bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dynamic climatology of the beaufort to laptev sea sector of the polar basin for the winters of 1975 and 1976
Authors: Ledrew Ellsworth F. 
Published: February 2007

AbstractThe dynamic climatology of the Asiatic and North American sectors of the Polar Basin is examined for the winter season using NMC grid data for 1975 and 1976. The relative contributions to the total vertical circulation field by the mechanisms of differential vorticity and thickness advection, the diabatic effects of latent heat release and surface heating, and the surface effects of friction and orography are evaluated for the major synoptic patterns of the region. From this analysis, the relative significance of advective versus local affects on synoptic development is determined. The results are compared with those from a similar study for the summer period.
The influence of the southern oscillation and volcanic eruptions on temperature in the tropical troposphere
Authors: Parker D. E. 
Published: February 2007

AbstractUpper‐air data for a network of tropical stations have been used to create seasonal and annual time‐series of 850‐500 mb and 500‐200 mb thickness for the zone 20°N–20°S for 1950‐1983.Linear regressions of thickness in each layer against a Southern Oscillation index show that in the northern winter about half the interannual variance of thickness is predicted by the Southern Oscillation index two seasons earlier. Similar but weaker results hold for the other seasons. Low Southern Oscillation index, implying low pressure in the southern tropical mid‐Pacific, is followed by a warm tropical troposphere.The residuals of thickness after the regressions against the Southern Oscillation index were examined for evidence of the effects of major volcanic eruptions. The cooling in 1964‐1965 cannot be ascribed unambiguously to the March 1963 eruption of Agung, and there has been no significant cooling in the two years following the April 1982 eruption of El Chichón.
Time variation in solar radiation in the negev, israel and its possible relation to the el chichon volcanic dust cloud
Authors: Zangvil Abraham , Aviv Oran Einhorn 
Published: February 2007

AbstractExtensive measurements of solar radiation at Sede Boqer, Israel revealed considerable changes in the direct and diffuse solar irradiance on clear days beginning in September 1982. The direct beam irradiance showed a consistent decrease of about 10 per cent compared to clear‐day values of the previous year. The diffuse irradiance data showed an increase of about 50 per cent and the ratio between diffuse and global irradiance increased by 63 per cent. The prominent effects were observed from autumn 1982 to spring 1983. Weak effects were still noticeable in winter 1983/1984 although a tendency of back to ‘normal’, though not quite, is evident in spring and summer 1984. Another interesting result of the analysis is that only very small changes in global irradiance were evident.These observations may be attributed to the El Chichon dust cloud since they are in accord with various types of measurements made of the dust cloud in other areas of the world.
Impact of the southern oscillation on australian crops
Authors: Nicholls Neville 
Published: February 2007

AbstractClimate plays a major role in determining variations in Australian crop production. The El Niño‐Southern Oscillation (ENSO) phenomenon is an important mode of climatic variation affecting the Australian region. Interannual fluctuations of Australian crop production and ENSO might thus be expected to be quite closely related. Analysis of the limited data available at present suggests that fluctuations in some Australian crops are in fact associated with ENSO and may be predictable, well in advance of harvest, from observed sea‐surface temperatures around northern Australia.
Solar radiation in Spain
Authors: Tena F. , Tinaut D. 
Published: February 2007

AbstractIn Spain there are only a few stations registering solar radiation, but by using correlations with other meteorological variables, an estimate of the solar radiation can be made in other areas throughout the country. The best results have been obtained using the correlation with hours of bright sunshine. Four linear expressions between the two variables have been obtained, corresponding to the four seasons of the year. Employing such expressions, monthly maps of solar radiation isolines have been plotted for the peninsular part of Spain. The mean deviation is not higher than 5 per cent.
Rainfall patterns in India
Authors: Vines R. G. 
Published: February 2007

