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

We conduct several sets of simulations with a version of NASA's Goddard EarthObserving System, version 5, (GEOS-5) Atmospheric Global Climate Model (AGCM)equipped with a two-moment cloud microphysical scheme to understand the roleof biomass burning aerosol (BBA) emissions in Southeast Asia (SEA) in thepre-monsoon period of February–May. Our experiments are designed so thatboth direct and indirect aerosol effects can be evaluated. Forclimatologically prescribed monthly sea surface temperatures, we conduct setsof model integrations with and without biomass burning emissions in the areaof peak burning activity, and with direct aerosol radiative effects eitheractive or inactive. Taking appropriate differences between AGCM experimentsets, we find that BBA affects liquid clouds in statistically significantlyways, increasing cloud droplet number concentrations, decreasing dropleteffective radii (i.e., a classic aerosol indirect effect), and locallysuppressing precipitation due to a deceleration of the autoconversionprocess, with the latter effect apparently also leading to cloud condensateincreases. Geographical re-arrangements of precipitation patterns, withprecipitation increases downwind of aerosol sources are also seen, mostlikely because of advection of weakly precipitating cloud fields. Somewhatunexpectedly, the change in cloud radiative effect (cloud forcing) at surfaceis in the direction of lesser cooling because of decreases in cloud fraction.Overall, however, because of direct radiative effect contributions, aerosolsexert a net negative forcing at both the top of the atmosphere and, perhapsmost importantly, the surface, where decreased evaporation triggers feedbacksthat further reduce precipitation. Invoking the approximation that direct andindirect aerosol effects are additive, we estimate that the overallprecipitation reduction is about 40% due to the direct effects ofabsorbing aerosols, which stabilize the atmosphere and reduce surface latentheat fluxes via cooler land surface temperatures. Further refinements of ourtwo-moment cloud microphysics scheme are needed for a more completeexamination of the role of aerosol–convection interactions in the seasonaldevelopment of the SEA monsoon

Modeling the influences of aerosols on pre-monsoon circulation and rainfall over Southeast Asia