Hélène Angot
Biographic Data
| ID | 6015588 |
|---|---|
| NAME | Hélène Angot |
| GIVEN NAMES | Hélène |
| FAMILY NAME | Angot |
| SIGNATURE | ANGOT H |
| AFFILIATIONS | Institut polytechnique de Grenoble |
| ORCID | 0000-0003-4673-8249 |
| VERIFIED | Yes |
| TOTAL WORKS | 19 |
| TOTAL CITATIONS | 1 |
| WORKS AS AUTHOR | 17 |
| WORKS AS EDITOR | 2 |
| FIRST PUBLICATION YEAR | 2020 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 1 |
Influence of warm and moist air intrusions on black carbon deposition and snowmelt in the central Arctic
In the central Arctic, warm and moist air intrusions (WAMIs) are increasingly prevalent during winter and spring, significantly affecting the near-surface energy budget. Here, we combine in situ observations from the 2019–2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition with model simulations to investigate the role of WAMIs in transporting pollutants and enhancing black carbon (BC) wet deposition. S…
Tara Polaris expeditions
The coupled Arctic system is in rapid transition and is set to undergo further dramatic changes over the coming decades. These changes will lead most likely to an ice-free ocean in summer, expected before mid-century. The Arctic will become more strongly influenced by atmospheric and oceanographic processes characteristic of midlatitudes, increasing the prevalence of contaminants and new biological species. This ongoing transition of the Arctic t…
Oceanography, biogeochemical cycles, and biodiversity in the Central Arctic Ocean
Climatic changes in the physical environment modulate biogeochemical cycles, biodiversity, and trophic interactions in the Central Arctic Ocean (CAO). Physical processes and sea-ice conditions are highly seasonal in the CAO and dependent on interactions that occur throughout the evolution of the upper ocean–sea ice–lower atmosphere system. Understanding these seasonal interactions is critical to comprehending and predicting the long-term trends a…
The biogenic sulfur cycle in the coupled ocean–sea ice–atmosphere system
Polar oceans and sea-ice regions are global hot spots for the production of biogenic volatile methylated sulfur (VMS) compounds: dimethyl sulfide (DMS) and methanethiol (MeSH). VMS compounds make important contributions to atmospheric particle formation and cloud property modulation, especially when polar atmospheres are pristine. As a result, the polar biogenic sulfur cycle may induce significant climate feedback in response to ongoing sea ice d…
Environmental impact assessments of scientific fieldwork as a path to sustainability
Polar environments are increasingly important to study as they are some of the regions most dramatically impacted by climate change. However, large field campaigns in these remote and sensitive regions may have impacts on both the local environment they aim to study and the global climate. Understanding the impact of such activities is necessary to weigh the costs and benefits and minimize negative impacts. This study provides the first example o…
Methane and volatile organic compounds and their influence on air quality in Boulder, Colorado
The Northern Colorado Front Range (NCFR) has a long history of air pollution problems, which include summertime ozone levels regularly exceeding the ozone National Ambient Air Quality Standard (NAAQS). The NCFR has been designated as a nonattainment area for the ozone NAAQS since 2007. Contributing factors to the elevated pollution buildup include meteorological conditions such as the mountain-valley thermal forcing that recirculates air enriched…
Melt pond CO2 dynamics and fluxes with the atmosphere in the central Arctic Ocean during the summer-to-autumn transition
Melt ponds are a common feature of the Arctic sea-ice environment during summer, and they play an important role in the exchange of heat and water vapor between the ocean and the atmosphere. We report the results of a time-series study of the CO2 dynamics within melt ponds (and nearby lead) and related fluxes with the atmosphere during the summer-to-autumn transition in the central Arctic Ocean during the Multidisciplinary drifting Observatory fo…
Characteristics and effects of aerosols during blowing snow events in the central Arctic
Sea salt aerosol (SSaer) significantly impacts aerosol-radiation and aerosol-cloud interactions, and sublimated blowing snow is hypothesized to be an important SSaer source in polar regions. Understanding blowing snow and other wind-sourced aerosols’ climate relevant properties is needed, especially during winter when Arctic amplification is greatest. However, most of our understanding of blowing snow SSaer comes from modeling studies, and direct…