AbstractIndian rainfall figures from World Weather Records have been subjected to filter analysis and the results suggest substantial coherence of data for central and north‐west India. The analysis indicates that there is a long‐term fluctuation in rainfall of period c. 22 years—possibly linked to the double sunspot cycle—and another of period c. 16 years, with which the first interacts. There is also some suggestion of an 18 to 19 year rainfall fluctuation, which is geared to the lunar (MN) cycle as first proposed by Campbell, Blechman and Bryson, and later by Currie.There is further evidence of a 10 to 11 year fluctuation (medium‐term) which is possibly connected with the single sunspot cycle, and an additional (short‐term) fluctuation of 6 to 7 years. Comparisons are made between these findings and those previously reported in analyses of rainfall records from both northern and southern hemispheres.
Some characteristics of storms on the transvaal highveld
Authors: Mader G. N. , Neishlos H. , Saunders M. M. , Carte A. E. 
Published: February 2007

AbstractStorm climatological statistics were extracted from digitized weather radar records. The effects of using various definitions for storm cells were small for most attributes and data from 20 to 30 days spread over a few years gave representative results. Only a few per cent lasted for more than an hour and about half of all cells travelled slower than 25 km h−1. Cells defined by the 45 dBz contour at 5 to 8 km above mean sea level lasted on average 18 minutes and travelled at 26 km h−1, compared to 20 minutes and 23 to 31 km h−1 in north‐eastern Colorado. The distributions of speeds, lifetimes and areas for the Transvaal were also similar to those for Colorado and they were nearly log‐normal. There was a wide range of cell behaviour from day to day and for storms on individual days.
Economic use of weather and climate information: Concepts and an agricultural example
Authors: Sonka Steven T. , Lamb Peter J. , Hollinger Steven E. , Mjelde James W. 
Published: February 2007

AbstractAlthough changing economic, conditions suggest a growing potential for the business application of weather and climate information, the actual use of that information will be affected by its suitability for decision‐making purposes. This article suggests the use of decision analytic techniques for evaluating the appropriatenesses and value of weather and climate information. The conceptual steps involved in this process are defined. The need for interdisciplinary modelling efforts to determine the economic use of weather and climate information is illustrated for an agricultural example.
The interaction of valley/mountain winds with A diurnally veering sea/land breeze
Authors: Goldreich Y. , Druyan L. M. , Berger H. 
Published: February 2007

AbstractSummer‐time wind patterns have been monitored within and above a transverse valley of the Judaean Hills. Near surface anemograph records and pilot balloon observations have been analysed to identify three vertically separated wind regimes. Classical mountain/valley winds dominate the flow within the valley walls whereas the regional gradient flow is discerned above 400 m AGL or 700 m ASL. Sandwiched between these regimes is a breeze layer which reflects the diurnal rhythm of the coastal, mesoscale breezes which are driven by local sea‐land temperature contrasts under the influence of the inland hills and the Coriolis force.
The effect of the prescription of zonally‐uniform sea surface temperatures in a general circulation model
Authors: Simmonds Ian , Smith Ian N. 
Published: February 2007

AbstractTo assess the impact on the global atmospheric circulation of zonally‐varying sea surface temperature (SST), a general circulation model experiment has been run in which this variation has been removed for a January climate simulation. This results in an adjustment of the atmospheric parameters on a global scale, and particularly in the tropics. Surface pressure increases and rainfall decreases in the Australian‐Indonesian region and rainfall increases in the east Pacific and over Peru. Large changes occur in the Walker‐type circulations along the equator. Even though the mean meridional SST gradient is left unchanged in the experiment, the modelled Hadley cells are, perhaps surprisingly, weakened and the reduction in condensational heating leads to an equatorial troposphere which is cooler than the control run by up to 1°C. Outside the tropics the model response is predominantly barotropic. Our experiment demonstrates the fundamental role of the longitudinal variation of SST in determining the location of the subtropical highs in the Southern Hemisphere.The observation that the SST ‘anomaly’ distribution used is similar in some respects to that observed during an El Niño (particularly the 1982–1983 event) led us to compare the model response to anomalies observed during that time. The change in the Walker circulation and the shift in the surface pressure and rainfall distributions bore considerable similarity to those observed. However, the weakening of the Hadley cells and the cooling of the tropical troposphere were rather different to what actually occurred. Our results suggest that regions of forcing other than, or taken in conjunction with, that in the ‘key region’ in the east Pacific can influence global response.
Droughts/floods in the summer monsoon season over different meteorological subdivisions of India for the period 1871–1984
Authors: Parthasarathy B. , Sontakke N. A. , Monot A. A. , Kothawale D. R. 
Published: February 2007

