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

. The Indo-Gangetic Plain (IGP) is home to 9 % of the global population and is responsible for alarge fraction of agricultural crop production in Pakistan, India, and Bangladesh. Levels of fine particulate matter (mean diameter &lt;2.5 µm, PM2.5)across the IGP often exceed human health recommendations, makingcities across the IGP among the most polluted in the world. Seasonalchanges in the physical environment over the IGP are dominated by thelarge-scale south Asian monsoon system that dictates the timing ofagricultural planting and harvesting. We use the WRF-Chem model to study the seasonal anthropogenic,pyrogenic, and biogenic influences on fine particulate matter and itsconstituent organic aerosol (OA) over the IGPthat straddles Pakistan, India, and Bangladesh during 2017–2018. We find that surface air qualityduring pre-monsoon (March–May) and monsoon (June–September) seasons isbetter than during post-monsoon (October–December) and winter(January–February) seasons, but all seasonal mean values of PM2.5still exceed the recommended levels, so that air pollution is a year-round problem. Anthropogenicemissions influence the magnitude and distribution of PM2.5 andOA throughout the year, especially over urban sites, while pyrogenicemissions result in localised contributions over the central and upperparts of IGP in all non-monsoonal seasons, with the highest impact duringpost-monsoon seasons that correspond to the post-harvest season in theagricultural calendar. Biogenic emissions play an important role inthe magnitude and distribution of PM2.5 and OA during the monsoonseason, and they show a substantial contribution to secondary OA (SOA),particularly over the lower IGP. We find that the OA contribution toPM2.5 is significant in all four seasons (17 %–30 %), with primaryOA generally representing the larger fractional contribution. We findthat the volatility distribution of SOA is driven mainly by the meantotal OA loading and the washout of aerosols and gas-phase aerosolprecursors that result in SOA being less volatile during thepre-monsoon and monsoon season than during the post-monsoon and winterseasons.

Seasonal distribution and drivers of surface fine particulate matter and organic aerosol over the Indo-Gangetic Plain