Climatology measurement

See also Barometry Climate Engineering Climate Modeling Climatology Measurement and Units Meteorology Remote Sensing Temperature Measurement. 

Thermal turbulence is turbulence induced by the stability of the atmosphere. When the Earth s surface is heated by the sun s radiation, the lower layer of the atmosphere tends to rise and thermal turbulence becomes greater, especially under conditions of light wind. On clear nights with wind, heat is radiated from the Earth s surface, resulting in the cooling of the ground and the air adjacent to it. This results in extreme stabihty of the atmosphere near the Earth s surface. Under these conditions, turbulence is at a minimum. Attempts to relate different measures of turbulence of the wind (or stability of the atmosphere) to atmospheric diffusion have been made for some time. The measurement of atmospheric stabihty by temperature-difference measurements on a tower is frequently ntihzed as an indirect measure of turbulence, particularly when climatological estimates of turbulence are desired. 

Another classification of model is related to the time and space scales of interest. Ambient air quality standards are stated for measurement averaging periods varying from an hour to a year. However, for computational purposes, it is often necessary to use periods of less than an hour for a typical resolution-cell size in a model. Spatial scales of interest vary from a few tenths of a meter (e.g., for the area immediately adjacent to a roadway) up to hundreds of kilometers (e.g., in simulations that will elucidate urban-rural interactions). Large spatial scales are also warranted when multiday simulations are necessary for even a moderate-sized urban area. Under some climatologic conditions, recirculations can cause interaction of today s pollution with tomorrow s. Typical resolution specifications couple spatial scales with temporal sc es. Therefore, the full matrix of time scales and space scales is not needed, because of the dependence of time scales on space scales. Some typical categories by scale are as follows ... 

FIGURE 12.35 Monthly integrated ozone partial column in the (16- to 28-km) measured at Brazzaville (dotted line) and expected from SAGE II climatology (solid line) (adapted from Grant et al., f994). 

Thomason, L. W L. R. Poole, and T. Deshler, A Global Climatology of Stratospheric Aerosol Surface Area Density Deduced from Stratospheric Aerosol and Gas Experiment II Measurements 1984-1994, J. Geophys. Res., 102, 8967-8976 (1997). 

In the cases that accurate measurements of UV flux at the earth s surface have been published and discussed in the literature, an attenuation of UV flux (global, i.e. direct plus diffuse) is apparent for absorbing aerosols, urban or rural (see figure 3 ) [Lorente at al., 1993].The authors describe different types of aerosol according to their climatology (origin). The four cases in Barcelona, Spain correspond to ... 

Diamonds represent measured data collected under all sky conditions. The solid line represents the UV (290-325 am) irradiance calculated at local noon by means of the STAR model for cloud-free conditions as described in [5]. Climatological values of the model input parameters for both stations are used (Table 1). 

Vertical profiles of long lived trace gases can be used as a basis for the analysis of stratospheric dynamics. The structure of these profiles gives indications for vertical and horizontal transport processes, i.e. descent inside and filamentation of the vortex. An attempt of a vortex climatology describing seasonal subsidence and the position of the measured air parcels relative to the vortex centre is made by comparing the correlation of N20 mixing ratios versus PV values for different years. 

The impact of forest on the hydrology and climatology of a region must in effect be the sum of events taking place on individual forested areas, such as watersheds and basins. The interception of precipitation and evapotranspiration by the forest are major events which can be determined over a defined area. In Brazil, measurements of interception in sub-tropical forest were carried out by Freise (1934, 1936) almost fifty years ago. He found that 34% of precipitation became throughfall, 28%... 

Another approach to determining the residence time of °Pb in the atmosphere is to divide the mean air column inventory of °Pb by the flux of °Pb to the surface at a given location. This quotient yields a climatological average for the removal processes at that particular site. Graustein and Turekian (1986) used the atmospheric profiles of °Pb from Moore et al. (1973) and their own measured °Pb fluxes from soil profiles and bucket collection to obtain a value of 6 d over the central and eastern United States. As the source of Rn and thus Pb is from the ground and the major removal by precipitation is in the lower troposphere, the mean residence time is dominated by the processes of the lower troposphere. Modeling by Balkanski et al. (1993)... 

Ochumba P. B. O. (1996) Measurement of water currents, temperature, dissolved oxygen and winds on the Kenyan Lake Victoria. In The Limnology, Climatology, and Paleoclimatol-ogy of the East African Lakes (eds. T. C. Johnson and E. O. Odata). Gordon and Breach, Austraha, pp. 155-167. 

The climatological characteristics of sea states at individual positions and in all parts of the Baltic Sea are presented. Shipboard observations, measurements at fixed positions on the coast and in the open sea as well as calculations using numerical models (hindcasts) were used to calculate the characteristics. 

This climatology is also stored on the data CD. InTable 7.12, the average and extreme values of the wind and sea state in the measuring period are compiled. 

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