Publications related to Southern Hemisphere

Semiclassical Estimates for Eigenvalue Means of Laplacians on Spheres

Joachim Stubbe, Luigi Provenzano, Paolo Luzzini, Davide Buoso

We compute three-term semiclassical asymptotic expansions of counting functions and Riesz-means of the eigenvalues of the Laplacian on spheres and hemispheres, for both Dirichlet and Neumann boundary conditions. Specifically for Riesz-means we prove upper ...

SPRINGER2023

Key challenges for tropospheric chemistry in the Southern Hemisphere

Julia Schmale

This commentary paper from the recently formed International Global Atmospheric Chemistry (IGAC) Southern Hemisphere Working Group outlines key issues in atmospheric composition research that particularly impact the Southern Hemisphere. In this article, we ...

2022

The first generations of stars in the Local Group

Romain Ely Roland Lucchesi

The different projects of this thesis contribute to improving our understanding of the early chemical evolution of the galaxies. The standard cosmological model states an hierarchical formation of the galaxies, the dwarf galaxies being the first stellar sy ...

EPFL2022

A mechanistic assessment of urban heat island intensities and drivers across climates

Gabriele Manoli, Ziyan Zhang

The urban heat island effect (UHI) has been widely observed globally, causing climate, health, and energy impacts in cities. The UHI intensities have been found to largely depend on background climate and the properties of the urban fabric. Yet, a complete ...

2022

Exploring the link between austral stratospheric polar vortex anomalies and surface climate in chemistry-climate models

Nora Bergner

Extreme events in the stratospheric polar vortex can lead to changes in the tropospheric circulation and impact the surface climate on a wide range of timescales. The austral stratospheric vortex shows its largest variability in spring, and a weakened pola ...

Copernicus GmbH2022

Temporary pause in the growth of atmospheric ethane and propane in 2015–2018

Hélène Paule Angot, Ilann Ernest Valentin Bourgeois

Atmospheric non-methane hydrocarbons (NMHCs) play an important role in the formation of secondary organic aerosols and ozone. After a multidecadal global decline in atmospheric mole fractions of ethane and propane – the most abundant atmospheric NMHCs – pr ...

Copernicus Publications2021

An overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project: aerosol-cloud-radiation interactions in the southeast Atlantic basin

Athanasios Nenes

Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their ...

Copernicus GmbH2021

Atmospheric mercury sources in a coastal-urban environment: a case study in Boston, Massachusetts, USA

Hélène Paule Angot

Mercury (Hg) is an environmental toxicant dangerous to human health and the environment. Its anthropogenic emissions are regulated by global, regional, and local policies. Here, we investigate Hg sources in the coastal city of Boston, the third largest met ...

2021

Simulation of long-term spatiotemporal variations in regional-scale groundwater recharge: contributions of a water budget approach in cold and humid climates

Emmanuel Qays Dubois

Groundwater recharge (GWR) is a strategic hydrologic variable, and its estimate is necessary to implement sustainable groundwater management. This is especially true in a global warming context that highly impacts key winter conditions in cold and humid cl ...

2021

3D Smith chart constant quality factor semi-circles contours for positive and negative resistance circuits

Mihai Adrian Ionescu, Andrei Müller

The article firstly proves that the constant quality factor (Q) contours for passive circuits, while represented on a 2D Smith chart, form circle arcs on a coaxal circle family. Furthermore, these circle arcs represent semi-circles families in the north he ...

2020

Cycling of zinc and its isotopes across multiple zones of the Southern Ocean: Insights from the Antarctic Circumnavigation Expedition

Christel Sybille Hassler

Zinc (Zn) is an essential micronutrient, playing an important role in several key processes in marine phytoplankton. Here, we present the first high-resolution depth profiles for dissolved Zn and delta Zn-66 from all major zones of the Southern Ocean, coll ...

2020

Unified Neural Encoding of BTFs

Wenzel Alban Jakob

Realistic rendering using discrete reflectance measurements is challenging, because arbitrary directions on the light and view hemispheres are queried at render time, incurring large memory requirements and the need for interpolation. This explains the des ...

WILEY2020

Hexachlorobenzene exerts genotoxic effects in a humpback whale cell line under stable exposure conditions

Kristin Schirmer, Jenny Maner

Humpback whales, like other polar wildlife, accumulate persistent organic pollutants. In Southern hemisphere populations, hexachlorobenzene (HCB) dominates the contaminant profiles. HCB is linked to a variety of health effects and is classified as a group ...

2019

Neural BTF Compression and Interpolation

Wenzel Alban Jakob

The Bidirectional Texture Function (BTF) is a data-driven solution to render materials with complex appearance. A typical capture contains tens of thousands of images of a material sample under varying viewing and lighting conditions. While capable of fait ...

WILEY2019

Reviews and syntheses: the GESAMP atmospheric iron deposition model intercomparison study

Athanasios Nenes

This work reports on the current status of the global modeling of iron (Fe) deposition fluxes and atmospheric concentrations and the analyses of the differences between models, as well as between models and observations. A total of four global 3-D chemistr ...

2018

Implementation of a comprehensive ice crystal formation parameterization for cirrus and mixed-phase clouds in the EMAC model (based on MESSy 2.53)

Athanasios Nenes

A comprehensive ice nucleation parameterization has been implemented in the global chemistry-climate model EMAC to improve the representation of ice crystal number concentrations (ICNCs). The parameterization of Barahona and Nenes (2009, hereafter BN09) al ...

2018

Interactions between drifting snow and surface dynamics

Philip Crivelli

In the cryosphere, the snow cover is the fastest changing component. Amongst other characteristics, the snow cover acts as a resource of water or has the ability to reflect the suns radiation and therefore significantly influence the climate on a global sc ...

EPFL2018

Impacts of Polar Changes on the UV-induced Mineralization of Terrigenous Dissolved Organic Matter

Jeremy Samuel Arey

Local climates in the Northern and Southern Hemisphere are influenced by Arctic Amplification and by interactions of the Antarctic ozone hole with climate change, respectively. Polar changes may affect hydroclimatic conditions in temperate regions, for exa ...

Amer Chemical Soc2016

Hydrological dynamics and fire history of the last 1300 years in western Siberia reconstructed from a high-resolution, ombrotrophic peat archive

Alexandre Buttler, Vincent Eric Jules Jassey, Mariusz Lamentowicz

Siberian peatlands provide records of past changes in the continental climate of Eurasia. We analyzed a core from Mukhrino mire in western Siberia to reconstruct environmental change in this region over the last 1300 years. The pollen analysis revealed lit ...

Academic Press Inc Elsevier Science2015

Nitrogen limitation and microbial diversity at the treeline

Alexandre Buttler, Julien Roy, Aurélie Thébault

Tree growth limitation at treeline has mainly been studied in terms of carbon limitation while effects and mechanisms of potential nitrogen (N) limitation are barely known, especially in the southern hemisphere. We investigated how soil abiotic properties ...

Nordic Ecological Society2014