AbstractAbnormalities in the performance of the Indian summer monsoon (June to September) rainfall, which provides 75–90 per cent of annual rainfall, have been studied during the period 1871 to 1984 over different meteorological subdivisions into which the country has been divided. Long homogeneous monsoon rainfall series of 29 subdivisions, prepared on the basis of a constant 306 rain gauges, have been tabulated for the users in view of their great importance. The criterion adopted in identification of drought/flood over a subdivision is the percentage of rainfall departures from normal, as officially used in the India Meteorological Department.The worst drought years were 1877, 1899, 1911, 1918, 1920, 1951, 1965 and 1972 and the worst flood years were 1892, 1933, 1961 and 1983 when many subdivisions reported extremely low and excess rainfall, respectively. The probabilities of occurrence of droughts/floods are high in Haryana, Punjab, west Rajasthan, Gujarat and Saurashtra and Kutch subdivisions. The area of the country affected by drought conditions was at a maximum during the decade 1911–1920 and at a minimum during the decade 1881–1890. The decades 1971–1980 and 1921–1930 were characterized by maximum and minimum areas, respectively, under flood conditions. The percentage area of India which suffered from drought and flood was low during the continuous three decades 1921–1930, 1931–1940 and 1941–1950.
Northern hemisphere ice sheets and planetary waves: A strong feedback mechanism
Authors: Lindeman M. , Oerlemans J. 
Published: February 2007

AbstractWe carried out a statistical analysis of the relation between the net mass balance of high‐latitude glaciers and 500 mb height deviations of the seasonal mean atmosphere. Mass‐balance series of 23 glaciers and ice caps were used, ranging in length from 8 to 30 yr. Considering the sample as a whole, it appeared that the only significant predictor for mass balance variations is the summer anomaly of the 500mb height. Except for a few individual glaciers, correlations with mean vorticity and meridional wind component turned out to be insignificant.To investigate the potential feedback between ice‐age ice sheets and planetary waves, we used a stationary two‐layer atmospheric model to calculate the response to the CLIMAP (1976) ice‐sheet topography for 18,000 YBP. Combining the result with the statistical analysis reveals that the feedback is important: the planetary‐wave pattern forced by the ice sheets leads to deviations of the equilibrium‐line altitude of about 500m.
Precipitation—temperature relationships in England and Wales summers
Authors: Tout D. G. 
Published: February 2007

AbstractUsing aggregate precipitation and the mean temperatures of July and August for 1766–1980 and seven 30 year periods, the relationships between precipitation and temperature in England and Wales summers are investigated. Wet summers tend to be cool and dry summers warm. The highest correlation coefficients are for the two most recent 30 year periods. In contrast to winter, there is no evidence of changed precipitation temperature relationships in recent years. Between 1766 and 1985 there were only two summers with precipitation above 200mm and temperature above 17°C.
Spatial patterns of daily rainfall in central Kenya: Application of principal component analysis, common factor analysis and spatial correlation
Authors: Bärring Lars 
Published: February 2007

