338 research outputs found
numerical analysis defects, thermolysis, infinite cylindrical ceramic moulding
Some aspects of the meridional circulation of the atmosphere are considered. It is corroborated that: (a) the existence of the meridional circulation is primarily determined by the eddies, and (b) that the meridional circulation is set up by surface friction in the zone of the westerlies in the case of strong baroclinicity
Experiments using atmospheric forcing from a FGGE analysis to drive an upper ocean model
Results are presented of a series of numerical experiments in which an upper ocean model is driven by surface heat fluxes and stress fields derived from the FGGE SOP-1 GLAS analysis/forecast system (Halem, et al., 1982). The model results show that most changes in the mixed layer height and horizontal velocity occurs in the first days. On the other hand, changes in the temperature field take a longer time to develop. In the most realistic case (real initial conditions, instantaneous forcing fields from the atmospheric analysis), the resulting changes in temperature were larger than observed and the correlation between observed and predicted changes was poor. The deficiency in the forecast of SST changes may be due to several factors: lack of sufficient ocean resolution, improper initialization, lack of feedback between the ocean and the atmosphere and the absence of transports by the strong boundary currents, and perhaps unrealistic surface fluxes of heat and momentum. Unless these problems are alleviated it is not reasonable to perform coupled atmospheric ocean forecasts
On the Stability of the Basic East-West Velocity Flow
Instability due to the horizontal shear of the basic state velocity, V, is addressed. It is corroborated that instability happens whenever a2 VI of co variates negatively with V
Monthly and Annual Distribution of Both the Frequency of Rainy Days and Rainfall Intensity in Peninsular Malaysia
The aim of this study is to analyze both the monthly and the annual distributions
of both the frequency of rainy days and the rainfall intensity in Peninsular
Malaysia. The most relevant findings of this study may be summarized as: (a)
the monthly distribution of the frequency of rainy days is similar to the monthly
rainfall distribution at the western side of the principal mountain range; (b) an
important gradient of both the frequency of rainy days and the rainfall intensity
is recorded at the Titiwangsa mountain range where a maximum is observed at
its western side and a minimum at its eastern side; (c) the distribution of both
the frequency of rainy days and the rainfall intensity is very homogeneous from
the eastern side of the mountain range up to a distance of 50 km from the east
coast; and (d) minimum of both the frequency of rainy days and intensity
rainfall is recorded in the northwestern sector of the Peninsula during the
boreal winter
Maritime Circulation of the South China Sea: A Numerical Study
A numerical model employing the classic hydrodynamic equations of conservation of mass and momentum, vertically integrated, has been developed. The model solves the external, or barotropic, mode. The computational mode is eliminated by employing a Euler backward scheme
at every N (odd) time level. A similar model is used for issuing flood warnings of hurricanes and extra tropical storms. This type of model is also used in a variety of situations such as oil spill simulations, storm surges,
tsunamis, and tidal simulations. The aim of this investigation is to gain some insight into the circulation of the South China Sea during the NE
and SW monsoon seasons. Thus the circulation of the Malaysian EEZ has been simulated. Our results compare well with Wyrtki's (1961) observations
Stability Conditions for an Alternated Grid in Space and Time
The stability conditions of a staggered lattice in space and time are derived.
The grid used is known as the Eliassen grid (Eliassen 1956). It is shown that the
stability conditions of the shallow water wave equations, for this type of lattice,
have essentially the same stability condition as the unstaggered grid and
Arakawa's B and C lattice. Upon implementation of a leapfrog scheme in a
staggered grid in space and time, there will be no computational modes. No
smoothing is needed to compute the Coriolis (gravity wave) terms as required
in Arakawa's C (B) grid. Furthermore, the usage of an Eliassen grid halves the
computation time required in Arawaka's B or C grid (Mesinger and Arakawa
1976). Therefore, there are fundamental advantages for the usage of an
alternated grid in space and time
The Poleward Transport of Heat by the Atmosphere
A warm low pressure and a cold high pressure imply the contribution of potential energy to kinetic energy. In the tropics, this represents the typical situation of the
Hadley cell, also known as a direct cell. On the other hand, a cold low pressure and a warm high pressure indicate the contribution of the mean kinetic energy
to the mean potential energy, which represents the typical process of the Ferell cell (also referred to as an indirect cell). This paper examines the poleward heat
transport of the atmosphere. It is noted that eddies play the primary role in
poleward heat transport. Furthermore, this is the way the atmosphere
counterbalances the deficit of radiation at polar latitudes
Wind-driven circulation of Peninsular Malaysia's eastern continental shelf
In the course of this investigation, a nonlinear hydrodynamic, barotropic, numerical model for Peninsular Malaysia's eastern continental shelf has been developed. In the investigation, results of the wind driven ocean circulation are presented, with particular emphasis given to the ocean's response to the north-east (NE) and the south-west (SW) monsoon winds. Qualitatively, the results compare favorably with observations: the current flowing along the Vietnamese coast and along Peninsular Malaysia's east coast, during both monsoon seasons, is well resolved. The gyre on the South China Sea, is well resolved. It is shown that the existence of this gyre is only due to topographical effects. Quantitatively, our results, for the mass transports, along the Vietnamese coast and along Peninsular Malaysia's eastern continental shelf, are quite similar to the ones obtained in previous investigations
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