Characteristics and sources of fluorescent aerosols in the central Arctic Ocean
The Arctic is sensitive to cloud radiative forcing. Due to the limited number of aerosols present throughout much of the year, cloud formation is susceptible to the presence of cloud condensation nuclei and ice nucleating particles (INPs). Primary biological aerosol particles (PBAP) contribute to INPs and can impact cloud phase, lifetime, and radiative properties. We present yearlong observations of hyperfluorescent aerosols (HFA), tracers for PB…
Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring
Near-surface mercury and ozone depletion events occur in the lowest part of the atmosphere during Arctic spring. Mercury depletion is the first step in a process that transforms long-lived elemental mercury to more reactive forms within the Arctic that are deposited to the cryosphere, ocean, and other surfaces, which can ultimately get integrated into the Arctic food web. Depletion of both mercury and ozone occur due to the presence of reactive h…
Untangling the influence of Antarctic and Southern Ocean life on clouds
Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over Antarctica and the Southern Ocean where observations are severely limited and the environment is far from anthropogenic influences. In this commentary, we outline major gaps in our knowledge, eme…
Low ozone dry deposition rates to sea ice during the MosaiC field campaign
Dry deposition to the surface is one of the main removal pathways of tropospheric ozone (O3). We quantified for the first time the impact of O3 deposition to the Arctic sea ice on the planetary boundary layer (PBL) O3 concentration and budget using year-round flux and concentration observations from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign and simulations with a single-column atmospheric chemist…
Polar oceans and sea ice in a changing climate
Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmosphere Study (SOLAS) project key focus, is essential to understanding the Earth system in the context of climate change. However, our ability to monitor the pace and magnitude of changes in the polar…
Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features
The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, they are rarely detected by standard methods, but…
Global change effects on biogeochemical mercury cycling
Past and present anthropogenic mercury (Hg) release to ecosystems causes neurotoxicity and cardiovascular disease in humans with an estimated economic cost of $117 billion USD annually. Humans are primarily exposed to Hg via the consumption of contaminated freshwater and marine fish. The UNEP Minamata Convention on Hg aims to curb Hg release to the environment and is accompanied by global Hg monitoring efforts to track its success. The biogeochem…
Overview of the MosaiC expedition
With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team desig…
Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions
From 2008 to mid-2016, there was more than a 7-fold increase in oil production and nearly a tripling of natural gas production in the Colorado Denver–Julesburg Basin (DJB). This study utilized air samples collected at the Boulder Atmospheric Observatory (BAO) tower in southwestern Weld County in the DJB to investigate atmospheric mole fraction trends of methane and volatile organic compounds (VOCs). Elevated methane and propane mole fractions and…
Seasonal gaseous elemental mercury fluxes at a terrestrial background site in south-eastern Australia
Terrestrial air-surface exchange of mercury (Hg) forms an important component of the global Hg cycle, with drivers varying across spatial and temporal scales. These drivers include substrate properties, atmospheric chemistry, and meteorological factors. Vegetation uptake represents the dominant pathway of atmospheric Hg deposition to terrestrial surfaces. This study investigated the drivers of net ecosystem exchange of gaseous elemental mercury (…
Historical mercury losses from the gold mines of Victoria, Australia
Health and ecological risks associated with the use of mercury in gold mining are well known, with much recent attention focussed on contemporary small-scale artisanal mining. Legacy tailings from historical gold mining may also present ongoing risks, as the industry used large quantities of mercury with minimal environmental regulation to limit its discharge. This occurred in both alluvial (placer) mining and in processing auriferous ores. Analy…
Global change effects on biogeochemical mercury cycling
