Calibration of Arctic ice core bromine enrichment records for past sea ice reconstructions.

Bromine in ice cores has been proposed as a qualitative sea ice proxy to produce sea ice reconstructions for the polar regions. Here we report the first statistical validation of this proxy with satellite sea ice observations by combining bromine enrichment (with respect to seawater, Br) records from three Greenlandic ice cores (SIGMA-A, NU and RECAP) with satellite sea ice imagery, over three decades. We find that during the 1984-2016 satellite-era, ice core Br values are significantly correlated with first-year sea ice formed in the Baffin Bay and Labrador Sea supporting that the gas-phase bromine enrichment processes, preferentially occurring over the sea ice surface, are the main driver for the Br signal in ice cores.

Developing an insulation box with automatic temperature control for PM measurements in cold regions.

Low-cost PM sensors are now used worldwide to assess air pollution. However, their operation is generally challenging in severely cold regions like Siberia, Alaska, the Arctic, and Antarctica. We made an insulation box with automatic internal temperature control developed for a low-cost PM sensor to maintain a warm operational environment with four light-bulb heaters when the air temperature inside of the insulation box falls slightly below 5 °C under the current preset temperature setting.

Isotopic evidence for acidity-driven enhancement of sulfate formation after SO emission control.

After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO) emissions. However, a lack of observational evidence has hindered the identification of causal feedback mechanisms. Here, we report an increase in the oxygen isotopic composition of sulfate ([Formula: see text]) in a Greenland ice core, implying an enhanced role of acidity-dependent in-cloud oxidation by ozone (up to 17 to 27%) in sulfate production since the 1960s.

Atmospheric sea-salt and halogen cycles in the Antarctic.

Atmospheric sea-salt and halogen cycles play important roles in atmospheric science and chemistry including cloud processes and oxidation capacity in the Antarctic troposphere. This paper presents a review and summarizes current knowledge related to sea-salt and halogen chemistry in the Antarctic. First, presented are the seasonal variations and size distribution of sea-salt aerosols (SSAs).