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/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

We have obtained spatially resolved near-infrared spectroscopy of the Venusnightside on 15 nights over three observing seasons. We use the depth of the COabsorption band at 2.3 microns to map the two-dimensional distribution of COacross both hemispheres. Radiative transfer models are used to relate themeasured CO band depth to the volume mixing ratio of CO. The results confirmprevious investigations in showing a general trend of increased CO abundancesat around 60 degrees latitude north and south as compared with the equatorialregions. Observations taken over a few nights generally show very similar COdistributions, but significant changes are apparent over longer periods. Inpast studies it has been assumed that the CO latitudinal variation occurs near35 km altitude, at which K-band sensitivity to CO is greatest. By modeling thedetailed spectrum of the excess CO at high latitudes we show that it occurs ataltitudes around 45 km, much higher than has previously been assumed, and thatthere cannot be significant contribution from levels of 36 km or lower. Wesuggest that this is most likely due to downwelling of CO-rich gas from theupper atmosphere at these latitudes, with the CO being removed by around 40 kmthrough chemical processes such as the reaction with sulfur trioxide.

The Distribution of Carbon Monoxide in the Lower Atmosphere of Venus