Two commercial quadcopters (DJI Matrice 100 and M210 RTK) were equipped with an air temperature measurement system. They were flown at the Polar Environment Atmospheric Research Laboratory, Eureka, Nunavut, Canada, at 80° N latitude to study surface-based temperature inversion during February–March field campaigns in 2017 and 2020. It was demonstrated that the drones can be effectively used in the High Arctic to measure vertical temperature profiles up to 75 m off the ground.

Very thin (< 10 m) laminations in Arctic mixed phase clouds are detected at Eureka, Nunavut on 52 % of measured days, and 62 % of cloudy measured days during a 3.5-year study by the CANDAC Rayleigh-Mie-Raman lidar (CRL) at the Polar Environment Atmospheric Research Laboratory (PEARL). Precipitating snow reported by Environment and Climate Change Canada is strongly correlated with laminated clouds, and anti-correlated with non-laminated clouds, yielding constraints on precipitation formation.

Very thin (<10 m) laminations within Arctic clouds have been observed in all seasons using the Canadian Network for the Detection of Atmospheric Change (CANDAC) Rayleigh–Mie–Raman lidar (CRL) at the Polar Environment Atmospheric Research Laboratory (PEARL; Eureka, Nunavut, Canadian High Arctic). The laminations can last longer than 24 h and are often associated with precipitation and atmospheric stability. This has implications for our understanding of cloud internal structure and processes.

A satellite retrieval for water vapour column was adapted for use over different surfaces in the wintertime Arctic. The retrieval was validated at multiple locations where there was excellent agreement. Reanalyses were found to be 10–15 % drier compared to our water vapour retrieval. Reanalyses represent the present day understanding of the atmosphere so this discrepancy between reanalyses and our retrieval could have implications for the current understanding of the climate.

Measuring the phase (liquid and ice) of Arctic clouds is essential for understanding the changing global climate. Using a lidar, two polarized signals are usually needed. At CRL lidar, one of these signals is small, so phase measurements have low resolution. Another method can use a large unpolarized signal in place of the small polarized signal. We show how to use the original low-resolution measurement to calibrate the new high-resolution method. At CRL, this gives 20 times higher resolution.

CRL lidar in the Canadian High Arctic uses lasers and a telescope to study polar clouds, essential for understanding the changing global climate. Hardware added to CRL allows it to measure the polarization of returned laser light, indicating whether cloud particles are liquid or frozen. Calibrations show that traditional analysis methods work well, although CRL was not originally set up to make this type of measurement. CRL can now measure cloud particle phase every 5 min, every 37.5 m, 24h/day.

Measurements in the high Arctic from two ground-based and one space-borne infrared Fourier transform spectrometer agree well over an 8-year time period (2006–2013). These comparisons show no notable degradation, indicating the consistency of these data sets and suggesting that the space-borne measurements have been stable. Increasing ozone, as well as increases of some other atmospheric gases, has been found over this same time period.

We have compared techniques used by several PEARL instruments to measure atmospheric water vapour. No single instrument can comprehensively map the atmosphere. We documented how well these techniques perform and quantified the agreement and biases between them. This work showed that new FTIR datasets at PEARL capture accurate measurements of High Arctic water vapour.

Methane is a powerful greenhouse gas, and we need to measure it globally with satellite instruments. We compare measurements from two satellites with measurements from the ground in Eureka, Nunavut, Canada to assess their different strengths and weaknesses. The differences between measurements are discussed and assessed considering the details of each measurement technique and processing. Recommendations are provided for utilization of these data sets for monitoring methane in the high Arctic.

Turbulent energy dissipation rates are calculated using MF-radar signals from 70 and 52° N for the period 2001–2014 inclusive, and they are used to estimate turbopause altitudes. A positive trend in turbopause altitude is identified for 70° N in summer, but not in winter and not at 52° N. The turbopause altitude change between 2001 and 2014 can be used to hypothesize a corresponding change in atomic oxygen concentration.