Publications de Philip Crivelli

Probing the explanation of the muon (g-2) anomaly and thermal light dark matter with the semi-visible dark photon channel

We report the results of a search for a new vector boson (A') decaying into two dark matter particles chi 1 chi 2 of different mass. The heavier chi(2) particle subsequently decays to chi 1 and an off-shell Dark Photon A'* -> e(+)e(-). For a sufficiently l ...

SPRINGER2021

Spatiotemporal dynamics of snow erosion, deposition and horizontal mass flux

Michael Lehning, Enrico Paterna, Philip Crivelli

The quantification of snow transport, both in wind tunnels and the field, apply particle counting methods limited to punctual sampling of relatively small volumes. Particle counting can only capture horizontal mass fluxes, failing to measure snow erosion o ...

2019

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

Wind tunnel observations of weak and strong snow saltation dynamics

Michael Lehning, Enrico Paterna, Philip Crivelli

Theoretical considerations suggest that saltation dynamics is dominated by either aerodynamic entrainment or by a combination of ejection and rebound at a given time and location. Calling these two regimes weak and strong saltation, respectively, we have i ...

Amer Geophysical Union2017

Decoupling of mass flux and turbulent wind fluctuations in drifting snow

Michael Lehning, Enrico Paterna, Philip Crivelli

The wind-driven redistribution of snow has a significant impact on the climate and mass balance of polar and mountainous regions. Locally, it shapes the snow surface, producing dunes and sastrugi. Sediment transport has been mainly represented as a functio ...

Amer Geophysical Union2016

Quantifying Particle Numbers and Mass Flux in Drifting Snow

Michael Lehning, Enrico Paterna, Philip Crivelli

We compare two of the most common methods of quantifying mass flux, particle numbers and particle-size distribution for drifting snow events, the snow-particle counter (SPC), a laser-diode-based particle detector, and particle tracking velocimetry based on ...

2016

Wind tunnel experiments: cold-air pooling and atmospheric decoupling above a melting snow patch

Michael Lehning, Enrico Paterna, Philip Crivelli

The longevity of perennial snowfields is not fully understood, but it is known that strong atmospheric stability and thus boundary-layer decoupling limit the amount of (sensible and latent) heat that can be transmitted from the atmosphere to the snow surfa ...

Copernicus GmbH2016