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Publications associées (55)

Influence of sun cups on surface albedo of wet Alpine snowpack

Michael Lehning, Mathias Thierry Pierre Bavay, Francesca Carletti

In high elevation Alpine areas, characterised by high snow accumulation and radiation-driven melt processes, the formation of peculiar ablation features called sun cups can be observed. Sun cups likely influence the energy and mass balance of the wet snowp ...

2024

New Particle Formation Events Can Reduce Cloud Droplets in Boundary Layer Clouds at the Continental Scale

Athanasios Nenes, Spyros Pandis

New particle formation (NPF) substantially contributes to global cloud condensation nuclei (CCN), and their climate impacts. Individual NPF events are also thought to increase local CCN, cloud droplet number (CDN), and cloud albedo. High resolution simulat ...

Washington2024

Turbulence in the Strongly Heterogeneous Near-Surface Boundary Layer over Patchy Snow

Michael Lehning, Dylan Stewart Reynolds, Michael Haugeneder

The near-surface boundary layer above patchy snow cover in mountainous terrain is characterized by a highly complex interplay of various flows on multiple scales. In this study, we present data from a comprehensive field campaign that cover a period of 21 ...

2024

Shape Models of Lucy Targets (3548) Eurybates and (21900) Orus from Disk-integrated Photometry

Stephan Hellmich

We use our new light curves, along with historical data, to determine the rotation state, photometric properties, and convex shape models of the targets of the Lucy mission (3548) Eurybates and (21900) Orus. We determine a retrograde spin for both targets, ...

IOP Publishing Ltd2023

Investigation of the effects of the Greek extreme wildfires of August 2021 on air quality and spectral solar irradiance

In August 2021, a historic heatwave was recorded in Greece which resulted in extreme wildfire events that strongly affected the air quality over the city of Athens. Saharan dust was also transferred over Greece on certain days of the same period due to the ...

2023

Towards a fully physical representation of snow on Arctic sea ice using a 3D snow-atmosphere model

Michael Lehning, Adrien Michel, Mahdi Jafari, Océane Hames, Nander Wever, Marc Schneebeli Zeugin, David Nicholas Wagner

2023

Calibration of ground surface albedo models

Christophe Ballif, Pierre-Jean Alet, Arttu Matias Tuomiranta

The emergence of bifacial photovoltaics as a serious option for large-scale power generation makes the accuracy of the in-situ estimation of ground surface albedo increasingly critical. Recent studies have evaluated the performance of different models but ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Observing the Central Arctic Atmosphere and Surface with University of Colorado uncrewed aircraft systems

Julia Schmale, Radiance Flore Aurore Calmer

Over a five-month time window between March and July 2020, scientists deployed two small uncrewed aircraft systems (sUAS) to the central Arctic Ocean as part of legs three and four of the MOSAiC expedition. These sUAS were flown to measure the thermodynami ...

NATURE PORTFOLIO2022

Analyzing the effects of snow-atmosphere interactions on snow surface dynamics based on automated 3D laser scanning data

The snow surface morphology is shaped throughout a winter season by atmospheric conditions, like precipitation, wind, solar irradiance, air temperature or relative humidity. Changes in morphology affect the snow surface roughness which influences the turbu ...

2022

Comparison of particle number size distribution trends in ground measurements and climate models

Jakob Boyd Pernov

Despite a large number of studies, out of all drivers of radiative forcing, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but ...

2022

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