Local Climatic Factors Research Articles

The mosque: history, architectural development & regional diversity

This book, with contributions by 16 eminent scholars, traces the history and development of the mosque since its origins in Medina in the time of the Prophet Muhammad, explaining its traditional religious and teaching role in Muslim society, as well as its architectural and decorative features. The historical development of the mosque and its architecture is presented region by region, from North Africa to Southeast Asia, taking into account local building materials, climatic factors, and craft skills, as well as the cultural influences and major political developments, such as the rise of the Ottoman and Mughal Empires. The physical form of the mosque is analysed and fully illustrated with plans and photographs; its modern role as a religious and social institution is reviewed; and contemporary mosques worldwide are discussed in a separate chapter, encompassing not only those built by leading Muslim architects, but also those designed by Western architects. Illustrated with much unfamiliar pictorial material drawn from a wide range of sources, this book provides a comprehensive coverage of the architecture of the mosque, and also serves as a guide to an understanding of its role in Muslim society and culture. Martin Frishman is an architect and a lecturer at University College, London. Hasan-Uddin Khan is an architect, writer and former Director of Special Projects and Public Education at the Aga Khan Trust for Culture, Geneva. Both are specialists in Islamic Architecture.

Development of Sphagnum-dominated peatlands in boreal continental Canada

Peat cores from five Sphagnum-dominated peatlands in boreal continental Canada were analyzed for plant macro fossils. Results indicate that peatland development was influenced both by local autogenic and regional climatic factors. The general direction in peatland development from rich fen to poor fen to bog can primarily be ascribed to internal processes, especially peat accumulation. Quantitative paleoenvironmental reconstructions based on fossil moss assemblages indicate that all five peatlands were initially dominated by brown mosses with inferred pHs of approximately 6.0, and a water table at 5–15 cm below the surface of the peatland. Subsequently, Sphagnum-dominated peatlands developed with pHs of 4.0–4.5 and a water table at 15–30 cm of depth. Chemical factors triggered a rapid transition from rich fen (pH > 6) to poor fen and bog (Ph < 5). The two most southerly peatlands are youngest, with basal dates of 4670 BP and 4230 BP. Sphagnum peat accumulation at these sites started at 2620 BP and 1790 BP, respectively. Two sites located at intermediate latitudes have basal dates of > 5140 BP and 5020 BP, while the development of Sphagnum-dominated ecosystems dates back to ≈ 3100 BP and 3710 BP, respectively. The most northerly site has the oldest basal date (> 7870 BP), and the oldest date for the initiation of Sphagnum peat accumulation (≈ 7000 BP). The younger age of the peat deposits in the four southern sites is due to warm and dry climatic conditions during the middle Holocene that prevented peatland development until after 6000 BP when the climate gradually became cooler and moister. Farther north the climate was cool and moist enough to allow peatland development during the early to middle Holocene. In three southern peatlands, the development into a Sphagnum-dominated ecosystem took > 2000 years, while at the more northerly sites Sphagnum became dominant after < 1500 years. Key words: Sphagnum, peatlands, boreal, Holocene, climate.

An Altitudinal Zonation of Tropical Rain Forests Using Byrophytes

Recent studies on the cover, phytomass and turnover of bryophytes in tropical rain forests along altitudinal transects in the high mountains of Columbia, Peru, Borneo and Papua New Guinea reveal the existence of similar altitudinal zonations in different parts of the humid Tropics. As bryophytes are excellent climate indicators, are rather few in terms of species number, have very wide geographical ranges, and are a characteristic component of the structure of the tropical rain forest, they may be useful tools for the construction of a general scheme of the altitudinal zonation of tropical rain forests. Five altitudinal belts are distinguished: the lowland forest, the submontane forest, the upper lower montane forest, the montane forest, and the subalpine forest. A comparison is made with other zonation terminologies and the elevational variations of the belts, due to local climate, latitude, and other factors, are discussed briefly.

