Atmospheric Dimethylsulfide Research Articles

A comparison of dimethylsulphide (DMS) data from the Atlantic Meridional Transect (AMT) programme with proposed algorithms for global surface DMS concentrations

Measurements of the climate-cooling trace gas dimethylsulphide (DMS) and other ancillary data, including pigments, nutrient concentrations and the depth of the mixed layer, were made over a wide latitude range during the UK Atlantic Meridional Transect (AMT) programme. The data were used to test algorithms from the recent literature for their effectiveness at predicting surface DMS concentrations. Dividing the data by research cruise (i.e. year and season) and into biogeochemical provinces aided data interpretation. For this new data set, many of the available algorithms over-predicted the measured DMS concentration. The best fit was found with a dilution model based on the depth of the mixed layer [Aranami, K., Tsunogai, S., 2004. Seasonal and regional comparison of oceanic and atmospheric dimethylsulfide in the northern North Pacific: dilution effects on its concentration during winter. Journal of Geophysical Research 109D (12), art. no. D12303], but there are still parts of the data that cannot be explained. We suggest that in order to test, improve and refine current predictive models, further data for DMS and related compounds are needed for remote oligotrophic regions.

Spatial distributions of volatile sulfur compounds in surface seawater and overlying atmosphere in the northwestern Pacific Ocean, eastern Indian Ocean, and Southern Ocean

Distributions of volatile sulfur compounds (carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), dimethyl sulfide (DMS)) in surface seawater and overlying atmosphere were measured in the northwestern Pacific, eastern Indian, and Southern Oceans (40°N–66°S, 40°E–140°E) in November–December 1996 during the 38th Japanese Antarctic Research Expedition cruise. Seawater measurements revealed that DMS was the dominant sulfur compound, with concentrations of 0.5–15.8 nM. High values were found in the Southern Ocean's marginal ice zone (84°E–63°E, 59°S–63°S), suggesting that the area during the bloom acts as an important source of atmospheric DMS. Atmospheric concentrations were 456–471 pptv for OCS, n.d. (not detected level) −13 pptv for CS2, n.d. −17 pptv for H2S, and n.d. −755 pptv for DMS. Concentrations of OCS were nearly constant. Concentrations of CS2 and H2S were high in terrigenic air masses and low in those of oceanic origin. Comparison of atmospheric DMS data and a steady state box model using sea‐to‐air fluxes of DMS and assumed OH radical concentrations revealed that atmospheric DMS concentrations in the equatorial region and most of the Southern Ocean were balanced with local oceanic emission residues and photochemical oxidation. Simultaneous measurements in the atmosphere showed DMS was the dominant sulfur gas that was oxidized rapidly to sulfate aerosols in the marine atmosphere.

Seasonal and Diurnal Cycles of Dimethylsulfide, Dimethylsulfoniopropionate and Dimethylsulfoxide at One Tree Reef Lagoon

Environmental Context. Coral reefs have now been highlighted as significant sources of dimethylsulfide and other organic sulfur compounds, which may be important for the formation of clouds over the ocean and climate regulation. However, no studies have reported the seasonal and diurnal cycles of these organic sulfur substances in reef waters. This study describes the cycling of dimethylsulfide and related organic substances at One Tree Reef, in the southern part of the Great Barrier Reef, as well as their production from staghorn coral in chamber experiments. The results suggest that coral reefs are significant sources of dimethylsulfide to reef waters and possibly the reef atmosphere, but the effect of this substance on the radiative climate over the Great Barrier Reef is unknown. Abstract. Seasonal and diurnal studies conducted at One Tree Reef lagoon in the Great Barrier Reef (GBR) highlight increased production of dissolved dimethylsulfide, atmospheric dimethylsulfide, dissolved and particulate dimethylsulfoniopropionate, and dimethylsulfoxide during the summer months, and when the lagoon is moated with inter-reefal water. This production is due to both the growth of phytoplankton populations within the lagoon, and benthic corals and algae in or on sediments and attached to solid substrates. The relative importance of these two processes was not determined in this study, although benthic production from corals was shown to be significant in chamber experiments. The diurnal cycles of the organic sulfur substances measured at One Tree Reef provide unequivocal evidence that coral reefs produce significant quantities of these organic sulfur substances during the day and suggest that coral reefs could be significant sources of atmospheric dimethylsulfide.

