bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Canadian operational procedure for forecasting total ozone and UV radiation
Authors: Burrows William R , Vallée Marcel , Wardle David I , Kerr James B , Wilson Laurence J , Tarasick David W 
Published: June 2010

AbstractIn the spring of 1992 Environment Canada started daily forecasts of ultraviolet‐B radiation reaching the ground for locations in Canada. The forecast quantity is a ‘UV Index’ based on an empirical formula relating UV flux at the ground to solar zenith angle, total depth of ozone in a vertical column, and the time of year. The primary subject of this paper is the procedure for forecasting total ozone that has been used operationally since June 1993. The UV forecast is produced in three steps. First, total ozone it estimated over all of the northern hemisphere using a regression relationship between upper atmospheric variables and total ozone. Second, a correction is made to the forecast based on current measurements of ozone over Canada. Third, the total ozone estimates are fed to the formula to obtain the UV Index. The procedure runs in a ‘perfect prog’ real‐time forecast mode, with values of the atmospheric variables taken from predictions of the Canadian global spectral model.The predictand data consisted of total ozone observations for the northern hemisphere for the period 1987‐1991, measured by the Total Ozone Mapping Spectrometer (TOMS) instrument aboard the Nimbus‐7 spacecraft. The predictors were obtained from an assortment of upper‐tropospheric and lower‐stratospheric meteorological variables, analyses of which were processed into a set, of predictors known from previous work to be related to total ozone. To these variables were added climatological total ozone and various functions of latitude to represent the observed large‐scale latitudinal and seasonal variations in total ozone. Six equations were developed, one for each of three latitude bands in each of two seasons. Selection of the latitude bands toot designed so that separate regressions would be applied in tropical and extra‐tropical latitudes in winter and summer, since there are significant differences in total ozone patterns.It was found that up to about 82% of the variance in total ozone could be explained with six predictors. Further tests with independent data suggested root mean square error (RMSE) levels of about 16 Dobson units in regression forecasts for Canadian locations for the summer of 1992 and about 23 Dobson units for the summer of 1993, which was an abnormal period of persistent record‐low stratospheric ozone. Although the forecasts show considerable skill, they are improved by the application of a correction procedure before the UV Index formula is applied. The correction procedure uses observations from a network of 13 Brewer spectrophotometers in Canada and a standard successive correction objective analysis procedure to obtain a field that is used to correct the next day's forecast. The correction procedure successfully removes the bias and reduces the RMSE of the ozone forecasts to about II Dobson units in both summers of 1992 and 1993.
Using statistical techniques to deduce local climate distributions. An application for model validation
Authors: Noguer M. 
Published: June 2010

AbstractDue to increasing interest in the prediction of detailed regional climate, a method to deduce local climate distributions from large‐scale variables is proposed. Since surface parameters are difficult to reproduce with the current resolution of General Circulation Models (GCMs), a statistical approach is used to fill the gap between GCM outputs and regional climate. The idea is to find relationships between local climate variables (the predictands) and predictors based on the large‐scale flow using Canonical Correlation Analysis, and then to find a regression model to relate the important canonical variables to each of the local surface variables‐ Predictor variables are provided by the monthly average mean sea‐level pressure field simulated by the Hadley Centre coupled model over the North Atlantic region. The predictands are the simultaneous monthly average precipitation Simulated over the Iberian Peninsula at four grid points, where the grid‐point values are interpreted as a proxy for station data. The results suggest that the technique can reproduce the major variations in regional climate on the monthly time scale.
Validation of computed power station plume trajectories using aircraft observations
Authors: Buckland A T 
Published: June 2010

AbstractAircraft measurements of SO2 were made on seven separate occasions to test whether trajectory methods could be used to predict realistic concentrations for the UK composite plume and identify individual sources. The profiles between computed and observed concentrations in south‐westerly meteorological situations were comparable but the agreement is less marked in different and more complex conditions.
A Bayesian approach to estimating benefits of improved forecasts
Authors: Kite‐Powell Hauke L. , Solow Andrew R. 
Published: June 2010

AbstractWe describe a Bayesian approach to estimating the economic benefits from improved forecasts. The approach takes explicit account of how decision makers use forecast information, and can provide more reliable estimates of benefits than methods based on mitigated impacts. We discuss some practical considerations in applying the approach to weather and climate forecasts, and describe the results of an application to ENSO prediction.
Forecasting the movement of tropical cyclones at the Met. Office
Authors: Radford A M 
Published: June 2010

