منابع مشابه
Near-infrared spectroscopy of powerful compact steep-spectrum radio sources
We have obtained near-infrared spectroscopy of a small sample of powerful Compact Steep-Spectrum (CSS) radio sources mainly, but not exclusively, from the 3CR sample. We find no differences between the distributions in the equivalent width and luminosity of the [Oiii]5007 line for our sample and other larger, presumably older, high-redshift 3C objects, suggesting that the underlying quasar lumi...
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For over one hundred years it has been known that atmospheric depressions have cold frontal regions in which typically the temperature falls rapidly, the wind changes, and precipitation occurs. Sixty years ago Norwegian meteorologists shaped their polar front model in which depressions were considered to grow on a preexisting sloping thermal discontinuity; as the depressions grew it was conside...
متن کاملOceanic restratification forced by surface frontogenesis
Potential vorticity (PV) conservation implies a strong constraint on the time evolution of the mean density at a given depth. We show that, on an f -plane and in the absence of sources and sinks of PV, it only depends on two terms, namely the time evolution of the product between density anomaly and relative vorticity, and the vertical PV flux. This primitive-equation result, that applies at an...
متن کاملLee-side Frontogenesis in the Rocky Mountains
The development and motion of fronts associated with lee-side troughs on large mountain barriers has been investigated. These fronts differ from ordinary cold fronts in their horizontal temperature field, which is characterized by a sinusoidal thermal ridge. The thermal ridge intensifies, while remaining stationary with respect to the mountains, and moves eastward upon the approach of a Pacific...
متن کاملAn Orographic Mechanism for Rapid Frontogenesis
Observations of the New England coastal front show that the extraordinary temperature gradients are caused by ageostrophic wind deformation, that is, deformation in the vertical plane. The phenomenon is therefore an instance of rapid (non-classical) frontogenesis, a process broadly characterized by a lack of geostrophic balance between the temperature gradient and vertical wind shear. The prima...
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ژورنال
عنوان ژورنال: Tellus A: Dynamic Meteorology and Oceanography
سال: 1990
ISSN: 1600-0870
DOI: 10.3402/tellusa.v42i2.11876