Current Mesoscale Meteorological Research in the United States (1981) / Chapter Skim
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SURVEY OF CURRENT RESEARCH ON MESOSCALE METEOROLOGY
SURVEY OF CURRENT RESEARCH ON MESOSCALE METEOROLOGY
Pages 6-23
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From page 6... ...
Once a phenomenon is identified, case-study analyses help to define the phenomenon and suggest hypotheses in terms of fundamental processes. Theoretical studies seek to explain the phenomenon in terms of the evolution of the structure from an initial or basic state as a function of the boundary conditions and internal forcing mechanisms.
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From page 7... ...
In addition to the importance and value of small- and medium-sized projects, there is increasing realization among scientists that occasional major, coordinated research efforts involving scientists from all four areas of research are necessary to make major progress in understanding important atmospheric phenomena and to apply the knowledge gained to national needs. Such projects involve large computer simulation studies to help design the project; tightly organized field projects utilizing modern remote-sensing techniques as well as conventional data sources; and extensive data processing, analysis, and numerical modeling efforts after the field program to extract maximum information from the data.
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From page 8... ...
Unlike case studies of large-scale meteorological systems, which have benefited greatly by operational data bases and analyses, mesoscale observational studies generally require special measurement programs to obtain the high spatial and temporal resolution data necessary to describe the evolution and structure of the mesoscale phenomena. Most of the recent mesoscale field programs (Table 2)
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From page 11... ...
e S £ H I* o ^ cT and to assess associated hazards to aircraft To improve short-term prediction of hurricane landfall and intensity Description and understanding of the mesoscale structure of winte cyclones in the Pacific Northwest Assessment of potential t enhance winter/spring orographic precipitatioi in American River Basil includes mesoscale o"servations Determine nature and origin of storms over Lake Michigan caused by cold-air outbreaks from "anada Understanding and predictability of lee cyclogenesis and other large and mesoscale effects of an airflow over large mountain massifs ibieviations to organizations.
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From page 12... ...
2.3 MESOSCALE COMPUTER SIMULATION MODELS An extremely important area of research is the field of numerical simulation, and a large fraction of the theoretical talent in meteorology works in that field. Much progress is being made in developing and applying new approaches to the problem of artificial lateral and upper-boundary constraints (an aspect of atmospheric indivisibility)
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From page 13... ...
In principle, the basic dynamical framework of these models is very general. By altering the parameterization of the physical processes (e.g., shortwave and long-wave radiation, change of phase of water vapor, sensible and latent heat fluxes from the surface, turbulent mixing, cumulus convection, and terrain effects)
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^ •5 E g 4> " -- > 3 0. o 'ti fe E o •a N S '3 E g US fl sed to predict variates in wei modification ]
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From page 15... ...
4J c 3 CO 1 •a i DO S o Pi e3 & S 1 O 3 i a o •«-• o * 1 3 etailed cloud microelectrification, cloud modification etailed microphysics, hailstone growth, cloud electrification ropical ", ice bulk water microphysics etailed microphysics, particularly ice phase M O ropical " , mountain " ropical "u, detailed liquid microphysics physics, ice and liquid processes ailstorms, cloud :vere storms :vere storms ailstorms Drnado genesis a 1 | Q as Q H Q on H V >_, H H H CO BH £ 1 >o x x X X X |
From page 16... ...
2.4 THEORETICAL STUDIES Although much of the research involving the numerical simulation models summarized in the previous section can be considered theoretical, the uncertainties in the numerical formulations (such as the finite-difference equations or boundary conditions) set this method of theoretical analysis apart from analytic studies in which closed mathematical solutions are obtained (usually for a physical problem that is greatly simplified compared with the ones investigated with numerical models)
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From page 17... ...
often observed in thunderstorms. 2.4.3 Nocturnal Boundary Layers Theoretical understanding of the stable, nocturnal boundary layer has lagged behind understanding of the unstable, convectively driven boundary layer.
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From page 20... ...
2.4.5 Small-Scale Convection Theoretical work on small-scale and moist convection is achieving some success through analytical studies, using limited spectral models, of the transitions between flow regimes. In laboratory experiments, a distinct sequence of flow types involving motionless conduction, steady flows, periodic flows, and turbulence is produced as the intensity of the forcing is increased.
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From page 21... ...
program, NOAA's Wave Propagation Laboratory is developing a continuous, remote-sensing profiler that determines wind profiles using the radars mentioned above and defines temperature and humidity profiles using microwave radiometers similar to those operating on satellites. Total water vapor and liquid-water content are observed using another microwave radiometer.
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From page 22... ...
At this stage in our conceptual and theoretical understanding of mesoscale weather systems and their structure and dynamics, it is difficult to analyze and interpret completely a comprehensive set of observational data. However, interactive data processing and display tools greatly simplify the task of synthesizing the information content of various meteorological fields and cloud and radar imagery.
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From page 23... ...
Arrangements to allow selective request-reply services and "targeted" broadcasting are under test by industry. It is up to the meteorological and hydrological communities to develop information products that are suited to these future dissemination systems.
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