Themed collection Atmospheric chemistry in cold environments

This paper summarizes the meeting on Atmospheric Chemistry in Cold Environments held in London. It puts the meeting into the context of this rapidly evolving scientific field and provides perspectives based on the discussions. Photo credit: K. Jacot.

A schematic of the “Himalayan aerosol factory”. Courtesy of Sole Lätti (https://kuvittajat.fi/).

Sulfate comprises an average of 20% of the ambient PM_2.5 mass during the winter months in Fairbanks, based on 24-hour filter measurements.

Adsorption of methanol on the surface of ice induces premelting whereas acetone does not.

We present shipborne observations of volatile organic compounds such as dimethylsulfide (DMS), isoprene, acetaldehyde, acetone, and methanol over the Southern Ocean in April and May 2018.

Low-cost electrochemical sensing of CO, NO, NO₂, and O₃ at ppbv-level: tracing atmospheric chemistry, characterising emissions, and vertically probing atmospheric composition.

We present an ambient pressure X-ray photoelectron spectroscopy investigation of the adsorption of ammonia on ice over the temperature range −23 °C to −50 °C.

The improved model performance and additional sulfur chemistry for cold and dark winter climates allowed the CMAQ model to be used as a tool for making policy decisions that affect the community and ultimately work towards improving the air quality.

Photolysis of iodide in surface snow is a plausible mechanism for supplying reactive volatile iodine to the Arctic atmosphere.

Tropospheric ozone is frequently depleted in the springtime Arctic, influencing atmospheric oxidation on large spatial scales. Anthropogenic pollution causes more local, intermittent depletion year-round.

Cloud residual particles composed of dust or biological material have been observed in clean arctic boundary layer clouds. They are transported from continental Canada and entrained from the lower tropospheric air, influencing ice formation.

Modeling of atmosphere–snow exchange provides insight into fundamental processes driving pollutant deposition. Gas properties, such as solubility and stickiness to ice, influence the role of the snowpack as a trace gas reservoir and chemical reactor.

Organic compounds were measured in both the gas and particle phases in Fairbanks, Alaska, using a real-time, high-resolution proton transfer reaction-time of flight mass spectrometer (PTR-ToF MS) during a wintertime campaign.

A comprehensive analysis of various potential local sources of natural aerosols in the high Arctic over the pack ice during the ARTofMELT expedition in May–June 2023 was conducted.

The behaviour of one-molecule thin layers of linoleic acid when exposed to ozone in multi-component films at the air–water interface is examined at two temperatures.

Elevated NH₃ concentrations in the summertime Arctic suggest bird colonies and tundra emissions are important sources that can impact aerosol.

We present direct observations of 2-methyltetrol in the gas- and particle phase from the high-altitude measurement station Chacaltaya in the Bolivian Andes and investigate its sources and transport in air masses from Amazonia.

Metastable ONONO₂ is prepared using molecular beam techniques and adsorbed at the surface of an ice film at 40 K allowing this heterogeneous NO₂ hydrolysis reaction intermediate to be trapped and characterized in situ using vibrational spectroscopy.

The microstructure of sea ice depends on ice growth rate. During cooling and internal freezing the pore space evolves in a way that its directed percolation threshold ϕ_c increases with the cubic root of the growth velocity.

Anthropogenic NO_x emissions have observable impacts on naturally occurring chemical processes in remote areas hundreds of kilometers downwind.

We use the TOMCAT 3-D atmospheric model to investigate the impacts of a Hunga-like volcanic eruption preceding a very cold Arctic winter such as that of 2019/2020, on ozone. Around an additional 16 DU of ozone depletion would occur in mid-March.

Molecular dynamics simulations and topological graph analysis explore water–alcohol surface freezing from 283 K to 192 K. During cooling, the interfacial hydrogen-bonded network adjusts to incorporate alcohol hydroxyl groups into polygonal structures.

Biogenic ice nucleating particles (INPs) are key over the Arctic Ocean. Significant links between marine biogenic activity, aerosolization, and INP abundance are highlighted, advancing our understanding of ice nucleation for Arctic clouds.