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

. Winds measured by lidar from the Aeolus satellite arecompared with winds measured by two ground-based radars – MARA in Antarctica(70.77∘ S, 11.73∘ E) and ESRAD (67.88∘ N,21.10∘ E) in Arctic Sweden – for the period 1 July–31 December2019. Aeolus is a demonstrator mission to test whether winds measured byDoppler lidar from space can have sufficient accuracy to contribute toimproved weather forecasting. A comprehensive programme of calibration andvalidation has been undertaken following the satellite launch in 2018, but,so far, direct comparison with independent measurements from the Arctic orAntarctic regions have not been made. The comparison covers heights from thelow troposphere to just above the tropopause. Results for each radar siteare presented separately for Rayleigh (clear) winds, Mie (cloudy) winds,sunlit (“summer”) and non-sunlit (“winter”) seasons, and ascending and descending satellite tracks. Horizontally projected line-of-sight (HLOS) winds fromAeolus, reprocessed using baseline 2B10, for passes within 100 km of theradar sites, are compared with HLOS winds calculated from 1 h averagedradar horizontal wind components. The agreement in most data subsets is verygood, with no evidence of significant biases (&lt;1 m s−1).Possible biases are identified for two subsets (about −2 m s−1 forthe Rayleigh winds for the descending passes at MARA and about 2 m s−1 for the Mie winds for the ascending passes at ESRAD, both in winter), but these are only marginally significant. A robustsignificant bias of about 7 m s−1 is found for the Mie winds for the ascending tracks at MARA in summer. There is also some evidence for increasedrandom error (by about 1 m s−1) for the Aeolus Mie winds at MARA insummer compared to winter. This might be related to the presence of sunlightscatter over the whole of Antarctica as Aeolus transits across it duringsummer.

Validation of Aeolus winds using ground-based radars in Antarctica and in northern Sweden