bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regionalization of Botswana rainfall during the 1980s using principal component analysis
Authors: van Regenmortel G. 
Published: February 2007

AbstractA regionalization of decadal rainfall for Botswana is presented. Situated on the southern African plateau, this subtropical country offers little physiographical variation on which geographical subdivision can be based. Following similar studies a varimax rotated principal component analysis was selected as the regionalization method. Nine years of rainfall (1980–1988) for 49 stations were analysed. Component loading fields, and hence regions, are interpreted in terms of the varying influence of synoptic configurations on the various parts of the country. The first component, explaining about half of the total variance, is found to be associated with the dominant position of the surface trough in summer, with which most rainfall in Botswana is associated. The other components are interpreted as variations of this primary synoptic pattern.
The distribution and transport of atmospheric water vapour over the Arctic Basin
Authors: Serreze Mark C. , Rehder Mark C. , Barry Roger G. , Kahl Jonathan D. , Zaitseva Nina A. 
Published: February 2007

AbstractA comprehensive rawinsonde archive, comprising atmospheric soundings from fixed stations, ships, and the former Soviet Union ‘North Pole’ series of drifting ice stations, is used to examine features of the distribution and transport of Arctic water vapour. Results are based on analysis of climatological, gridded seasonal and monthly fields north of 65°N of precipitable water, vertically integrated vapour fluxes, and profiles of specific humidity, vapour fluxes, temperature, and winds, compiled from objective interpolation of the quality controlled soundings. Emphasis is placed on contrasting conditions for winter and summer, with due attention paid to the potential effects of uncertainties in the rawinsonde humidity data.For zonal means, specific humidity for all seasons typically displays a surface maximum, decreasing poleward at all levels. Precipitable water (surface‐300 hPa), has winter values ranging from 3.8 mm for 65°−70°N and 1.8 mm for 80°–90°N, with annual maxima in July of 18.2 and 12.5 mm, respectively. These zonal means, however, mask large spatial variations; precipitable water for winter, spring, and autumn shows a marked equatorward increase towards the Atlantic side of the Arctic only. Minima are found over north‐east Canada during spring, summer, and autumn.Vapour fluxes tend to peak in the lower troposphere at about 850 hPa in winter, but over a broader layer in summer. During winter, the largest vertically integrated (surface‐300 hPa) zonal and meridional vapour transports are found between Iceland and Scandinavia. The Beaufort Sea and western Canada are the only regions where vertically integrated meridional fluxes are equatorward. During summer, the vertically integrated total flux (zonal plus meridional components) increases sharply over the Beaufort Sea. Equatorward meridional fluxes are again found over western Canada, with strong poleward meridional transports over the Atlantic sector.
Early instrumental weather data from Cadiz: A study of late eighteenth and early nineteenth century records
Authors: Wheeler Dennis 
Published: February 2007

AbstractThis paper examines some of the oldest instrumental records in Spain. They cover the period 1789 to 1816 for the Cádiz region and reveal strong evidence of a significant and approximately quantifiable degree of warming since those times. In contrast to the middle latitudes, greater temperature increases have occurred during the summer months. Wind records also indicate that the general circulation may have been more meridional than today.
Signals in atmospheric pressure variations from 2 to ca. 70 months: Part I, simulations by two coupled ocean—atmosphere GCMs
Authors: Hameed Sultan , Currie Robert G. , Lagrone Howard 
Published: February 2007

AbstractThe Fourier transform of daily averaged solar flux at the top of the atmosphere shows that the spectrum is discrete at all latitudes with lines at 12, 6, 4, 3, 2·4, 2 months, etc., which follows from the orbital characteristics of the Earth. Application of the Fourier transform to over 6000 monthly air pressure series simulated by two different versions of the Oregon State University (OSU) general circulation model (OSU‐GCM) shows the same structure, and world‐wide the mean contributions of 12, 6, and 4·2 month signals to total variance are 40, 10, and 4 percent, respectively. The Fourier spectra also yield significant subharmonic peaks, with periods T1 ≃ 40 and T2 ≃ 26 months, the quasi‐triennial (QTO) and quasi‐ biennial (QBO) oscillations, and with a period T3 ≃ 14 months, the atmospheric pole tide (APT). The spectra also yield evidence for a further 33 significant peaks, which can be explained as summation and difference tones caused by interaction of the annual and its five harmonics (first set of parents) with the subharmonics Ti, i = 1 to 3 (second parents), and the expression for the tones is