Past and present anthropogenic mercury (Hg) release to ecosystems causes neurotoxicity and cardiovascular disease in humans with an estimated economic cost of $117 billion USD annually. Humans are primarily exposed to Hg via the consumption of contaminated freshwater and marine fish. The UNEP Minamata Convention on Hg aims to curb Hg release to the environment and is accompanied by global Hg monitoring efforts to track its success. The biogeochem…
Seasonal gaseous elemental mercury fluxes at a terrestrial background site in south-eastern Australia
Terrestrial air-surface exchange of mercury (Hg) forms an important component of the global Hg cycle, with drivers varying across spatial and temporal scales. These drivers include substrate properties, atmospheric chemistry, and meteorological factors. Vegetation uptake represents the dominant pathway of atmospheric Hg deposition to terrestrial surfaces. This study investigated the drivers of net ecosystem exchange of gaseous elemental mercury (…
Historical mercury losses from the gold mines of Victoria, Australia
Health and ecological risks associated with the use of mercury in gold mining are well known, with much recent attention focussed on contemporary small-scale artisanal mining. Legacy tailings from historical gold mining may also present ongoing risks, as the industry used large quantities of mercury with minimal environmental regulation to limit its discharge. This occurred in both alluvial (placer) mining and in processing auriferous ores. Analy…
Atmospheric oil and natural gas hydrocarbon trends in the Northern Colorado Front Range are notably smaller than inventory emissions reductions
From 2008 to mid-2016, there was more than a 7-fold increase in oil production and nearly a tripling of natural gas production in the Colorado Denver–Julesburg Basin (DJB). This study utilized air samples collected at the Boulder Atmospheric Observatory (BAO) tower in southwestern Weld County in the DJB to investigate atmospheric mole fraction trends of methane and volatile organic compounds (VOCs). Elevated methane and propane mole fractions and…
Overview of the MosaiC expedition
With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team desig…
Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring
Near-surface mercury and ozone depletion events occur in the lowest part of the atmosphere during Arctic spring. Mercury depletion is the first step in a process that transforms long-lived elemental mercury to more reactive forms within the Arctic that are deposited to the cryosphere, ocean, and other surfaces, which can ultimately get integrated into the Arctic food web. Depletion of both mercury and ozone occur due to the presence of reactive h…
Untangling the influence of Antarctic and Southern Ocean life on clouds
Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over Antarctica and the Southern Ocean where observations are severely limited and the environment is far from anthropogenic influences. In this commentary, we outline major gaps in our knowledge, eme…
Low ozone dry deposition rates to sea ice during the MosaiC field campaign
Dry deposition to the surface is one of the main removal pathways of tropospheric ozone (O3). We quantified for the first time the impact of O3 deposition to the Arctic sea ice on the planetary boundary layer (PBL) O3 concentration and budget using year-round flux and concentration observations from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) campaign and simulations with a single-column atmospheric chemist…
Polar oceans and sea ice in a changing climate
Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmosphere Study (SOLAS) project key focus, is essential to understanding the Earth system in the context of climate change. However, our ability to monitor the pace and magnitude of changes in the polar…
Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features
The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, they are rarely detected by standard methods, but…
Global change effects on biogeochemical mercury cycling
Past and present anthropogenic mercury (Hg) release to ecosystems causes neurotoxicity and cardiovascular disease in humans with an estimated economic cost of $117 billion USD annually. Humans are primarily exposed to Hg via the consumption of contaminated freshwater and marine fish. The UNEP Minamata Convention on Hg aims to curb Hg release to the environment and is accompanied by global Hg monitoring efforts to track its success. The biogeochem…
Characteristics and sources of fluorescent aerosols in the central Arctic Ocean
The Arctic is sensitive to cloud radiative forcing. Due to the limited number of aerosols present throughout much of the year, cloud formation is susceptible to the presence of cloud condensation nuclei and ice nucleating particles (INPs). Primary biological aerosol particles (PBAP) contribute to INPs and can impact cloud phase, lifetime, and radiative properties. We present yearlong observations of hyperfluorescent aerosols (HFA), tracers for PB…