Tide Gauge Records, Water Level Rise, and Subsidence in the Northern Gulf of Mexico

Long-term water level changes in the northern Gulf of Mexico were examined using tide gauge records for this century. Strong coherence exists between the annual mean water changes at Galveston, Texas, and (1) the relatively geologically-stable west coast of Florida, (2) global mean sea level, and 93) the subsiding Louisiana coast. Water levels at the Galveston gauge, one of the longest records (81 yr), have risen steadily, but not accelerated over the long-term. The apparent acceleration of water rise in the recent two decades is within the historical pattern, and is probably driven by regional or global, but not local climatic factors. Because eustatic sea level has risen steadily this century, the analysis supports the conclusion that regional geologic subsidence has not varied significantly over the tide gauge record (1909–1988). Variations in the estimates of subsidence in the surface layers are generally consistent with the generally accepted understanding of the geology of deltaic processes on this coast.

Subalpine heaths as an indicator of a periglacial environment

Subalpine heaths in Abisko Valley, northern Sweden, are considered an indicator of a periglacial environment. Geomorphological frost features such as active nonsorted circles, stone pits and frost-heaved stones and boulders are found on subalpine heaths. Soil studies indicate that cryoturbation and solifluction have been and are currently active on subalpine heaths. Temperature measurements show that in years with low precipitation and cold winters, ground temperature docs not rise above 0° 200 cm depth on vegetation covered sites on wet subalpine heaths. Seasonal frost processes are reinforced by local climatic factors and edaphic conditions resulting in the development and maintenance of periglacial features in environments below the tree-line.

Holocene glacier variations in New Zealand: A review

In the central Southern Alps of New Zealand, ice-surface lowering has exposed extensive sections of lateral moraines, allowing investigation of moraine stratigraphy and genesis. The presence of multiple superposed palaeosurfaces within moraine sequences allows recognition of any disturbances, displacements or contamination of till layers and interbedded organic material. Radiocarbon dating of buried wood and soils allows comparison between the Holocene glacial history of the Eastern Ranges and that of the Westland region. The periodicity of glacier response has been similar to both areas, although the precise timing of events has differed due to local climatic and environmental factors. In general, glaciers in New Zealand expanded about 5000, 4500-4200, 3700, 3500-3000, 2700-2200, 1800-1700, 1500, 1100, 900, 700-600 and 400-100 BP.

Atmospheric Turbidity at Tucson, Arizona, 1956–83: Variations and Their Causes

Abstract Solar radiation data collected over the last 27 years at the University of Arizona have been analyzed to determine the major causes of time variations in the local turbidity of the atmosphere. The most extreme perturbations have been associated with significant volcanic eruptions, Agung on Bali in 1963 and, especially, El Chichon in Mexico in 1982. There is also evidence for a correlation of turbidity with local climatic factors and local smelter activity, but no detectable long-term upward or downward trend in turbidity has been observed. Routine pyrheliometric measurements were used to calculate monthly Linke turbidity factors for the period from June 1956 to June 1983 and related monthly aerosol values for the period from January 1977 to February 1983.

Further evidence for impact of solar flares on potential gradient and air-earth current characteristics at high mountain stations

For the period February 1967–May 1969, a period of increasing solar activity, unrestricted substantiation was obtained of earlier results which had indicated that subsequent to Hα-flares potential gradient and air-earth current will increase significantly. A presupposition of this result is that the atmospheric electrical elements are recorded at stations with only minimal local climatic and aerosol physical disturbance factors, and that only meteorologically undisturbed days are used. It was ascertained that the exclusive use of fine weather days is of no influence on the results. The confirmed solar-terrestrial relation is even more pronounced when measurements are based on flares in the vicinity of the central meridian of the sun. It was further substantiated that the frequency of sferics pulses is significantly increased from the flare day on. As the cause for this a solar-triggered increase in thunderstorm frequency is suggested which, in turn, leads to an increase of the potential gradient and earth current. Proton flares have an effect analogous to that of Hα-flares. If Hα-flare key days are used on which significant changes were observed in the distribution of pressure over the northern hemisphere, a significant increase of potential gradient and air-earth current is found even with these flare key days. Thus for the first time a connection is made between solar-caused atmospheric electrical effects and synchronous global meteorological changes.