cycles per month (cpm), where j = 0,…5. The only requirement physically for these interactions is that the atmosphere be weakly non‐linear, a requirement now obviated by a simplified atmospheric model of O'Brien and Currie. World‐wide, the contribution to total variance of the 33 tones and three subharmonics is 26·8 per cent, whereas the contribution of noise is 19·4 per cent. The root‐mean‐square (RMS) errors between observations of the 33 frequencies, and between those predicted by the above equation, in the two OSU‐GCM simulations are 0·0015 and 0·0010 cpm, respectively. The two sets of parents and 33 tones vary in period from 2 to ca. 70 months and demonstrate that the spectrum of climate on these time‐scales is ‘signal‐like’ rather than ‘noise‐like’ as traditionally believed.
Prediction of annual tropical cyclone activity over the western North Pacific and the South China Sea
Authors: Chan Johnny C. L. 
Published: February 2007

AbstractThis study investigates the relationship between the spatial distribution of sea‐surface temperature (SST) and the annual tropical cyclone (TC) activity over the western North Pacific and the South China Sea. Monthly distributions of SST are represented by a set of empirical orthogonal functions (EOFs). The principal components (PCs) of the monthly SST associated with these EOFs are then correlated statistically with the annual number of TCs occurring over (i) the western North Pacific and (ii) the South China Sea using a forward stepwise linear multiple regression scheme.It is found that four PCs of the monthly SST distribution together explain 89 per cent of the total variance of the annual number of TCs over the western North Pacific. Predictions of this number from both the dependent and independent (simulated using the jack‐knife method) samples have errors of less than half a standard deviation of the actual number. Two of these PCs are from the September SST, whereas the other two are from May and June SSTs. If only the latter two PCs are used, the accuracies of the prediction are slightly reduced. Therefore, a preliminary prediction can be made using these two PCs and a modified prediction can be performed at the end of September.Two PCs are found to correlate significantly with annual TC activity over the South China Sea, representing the SST distribution in May and July. Predictions using these two PCs also give very reasonable results for both the dependent and independent samples.
Temperature trends and change points in the northern Spanish Plateau during the last 100 years
Authors: Esteban‐Parra M. J. , Rodrigo F. S. , Castro‐Díez Y. 
Published: February 2007

AbstractIn this work we have analysed the mean, maximum, and minimum temperature records of five localities in the northern Spanish Plateau during the last century. We have used the short‐cut Bartlett test to examine their homogeneity. Our main proposal is the detection of trends and abrupt changes, using the Mann‐Kendall test and the estimation of the magnitude of these. We have found that the minimum and mean temperatures have increased. The maxima do not present special behaviour. So the minimum temperatures show more influence over the mean temperatures than the others. Briefly, we have studied the possible linkage between the increase of minimum temperatures and urban growth in the area studied.
Fuzzy rule‐based classification of atmospheric circulation patterns
Authors: Bardossy Andras , Duckstein Lucien , Bogardi Istvan 
Published: February 2007

AbstractA fuzzy rule‐based methodology is applied to the problem of classifying daily atmospheric circulation patterns (CP). The purpose of the approach is to produce a semi‐automated classification that combines the expert knowledge of the meteorologist and the speed and objectivity of the computer. Rules are defined corresponding to the geographical location of pressure anomalies. A CP is described by the location of four different possible pressure anomalies. The rules are formulated with fuzzy sets, allowing a certain flexibility because slightly different pressure maps may correspond to a given CP. Accordingly the degree of fulfilment of a rule is defined in order to measure the extent to which a pressure map may indeed belong to a CP type. As an output of the analysis, the CP on any given day is assigned to one, and only one, CP type to a varying degree of credibility.The methodology is applied to a European case study. The subjective classification of European CPs given by Hess and Brezowsky provides a basis for constructing the rules. The classification obtained can be used, for example, to simulate local precipitation conditioned on the 700 hPa pressure field. The information content of the fuzzy classification as measured by precipitation‐related indices is similar to that of existing subjective classifications. The fuzzy rule‐based approach thus has potential to be applicable to the classification of GCM produced daily CPs for the purpose of predicting the effect of climate change on space‐time precipitation over areas where only a rudimentary classification exists or where none at all exists.
Surface aggregation and subgrid‐scale climate
Authors: Klink Katherine 
Published: February 2007

