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This paper constructs annual homogenised precipitation series for 13 locations in Scotland (1861–1991) from non-standard sources. Whilst the British Rainfall series represents the backbone of most UK rainfall records before the middle of the twentieth century, this paper returns to the original records to examine spatial and temporal variations in Scottish precipitation. The records were subjected to trend analysis and principal components analysis (PCA), and then related to atmospheric circulation parameters to understand the synoptic- scale mechanisms involved. Upward (downward) trends in precipitation were noted in western (eastern) Scotland over the period 1870–1991. Precipitation variability in western (eastern) Scotland is best explained by fluctuations in the westerly circulation (pressure), with the west- east precipitation gradient closing in those years with below average pressure, and a greater frequency of northerly and/or easterly winds. Precipitation trends cannot be explained by changes in atmospheric circulation patterns, suggesting that other factors must be involved. [ABSTRACT FROM AUTHOR]

A government-funded scheme, the UK Climate Change Communications Initiative (UKCCCI), has provided money for organisations to deliver projects that attempt to impact positively on people's attitudes towards climate change. This devolution of communications is a relatively novel approach after previous centralised campaigns. This paper considers what size of target audience is most appropriate for attitude change initiatives. It compares data from a regional UKCCCI project aimed at residents of two counties with a nationally representative dataset. Regional data are also analysed to see if there are differences in attitudes within the two-counties target audience. The study suggests that attitude change interventions must strike a balance between personalisation of information and the higher cost of targeting smaller groups with more specific material. [ABSTRACT FROM AUTHOR]

Each year flash floods cause considerable property damage and loss of life, yet the heavy precipitation events responsible for flash floods remain extremely difficult to forecast, especially during summer. This paper presents synoptic analog models for use in the shod-range prediction of summertime extreme rainstorms in Minnesota. To develop these analog models, forty-three heavy rain events that occurred from 1974-78 first were classified into four similar categories on the basis of the spatial properties of their rainfall distributions. Next, composite fields of surface and upper-air parameters were prepared for each of the four categories, and features on the composite maps that contributed most to the occurrence of heavy rainfall were incorporated into synoptic analog models. The analog models reveal that the typical circulation patterns for the four rainfall types vary significantly and that the spatial characteristics of extreme rainstorms are determined by the synoptic-scale circulation regime in which the rainstorms form. This interrelationship between the spatial characteristics and atmospheric circulation can be used to improve subjective forecasts of location and areal extent of extreme rainstorms. The results of this study also indicate that the preparation of synoptic analog models for local areas can improve our understanding of the climatology of heavy precipitation. [ABSTRACT FROM AUTHOR]

The article presents an overview of the doctoral thesis "Late Weichselian and Holocene Glacier Fluctuations Along a South-North Transect in Norway: Climatic and Methodological Implications," by Jostein Bakke. The main palaeoclimatic objective within the thesis is to provide records of glacier variations during the late-glacial and Holocene from a south-north Norwegian transect. The aim is to reconstruct continuous records of variations in glacier size and to use these to derive records of glacier equilibrium-line altitude (ELA). ELA variations are, in turn, the key to the inference of changes in winter precipitation and hence understanding the significance and effect of large-scale atmospheric circulation patterns in the North Atlantic region.

We examine a distributed control problem for internal flow management in a multi-zone climate unit. The problem consists of guaranteeing prescribed indoor climate conditions in a cascade connection of an arbitrarily large number of communicating zones, in which air masses are exchanged to redirect warm air from hot zones (which need to be cooled down) to cold zones (which need to be heated up), and to draw as much fresh air as possible to hot zones, relying on the ventilation capacity of neighbouring "collaborative" zones. The controller of each zone must be designed so as to achieve the prescribed climate condition, while fulfilling the constraints imposed by the neighbouring zones - due to their willingness to cooperate or not in the air exchange - and the conservation of flow, and despite the action of unknown disturbances. We devise control laws which yield hybrid closed-loop systems, depend on local feedback information, take on values in a finite discrete set, and cooperate with neighbour controllers to achieve different compatible control objectives, while avoiding conflicts. [ABSTRACT FROM AUTHOR]

