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

. Improvements in air quality and Earth's climatepredictions require improvements of the aerosol speciation in chemicaltransport models, using observational constraints. Aerosol speciation (e.g.,organic aerosols, black carbon, sulfate, nitrate, ammonium, dust or seasalt) is typically determined using in situ instrumentation. Continuous, routineaerosol composition measurements from ground-based networks are notuniformly widespread over the globe. Satellites, on the other hand, canprovide a maximum coverage of the horizontal and vertical atmosphere butobserve aerosol optical properties (and not aerosol speciation) based onremote sensing instrumentation. Combinations of satellite-derived aerosoloptical properties can inform on air mass aerosol types (AMTs). However,these AMTs are subjectively defined, might often be misclassified and arehard to relate to the critical parameters that need to be refined in models. In this paper, we derive AMTs that are more directly related to sources andhence to speciation. They are defined, characterized and derived usingsimultaneous in situ gas-phase, chemical and optical instruments on the sameaircraft during the Study of Emissions and Atmospheric Composition, Clouds,and Climate Coupling by Regional Surveys (SEAC4RS, an airborne fieldcampaign carried out over the US during the summer of 2013). We finddistinct optical signatures for AMTs such as biomass burning (fromagricultural or wildfires), biogenic and polluted dust. We find that allfour AMTs, studied when prescribed using mostly airborne in situ gas measurements,can be successfully extracted from a few combinations of airborne in situ aerosoloptical properties (e.g., extinction Ångström exponent, absorption Ångströmexponent and real refractive index). However, we find that the opticallybased classifications for biomass burning from agricultural fires andpolluted dust include a large percentage of misclassifications that limitthe usefulness of results related to those classes. The technique and results presented in this study are suitable to develop arepresentative, robust and diverse source-based AMT database. This databasecould then be used for widespread retrievals of AMTs using existing andfuture remote sensing suborbital instruments/networks. Ultimately, it hasthe potential to provide a much broader observational aerosol dataset toevaluate chemical transport and air quality models than is currentlyavailable by direct in situ measurements. This study illustrates how essential itis to explore existing airborne datasets to bridge chemical and opticalsignatures of different AMTs, before the implementation of future spacebornemissions (e.g., the next generation of Earth Observing System (EOS)satellites addressing Aerosols, Cloud, Convection and Precipitation (ACCP)designated observables).

Identifying chemical aerosol signatures using optical suborbital observations: how much can optical properties tell us about aerosol composition?