AbstractLand‐surface representations used by the climate modelling community characterize locally heterogeneous surfaces as larger, homogeneous units. This loss of detail in land‐surface properties has prompted research into methods by which subgrid‐scale properties may be included within global climate models (GCMs). Coupling a regional model within a GCM represents one possible approach to resolving subgrid‐scale heterogeneity, but this method is computationally demanding. For use at global scales, two aggregation schemes have been proposed in the literature. The first assigns to each GCM grid‐cell the area‐weighted values of structural and physiological parameters typical of each subgrid surface type; the second computes separate energy balances for each surface type within the cell, then averages their responses based on areal coverage. Neither of these aggregation schemes, however, account for subgrid surface‐atmosphere interaction, surface geography, or advective effects.This study examines climate sensitivity to methods of surface aggregation by comparing climates simulated using a three‐dimensional, mesoscale atmosphere‐land‐surface model with those produced by parameter‐based (‘averaged geography’) and energy‐balance‐based (‘mosaic geography’) aggregation schemes. Simulations are carried out for a 240 kmx240 km area using three land‐surface configurations. Each domain contains a small area of bare soil, along with varying amounts of grass and coniferous trees.Model comparisons indicate that the averaged geography scheme tends to overestimate the latent and sensible heat flux from the model domain, and to yield surface temperatures that are cooler (by as much as 1.8°C) than control‐simulated values. Mosaic geography results are more similar to control climates, but tend to underestimate surface sensible heat flux and to overestimate the latent heat flux. Surface temperatures produced by mosaic runs are warmer than control values by up to 0.8°C. Overall, the mosaic aggregation scheme appears superior to the averaged geography method in its ability to capture the domain‐averaged climatic effects of subgrid heterogeneity. However, relatively large differences between the climates simulated by mosaic and control experiments for the individual grass, coniferous tree, and bare soil areas suggest that studies of subgrid climatic forcing and response are best performed with regional‐scale or coupled regional‐global climate models.
Rainfall variability associated with Lamb weather types: The case for incorporating weather fronts
Authors: Wilby R. L. , Barnsley N. , O'Hare G. 
Published: February 2007

AbstractThe value of weather generators for down‐scaling the output of general circulation models for regional impact assessments is limited by the assumption of stationary‐rainfall‐circulation‐pattern relationships. This note assesses the potential of incorporating weather front data into existing stochastic precipitation models to describe intraweather pattern rainfall variability.
Geologisch‐archäologische Untersuchungen zu den Entstehungsbedingungen der Marschen in Nordfriesland
Authors: Prange Werner 
Published: February 2007

Geological and archaeological investigation of the mode of origin of the marshes in Nordfriesland (Germany)In the bogs between marine sediments and Pleistocene uplands on the mainland of Nordfriesland, saltbearing peat for salt production was dug before, as well as while, the bogs were covered by sediments with high clay content. Additionally, there is not much fresh‐water coming from the Pleistocene uplands and carbonate is only preserved in the “Klei” deposited in the resulting holes. These facts show, that the “Klei” was originally calcareous and that it was deposited in water with a high salt content. Therefore one cannot conclude that adsorbed cations and narrow Ca:Mgratio (0.5–1.5) indicate sedimentation in brackish water and deposition of sediments with a low, or indeed, no carbonate content. Hence adsorbed cations and the Ca:Mgratio do not allow the separation of marsh soils from soils of a marine or brackish origin.
Die Bleikontamination von Pflanzen und Böden durch Kraftfahrzeugabgase
Authors: Sommer G. , Rosopulo A. , Klee J. 
Published: February 2007

