Eureka, Nunavut (80.05° N, 86.42° W) provides a valuable vantage point for Arctic studies. Its High Arctic latitude offers one of the world’s most northern facilities for scientific research. The Canadian Network for the Detection of Atmospheric Change established the Polar Environment Atmospheric Research Laboratory (PEARL) near Eureka in 2005. A suite of instruments enables PEARL researchers and partners to investigate a wide range of atmospheric science topics, including climate change, ozone depletion, and air quality. The research presented will describe recent efforts to expand PEARL’s observational capabilities in order to improve our understanding of water vapour in the High Arctic atmosphere.
The expansion of water vapour observations includes participation in the MUSICA (Multi-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) network. MUSICA aims to answer outstanding questions regarding the atmospheric water cycle. Participation in MUSICA has enabled the retrieval of accurate atmospheric water vapour total columns from PEARL’s high-resolution Fourier transform infrared (FTIR) spectrometer measurements of solar absorption. Significantly, the MUSICA retrieval technique gives unique insight into water isotopologues, opening up possibilities for investigating the evolution and transport processes of water vapour, which remain poorly understood, especially in the Arctic.
This new PEARL FTIR dataset provides a window into the concentration, seasonal variability, and other characteristics of water vapour in the High Arctic, helping to address the paucity of water cycle data currently available in the region. Understanding the variability in concentration is important because water vapour plays a critical role in Earth’s radiation balance as a greenhouse gas and through feedback effects. In addition, because of the large impact that water vapour can have on atmospheric spectroscopy generally, this knowledge informs the study of other gases.
The accuracy and reliability of the PEARL FTIR water vapour dataset has been verified using many other instruments at PEARL (e.g. Sun Photometer, Microwave Radiometer, Atmospheric Emitted Radiance Interferometer) and through comparisons with radiosondes launched from the nearby Environment Canada Eureka Weather Station and with satellite measurements by instruments on the Atmospheric Chemistry Experiment (ACE) mission. PEARL FTIR results are presented here and compared to data produced by these instruments, providing a more complete and robust picture of water vapour at Eureka. This knowledge provides a valuable contribution to ongoing studies of climate and the Arctic atmosphere.