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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Determining the habitability and interpreting atmospheric spectra ofexoplanets requires understanding their atmospheric physics and chemistry. Weuse a 3-D Coupled Climate-Chemistry Model, the Met Office Unified Model withthe UK Chemistry and Aerosols framework, to study the emergence of lightningand its chemical impact on tidally-locked Earth-like exoplanets. We simulatethe atmosphere of Proxima Centauri b orbiting in the Habitable Zone of itsM-dwarf star, but the results apply to similar M-dwarf orbiting planets. Ourchemical network includes the Chapman ozone reactions and hydrogen oxide(HO$_{\mathrm{x}}$=H+OH+HO$_2$) and nitrogen oxide(NO$_{\mathrm{x}}$=NO+NO$_2$) catalytic cycles. We find that photochemistrydriven by stellar radiation (177-850 nm) supports a global ozone layer between20-50 km. We parameterise lightning flashes as a function of cloud-top heightand the resulting production of nitric oxide (NO) from the thermaldecomposition of N$_2$ and O$_2$. Rapid dayside convection over and around thesubstellar point results in lightning flash rates of up to 0.16 flasheskm$^{-2}$yr$^{-1}$, enriching the dayside atmosphere below altitudes of 20 kmin NO$_{\mathrm{x}}$. Changes in dayside ozone are determined mainly by UVirradiance and the HO$_{\mathrm{x}}$ catalytic cycle. ~45% of the planetarydayside surface remains at habitable temperatures (T$_{\mathrm{surf}}$>273.15K) and the ozone layer reduces surface UV radiation levels to 15%.Dayside-nightside thermal gradients result in strong winds that subsequentlyadvect NO$_{\mathrm{x}}$ towards the nightside, where the absence ofphotochemistry allows NO$_{\mathrm{x}}$ chemistry to involve reservoir species.Our study also emphasizes the need for accurate UV stellar spectra tounderstand the atmospheric chemistry of exoplanets.

Lightning-induced chemistry on tidally-locked Earth-like exoplanets