Lead Contamination of Plants and Soils Caused by Automobile Exhaust GasesThe examination of grassland, wheat, maize and potatoes has shown that the lead content of plants in the vicinity of roads rises with increasing traffic intensity and falls with increasing distance from a motorroad. An increase in the coating of lead is observable up to a distance of 50 m from an autobahn. A roadside sample of grass from the Munich–Stuttgart autobahn was found to contain 470 mg lead/kg dry matter. The lead content of grass growing immediately near (≦ 1 m) roads was found to vary between 40 and 140 mg lead/kg dry matter. The lead content of samples taken from the same place at different times varies considerably, doubtless due to the influence of different exposure times, rate of growth and meteorological conditions. Different plants from comparable positions contain different amounts of lead; even different grass species vary. Roots, growing or otherwise, are protected from the action of dust and contain accordingly a low lead content which is independent of position. Drying fresh plant material in a forced draught oven, even at the low temperature of 35°C, causes losses of up to 50%. The risk to health of men and animals due to the consumption of plant foods growing near heavily used roads is discussed and preventative measures proposed.
Der Einfluß einer variierten K‐Ernährung auf die Inkorporierung von markiertem Stickstoff (15N) bei jungen Sonnenblumen (Helianthus annuus L.)
Authors: Mengel K. , Koch K. 
Published: February 2007

The effect of a varied K nutrition upon the incorporation of labelled nitrogen (15N) in young sun flower plants (Helianthus annuus L.)1. The influence of the potassium nutritional status upon the incorporation of labelled nitrogen (15N) into the soluble amino fraction and into the protein fraction was studied with young sun flower plants (Helianthus annuus L.). The plants were cultivated in a solution culture with 3 different nitrogen and 2 different potassium levels. During the last 24 hours of this cultivation the nitrogen of the nutrient solution was labelled by 15N‐nitrate in the various treatments.2. The growth of the plants was affected considerably by the various nutritional treatments. The yield of the plant matter increased with increasing nitrogen supply. This nitrogen effect was enhanced by the better potassium nutrition.3. The contents of soluble amino compounds in roots and upper plant parts increased with the increasing nitrogen application. This tendency was reduced by the higher potassium supply. The contents of protein nitrogen rose with the nitrogen nutrition. Potassium reduced the content of protein nitrogen in treatments with high growth rates.4. Related on a single plant the incorporation rate of nitrate nitrogen into the organic matter was higher in plants with a good potassium nutritional status than in plants with a low potassium nutritional status. This effect was especially evident in the treatments with the highest nitrogen supply. Here the nitrate incorporation rate was 5–7 times higher with the higher potassium application.5. This favorable effect of potassium upon the assimilation of nitrate nitrogen was also evident, if the incorporation rate was not related to a single plant, but on the unit of weight of plant material (fresh matter). Thus with high nitrogen supply the quantity of labelled nitrogen of the amino fraction was about 2 times higher in the plants with a high potassium nutritional status compared with plants of a low potassium nutritional status. In the protein fraction this potassium effect was still more evident. The influence of potassium upon the nitrate nitrogen assimilation was the better the better the plants were supplied with nitrate.
On the Adsorption of CaOH+ and BaOH+ by Clays and Soils
Authors: Papanicolaou E. P. 
Published: February 2007

Über die Sorption von BaOH+ und CaOH+ durch Tone und BödenEin Ton (Wyoming Bentonit), ein Boden (Yolo Lehm von Davis, Kalifornien) und fünf verschiedene griechische Böden wurden mit Ba++ und Ca++ (Behandlung mit Ba(OH)2 und Ca(OH)2 unter CO2‐freier Luft) gesättigt. Die adsorbierte Barium‐ und Calciummenge wurde sowohl mittels isotopischer Verdünnung als auch aus Gesamtkationenmenge und Gesamthydroxidmenge bestimmt. Das adsorbierte Barium oder Calcium zeigte in beiden Fällen fast die gleichen Werte. Aus diesen Ergebnissen kann man schließen, daß eine Adsorption von CaOH+‐ und BaOH+‐Kationen sehr wahrscheinlich nicht stattgefunden hat.
Beziehungen zwischen Zink‐ und Kupfergehalt in Haferpflanzen und Böden
Authors: Beyme B. 
Published: February 2007