High olfactory sensitivity for dimethyl sulphide in harbour seals

Productive areas are patchily distributed at sea and represent important feeding grounds for many marine organisms. Although pinnipeds are known to travel on direct routes and return regularly to particular feeding sites, the environmental information seals use to perform this navigation is as yet unknown. As atmospheric dimethyl sulphide (DMS) has been demonstrated to be a reliable indicator for profitable foraging areas, we tested seals for their ability to smell DMS at concentrations typical for the marine environment. Using a go/no-go response paradigm we determined the DMS detection threshold in two harbour seals (Phoca vitulina vitulina). DMS stimuli from 8.05 x 108 to 8 pmol (DMS)m(-3)(air) were tested against a control stimulus using a custom-made olfactometer. DMS-thresholds determined for both seals (20 and 13 pmol m(-3)) indicate that seals can detect ambient concentrations associated with high primary productivity, e.g. in the North Atlantic. Thus, seals possess an extraordinarily high olfactory sensitivity for DMS, which could provide a sensory basis for identifying or orienting to profitable foraging grounds.

The net effect of ultraviolet radiation on atmospheric dimethylsulphide over the Southern Indian Ocean

Dimethylsulphide (DMS) in the atmosphere may play an important role in the climate system. This study shows an inverse relationship between ultraviolet extremes and atmospheric DMS, independent of changes in wind speed, sea-surface temperature and photosynthetically active radiation, as measured at Amsterdam Island in the Southern Indian Ocean.

The influence of coral reefs on atmospheric dimethylsulphide over the Great Barrier Reef, Coral Sea, Gulf of Papua and Solomon and Bismarck Seas

Marked regional differences in dissolved dimethylsulphide (DMS), atmospheric DMS and DMS flux were recorded during July 1997 through the northern Great Barrier Reef, Coral Sea, Gulf of Papua, Solomon and Bismarck Seas. Highest concentrations of dissolved DMS occurred in the Coral Sea, Gulf of Papua and Bismarck Sea, with lower concentrations in the Great Barrier Reef and Solomon Sea. Elevated levels of atmospheric DMS often occurred in south-easterly to southerly trade winds sampled in the region 18°32′–8°12′S to 145°–151°E, where the highest biomass of coral reefs occurred. Atmospheric DMS often increased in the day after low tides and was positively correlated with tidal height in the northern Great Barrier Reef (r = 0.91, P < 0.05). For tides less than 1.6 m, atmospheric DMS increased on the rising tide for the northern GBR and NW Coral Sea (r = 0.66; P < 0.05) and for the whole voyage (r = 0.25; P < 0.05). As coral reefs have been identified as significant sources of DMS, it is suggested that the daytime increase in atmospheric DMS over much of the study area was mainly a result of high winds and extremely low tides in July, which exposed the reefs during the day.

Seawater, atmospheric dimethylsulfide and aerosol ions in the Pearl River Estuary and the adjacent northern South China Sea

The spatial and temporal distribution of dimethylsulfide (DMS) was investigated in surface seawater and in the marine atmosphere in the Pearl River Estuary and northern South China Sea during three cruises in July 2000, May 2001 and November 2002. Sea-to-air fluxes of DMS were subsequently estimated based upon seawater DMS concentration, temperature of surface seawater and wind speed over sea. The seawater DMS concentration of the three cruises ranged from 0.1 to 52.7 nmol l −1 (n=76). DMS concentrations showed remarkable spatial and temporal distributions and highest values were observed at the mouth of the Pearl River Estuary. Throughout the study area we observed high levels of DMS in the water with great sea-to-air flux and relatively low levels of atmospheric DMS (1.70±1.16 nmol m −3 in May 2001 and 2.25±0.38 nmol m −3 in November 2002). Aerosol components, potentially linked with DMS oxidation, were also measured. The atmospheric concentrations of nss-sulfate and nitrate were much higher in the Pearl River Estuary than in the offshore area, with mean values of 12.11 and 4.45 μg m −3 for nss-sulfate, 4.88 and 2.21 μg m −3 for nitrate. Aerosol mass and components' concentrations decreased from the inner estuary to outer waters. High concentrations of nss-sulfate and nitrate in sea salt particles imply that oxidation of atmospheric DMS is related with anthropogenic sources and heavy ozone, NO x and SO 2 pollution in the study area.

