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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present measurements of the wind speeds at the nightside lower clouds ofVenus from observations by JAXA's mission Akatsuki during 2016, complementedwith new wind measurements from ground-based observations acquired withTNG/NICS in 2012 and IRTF/SpeX in 2015 and 2017. Zonal and meridionalcomponents of the winds were measured from cloud tracking on a total of 466Akatsuki images of Venus acquired by the camera IR2 using the 2.26-$\mathrm{\mum}$ filter, with spatial resolutions ranging 10--80 km per pixel and coveringfrom 2016 March 22 to October 31. More than 149,000 wind vectors were obtainedwith an automatic technique of template matching, and 2,947 wind vectors wereinferred with the manual procedure. The meridional profiles for both componentsof the winds are found to be consistent with results from the Venus Expressmission during 2006--2008, although stronger wind variability is found for thezonal component at equatorial latitudes where Akatsuki observations have betterviewing geometry than Venus Express. The zonal winds at low latitudes alsosuggest a zonal variability that could be associated with solar tides orvertically propagating orographic waves. Finally, the combination of our windmeasurements from TNG/NICS, IRTF/SpeX and Akatsuki images with previouslypublished and based in data from 1978 to 2017 suggests variations of up to 30 ms$^{-1}$ in the winds at the lower clouds of the Venus nightside.

the astrophysical journal. supplement series/astrophysical journal. supplement series

Nightside Winds at the Lower Clouds of Venus with Akatsuki/IR2:  Longitudinal, local time and decadal variations from comparison with previous  measurements