منابع مشابه
Noctilucent clouds and the mesospheric water vapour
The topic of this paper is the expected (from modelling) and observed sensitivity of the brightness β of noctilucent clouds (NLC) on the ambient water vapour mixing ratio f (H 2 O). Firstly, we show that state-of-the-art models of NLC layer formation predict that in the Arctic summer, a 10% increase of f (H 2 O) in the upper mesosphere should 5 lead to a 22% increase in β. Secondly, we review o...
متن کاملNoctilucent clouds and the mesospheric water vapour: the past decade
The topic of this paper is the sensitivity of the brightness of noctilucent clouds (NLC) on the ambient water vapour mixing ratio f(H2O). Firstly, we use state-of-the-art models of NLC layer formation to predict NLC brightness changes in response to changes in the 80 km mixing ratio f(H2O) for the two cases of ground-based 532 nm lidar observations at 69 N and for hemispheric satellite SBUV obs...
متن کاملReal-Time Global Illumination in Point Clouds
In this paper we present a real-time global illumination approach for illuminating scenes containing huge point clouds. Our GI approach is based upon the distribution of Virtual Point Lights (VPLs) in the scene, which are then used for the indirect illumination of the scene geometry, using Imperfect Shadow Maps for visibility calculation of the VPLs. We are able to render multiple indirect ligh...
متن کاملHh Illumination of Clumps within Molecular Clouds
Molecular clouds are clumpy. Much of the clumpiness is unresolved by single-dish telescopes but is apparent in the data from array telescopes. Even in the unresolved observational data, the existence of clumpiness can be inferred from the distribution of molecular species. This evidence requires that “early-time” molecular species are widespread, while “late-time” species are more confined, and...
متن کاملFirst observations of noctilucent clouds by lidar at Svalbard, 78 N
In summer 2001 a potassium lidar was installed near Longyearbyen (78 N) on the north polar island of Spitsbergen which is part of the archipelago Svalbard. At the same place a series of meteorological rockets (“falling spheres”, FS) were launched which gave temperatures from the lower thermosphere to the stratosphere. The potassium lidar is capable of detecting noctilucent clouds (NLCs) and of ...
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ژورنال
عنوان ژورنال: Physics Today
سال: 2005
ISSN: 0031-9228,1945-0699
DOI: 10.1063/1.1897550