Fluxes and gas transfer rates of the biogenic trace gas DMS derived from atmospheric gradients

Gas transfer rates were determined from vertical profile measurements of atmospheric dimethylsulfide (DMS) gradients over the equatorial Pacific Ocean obtained during the GasEx‐2001 cruise. A quadratic relationship between gas transfer velocity and wind speed was derived from the DMS flux measurements; this relationship was in close agreement with a parameterization derived from relaxed eddy accumulation measurements of DMS over the northeastern Pacific Ocean. However, the GasEx‐2001 relationship results in gas transfer rates that are a factor 2 higher than gas transfer rates calculated from a parameterization that is based on coincident eddy correlation measurements of CO2 flux. The measurement precision of both the profiling and eddy correlation techniques applied during GasEx‐2001 is comparable; the two gas transfer data sets are in agreement within their uncertainty. Differences in the number of samples and the wind speed range over which CO2 and DMS fluxes were measured are likely causes for the observed discrepancy.

Seasonal and regional comparison of oceanic and atmospheric dimethylsulfide in the northern North Pacific: Dilution effects on its concentration during winter

Concentrations of dimethylsulfide (DMS) in the mixed layer depth (MLD) and in the atmospheric boundary layer (ABL) and carbon disulfide (CS2) and carbonyl sulfide (COS) in the ABL were measured in the northern North Pacific during summer (July–September 1997) and autumn‐winter (November–December 1998). Seasonal and regional variability in sea surface DMS was roughly explained by a simple dilution model (DMS × MLD = constant). Temporal and spatial comparison of COS and CS2 suggests that during autumn‐winter, there would be strong perturbation by transport of terrestrial polluted air masses from the free troposphere (FT) into the ABL. The seasonal difference in the DMS budget in the ABL was assessed by the time series mass‐balance model. This calculation showed that during autumn‐winter, most DMS supplied from the ocean should have escaped from the ABL, while during summer, most DMS should be oxidized in the ABL. Our results suggest the possibility that the strong seasonality of oceanic and atmospheric DMS might be produced mainly by dilution effects due to strong mixing during winter.

Spatial, Temporal and Interannual Variability of Methanesulfonate and Non-Sea-Salt Sulfate in Rainwater in the Southern Indian Ocean (Amsterdam, Crozet and Kerguelen Islands)

Methanesulfonate (MS−) and non-sea-salt sulfate (nss-SO42−), two of the major oxidation products of atmospheric dimethylsulfide (DMS), have been continuously measured in rainwater at three remote islands in the Southern Indian Ocean: Amsterdam since 1991, Crozet since 1992, and Kerguelen since 1993. The annual volume weighted mean (VWM) concentrations of nss-SO42− in rainwater were 3.19, 3.04 and 4.57 μ eq l−1 at Amsterdam, Crozet, and Kerguelen, respectively while the VWM of MS− were 0.24, 0.15 and 0.30 μ eq l−1, respectively. At all three islands, MS− presented a well-distinguished seasonal variation with a maximum during summer whereas the seasonal variation of nss-SO42− was less pronounced, possibly due to the increased anthropogenic influence during the winter period. Furthermore, MS− presented significant interannual variations, in particular at Amsterdam and Crozet, which is closely related to the sea-surface temperature (SST) anomalies). Finally, the nss-SO42− deposition at Crozet Island presented a decreasing interannual trend, reflecting probably reductions in sulfur emissions from Southern Africa. On the contrary no interannual tendency was observed in the nss-SO42− concentrations at Amsterdam Island, indicating that the biogeochemical sulfur cycle at this area is mainly influenced by biogenic emissions.

Biogenic emission of dimethylsulfide from a highly eutrophicated coastal region, Masan Bay, South Korea

Abstract Atmospheric dimethylsulfide (DMS), water-soluble ionic species in aerosol such as non-seasalt sulfate and methanesulfonic acid (MSA), and seawater DMS were measured in highly eutrophicated Masan Bay, Korea in July–August 1997. Mean (median) concentrations of atmospheric DMS, seawater DMS, non-seasalt sulfate, and MSA during the experiment were 188 pptv (49 pptv), 6.3 nM (5.3 nM), 3.0 μg m −3 (2.3 μg m −3 ), and 0.010 μg m −3 (0.008 μg m −3 ), respectively. The vertical profiles of seawater, especially in inner bay, reveal that DMS concentrations were enhanced near the bottom coincidently with extremely low levels of chlorophyll- a and depleted oxygen. There were several episodes of high DMS mixing ratios up to a few ppbv, which was associated with strong wind and elevated DMS but very low chlorophyll- a and relatively low dissolved oxygen contents in the surface water. It indicates that DMS accumulated in anoxic bottom water was often transferred to the overlying water column, consequently leading to elevated DMS in the atmosphere. The mean (median) molar ratio of MSA to non-seasalt sulfate was 0.41% (0.30%), which implies the major contribution of anthropogenic SO 2 to sulfur budget in the study area. The median flux of DMS from sea to air was estimated to 3.2 μm m −2 d −1 .