Relationship between Zn and Cu Contents in Oat Plants and SoilsThe Zn concentration in oatplants at the stage of appearing panicles from agricultural fields were higher and more varying on soils of sandy texture than on soils of loess. With the former Zn in plants correlated with n‐MgCl2 extractable Zn in the soil (r = 0.745), and also with 0,5 n‐HNO3 extractable Zn if the pH dependance was taken into account. Zn in plants from soils of loess correlated with HNO3 extractable Zn only. Cu concentrations in plants were lower on soils of sandy texture. A correlation to 0.5 n‐HNO3 extractable Cu in the soil existed in the group of loess derived soils only (r = 0.474), a negative correlation between Cu in plants and soil pH only with sandy soils (r = —0.500). Zn and Cu concentrations of plants were based on total N contents of plants instead of on dry matter, with the aim of mitigating growth dependent differences in Zn and Cu originating from unequal stage of plant development at harvesting.
Beziehungen zwischen Mangan‐Gehalten in Haferpflanzen und Böden
Authors: Beyme B. 
Published: February 2007

Relationship between Mn in Oat Plants and SoilsThe Mn concentration of oat plants in the stage of appearing panicles from agricultural fields were put in relationship to extractable Mn. With soils of sandy texture (clay < 4%, pH 4,7–6,6) a correlation existed between Mn in plants and n‐MgCl2 extractable Mn, however, no additional relationship with the easyly reducible Mn. A negative correlation between pH and Mn in plants was traced to the pH dependence of exchangeable Mn. With soils of loess (clay 5–28%, pH 6,6–7,7) a significant correlation existed between Mn in plants and easyly reducible Mn fractions (methods by Schachtschabel: extracting solutions containing Na2SO3, pH 8,0, or Na2SO3 + NaHSO3, pH 5,5), however, only if an interrelationship with the pH of the soil was allowed for. The higher the pH of the soil the lower its level of extractable Mn might be, to reach a certain concentration of Mn in plants. This relationship seems to be caused through a modifying influence of the soil pH on the reducing power of the extracting solutions.
Der Einbau radioaktiven Schwefels in Blattproteine von Ölrettichpflanzen
Authors: Pauler B. 
Published: February 2007

The 35‐incorporation into protein components of oil radish plantsAfter a vegetation period of 4 weeks the fresh weight, dry weight and total protein content of the plants were not significantly affected by two different sulphur levels in the nutrient medium.At defined conditions for protein extraction and fractionation, seven apparently identical protein fractions were observed in oil radish plants within the sulphur fertilization variants used.The concentration and 35S‐labeling of some protein components were influenced by the amount of sulphur supplied.Combining the results of Sephadex gel filtration and isoelectric focusing, it was possible to characterize the single protein components by their isoelectric points and molecular weight ranges.Moreover, the rate of 35S‐labeling of total protein was increased by higher sulphur supply, while the 35S‐sulphate content in the protein extracts was deminished.
Schwefeldioxid, Schwefelwasserstoff, nitrose Gase und Ammoniak als ausschließliche S‐ bzw. N‐Quellen der höheren Pflanze
Authors: Faller N. 
Published: February 2007

Sulphur dioxid, hydrogen sulphate, nitrous gases, and ammonia as sole source of S and N for higher plantsLong duration gasing experiments using SO2, H2S, nitrous gases and NH3, showed, that higher plants can use these gases as only source of S or N respectively, without affecting their normal growth during the whole vegetation period.The sulphur and nitrogen of these high oxidized or high reduced gas forms were taken up by the plants and were also translocated to the roots.The assimilation of sulphur, given as SO2, was more intensive than that given as H2S. The uptake of nitrogen, given as ammonia, was higher than that given as nitrous gases.
Aufnahme und Sorption von zwei‐ und dreiwertigem Eisen durch Sonnenblumenpflanzen (Heliantus annuus L.)
Authors: Höfner W. 
Published: February 2007

Uptake and adsorption of ferrous and ferric iron by sunflower plantsThe uptake of iron by 13 day‐old sunflower seedlings in water culture experiments was studied using FeCl3, Fe‐citrate and ferroammoniumsulfat (Mohr'sches Salz) in the‐nutrient solution.By raising the N‐, K‐ and Ca‐content and lowering the P‐content of the nutrient solution at the same time the iron content of the exudate in the FeCl3‐treatment was increased up to 200 %. In the case of Fe‐citrate, similar values were obtained only under aeration conditions of the nutrient medium.Application of iron as ferrous sulfate led to an increase of the iron content in the exudate and in the aerial plant parts amounting to about 200 and 400 %. respectively over that of the FeCl3 treatment.After 15 hr‐uptake, most of the iron, taken up by the seedlings was in an unexchangeable form in the root system.The results give a further evidence for the peferential uptake of iron in the ferrous form.