Concept

Brouillard

Publications associées (64)

Modeling Extreme Warm-Air Advection in the Arctic During Summer: The Effect of Mid-Latitude Pollution Inflow on Cloud Properties

Usually the Arctic is relatively free of anthropogenic influence in summer, which means that particles from natural sources can be the most significant nuclei for cloud droplets. However, this is not the case during anomalously warm-air intrusions when the ...

2021

Mixed-Phase Clouds and Precipitation in Southern Ocean Cyclones and Cloud Systems Observed Poleward of 64 degrees S by Ship-Based Cloud Radar and Lidar

Etienne Gabriel Henri Vignon

Mixed-phase clouds (MPCs), composed of both liquid and ice, are prevalent in Southern Ocean cyclones. A characterization of these clouds on fine vertical scales is required in order to understand the microphysical processes within these clouds, and for mod ...

2021

Historical Changes in Seasonal Aerosol Acidity in the Po Valley (Italy) as Inferred from Fog Water and Aerosol Measurements

Athanasios Nenes, Spyros Pandis

Acidity profoundly affects almost every aspect that shapes the composition of ambient particles and their environmental impact. Thermodynamic analysis of gas-particle composition datasets offers robust estimates of acidity, but they are not available for l ...

AMER CHEMICAL SOC2021

Pan-Arctic seasonal cycles and long-term trends of aerosol properties from ten observatories

Julia Schmale, Jakob Boyd Pernov

Even though the Arctic is remote, aerosol properties observed there are strongly influenced by anthropogenic emissions from outside the Arctic. This is particularly true for the so-called Arctic haze season (January through April). In summer (June through ...

2021

Leveraging meteorological radars to investigate the influence of atmospheric dynamics on snowfall microphysics

Josué Etienne Gehring

Precipitation is the result of a chain of meteorological processes ranging from the large- to the micro-scale. While the transport of moisture and lifting mechanisms leading to cloud formation are mostly governed by dynamical processes, the formation and g ...

EPFL2021

The impact of secondary ice production on Arctic stratocumulus

Athanasios Nenes, Georgia Sotiropoulou

In situ measurements of Arctic clouds frequently show that ice crystal number concentrations (ICNCs) are much higher than the number of available ice-nucleating particles (INPs), suggesting that secondary ice production (SIP) may be active. Here we use a L ...

COPERNICUS GESELLSCHAFT MBH2020

Size distribution of interstitial and total particles between 18 and 660 nm collected during the Arctic Ocean 2018 expedition

Julia Schmale, Andrea Baccarini

The aerosol size distribution was measured with a custom made scanning mobility particle sizer (SMPS), range 18⁠ – ⁠660 nm. Aerosols are important for a variety of reasons, one of the most prominent is that a sub-set of the aerosol population can act as cl ...

2020

The acidity of atmospheric particles and clouds

Athanasios Nenes, Tao Wang

Acidity, defined as pH, is a central component of aqueous chemistry. In the atmosphere, the acidity of condensed phases (aerosol particles, cloud water, and fog droplets) governs the phase partitioning of semivolatile gases such as HNO3, NH3, HCl, and orga ...

2020

Synoptic conditions and atmospheric moisture pathways associated with virga and precipitation over coastal Adelie Land in Antarctica

Alexis Berne, Etienne Gabriel Henri Vignon, Nicolas Jean François Jullien

Precipitation falling over the coastal regions of Antarctica often experiences low-level sublimation within the dry katabatic layer. The amount of water that reaches the ground surface is thereby considerably reduced. This paper investigates the synoptic c ...

2020

Ship-based measurements of ice nuclei concentrations over the Arctic, Atlantic, Pacific and Southern oceans

Julia Schmale, André Welti

Ambient concentrations of ice-forming particles measured during ship expeditions are collected and summarised with the aim of determining the spatial distribution and variability in ice nuclei in oceanic regions. The presented data from literature and prev ...

2020

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