Publications de Hélène Paule Angot

Observations of high-time-resolution and size-resolved aerosol chemical composition and microphysics in the central Arctic: implications for climate-relevant particle properties

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Andrea Baccarini, Lubna Dada, Hélène Paule Angot, Jakob Boyd Pernov, Nora Bergner, Markus Frey

Aerosols play a critical role in the Arctic's radiative balance, influencing solar radiation and cloud formation. Limited observations in the central Arctic leave gaps in understanding aerosol dynamics year-round, affecting model predictions of climate-rel ...

Copernicus GmbH2025

Characteristics and effects of aerosols during blowing snow events in the central Arctic

Jian Wang, Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot, Jakob Boyd Pernov, Nora Bergner, Michael Lonardi

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’ clima ...

University of California Press2025

Characteristics and sources of fluorescent aerosols in the central Arctic Ocean

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Margarida Teles Nogueira Rolo, Hélène Paule Angot, Oliver Müller, Jakob Boyd Pernov, Nora Bergner, Alireza Moallemi, Markus Frey

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 biologic ...

2024

The annual cycle and sources of relevant aerosol precursor vapors in the central Arctic during the MOSAiC expedition

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot

In this study, we present and analyze the first continuous time series of relevant aerosol precursor vapors from the central Arctic (north of 80°N) during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. These ...

Copernicus Publications2024

Polar oceans and sea ice in a changing climate

Jenny Thomas, Julia Schmale, Hélène Paule Angot

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 Atmospher ...

2023

Cloud Condensation Nuclei (CCN) concentrations measured in the Swiss container during MOSAiC 2019/2020

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot, Nora Bergner

This dataset contains CCN concentrations at five supersaturation levels, averaged to 1 min time resolution, measured during the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to Septem ...

2023

Untangling the influence of Antarctic and Southern Ocean life on clouds

Jenny Thomas, Julia Schmale, Hélène Paule Angot, Markus Frey

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 A ...

2023

Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring

Jenny Thomas, Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

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 ...

2023

Measurements of aerosol microphysical and chemical properties in the central Arctic atmosphere during MOSAiC

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot, Nora Bergner

The Arctic environment is transforming rapidly due to climate change. Aerosols’ abundance and physicochemical characteristics play a crucial, yet uncertain, role in these changes due to their influence on the surface energy budget through direct interactio ...

2023

Bulk size-resolved chemical composition and mass concentration of non-refractory submicron aerosols measured in the Swiss container during MOSAiC 2019/2020

Benjamin Jérémy Laurent Heutte, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot, Imad El Haddad

This dataset contains the bulk size-resolved chemical composition and mass concentration of non-refractory submicron aerosols (NR-PM1) measured during the MOSAiC expedition from October 2019 to July 2020. These include the mass concentrations of sulfate (S ...

Zenodo2023

Widespread detection of chlorine oxyacids in the Arctic atmosphere

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Observations are reported of HClO3 and HClO4 in the atmosphere and their widespread occurrence over the pan-Arctic during spring, providing further insights into atmospheric chlorine cycling in the polar environment. ...

Nature Portfolio2023

The Marginal Ice Zone as a dominant source region of atmospheric mercury during central Arctic summertime

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Atmospheric gaseous elemental mercury (GEM) concentrations in the Arctic exhibit a clear summertime maximum, while the origin of this peak is still a matter of debate in the community. Based on summertime observations during the Multidisciplinary drifting ...

Nature Research2023

Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features

Ilker Fer, Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot, Oliver Müller

2023

Low ozone dry deposition rates to sea ice during the MOSAiC field campaign: Implications for the Arctic boundary layer ozone budget

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

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-ro ...

2023

Pollution mask for the continuous corrected particle number concentration data in 1 min time resolution measured in the Swiss aerosol container using a whole air inlet during MOSAiC 2019/2020

Julia Schmale, Ivo Fabio Beck, Andrea Baccarini, Hélène Paule Angot

This dataset contains particle number concentrations and a pollution flag in 1 min time resolution. It is derived by the pollution detection algorithm (PDA, doi:10.5281/zenodo.5761101) based on the corrected particle number concentration data of the CPC377 ...

Zenodo2023

A full year of aerosol size distribution data from the central Arctic under an extreme positive Arctic Oscillation: insights from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition

Benjamin Jérémy Laurent Heutte, Federico Bianchi, Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot, Jakob Boyd Pernov

The Arctic environment is rapidly changing due to accelerated warming in the region. The warming trend is driving a decline in sea ice extent, which thereby enhances feedback loops in the surface energy budget in the Arctic. Arctic aerosols play an importa ...

Copernicus Publications2023

Overview of the MOSAiC expedition—Atmosphere

Thomas Krumpen, Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot, Markus Frey, Radiance Flore Aurore Calmer, Michael Lonardi

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 ic ...

2022

Substantial contribution of iodine to Arctic ozone destruction

Julia Schmale, Ivo Fabio Beck, Lubna Dada, Hélène Paule Angot

Unlike bromine, the effect of iodine chemistry on the Arctic surface ozone budget is poorly constrained. We present ship-based measurements of halogen oxides in the high Arctic boundary layer from the sunlit period of March to October 2020 and show that io ...

2022

Evidence that Pacific tuna mercury levels are driven by marine methylmercury production and anthropogenic inputs

Hélène Paule Angot

Pacific Ocean tuna is among the most-consumed seafood products but contains relatively high levels of the neurotoxin methylmercury. Limited observations suggest tuna mercury levels vary in space and time, yet the drivers are not well understood. Here, we m ...

National Academy of Sciences2022

Arctic mercury cycling

Hélène Paule Angot

Anthropogenic mercury (Hg) emissions have driven marked increases in Arctic Hg levels, which are now being impacted by regional warming, with uncertain ecological consequences. This Review presents a comprehensive assessment of the present-day total Hg mas ...

2022