A5003027806- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Atmospheric Ozone and Climate
- Arctic and Antarctic ice dynamics
- Polar Research and Ecology
- Climate change and permafrost
- Geology and Paleoclimatology Research
- Atmospheric aerosols and clouds
- Isotope Analysis in Ecology
- Marine and coastal ecosystems
- Methane Hydrates and Related Phenomena
- Icing and De-icing Technologies
- Ocean Acidification Effects and Responses
- Cell Image Analysis Techniques
- Per- and polyfluoroalkyl substances research
- High Altitude and Hypoxia
- Groundwater and Isotope Geochemistry
- Freezing and Crystallization Processes
- Winter Sports Injuries and Performance
- Climate variability and models
- 3D Printing in Biomedical Research
- Air Quality and Health Impacts
- Image Processing Techniques and Applications
- Nuclear physics research studies
British Antarctic Survey
2016-2025
École Polytechnique Fédérale de Lausanne
2024-2025
Natural Environment Research Council
2016-2025
National Institute for Environmental Studies
2024
Kavli Institute for Systems Neuroscience
2023
Max Planck Institute for Human Cognitive and Brain Sciences
2023
Texas A&M University
2015-2017
University of California, Merced
2006-2013
Université Grenoble Alpes
2008-2009
Laboratoire de Glaciologie et Géophysique de l’Environnement
2007-2009
Abstract. It has been shown that sunlit snow and ice plays an important role in processing atmospheric species. Photochemical production of a variety chemicals recently reported to occur snow/ice the release these photochemically generated species may significantly impact chemistry overlying atmosphere. Nitrogen oxide oxidant precursor fluxes have measured number covered environments, where some cases emissions boundary layer. For example, photochemical ozone (such as occurring polluted...
With the Arctic rapidly changing, needs to observe, understand, and model changes are essential. To support these needs, an annual cycle of observations atmospheric properties, processes, interactions were made while drifting with sea ice across central during Multidisciplinary Observatory for Study Climate (MOSAiC) expedition from October 2019 September 2020. An international team designed implemented comprehensive program document characterize all aspects system in unprecedented detail,...
Year-round observations of the physical snow and ice properties processes that govern pack evolution its interaction with atmosphere ocean were conducted during Multidisciplinary drifting Observatory for Study Arctic Climate (MOSAiC) expedition research vessel Polarstern in Ocean from October 2019 to September 2020. This work was embedded into interdisciplinary design 5 MOSAiC teams, studying atmosphere, sea ice, ocean, ecosystem, biogeochemical processes. The overall aim characterize cover...
The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from Greenland NEEM core to reconstruct environmental alterations in source regions accompanying these changes. Separating transport effects, find strongly reduced terrestrial biogenic emissions glacial times reflecting net loss of vegetated...
The spatial and temporal (event seasonal timescale) variability of major runoff components in the mountainous Brugga basin (Black Forest, Germany) were examined. mesoscale (40 km 2 ) study represented an extraordinary challenge as comparable studies have been undertaken mainly smaller headwater basins. Discharge data, tracer concentrations 18 O, 3 H, CFCs, dissolved silica, anions cations analyzed during single events over a period years. Three main defined: event water with residence time...
Satellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6 degrees S increased in mass by 45 +/- 7 billion metric tons per year from 1992 to 2003. Comparisons with contemporaneous meteorological model snowfall estimates suggest gain was associated precipitation. A this magnitude is enough slow sea-level rise 0.12 0.02 millimeters year.
Atmospheric nitrogen oxides (NOx =NO+ NO2) play a pivotal role in the cycling of reactive (ultimately deposited as nitrate) and oxidative capacity atmosphere. Combined measurements oxygen stable isotope ratios nitrate collected Arctic atmosphere were used to infer origin fate NOx on seasonal basis. In spring, photochemically driven emissions from snowpack into make local oxidation by bromine oxide major contributor budget. The comprehensive isotopic composition provides strong constraints...
The comprehensive isotopic composition of atmospheric nitrate (i.e., the simultaneous measurement all its stable isotope ratios: 15 N/ 14 N, 17 O/ 16 O and 18 O) has been determined for aerosol samples collected in marine boundary layer (MBL) over Atlantic Ocean from 65°S (Weddell Sea) to 79°N (Svalbard), along a ship‐borne latitudinal transect. In nonpolar areas, δ N mostly deriving anthropogenically emitted NO x is found be significantly different (from 0 6‰) sampled locations influenced...
Abstract. The nitrogen (δ15N) and triple oxygen (δ17O δ18O) isotopic composition of nitrate (NO3−) was measured year-round in the atmosphere snow pits at Dome C, Antarctica (DC, 75.1° S, 123.3° E), surface on a transect between DC coast. Comparison to signal atmospheric NO3− shows that is significantly enriched δ15N by >200‰ depleted δ18O <40‰. Post-depositional fractionation Δ17O(NO3−) small, potentially allowing reconstruction past shifts tropospheric oxidation pathways from ice...
Abstract. Here we report the measurement of comprehensive isotopic composition (δ15N, Δ17O and δ18O) nitrate at air–snow interface Dome C, Antarctica (DC, 75°06' S, 123°19' E), in snow pits along a transect across East Antarctic Ice Sheet (EAIS) between 66° S 78° S. In most pits, loss (either by physical release or UV photolysis nitrate) is observed fractionation constants associated are calculated. Nitrate collected from on plateau (snow accumulation rate below 50 kg m−2 a−1) displays...
