First Assessment of Mountains on Northwestern Ellesmere Island, Nunavut, as Potential Astronomical Observing Sites

TL;DR

This study evaluates the potential of high-altitude mountains on Northwestern Ellesmere Island as prime sites for astronomical observations, based on three years of weather and sky clarity data from robotic stations.

Contribution

First assessment of remote Arctic mountain sites for astronomy, providing empirical weather and sky clarity data to identify promising observational locations.

Findings

Coastal mountain sites have low wind speeds and high clear-sky fractions.

Sites are above thermal inversions, promising stable observing conditions.

Operational considerations for remote Arctic sites are discussed.

Abstract

Ellesmere Island, at the most northerly tip of Canada, possesses the highest mountain peaks within 10 degrees of the pole. The highest is 2616 m, with many summits over 1000 m, high enough to place them above a stable low-elevation thermal inversion that persists through winter darkness. Our group has studied four mountains along the northwestern coast which have the additional benefit of smooth onshore airflow from the ice-locked Arctic Ocean. We deployed small robotic site testing stations at three sites, the highest of which is over 1600 m and within 8 degrees of the pole. Basic weather and sky clarity data for over three years beginning in 2006 are presented here, and compared with available nearby sea-level data and one manned mid-elevation site. Our results point to coastal mountain sites experiencing good weather: low median wind speed, high clear-sky fraction and the expectation of excellent seeing. Some practical aspects of access to these remote locations and operation and maintenance of equipment there are also discussed.