AbstractSpatial patterns of daily rainfall in central Kenya were investigated using principal component analysis {PCA) and common factor analysis (CFA) of covariance matrices, together with spatial correlation analysis. Data consisted of daily values from 42 stations for the period January 1971 to November 1979. All statistical analyses were made both on the whole data set, and by month.The number of components/factors to retain for rotation could not be unambiguously determined by means of scree tests. Therefore, various numbers of components/factors were rotated, mainly by using the Direct Oblimin procedure. It was not possible to obtain simple structure solutions from the PCA, which explained 50–70 per cent of the total variance. CFA explained 30–40 per cent of the total variance and was easily rotated to simple structure. It is concluded that this difference is due to the large portion of unique variance in the data. Because of this, maximum likelihood CFA is judged superior. Also the scale‐independence of the method is considered advantageous.The PCA and CFA correctly located the limit between the region of two pronounced rainy seasons, and the region of more complex and less distinct rainfall seasonality.Spatial correlation analyses suggest two seasonal rainfall regimes, one of ‘random’ convection during December‐March, and another of rainfall organized in approximately NE‐SE direction. The latter is mainly attributed to orographic influence, but possible links to fluctuations in the general SE‐monsoonal flow and the East African low‐level jet are briefly discussed.
The role of radiation geometry in the climate response of Mount Kenya's glaciers, part I: Horizontal reference surfaces
Authors: Kruss Phillip D. , Hastenrath Stefan 
Published: February 2007

AbstractModel calculations of incident shortwave radiation were performed for the Mount Kenya massif with the objectives of: (i) exploring the major factors controlling the ice distribution in the peak region: and (ii) determining the primary forcings that led to the differential retreat of the various glaciers.The ice distribution on Mount Kenya, characterized by largest glaciers lo the south and east, is primarily controlled by the precipitation pattern. By contrast, the radiation pattern is unconducive to maintaining this ice distribution, as insolation tends to be higher on these largest glaciers. Spatial variability in the incident radiation is mostly due to shading effects, with cloudiness however being more important in reducing absolute values. Steep slopes, essentially above 5,100 m, and higher temperatures below 4,600 m are further limiting factors.A drastic glacier recession is borne out by mappings of the ice extent in 1899 and 1963. Over this time span, the number of glaciers diminished from 18 to 11, and another disappeared since 1978. Of the eight defunct ice entities, six were small. By far the largest glacier to disappear since the turn of the century was the Kolbe, in a precipitation‐abundant but radiationally very exposed location on the eastern flank of the mountain. The largest and now easternmost ice body, the Lewis, which occupies the radiationally most exposed location of all the glaciers, has experienced the greatest ice wastage.The model calculations indicate that the drastic ice recession since the late 1800s is largely due to an increase in absorbed shortwave radiation accompanying, and in part brought about by, changes in cloudiness, precipitation, and temperature. In addition to the consequences for the overall ice amount, the spatial distribution of radiation totals, as influenced by topographical shading, appears to account for the remarkably diverse shrinkage of the glaciers on Mount Kenya.
Cave climate: Assessment of heat and moisture exchange
Authors: de Freitas C. R. , Littlejohn R. N. 
Published: February 2007

AbstractEarlier work on the role of airflow and ventilation in cave climate is extended to include the processes of heat and mass transfer. The study site is Glowworm Cave in New Zealand which is of special interest because of the existence of climate sensitive cave fauna on which the value of a cave as a tourist resource depends. However, the purpose is to provide greater insight into processes governing cave climate generally. Detailed measurements of temperature, humidity and evaporation were made over a 12‐month period and a thermodynamic advection model calibrated to help explain climatic patterns observed and processes operating. The results show that the spatial and temporal distribution of cave air temperature and humidity, as well as direction of airflow, can be determined from external air temperature and humidity. The dominant processes are the vapour and sensible and latent heat fluxes to and from both the air moving through the cave and the cave surfaces. Tn winter there is strong drying and cooling of the cave environment as external air entering the cave is warmed. In summer, humidity levels in the cave rise substantially and result in condensation (wetting) through the cave despite general warming of the cave air.
Soil heat flux in permafrost: Characteristics and accuracy of measurement
Authors: Halliwell David H. , Rouse Wayne R. 
Published: February 2007