Variability of atmospheric dimethylsulphide over the southern Indian Ocean due to changes in ultraviolet radiation

Dimethylsulphide (DMS) is a climatically important component of global biogeochemical cycles, through its role in the sulphur cycle. Changes in ultraviolet radiation (UV) exhibit both positive and negative forcings on the dynamics of production and turnover of DMS and its precursor dimethylsulphoniopropionate (DMSP). In this study we investigate the net forcing of UV on atmospheric DMS. The work is based on a 10‐year record of observed DMS at Amsterdam Island in the southern Indian Ocean, and satellite‐based retrievals of surface UV and photosynthetically active radiation (PAR). The results show an inverse relationship between UV radiation and atmospheric DMS associated with extreme changes (defined as the greatest 5%) in daily UV, independent of changes in wind speed, sea surface temperature, and PAR.

DMS atmospheric concentrations and sulphate aerosol indirect radiative forcing: a sensitivity study to the DMS source representation and oxidation

Abstract. The global sulphur cycle has been simulated using a general circulation model with a focus on the source and oxidation of atmospheric dimethylsulphide (DMS). The sensitivity of atmospheric DMS to the oceanic DMS climatology, the parameterisation of the sea-air transfer and to the oxidant fields have been studied. The importance of additional oxidation pathways (by O3 in the gas- and aqueous-phases and by BrO in the gas phase) not incorporated in global models has also been evaluated. While three different climatologies of the oceanic DMS concentration produce rather similar global DMS fluxes to the atmosphere at 24-27 Tg S yr -1, there are large differences in the spatial and seasonal distribution. The relative contributions of OH and NO3 radicals to DMS oxidation depends critically on which oxidant fields are prescribed in the model. Oxidation by O3 appears to be significant at high latitudes in both hemispheres. Oxidation by BrO could be significant even for BrO concentrations at sub-pptv levels in the marine boundary layer. The impact of such refinements on the DMS chemistry onto the indirect radiative forcing by anthropogenic sulphate aerosols is also discussed.

Determination of the vertical flux of dimethyl sulfide by eddy correlation and atmospheric pressure ionization mass spectrometry (APIMS)

An atmospheric pressure ionization mass spectrometer (APIMS) was developed to determine atmospheric dimethyl sulfide (DMS) with a frequency high enough (25 Hz) to compute vertical fluxes in the marine boundary by eddy correlation. High precision and immunity to sample loss, fluctuations in instrument sensitivity, etc., were achieved by adding isotopically labeled DMS (d3 or d6) continuously to the manifold as an internal standard. Because mixing ratios are determined and not mass concentration, the vertical fluxes obtained did not suffer from “Webb effect” errors. High sensitivity at high humidities was achieved by efficient drying and by preheating the sampled air to about 400 °C. During the National Science Foundation (NSF) Dynamics and Chemistry of Marine Stratocumulus Phase II: Entrainment Studies (DYCOMS II) and Passing Efficiency of the Low Turbulence Inlet (PELTI) programs, DMS and d3‐DMS (or d6‐DMS) were each determined with integration times of 20 ms. From these data the ambient DMS level was computed every 40 ms. Vertical fluxes were determined with a relative precision better than 13%.

The sulfur cycle at high‐southern latitudes in the LMD‐ZT General Circulation Model

