Spatial scale

The spatial scale of a stationary network is determined by monitoring objectives. Spatial scales include microscale (1-100 m), middle scale (100 m-0.5 km), neighborhood scale (0.5-4.0 km), urban scale (4-50 km), and regional scale (tens to hundreds of km). Table 15-1 shows the relationship between spatial scale and monitoring objectives (1). 

The mechanism of Self-organized criticality, a concept first introduced by Bak, Tang and Wiesenfeld [bak87a], may possibly provide a fundamental link between such temporal scale invariant phenomena and phenomena exhibiting a spatial scale invariance - familiar examples of which are given by fractal coastlines, mountain landscapes and cloud formations [mandel82],... 

Interferometry in astronomy is used to surpass the limitations on angular resolution set by the Earth s atmosphere (i. e., speckle interferometry), or by the diffraction of the aperture of a single telescope. We will focus in this lecture on interferometry with multiple telescope arrays with which it is possible to obtain information on spatial scales of the source beyond the diffraction limit of its member telescopes. 

The global system studies described by NASA (4) were presented to illustrate the variation in inputs and outputs, temporal and spatial scales, processes, and boundary interfaces associated with different aspects of global environmental studies. The reader should attempt to define these same characteristics for each paper in this volume. I will try to suggest important connections that may be of interest in these papers. How do each of these papers contribute to the understanding of global environmental chemistry What piece of the overall puzzle is provided by each of these papers Can the finding of each paper be tailored to form a piece in a different puzzle ... 

Budgets and cycles can be considered on very different spatial scales. In this book we concentrate on global, hemispheric and regional scales. The choice of a suitable scale (i.e. the size of the reservoirs), is determined by the goals of the analysis as well as by the homogeneity of the spatial distribution. For example, in carbon cycle models it is reasonable to consider the atmosphere as one reservoir (the concentration of CO2 in the atmosphere is fairly uniform). On the other hand, oceanic carbon content and carbon exchange processes exhibit large spatial variations and it is reasonable to separate the... 

The horizontal motion of the atmosphere (or wind) is characterized by four spatial scales. These, with their conventional names, are ... 

Going along with these spatial scales, we can define temporal scales as well. Micrometeoro-logic processes tend to be important for times less than an hour, mesoscale processes, up to about a day, and synoptic scale, a few days or more. 

The motions on the largest spatial scales amount to the aggregate of the world s synoptic weather systems, often called the general circulation. Both with respect to substances that have atmospheric lifetimes of a day or more and with regard to the advection of water, it is useful to depict the nature of this general circulation. The mean circulation is described to some extent in terms of the Hadley and Ferrell cells shown in Fig. 7-4. They describe a coupled circulation... 

The extreme events which have been discussed differ in their characteristic spatial scales of importance. Each event which causes wind-throw occurs on a smaller spatial scale than a pollution event, as recently seen by the very extensive scale of the Chernobyl fallout (Johnston, 1987). At an even greater scale, the projected extent of the nuclear winter will be global (Covey, 1987). Examples of this hierarchy of scales of events are shown in Table 1. 

These scales of extent define the manner in which the ideas of extreme events are applicable to agriculture and forestry. Wind-throw is a small-scale process and the forest manager must grow and manage plantation forests which will survive extreme wind speeds at the spatial scale of his plantation. The question is, how rare must this extreme event be, before it may be discounted. The answer is likely to be dominated by economics and also the longevity of the plants with a 50 year harvesting interval, it seems clear that the return periods of extreme events up to 50 years (at least) are crucial. 

Weigel BM, Wang LZ, Rasmussen PW, Butcher JT, Stewart PM, Simon TP, Wiley MJ. 2003. Relative influence of variables at multiple spatial scales on sheam macro invertebrates in the Northern Lakes and Forest ecoregion, USA. Freshwat Biol 48 1440-1461. 

Full evaluation of functionalized ceramics requires the ability to characterize the spatial variations in structure and morphology. Using NMRI, it is possible to map the underlying structure on a spatial scale of hundreds of microns. 

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