Publications associées à Ours blanc

Untangling the influence of Antarctic and Southern Ocean life on clouds

Julia Schmale, Hélène Paule Angot, Jenny Thomas, 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

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

A Case Study on Drivers of the Isotopic Composition of Water Vapor at the Coast of East Antarctica

Michael Lehning, Armin Sigmund, Riqo Chaar

Stable water isotopes (SWIs) contain valuable information on the past climate and phase changes in the hydrologic cycle. Recently, vapor measurements in the polar regions have provided new insights into the effects of snow-related and atmospheric processes ...

AMER GEOPHYSICAL UNION2023

Aerobiology over the Southern Ocean – implications for bacterial colonization of Antarctica

Julia Schmale

Parts of the Antarctic are experiencing dramatic ecosystem change due to rapid and record warming, which may weaken biogeographic boundaries and dispersal barriers, increasing the risks of biological invasions. In this study, we collected air samples from ...

2022

Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) – concept and initial results

Julia Schmale, Imad El Haddad, Jakob Boyd Pernov, Jenny Thomas

The role of polar regions is increasing in terms of megatrends such as globalization, new transport routes, demography, and the use of natural resources with consequent effects on regional and transported pollutant concentrations. We set up the ERA-PLANET ...

Copernicus Publications2020

Bacteria: Driving polar growth

Neeraj Dhar

Profiling the phenotype of 200,000 mutants revealed a new cofactor that may help a group of rod-shaped bacteria elongate and grow. ...

2020

A biphasic growth model for cell pole elongation in mycobacteria

Georg Fantner, John McKinney, Haig Alexander Eskandarian, Mélanie Thérèse Marie Hannebelle, Chiara Toniolo, Joëlle Xiao Yuan Ven, Gaëlle Madeleine Vuaridel

Mycobacteria grow by inserting new cell wall material in discrete zones at the cell poles. This pattern implies that polar growth zones must be assembled de novo at each division, but the mechanisms that control the initiation of new pole growth are unknow ...

Nature Research2020

Fostering multidisciplinary research on interactions between chemistry, biology, and physics within the coupled cryosphere-atmosphere system

Julia Schmale, Jenny Thomas, Markus Frey

The cryosphere, which comprises a large portion of Earth's surface, is rapidly changing as a consequence of global climate change. Ice, snow, and frozen ground in the polar and alpine regions of the planet are known to directly impact atmospheric compositi ...

2019

Energetics of Radiatively Heated Ice-Covered Lakes

Alfred Johny Wüest, Damien Bouffard, Hugo Nicolás Ulloa Sánchez, Kraig Bates Winters

We derive the mechanical energy budget for shallow, ice-covered lakes energized by penetrative solar radiation. Radiation increases the available and background components of the potential energy at different rates. Available potential energy drives under- ...

2019

Transitions in the wintertime near-surface temperature inversion at Dome C, Antarctica

Etienne Gabriel Henri Vignon

In this work we study the dynamics of the surface-based temperature inversion over the Antarctic Plateau during the polar winter. Using 6 years of observations from the French-Italian Antarctic station Concordia at Dome C, we investigate sudden regime tran ...

2019

Wind tunnel experiments: saltation is necessary for wind-packing

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

Wind-packed snow in the form of slabs or crusts is an important part of alpine and polar snow covers. Yet, the formation process of such layers is poorly understood. For example, it remains unclear whether drifting snow is necessary for wind-packing or not ...

International Glaciological Society2017

The effect of abrupt climatic warming on biogeochemical cycling and N2O emissions in a terrestrial ecosystem

Jed Oliver Kaplan, Mirjam Pfeiffer

The large, rapid increase in atmospheric N2O concentrations that occurred concurrent with the abrupt warming at the end of the Last Glacial period might have been the result of a reorganization in global biogeochemical cycles. To explore the sensitivity of ...

Elsevier Science Bv2013

Response of terrestrial N2O and NOx emissions to abrupt climate change

Jed Oliver Kaplan, Mirjam Pfeiffer

Being a potent greenhouse gas, N2O emitted by the terrestrial biosphere during abrupt climate change events could have amplified externally forced warming. To investigate this possibility, we tested the sensitivity of terrestrial N2O emissions to an abrupt ...

2010