Expansion of the NCAR Upper Atmosphere Observations

While NCAR HAO is using a variety of models to study the mesosphere and thermosphere, it is important to have observational results to validate these simulations.    At the same time, observations can often lead to new discoveries, requiring more modeling investigations. NCAR HAO operates optical remote sensing Fabry-Perot interferometers (FPI) to measure nighttime mesospheric and thermospheric winds.   These observations are supported by National Science Foundation Regular/CORE funding contract No. M0856145.

Over the years, the FPI observations expanded from a single station in northern Canada to mid and lower latitudes. In February 2014, in collaboration with the Korean Polar Research Institute under grant No. HAO11518, an FPI was deployed at a new Korean Antarctic station called Jang Bogo (74.6S, 164.2E) (Fig. 1, left). This station, with magnetic latitude close to 80 degrees, is ideally located to monitor geomagnetic substorm activities inside the polar cap. Moreover, this new station complements the existing northern polar cap station in Canada because FPI operates only during long polar winter nights. The Canadian station operates from October to March, while Jang Bogo operates from April to September. Thus the two stations can provide polar cap coverage throughout the year.

HAO is also expanding its northern polar cap observations to Eureka, Canada (80N, 86W), in collaboration with University of New Brunswick, to measure thermospheric winds (Fig. 1, right). The Eureka observatory further enhances the existing NCAR capability inside the polar cap and allows us to examine thermosphere structure inside the polar region. The thermospheric responses to the geomagnetic substorm inside the polar cap can have a profound impact on the ionosphere and thermosphere from the high to mid latitudes. The polar region is usually the first impacted by the geomagnetic activity because the geomagnetic field lines from this region are directly connected to the magnetosphere with the solar wind from the sun. The HAO observation network will further support the science objectives of NCAR to understand the solar impact on the terrestrial environment.

Fabry-Perot interferometer image
Figure 1. Jang Bogo Fabry-Perot interferometer Sky Scanner with Mt. Melbourne near Terra Nova Bay in Victoria Land of Antarctica (left).  The sky scanner is a rotating mirror system, which allows the instrument to point any direction in the sky. Eureka Station in northern Canada is shown on the right.