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

. Atmospheric black carbon (BC) is the strongest solar radiativeabsorber in the atmosphere, exerting significant influences on the earth'sradiation budget. The mass absorption cross section (MAC) is a crucialparameter for converting the light absorption coefficient ( σab ) to theequivalent BC mass concentration (EBC). Traditional filter-based instruments,such as the AE33, use a constant MAC of 7.77 m 2 /g at 880 nm to derive the EBC,which may lead to uncertainty in the EBC. In this paper, a new method ofconverting σab to the EBC is proposed by incorporating thevariations of the MAC attributed to the influences of the aerosol coating state. A Miesimulation showed that the MAC varied dramatically with different core sizes andshell thicknesses. We compared our new method with the traditional method duringa field measurement at a site on the North China Plain. The results showed thatthe MAC at 880 nm was smaller (larger) than 7.77 m 2 /g for particlessmaller (larger) than 280 nm, resulting in an EBC mass size distributionderived from the new method that was higher (lower) than the traditional method forparticles smaller (larger) than 280 nm. The size-integrated EBC derived from thenew method was 16 % higher than that derived from the traditional method. Sensitivity analysisindicated that the uncertainty in the EBC caused by the refractive index (RI) waswithin 35 %, and the imaginary part of the RI had dominant influence on thederived EBC. This study emphasizes the necessity to take variations of the MACinto account when deriving the EBC from σab and can help constrainthe uncertainty in EBC measurements.

Determination of equivalent black carbon mass concentration from aerosol light absorption using variable mass absorption cross section