This modeling study was motivated by the recent publication of year‐round records of dimethylsulfide (DMS) and dimethylsulfoxide (DMSO) in Antarctica, completing the available series of sulfate and methanesulfonic acid (MSA). Sulfur chemistry has been incorporated in the Laboratoire de Météorologie Dynamique‐Zoom Tracers (LMD‐ZT) Atmospheric General Circulation Model (AGCM), with high‐resolution and improved physics at high‐southern latitudes. The model predicts the concentration of six major sulfur species through emissions, transport, wet and dry deposition, and chemistry in both gas and aqueous phases. Model results are broadly realistic when compared with measurements in air and snow or ice, as well as to results of other modeling studies, at high‐ and middle‐southern latitudes. Atmospheric MSA concentrations are underestimated and DMSO concentrations are overestimated in summer, reflecting the lack of a DMSO heterogeneous sink leading to MSA. Experiments with various recently published estimates of the rate of this sink are reported. Although not corrected in this work, other defects are identified and discussed: DMS concentrations are underestimated in winter, MSA and non‐sea‐salt (nss) sulfate concentrations may be underestimated at the South Pole, the deposition scheme used in the model may not be adapted to polar regions, and the model does not adequately reproduces interannual variability. Oceanic DMS sources have a major contribution to the variability of sulfur in these regions. The model results suggest that in a large part of central Antarctica ground‐level atmospheric DMS concentrations are larger in winter than in summer. At high‐southern latitudes, high loads of DMS and DMSO are found and the main chemical sink of sulfur dioxide (SO2) is aqueous oxidation by ozone (O3), whereas oxidation by hydrogen peroxide (H2O2) dominates at the global scale. A comprehensive modeled sulfur budget of Antarctica is provided.

Interannual variability of methanesulfonate in rainwater at Amsterdam Island (Southern Indian Ocean)

Methanesulfonate (MS −), an exclusive oxidation product of dimethylsulfide (DMS), has been analyzed in rainwater at Amsterdam Island (37°50′S 77°32′E) in the Southern Indian Ocean from 1991 to 1999. Rainwater MS − concentrations range from 0.004 to 4.59 μmol l −1 with a volume weighted mean value of 0.24 μmol l −1 and present a well distinguished seasonal variation with higher values in summer, in line with the seasonal variation of its gaseous precursor (DMS), which was measured on a daily basis since 1990. The interannual variability of MS − in rainwater follows closely that of DMS, indicating that MS − in rainwater can be used as a surrogate to study long-term variations of atmospheric DMS, and further confirms the findings of Sciare et al. (J. Geophys. Res. 105 (2000a) 26 369), that large-scale anomalies occurred in the biogenic sulfur cycle in the Southern Indian Ocean during the studied period. Furthermore, on a monthly basis, the MS − anomalies in the rainwater were found to be closely related to sea-surface temperature (SST) anomalies. The correlation between MS − and SST is consistent with that observed between gaseous DMS and SST in the area and indicates an important coupling between the oceanic and the atmospheric compartments of the biogeochemical sulfur cycle.

Performance characteristics and applications of a proton transfer reaction-mass spectrometer for measuring volatile organic compounds in ambient air.

Data illustrating the performance characteristics of a proton transfer reaction-mass spectrometer (PTR-MS) under both laboratory and field conditions are presented. Under laboratory conditions, we demonstrate that PTR-MS measures (within 10%) a 2.6 ppbv concentration of gaseous dimethyl sulfide. Using a stepwise dilution of a gaseous isoprene standard, we demonstrate the linearity of the response of PTR-MS across 3 orders of magnitude of mixing ratios, from 100 ppbv to less than 100 pptv. By combining this data set with that of its monosubstituted 13C isotopic analogue, we demonstrate the ability of the instrumentto reliably measure concentrations as low as approximately 50 pptv and to detect concentrations at significantly lower levels. We conclude our laboratory characterization by investigating the components of the instrument noise signal (drift, mean, and range) and develop an expression (noise statistic) that reliably predicts the instrumental noise associated with any signal across a wide range of masses. In the field, we deployed a PTR-MS at a clean-air coastal site and an urban kerbside monitoring station to demonstrate the measurement of atmospheric dimethyl sulfide and benzene concentrations, respectively. At both sites, we were able to monitor diurnal variations in concentrations at unprecedented temporal resolutions (<5 min between successive measurements). We then demonstrate how the noise statistic can be applied to enable real fluctuations in atmospheric VOC concentrations to be reliably distinguished from instrument noise. We conclude by demonstrating how PTR-MS can be used to measure real-time VOC emission rate changes from vegetation in response to external forcing by examining the effect varying photon-flux density has upon emissions of isoprene from a Sitka spruce tree.

