Showing papers on "Secondary circulation published in 1996"
TL;DR: In this article, the authors describe the three-dimensional circulation in a barotropic island wake in shallow waters, where bottom friction generates a closed circulation characterized by a strong upwelling (typically 10-20 m h(-1)) in the bulk of the eddy and an even larger downwelling velocity in a narrow zone along the edges of the island.
98 citations
TL;DR: In this paper, three-dimensional air velocity characteristics were measured in a full-scale, climate-controlled section of a livestock building with high airflow rate and simulated animal sensible heat.
43 citations
TL;DR: A complete yearly record (1988) of surface measurements is used to examine the atmospheric diurnal secondary circulations over the entire area of Hong Kong in conjunction with spatial and temporal variations of surface temperature, wind speed and rainfall as discussed by the authors.
Abstract: A complete yearly record (1988) of surface measurements is used to examine the atmospheric diurnal secondary circulations over the entire area of Hong Kong in conjunction with spatial and temporal variations of surface temperature, wind speed and rainfall. Evidence of atmospheric diurnal secondary circulations is found at 10 sites. The occurrence of a summer morning rainfall maximum over the coast results from the interaction of the large-scale summer monsoon and local mesoscale secondary circulations. The afternoon onshore secondary circulation accelerates the advection of warm, humid unstable air and, coupled with the upward orographic lifting, produces enhanced rainfall along windward mountain ridges.
15 citations
TL;DR: In this paper, the authors examined time series of the daily zonal variance of the Nimbus 7 limb infrared monitor of the stratosphere distributions of nitric acid vapor (HNO 3 ) mixing ratio.
Abstract: Several transport scenarios have been advanced in the literature to account for the exchange of tracers between the extratropics and tropics in the lower stratosphere. Each scenario involves a slow, net upward transport at low latitudes and varying degrees of mixing at middle latitudes plus detrainment across a subtropical region of enhanced tracer gradients. In situ observations for differentiating among these scenarios are generally lacking above about 21 km altitude. Existing satellite data sets can provide useful information throughout the lower stratosphere. In particular, we have looked for such exchange by examining time series of the daily zonal variance of the Nimbus 7 limb infrared monitor of the stratosphere distributions of nitric acid vapor (HNO 3 ) mixing ratio. This species is characterized by strong subtropical meridional gradients between about 10 and 100 hPa, which develop in response to extratropical wave activity and any associated mixing processes. The subtropical variance is a measure of that activity, its region of maximum values moving equatorward during late autumn and then relaxing and retreating in late spring. At and below the 45-hPa level there is not a clear maximum of variance at a given latitude, perhaps a result of the secondary circulation that was present during the 1978/1979 winter in response to the easterly phase of the quasi-biennial oscillation cycle. At the 30-hPa and 50-hPa levels, while we find occasions in winter when tongues of subtropical air were transported to higher latitudes, we find no clear evidence for a large-scale transport of extratropical air to lower latitudes through a subtropical region of enhanced gradients.
8 citations