dust atmospheric processes. Ground-based in situ measurements and in situfilter collection of Saharan dust were obtained during the Fennec campaign inthe central Sahara in 2011. This paper presents results of the absorption andscattering coefficients, and hence single scattering albedo (SSA), of theSaharan dust measured in real time during the last period of the campaignand subsequent laboratory analysis of the dust samples collected in twosupersites, SS1 and SS2, in Algeria and in Mauritania, respectively. Thesamples were taken to the laboratory, where their size and aspect ratiodistributions, mean chemical composition, spectral mass absorptionefficiency,and spectral imaginary refractive index were obtained from theultraviolet (UV) to the near-infrared (NIR) wavelengths. At SS1 in Algeria,the time series of the scattering coefficients during the period of thecampaign show dust events exceeding 3500 Mm −1 , and a relatively highmean SSA of 0.995 at 670 nm was observed at this site. The laboratoryresults show for the fine particle size distributions (particlesdiameter   5 µ m and mode diameter at 2–3  µ m) in bothsites a spectral dependence of the imaginary part of the refractive index Im(m) with a bow-like shape, with increased absorption in UV as well as in the shortwave infrared. The same signature was not observed, however,in the mixed particle size distribution (particlediameter   10  µ m and mode diameter at 4  µ m) inAlgeria. Im(m) was found to range from 0.011 to 0.001i for dust collected inAlgeria and 0.008 to 0.002i for dust collected in Mauritania over thewavelength range of 350–2500 nm. Differences in the mean elementalcomposition of the dust collected in the supersites in Algeria and inMauritania and between fine and mixed particle size distributions wereobserved from EDXRF measurements, although those differences cannot be usedto explain the optical properties variability between the samples. Finally,particles with low-density typically larger than 10  µ m in diameterwere found in some of the samples collected at the supersite in Mauritania,but these low-density particles were not observed in Algeria.

A detailed characterization of the Saharan dust collected during the Fennec campaign in 2011: in situ ground-based and laboratory measurements