Hydrogeology of Desert Basinsa

ABSTRACTHydrologic systems in arid lands normally include a recharge area in mountains and a discharge area in lowlands often with an intermediate area of lateral flow between recharge and discharge areas. This system is often modified by local geologic, climatic, and physiographic factors. Most water‐supply, contamination and disposal problems arise from a combination of features superimposed on this system by concentration of population and agricultural activity in the discharge areas. Also most of our data on the system comes from the lowlands and little data is available from the recharge areas.In the Great Basin two general categories of ground‐water flow systems are recognized: (1) local flow systems where drainage areas are usually small, flow paths are relatively short, interbasin flow is uncommon, springs have large fluctuations in discharge, water temperature is low, and concentration of Na, K, Cl, and SO4 is low, and (2) regional flow systems, where drainage areas are large, flow paths long, interbasin flow common, springs have large discharge, and the water is characteristically of higher temperature and contains higher concentrations of K, Na, Cl, and SO4. Hydrologic approaches used, in addition to conventional methods, include hydrologic budget, water‐potential, and water‐chemistry studies. Although detailed delineation of most flow systems in Nevada has not been accomplished, integration of hydrologic, geologic, and chemical methods allow approximate portrayal of many systems, both local and regional.Adequate methods upon which to base planning for optimum development of water resources in desert basins are now available. A conceptual model of optimal ground‐water reservoir development illustrates how to determine optimum use of storage and perennial yield provided the use to which the water is to be put and the time of withdrawal are known.

Genesis of Alluvial Soils in Arid and Semi-arid Tracts

The genesis of alluvial soils in arid, and semi-arid tracts of West Uttar Pradesh is reported in this paper. The analysis of clay fraction has given a clue that the clay fraction comprises a mixture of clay minerals like hydrous mica (Illite) and montmorillonite. The mineralogical analysis of fine sand fractions indicated that quartz, mien and feldspar wore the commonly occurring minorals in the light fractions and constituted moro than 95 por cent. Heavy minerals like magnetite, rutile, zircon, and apatito are found in traces. The minera- logical analysis of fino sand fractions thus indicated the origin of those alluvial soils from granitie and gneissie rocks and their further trans. port, by the action of water, to the plains. Depending upon the influence of local climatic factors and degree of weathering they have given rise to soils and clays with a mixture of clay minerala.

Flowering Sequence of a Local Flora

A study of the flowering dates of native plants has been conducted in the Swift Current, Saskatchewan, district in conjunction with range management investigations. The objects of the study were to determine the pattern of regularity of flowering dates of plants from year to year, and to assess the influence of weather on the development of species. The information obtained has been tested to forecast dates of grazing readiness of native rangelands. This report summarizes dates of flowering records for 145 species. Two reports of flowering dates of Northern Great Plains flora have been published. Criddle (1927) listed some 400 species from the vicinity of Treesbank, Manitoba, and Stevens (1956) published a list of 170 weedy plants growing in North Dakota. Both of these describe phenological observations near the eastern boundary of the Northern Great Plains and naturally the results presented are expressions of local climatic factors. Criddle presented his data as a matter of botanical interest, whereas Stevens was concerned primarily with flowering dates in relation to weed control.

A SEQUENCE OF BEECHWOOD SOILS ON THE CHILTERN HILLS, ENGLAND

SummaryThe chalk and associated superficial deposits of the Chiltern Hills give rise under beechwoods to a sequence of soils ranging from rendzina through brown earth (sol lessivé) to podzol, closely paralleled in developmental sequences established elsewhere on uniform calcareous materials. The salient features of the genetic soil types represented are described and their evolution discussed in relation to vegetation and site characteristics. On base‐deficient soils, mor formation under beech is conditioned by local climatic factors and management practices as well as by inherent fertility variations and is only associated with advanced podzolization on appreciably sandy materials. On silty plateau soils with imperfect drainage, ‘micro‐podzols’, which may be transitory, are formed.

