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 report results of a two-year campaign of measurements, during arcticwinter darkness, of optical turbulence in the atmospheric boundary-layer abovethe Polar Environment Atmospheric Laboratory in northern Ellesmere Island(latitude +80 deg N). The data reveal that the ground-layer turbulence in theArctic is often quite weak, even at the comparatively-low 610 m altitude ofthis site. The median and 25th percentile ground-layer seeing, at a height of20 m, are found to be 0.57 and 0.25 arcsec, respectively. When combined with afree-atmosphere component of 0.30 arcsec, the median and 25th percentile totalseeing for this height is 0.68 and 0.42 arcsec respectively. The median totalseeing from a height of 7 m is estimated to be 0.81 arcsec. These values arecomparable to those found at the best high-altitude astronomical sites.

Astronomical seeing and ground-layer turbulence in the Canadian High Arctic