Environmental impact assessments of scientific fieldwork as a path to sustainability
Polar environments are increasingly important to study as they are some of the regions most dramatically impacted by climate change. However, large field campaigns in these remote and sensitive regions may have impacts on both the local environment they aim to study and the global climate. Understanding the impact of such activities is necessary to weigh the costs and benefits and minimize negative impacts. This study provides the first example o…
Methane and volatile organic compounds and their influence on air quality in Boulder, Colorado
The Northern Colorado Front Range (NCFR) has a long history of air pollution problems, which include summertime ozone levels regularly exceeding the ozone National Ambient Air Quality Standard (NAAQS). The NCFR has been designated as a nonattainment area for the ozone NAAQS since 2007. Contributing factors to the elevated pollution buildup include meteorological conditions such as the mountain-valley thermal forcing that recirculates air enriched…
Melt pond CO2 dynamics and fluxes with the atmosphere in the central Arctic Ocean during the summer-to-autumn transition
Melt ponds are a common feature of the Arctic sea-ice environment during summer, and they play an important role in the exchange of heat and water vapor between the ocean and the atmosphere. We report the results of a time-series study of the CO2 dynamics within melt ponds (and nearby lead) and related fluxes with the atmosphere during the summer-to-autumn transition in the central Arctic Ocean during the Multidisciplinary drifting Observatory fo…
Characteristics and effects of aerosols during blowing snow events in the central Arctic
Sea salt aerosol (SSaer) significantly impacts aerosol-radiation and aerosol-cloud interactions, and sublimated blowing snow is hypothesized to be an important SSaer source in polar regions. Understanding blowing snow and other wind-sourced aerosols’ climate relevant properties is needed, especially during winter when Arctic amplification is greatest. However, most of our understanding of blowing snow SSaer comes from modeling studies, and direct…
Influence of warm and moist air intrusions on black carbon deposition and snowmelt in the central Arctic
In the central Arctic, warm and moist air intrusions (WAMIs) are increasingly prevalent during winter and spring, significantly affecting the near-surface energy budget. Here, we combine in situ observations from the 2019–2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition with model simulations to investigate the role of WAMIs in transporting pollutants and enhancing black carbon (BC) wet deposition. S…
Tara Polaris expeditions
The coupled Arctic system is in rapid transition and is set to undergo further dramatic changes over the coming decades. These changes will lead most likely to an ice-free ocean in summer, expected before mid-century. The Arctic will become more strongly influenced by atmospheric and oceanographic processes characteristic of midlatitudes, increasing the prevalence of contaminants and new biological species. This ongoing transition of the Arctic t…
Oceanography, biogeochemical cycles, and biodiversity in the Central Arctic Ocean
Climatic changes in the physical environment modulate biogeochemical cycles, biodiversity, and trophic interactions in the Central Arctic Ocean (CAO). Physical processes and sea-ice conditions are highly seasonal in the CAO and dependent on interactions that occur throughout the evolution of the upper ocean–sea ice–lower atmosphere system. Understanding these seasonal interactions is critical to comprehending and predicting the long-term trends a…
The biogenic sulfur cycle in the coupled ocean–sea ice–atmosphere system
Polar oceans and sea-ice regions are global hot spots for the production of biogenic volatile methylated sulfur (VMS) compounds: dimethyl sulfide (DMS) and methanethiol (MeSH). VMS compounds make important contributions to atmospheric particle formation and cloud property modulation, especially when polar atmospheres are pristine. As a result, the polar biogenic sulfur cycle may induce significant climate feedback in response to ongoing sea ice d…
Environmental Science (14 works) · Geology (13 works) · Arctic (10 works) · Arctic and Antarctic ice dynamics (9 works) · Geography (9 works) · Meteorology (9 works) · Oceanography (9 works) · Atmospheric chemistry and aerosols (8 works) · Climatology (8 works) · Atmospheric sciences (7 works)