The Lethal Temperatures of Some Common British Littoral Molluscs

The zonation of the more common British littoral molluscs is known from the work of various shore ecologists, but the causal factors which determine the vertical limits of distribution of these species between tide-marks are largely a matter of conjecture. Among what might be considered as the local climatic factors acting on intertidal organisms exposed to the air it appears that temperature, desiccation and possibly light effects are the most critical, i.e. the 'heat-lightdesiccation 'complex. In the case of organisms which inhabit permanent rock pools, the desiccation factor is eliminated, and it is likely that changes in the temperature and salinity of these pools during periods of exposure will be important. Intertidal algae have been the chief subject of investigations along these lines, and relatively few studies have been made on littoral fauna. The effect of heat, desiccation and salinity on a series of six gastropods has been studied experimentally by Broekhuysen (1940) in False Bay, South Africa, while Gowenloch & Hayes (1926) have investigated the action of certain factors of the physical environment on three species of Littorina in Canada. Little work of a similar nature seems to have been done on the British littoral molluscs, even though experimental work of this type could be used with advantage to supplement the data obtained in the field by shore ecologists. From what is already known it appears probable that the effects of temperature acting as an isolated factor (i.e. 'pure temperature effects') are of subsidiary importance to the drying action of supernormal temperatures in controlling the upper limits of distribution of littoral plants and animals. Thus in the case of the South African molluscs it was found that between the temperatures necessary to kill the snails in the laboratory and the temperatures to which they are normally subjected in their natural environment, there exists a sufficiently wide difference to rule out the possibility of heat death among these species on the shore. This principle will be examined with respect to certain British molluscs. Huntsman & Sparkes (1924) demonstrated that for marine organisms in general the degree of resistance to heat is correlated with the temperature ranges at which such species exist in nature. Gowenloch & Hayes (1926) reported that individuals of the same species (Littorina littorea, L. rudis or L. palliata) collected from different tidal levels on the shore exhibit a gradation in thermal death temperatures, i.e. a 'tidal level differentiation' exists in lethal temperatures. Henderson (1929) has shown that, among the lamellibranchs, deep-water forms are less tolerant of heat than those occurring in the lower part of the intertidal zone, that these in turn are less tolerant than upper-shore species, while lamellibranchs characteristically found in warmer waters are the most tolerant of all. Finally, Broekhuysen (1940) found that the series of thermal death points for his six gastropods is identical with the order in which these species are zoned on the shore of False Bay, L. knysnaensis, occurring to well above extreme high water of spring tides, has a lethal temperature of 48.60 C.; Oxystele sinensis, which barely reaches mean sea level, dies at 39.60; while the other four are zoned between these two species and have thermal death points intermediate between these temperatures. He also showed that, in their ability to withstand prolonged high temperatures, the six snails fall into a similar series. Furthermore Broekhuysen tabulates the lethal temperatures of a series of marine molluscs as determined by Vernon (I899), Gowenloch (1926), Gowenloch & Hayes (1926) and Henderson (1929), and concludes that 'generally speaking, the lowest lethal temperatures are found in snails inhabiting the lowest levels, while lethal temperatures increase with increasing height above low water level '. Thus, from all the evidence, it would appear that there exists a fairly definite correlation between the ability of various snails to withstand pure temperature effects and the temperatures to which they are likely to be exposed in nature. In the present paper, the results of experiments on eleven molluscs common on the shores of Cardigan Bay are described. The following species were chosen: Littorina neritoides (L.), L. rudis (Maton), L. littoralis (L.), L. littorea (L.), Gibbula cineraria (L.), G. umbilicalis (da Costa), Patella vulgata L., P. depressa Pennant, P. athletica Bean, Nucella lapillus (L.), Osilinus lineatus (da Costa). The distribution and zonation of these in Cardigan