相关论文: Study of the winter 2005 Antarctica polar vortex
Winds in Titan's lower and middle atmosphere have been determined by a variety of techniques, including direct measurements from the Huygens Probe over 0-150 km, Doppler shifts of molecular spectral lines in the optical, thermal infrared…
The optical turbulence above Dome C in winter is mainly concentrated in the first tens of meters above the ground. Properties of this so-called surface layer (SL) were investigated during the period 2007-2012 by a set of sonics anemometers…
Atmospherical mesoscale models can offer unique potentialities to characterize and discriminate potential astronomical sites. Our team has recently completely validated the Meso-Nh model above Dome C (Lascaux et al. 2009, 2010). Using all…
Recent studies revealed viewing-angle-dependent color and spectral trends in brown dwarfs, as well as long-term photometric variability (~100 hr). The origins of these trends are yet unexplained. Here, we propose that these seemingly…
Over recent decades, the Arctic Ocean has experienced dramatic changes due to climate change. Retreating sea ice has opened up large areas of ocean, resulting in an enhanced wave climate. Taking into account the intense seasonality and the…
Seeing, the angular size of stellar images blurred by atmospheric turbulence, is a critical parameter used to assess the quality of astronomical sites. Median values at the best mid-latitude sites are generally in the range of…
We analyse the potential vorticity of Saturn's polar regions, as it is a fundamental dynamical tracer that enables us to improve our understanding of the dynamics of these regions and their seasonal variability. In particular, we present…
We report site testing results obtained in night-time during the polar autumn and winter at Dome C. These results were collected during the first Concordia winterover by A. Agabi. They are based upon seeing and isoplanatic angle monitoring,…
The variation in the Arctic sea ice is dominated by the seasonal cycle with little inter-annual correlation. Though the mean sea ice area has decreased steadily in the period of satellite observations, a dramatic transition in the dynamics…
The winter polar vortices on Mars are annular in terms of their potential vorticity (PV) structure, a phenomenon identified in observations, reanalysis and some numerical simulations. Some recent modeling studies have proposed that…
The recent discovery of exceptional seeing conditions at Dome C, Antarctica, raises the possibility of constructing an optical observatory there with unique capabilities. However, little is known from an astronomer's perspective about the…
We propose a simple experiment to determine whether vortices persist above the superconducting transition temperature Tc in the pseudogap phase of high temperature cuprate superconductors. This involves using a magnetic dot to stabilize a…
The low infrared background and high atmospheric transparency are the principal advantages of Antarctic Plateau sites for astronomy. However, the poor seeing (between one and three arcseconds) negates much of the sensitivity improvements…
The Venus thermal radiation spectrum exhibits the signature of $CO_2$ absorption bands. By means of inversion techniques, those bands enable the retrieval of atmospheric temperature profiles. We have analyzed VIRTIS-M-IR night-side data…
High temporal resolution in--situ measurements of pancake ice drift are presented, from a pair of buoys deployed on floes in the Antarctic marginal ice zone during the winter sea ice expansion, over nine days in which the region was…
Energy dissipation and pressure fluctuations are features inherent to turbulent fluid motion, and the internal origin of spatial and temporal temperature fluctuations. By measuring local velocity, pressure or temperature, it is possible to…
The polar vortices play a crucial role in the formation of the ozone hole and can cause severe weather anomalies. Their boundaries, known as the vortex `edges', are typically identified via methods that are either frame-dependent or return…
Since the beginning of satellite observations, the Arctic sea ice extent has shown a downward trend. The decline has been weaker in the March maximum than in the September minimum and masked by inter-annual fluctuations. One of the less…
We present observations of Uranus in northern spring with the VLA from 0.7 cm to 5 cm. These observations reveal details in thermal emission from Uranus' north pole at 10s of bars, including a dark collar near 80N and a bright spot at the…
The polar cyclone at Jupiter's south pole and the five cyclones surrounding it oscillate in position and interact. These cyclones, observed since 2016 by NASA's Juno mission, present a unique opportunity to study vortex dynamics and…