Chemical Assessment of Oceanic and Terrestrial Sulfur in the Marine Boundary Layer over the Northern North Pacific during Summer

Dimethylsulfide (DMS) in surface seawater and the air, methanesulfonic acid (MSA) and non-sea-salt sulfate (nss-SO4 2−) in aerosol, and radon-222 (Rn-222) were measured in the northern North Pacific, including the Bering Sea, during summer (13 July – 6 September 1997). The mean atmospheric DMS concentrations in the eastern region (21.0 ± 5.8 nmole/m3 (mean ± S.D.), n=30) and Bering Sea (19.9 ± 9.8 nmole/m3, n=10) were higher than that in the western region (11.1 ± 6.4 nmole/m3, n=31) (p<0.05), although these regions did not significantly differ in the mean DMS concentration in surface seawater. Mean sea-to-air DMS flux in the eastern region (21.0 ± 10.4 μ mole/m2/day, n=19) was larger than those in the western region (11.3 ± 16.9 μ mole /m2/day, n=22) and Bering Sea (11.2 ± 7.8 μ mole/m2/day, n=7) (p<0.05). This suggests that the longitudinal difference in atmospheric DMS was produced by that in DMS flux owing to wind speed, while the possible causes of the higher DMS concentrations in the Bering Sea include (1) later DMS oxidation rates, (2) lower heights of the marine boundary layer, and (3) more inactive convection. The mean MSA concentrations in the eastern region (1.18 ± 0.84 nmole/m3, n=35) and Bering Sea (1.17 ± 0.87 nmole/m3, n=13) were higher than that in the western region (0.49 ± 0.25 nmole/m3, n=28) (p < 0.05). Thus the distribution of MSA was similar to that of DMS, while the nss-SO4 2− concentrations were higher near the continent. This suggests that nss-SO4 2− concentrations were regionally influenced by anthropogenic sulfur input, because the distribution of nss-SO4 2− was similar to that of Rn-222 used as a tracer of continental air masses.

DMS and SO2 at Baring Head, New Zealand: Implications for the Yield of SO2 from DMS

Atmospheric dimethyl sulfide (DMS) and sulfur dioxide (SO2) concentrations were measured at Baring Head, New Zealandduring February and March 2000. Anti-correlated DMS and SO2 diurnalcycles, consistent with the photochemical production of SO2 from DMS, were observed in clean southerly air off the ocean. The data is used to infer a yield of SO2 from DMS oxidation. The estimated yields are highly dependent on assumptions about the DMS oxidation rate. Fitting the measured data in a photochemical box model using model-generated OH levels and the Hynes et al. (1986) DMS + OH rate constant suggests that theSO2 yield is 50–100%, similar to current estimates for the tropical Pacific.However, the observed amplitude of the DMS diurnal cycle suggests that the oxidation rate is higher than that used by the model, and therefore, that theSO2 yield is lower in the range of 20–40%.

Sulfur chemistry over the central Arctic Ocean during the summer: Gas‐to‐particle transformation

Atmospheric gas‐to‐particle transformation of the oxidation products of dimethyl sulfide (DMS) was investigated over the central Arctic Ocean by using observational data and a coupled gas phase chemistry‐aerosol dynamics model. Chemical compounds investigated were sulfuric acid (H2SO4(g)), methasulfonic acid (MSA(g)), and sulfur dioxide (SO2(g)) in the gas phase, and non‐sea‐salt sulfate (nss‐SO42−) and MSA in the particulate phase. During the advection from the open ocean to over the pack ice region, the particulate phase was found to be influenced significantly by three processes: (1) rapid removal of particulate matter during the first 1–2 days of advection, (2) continual formation of particulate nss‐SO42− and MSA, and (3) local production of particles consisting mostly of matter other than nss‐SO42− and MSA over the pack ice. In the absence of clouds and fogs, the principal sink for the vapors H2SO4(g) and MSA(g) were their condensational transport to submicron particles. SO2(g) was influenced significantly by both dry deposition and gas phase oxidation. Although there is a local source of coarse sea‐salt particles within the pack ice region, the role of these particles in the budgets of nss‐SO42− and SO2(g), and probably also in the budget of MSA, is only minor, especially when compared with marine regions at lower latitudes. The performance of the DMS gas‐phase chemistry scheme was tested against field data using a measurement case influenced minimally by clouds/fogs and the free troposphere. The predicted concentration of nss‐SO42− was within the uncertainties of the analysis, whereas that of MSA was high by a factor of 3–6. This demonstrates that not only heterogeneous reactions involved in atmospheric DMS chemistry but also certain gas‐phase reactions require further investigation.