The presence of clouds and their interaction with aerosols in the High Arctic play a fundamental role in the energy balance of the region, particularly in relation to the seasonal prolonged periods of darkness and daylight. To investigate the properties of the Arctic atmosphere, an Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI) was installed at the Polar Environment Atmospheric Research Labratory (PEARL) at Eureka, Canada (80°N, 86°W) in October 2008. The E-AERI is a moderate resolution (1 cm−1) Fourier Transform Infrared Spectrometer that measures the absolute downwelling infrared spectral radiance from the atmosphere between 400 and 3000 cm−1. Spectra are recorded every 7 minutes year round, including during the polar night. In this study, E-AERI spectra are analyzed using two algorithms: the CLoud and Atmospheric Radiation Retrieval Algorithm (CLARRA) to retrieve cloud properties (temperature, vertical distribution, optical depth, ice fraction, ice crystal/liquid droplet effective radius), and SFIT4 to retrieve atmospheric trace gas concentrations. We investigate trends and variability of the retrieved variables over this period, including the four months of polar night, when solar-viewing measurements are not possible at PEARL. Of particular interest is the correlation between cloud microphysics and key tracers (such as CO) for transported wildfire emissions, for which we examine the degree to which such emissions can influence cloud characteristics in the Arctic.
Host: Ramina Alwarda