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

TL;DR

This study presents two-year measurements of atmospheric turbulence in the Canadian High Arctic, revealing exceptionally weak ground-layer turbulence and excellent seeing conditions comparable to top astronomical sites.

Contribution

It provides the first detailed characterization of optical turbulence in the Arctic boundary layer, demonstrating its potential for high-quality astronomical observations.

Findings

Ground-layer turbulence is often weak at Arctic site.

Median total seeing at 7 m height is 0.81 arcsec.

Arctic atmospheric conditions are comparable to premier observatory sites.

Abstract

We report results of a two-year campaign of measurements, during arctic winter darkness, of optical turbulence in the atmospheric boundary-layer above the Polar Environment Atmospheric Laboratory in northern Ellesmere Island (latitude +80 deg N). The data reveal that the ground-layer turbulence in the Arctic is often quite weak, even at the comparatively-low 610 m altitude of this site. The median and 25th percentile ground-layer seeing, at a height of 20 m, are found to be 0.57 and 0.25 arcsec, respectively. When combined with a free-atmosphere component of 0.30 arcsec, the median and 25th percentile total seeing for this height is 0.68 and 0.42 arcsec respectively. The median total seeing from a height of 7 m is estimated to be 0.81 arcsec. These values are comparable to those found at the best high-altitude astronomical sites.