Publications related to Northern celestial hemisphere

Where is M-theory in the space of scattering amplitudes?

Andrea Guerrieri, João Miguel Augusto Penedones Fernandes

We use the S-matrix bootstrap to carve out the space of unitary, analytic, crossing symmetric and supersymmetric graviton scattering amplitudes in nine, ten and eleven dimensions. We extend and improve the numerical methods of our previous work in ten dime ...

Springer Nature2023

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

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

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

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

Graph Spectral Clustering of Convolution Artefacts in Radio Interferometric Images

Paul Hurley, Matthieu Martin Jean-André Simeoni

The starting point for deconvolution methods in radioastronomy is an estimate of the sky intensity called a dirty image. These methods rely on the telescope point-spread function so as to remove artefacts which pollute it. In this work, we show that the in ...

IEEE2019

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

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

A deep crust-mantle boundary in the asteroid 4 Vesta

Philippe Gillet, Harold Gabriel Eugène Justin Clenet

The asteroid 4 Vesta was recently found to have two large impact craters near its south pole, exposing subsurface material. Modelling suggested that surface material in the northern hemisphere of Vesta came from a depth of about 20 kilometres, whereas the ...

Nature Publishing Group2014

OBSERVATION OF ANISOTROPY IN THE GALACTIC COSMIC-RAY ARRIVAL DIRECTIONS AT 400 TeV WITH ICECUBE

Shirit Cohen, Mathieu Ribordy, Matthias Wolf, Xiaoxia Bai

In this paper we report the first observation in the Southern hemisphere of an energy dependence in the Galactic cosmic-ray anisotropy up to a few hundred TeV. This measurement was performed using cosmic-ray-induced muons recorded by the partially deployed ...

2012

OBSERVATION OF ANISOTROPY IN THE ARRIVAL DIRECTIONS OF GALACTIC COSMIC RAYS AT MULTIPLE ANGULAR SCALES WITH IceCube

Shirit Cohen, Mathieu Ribordy, Matthias Wolf, Xiaoxia Bai

Between 2009 May and 2010 May, the IceCube neutrino detector at the South Pole recorded 32 billion muons generated in air showers produced by cosmic rays with a median energy of 20 TeV. With a data set of this size, it is possible to probe the southern sky ...

2011

Extreme events in total ozone over Arosa---Part 2: Fingerprints of atmospheric dynamics and chemistry and effects on mean values and long-term changes

Anthony Christopher Davison

In this study the frequency of days with extreme low (termed ELOs) and extreme high (termed EHOs) total ozone values and their influence on mean values and trends are analyzed for the world's longest total ozone record (Arosa, Switzerland). The results sho ...

Copernicus Publications2010

Mid- to late Holocene climate change- an overview

Jed Oliver Kaplan, Stefan Müller

The last 6000 years are of particular interest to the understanding of the Earth System because the boundary conditions of the climate system did not change dramatically (in comparison to larger glacial–interglacial changes), and because abundant, detailed ...

2008

A satellite- and model-based assessment of the 2003 Russian fires: Impact on the Arctic region

Isabelle Bey, Sylvia Generoso

In this paper, we address the issues of the representation of boreal fires in a global chemistry and transport model (GEOS-Chem) as well as their contribution to the Arctic aerosol optical thickness and black carbon (BC) deposition, with a focus on the 200 ...

2007

Alignment and signed-intensity anomalies in WMAP data

Pierre Vandergheynst, Yves Wiaux

Significant alignment and signed-intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three-year WMAP data, through a decomposition of the signal with steerable wavelets on the sphere. In addition to identifyin ...

2007

A global model study of ozone enhancement during the August 2003 heat wave in Europe

The European summer of 2003 was characterised by intense heat, prolonged isolation and suppressed ventilation of the boundary layer which, combined with large anthropogenic emissions and strong fires, resulted in a build up of an unprecedentedly high and l ...

2007