In this paper we describe the dynamic behaviour of Salajekna, a valley glacier, over the last 200 years using terrestrial observations, in situ measurements, remote sensing observations and glacier reconstructions. The response time of the glacier was calculated using analytical models and field measurements. We were subsequently able to attribute specific dynamic responses to climate trends in the available climate record. The glacier's historical maximum extension was reached around 1880–1910 and was the result of a more continental climate with multi-modal airflows in the late 18th and early 19th centuries. A transition to more maritime conditions in the mid-19th century resulted in a near-continuous 20th century retreat before the glacier adjusted to a near-steady state. [ABSTRACT FROM AUTHOR]

In this study an Artificial Neural Network called Self-Organizing Map (SOM) is used in order to classify the synoptic circulation over Europe and especially Eastern Mediterranean. The classification of circulation types is an effective way of summarizing and describing the atmospheric circulation and it is useful in climatology because it provides a better understanding of the climatic variability over an area. Here, the SOM methodology is applied on winter daily geopotential height anomalies of the 500 hPa level, for the period 1971–2000. Twelve unique circulation patterns are identified. Eight of these types are characterized as cyclonic, representing 61% of the total days examined and four types are characterized as anticyclonic, representing 39% of the study period. The results of this classification are comparable to other objective classifications applied on the same study region and present a similar image. Therefore, the SOM methodology is found to be applicable and useful in the classification of circulation types. [ABSTRACT FROM AUTHOR]

Common perception is that tornadoes travel in paths from the southwest quadrant of directions toward the northeast. This study examines path directions for 6,194 tornadoes that occurred in the eastern two-thirds of the United States during the twenty-three-year period 1980–2002. At the national scale, nearly 70 percent of tornadoes included in the study propagated from the west, west-southwest, and southwest, with west-southwest being the highest frequency origin direction. Nevertheless, distinct seasonal and regional variations were found. In central and northern areas of the country, a more westerly or northwesterly path origin prevails during late spring and summer. The midtropospheric flow, convective typology, and synoptic patterns of tornado outbreaks are thought to contribute to the distributions observed in the climatology. [ABSTRACT FROM AUTHOR]

The variability of Pennsylvania winter climate is shown to be the result of mechanisms working on two distinctly different time scales: interdecadal and interannual. Interdecadal variability is associated with hemispheric changes in large-scale atmospheric circulation regimes. During periods of zonal flow, Pennsylvania temperatures are above normal, while meridional flow is associated with below-normal temperatures. Precipitation is near normal during zonal regimes, but can be either very dry (as it was in the 1960s) or abnormally wet (like the 1970s) with meridional flow, depending on the exact placement of the deepened trough over the eastern United States. Imbedded in the interdecadal fluctuations is interannual variability which is related to two important Northern Hemisphere teleconnection patterns: the Pacific/North American (PNA) and North Atlantic Oscillation (NAO) patterns. Interannual changes in the atmospheric circulation, as expressed by indices of the two teleconnections, explain 50 percent of the variance in Pennsylvania winter temperature, but only 14 percent of the precipitation variance. It is argued that knowledge of such relationships provides a basis for refining and better interpreting models of greenhouse gas-induced climatic change. [ABSTRACT FROM AUTHOR]

Focuses on the dominant atmospheric circulation controls of summer climate in the U.S. Southwest shown from classification of daily charts for the period 1945 to 1984. Seasonal synoptic circulation indices; Relationship of the circulations with Arizona summer rainfall variations; Correlations of the summer rainfall to anticyclonic activity aloft.

Variation in atmospheric circulation and spatial and temporal patterns of sea-level pressure anomalies ever eastern North America are highly correlated in time with temperature trend in the Lake Superior area: Lake Superior region temperature trends have not been The same for all seasons .January and July temperatures were highest in the mid: 1930s; those for April and October culminated later Differences in the timing of temperature peaks ,within the Lake. Superior region are related mainly the variations in pressure anomalies over western Canada and with associated anomalous air flow components across the Lake. Pressure anomlies over the southwestern United States and, opposite anomalies: to the east have then less important and they have affected mainly the temperatures over the eastern part of the region. About seventy to tightly percent of the temperature variance for the Lake Superior region is related to about twenty-five to thirty percent of-the pressure variance for eastern North America. [ABSTRACT FROM AUTHOR]