AbstractSoil heat flux plates are a standard method of measuring soil heat flux in energy balance and related studies. Recent work has suggested that heat flux plates significantly underestimate the true flux value in permafrost terrain. Using data from two sites near Churchill, Manitoba, collected over two summer thaw periods, the calorimetric method of soil heat flux determination is used to assess the reliability of heat flux plate data. It is found that the heat flux plates underestimate the surface heat flux in organic permafrost terrain by about 50 per cent. The most likely cause of the error appears to be a combination of poor thermal contact between the plate and the peat soil, and possible vapour transport through the porous material. Recommendations are made to reduce errors in field determinations of soil heat flux.The calorimetric calculations indicate that the largest portion of the soil heat flux is stored as latent heat in the thawing of ground ice. The flux at 1–5 m depth constitutes a significant portion of the surface flux. The smallest component of the surface flux is the portion stored as sensible heat in the layer between the surface and the 1–5 m depth. Overall, the soil heat flux represents a high fraction (from 16 per cent to 18 per cent) of the net all‐wave radiation available at the surface.
Odelling radiation on south‐facing slopes
Authors: Wahab M. M. Abdel 
Published: February 2007

AbstractThe purpose of this study is to evaluate two models, the isotropic and the anisotropic, for estimating solar radiation on inclined surfaces. The models validation and analysis were applied to south‐facing slopes with inclinations of 30, 60, and 90°. A better performance was shown for the anisotropic one and this performance decreases with the increase of slope surface.
Objective analysis of monthly climatological fields of temperature, sunshine, rainfall percentage and rainfall amount
Authors: Hamilton J. E. M. , Lennon P. , O'Donnell B. 
Published: February 2007

AbstractAn objective method of drawing climatological maps of sunshine, temperature, rainfall percentage and rainfall amount, which is used operationally at the Irish Meteorological Service in Dublin, is described. The interpolation is based on McLain's method of distance weighted least squares quadratic approximation. The observations are interpolated directly to a regular (rectangular) mesh, without the use of a first‐guess, and the resultant field is contoured and shaded using a standard contouring package.This basic interpolation gave some spurious results near the coast and in data void areas when it was applied in its original form. These problems were overcome by the introduction of dummy values in such regions and a method was developed for calculating such values automatically based on nearby observations and various climatological normals.The method has been in operational use since February 1985 and the results are of quality comparable to the manual method which this computer method has replaced.
Tropical circulations and the associated rainfall anomalies during two contrasting years
Authors: Kayano Mary Toshie , Rao Vadlamudi Brahmananda , Moura Antonio Divino 
Published: February 2007

AbstractThe severe drought conditions observed during 1983 over a large extent of tropical lands were associated with the 1982–1983 El Niño event. In contrast, above normal rainfall was observed over these areas during 1984. The tropical circulations have been examined for these two contrasting years. The intensity and location of the rising and sinking motions were consistent with the rainfall anomalies and also with the outgoing longwave radiation anomalies. It was found that the north‐south migration of the tropical trough played an important role in modulating the tropical rainfall during these two years. In the context of the currently acceptable theoretical notions of the tropical circulation, some of the observed characteristics could be explained in terms of an atmospheric response to tropical heat sources. The results suggest that seasonal changes were involved in the 1982–1983 El Niño collapse.
The influence of upwelling extent upon fog incidence at Lüderitz, southern Africa
Authors: Olivier J. , Stockton P. L. 
Published: February 2007

AbstractThis paper examines the influence of the horizontal extent of the cold‐water upwelling on the incidence of fog at Lüderitz, Namibia, during 1983–1984. The spatial extent of the upwelling was measured on days with synoptic conditions conducive to fog formation, i.e. when a coastal low was centred to the south of the study area. A significant relationship was identified, indicating increased fog occurrence with an upwelling extent of less than 200 km and vice versa. The moisture necessary for fog formation was postulated as originating from the warm water to the seaward side of the upwelling zone. With a narrow upwelling, the circulation around the coastal low extends beyond the cold‐water mass, whereas when the extent of the upwelling exceeds that of the coastal low circulation, evaporation is limited, resulting in a relatively dry onshore air flow.