Abstract. Two consecutive cruises in the Weddell Sea, Antarctica, winter 2013 provided first direct observations of sea salt aerosol (SSA) production from blowing snow above ice, thereby validating a model hypothesis to account for time SSA maxima Antarctic. Blowing or drifting often leads increases during and after storms. For it is shown that on ice depleted sulfate relative sodium with respect seawater. Similar depletion bulk sized ∼0.3–6 µm evidence most originated not open ocean leads,...
Abstract. Measurements of e-folding depth, nadir reflectivity and stratigraphy the snowpack around Concordia station (Dome C, 75.10° S, 123.31° E) were undertaken to determine wavelength dependent coefficients (350 nm 550 nm) for light scattering absorption calculate potential fluxes (depth-integrated production rates) nitrogen dioxide (NO2) from due nitrate photolysis within snowpack. The top 80 cm Dome C generally consists three main layers:- a surface soft windpack (not ubiquitous), hard...
The Carrington Event of 1859 is considered to be among the largest space weather events last 150 years. We show that only one out 14 well‐resolved ice core records from Greenland and Antarctica has a nitrate spike dated 1859. No sharp spikes are observed in Antarctic cores studied here. In numerous 40 years surrounding 1859, but where other chemistry was measured, all large have unequivocal signal, including co‐located ammonium, formate, black carbon vanillic acid, biomass burning plumes. It...
Abstract Elevated concentrations of atmospheric bromine are known to cause ozone depletion in the Arctic, which is most frequently observed during springtime. We implement a detailed description and chlorine chemistry within WRF‐Chem 4.1.1 model, two different descriptions Arctic activation: (1) heterogeneous on surface snow sea ice, triggered by deposition (Toyota et al., 2011 https://doi.org/10.5194/acp-11-3949-2011 ), (2) reactions salt aerosols emitted through sublimation lofted blowing...
Abstract. Data from the Multidisciplinary drifting Observatory for Study of Arctic Climate (MOSAiC) expedition allowed us to investigate temporal dynamics snowfall, snow accumulation and erosion in great detail almost whole season (November 2019 May 2020). We computed cumulative water equivalent (SWE) over sea ice based on depth density retrievals a SnowMicroPen approximately weekly measured depths along fixed transect paths. used derived SWE cover compare with precipitation sensors...
Abstract The Arctic warms nearly four times faster than the global average, and aerosols play an increasingly important role in climate change. In Arctic, sea salt is a major aerosol component terms of mass concentration during winter spring. However, mechanisms production remain unclear. Sea are typically thought to be relatively large size but low number concentration, implying that their influence on cloud condensation nuclei population properties generally minor. Here we present...
Abstract Natural aerosols and their interactions with clouds remain an important uncertainty within climate models, especially at the poles. Here, we study behavior of sea salt (SSaer) in Arctic Antarctic 12 models from CMIP6. We investigate driving factors that control SSaer abundances show large differences based on choice source function, representation aerosol processes atmosphere. Close to poles, CMIP6 do not match observed seasonal cycles surface concentrations, likely due absence...
Abstract. In order to reduce the uncertainty of aerosol radiative forcing in global climate models, we need better understand natural sources which are important constrain current and pre-industrial climate. Here, analyse particle number size distributions (PNSDs) collected during a year (2015) across four coastal inland Antarctic research bases (Halley, Marambio, Dome C King Sejong). We utilise k-means cluster analysis separate PNSD data into six main categories. “Nucleation” “bursting”...
Abstract. Aerosols play a critical role in the Arctic's radiative balance, influencing solar radiation and cloud formation. Limited observations central Arctic leave gaps understanding aerosol dynamics year-round, affecting model predictions of climate-relevant properties. Here, we present first annual high-time-resolution submicron chemical composition during Ocean 2018 (AO2018) 2019–2020 Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expeditions. Seasonal variations mass...
Abstract An updated compilation of published and new data major-ion (Ca, Cl, K, Mg, Na, NO 3 , SO 4 ) methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, United Kingdom, States programme Finland. The comparison shows that chemistry vary up to four orders magnitude across Antarctica exhibit distinct...
Abstract. Concentrations of OH radicals and the sum peroxy radicals, RO2, were measured in boundary layer for first time on East Antarctic Plateau at Concordia Station (Dome C, 75.10° S, 123.31° E) during austral summer 2011/2012. The median concentrations RO2 3.1 × 106 molecule cm−3 9.9 cm−3, respectively. These values are comparable to those observed South Pole, confirming that elevated oxidative capacity atmospheric found Pole is not restricted but common over high plateau. At Concordia,...
Abstract. Atmospheric nitrogen oxides (NO and NO2) were observed at Dome C, East Antarctica (75.1° S, 123.3° E, 3233 m), for a total of 50 days, from 10 December 2009 to 28 January 2010. Average (±1σ) mixing ratios 1.0 m NO NO2, the latter measured first time on Antarctic Plateau, 111 (±89) 98 pptv, respectively. are average comparable those previously South Pole, but in contrast show strong diurnal variability: minimum around local noon maximum early evening coincide with development...
Abstract. Growing evidence suggests that the sea ice surface is an important source of salt aerosol and this has significant implications for polar climate atmospheric chemistry. It also potential to use core records as proxies past extent. To explore possibility in Arctic region, we a chemical transport model track emission, transport, deposition from both open ocean ice, allowing us assess relative importance each. Our results confirm (SISS) winter burden. For first time, explicitly...
Abstract. Blowing snow over sea ice has been proposed as a significant source of salt aerosol (SSA) (Yang et al., 2008). In this study, using salinity data and blowing particle measurements collected in the Weddell Sea zone (SIZ) during winter cruise, we perform comprehensive model–data comparison with aim validating parameterizations. Additionally, investigate possible physical mechanisms involved SSA production from snow. A global chemical transport model, p-TOMCAT, is used to examine...