AbstractOver the last decade global numerical weather prediction models have become sufficiently sophisticated to forecast the movement of tropical cyclones with a reasonable degree of accuracy. This paper describes the work being done at the Met. Office in Bracknell, UK, to improve and verify track forecasts, looking particularly at methods of ‘bogussing’ the initial conditions and of verifying the forecasts.
The importance of convective gusts
Authors: Bradbury W M S , Deaves D M , Hunt J C R , Kershaw R , Nakamura K , Hardman M E , Bearman P W 
Published: June 2010

AbstractThis paper examines the practical importance of convective gusts for operators of wind‐sensitive systems and for designers of Wind‐sensitive structures. The mechanics of gusts associated with turbulence (driven by momentum) and convective eddies (driven by buoyancy) are discussed‐Statistical analysis of gusts and gust factors is presented. This shows that extreme gust factors are always produced by the convective mechanism whereas extreme gusts can be produced by either mechanism. Severe convective gusts are shown to have important consequences for operators of Wind‐sensitive systems because they defy precise prediction, they can be isolated in their occurrence, they can occur in quite moderate mean winds and they can be associated with sudden changes of wind direction. Extreme convective gusts are of less importance to designers of wind‐sensitive structures. They are shown to have a relatively small influence on the magnitude of the predicted extreme gusts taken as design criteria for such structures. Nevertheless, there is a significant chance that when such extreme gusts occur, they are produced by the convective mechanism. When this occurs, the predicted aerodynamic effect may be underestimated, to some extent, because of inertial forces which change the nature of the flow and may increase the loading.
A study of the influence of topography on the climate of the region of Aegion, Greece
Authors: Ahmed Sh I , Mantas G P 
Published: June 2010

AbstractMeasurements of air temperature and wind speed and direction during the months of February, March and April 1988, at Aegion, Greece (38°14.25′ N, 22°7.5′ E) are analysed to detect topographic influences on the climate of this region. The analysis shows that this climate is controlled by nighttime weak cold katabatic winds from the south–south‐west sector, which is bounded by mountains, and stronger warmer daytime winds from the east–north–west sector, which is bounded by the Gulf of Corinth. The presence of weak katabatic winds is also supported by nighttime measurements of the air temperature along the Corinth–Patras road, which show significant temperature depressions at the openings of the several ravines that are found in this region.
Forecasts and warnings of natural disasters: The roles of national and international agencies
Authors: Hunt J C R 
Published: June 2010

AbstractNatural disasters are caused by natural events, which can be grouped as (i) extreme unstable events; (ii) large ‘variability’ events associated with extremes of the inherent variability and chaotic behaviour of geophysical systems; and (iii) global change events. These primary events are usually followed by equally harmful secondary events, such as mud slides or tsunamis following volcanic eruptions. Whether these events lead to disasters depends to a large extent on the preparedness and resistance of the afflicted community – i.e. its vulnerability. Forecasts for these different categories of event are of two types: ‘risk’ forecasts based on data of previous events, and real‐time forecasts. For group (i) events, these forecasts only begin following some initial detection, whereas for groups (ii) and (iii), forecasts are made before any indication of the event. Many (but not all) types of secondary event may also be forecast with increasing accuracy using local geophysical data and computational models of relevant processes. In this paper the organisation of forecasts and warnings is described, as is how it involves geophysical and disaster or emergency centres at the national, regional and international level. Satisfactory arrangements for issuing, receiving and acting on forecasts and warnings between countries (including the use of broadcasting media) require carefully negotiated procedures at the intergovernmental level. It is pointed out that international procedures developed for meteorology need to be extended to include other types of geophysical event and disaster. The final section of this paper reviews the need for defining targets for improvement in forecasting during the current International Decade for Natural Disaster Reduction (IDNDR), and that this should be preceded by establishing the accuracy of current methods, i.e. the baseline. Clarification of our objectives and targets may well lead to greater financial support from governments and other donors.
Data filtering for thermal mapping of road surface temperatures
Authors: Shao J , Lister P J 
Published: June 2010

Abstract‘Thermal mapping’ is the name given to the measurement of the variation in road surface temperatures across a region on winter nights. The method involves the use of infrared thermometers and data loggers mounted in modified vehicles. The signal recorded by the data logger is composed of two parts: that due to the road surface temperature and that due to error. Because relative temperature differences, as opposed to absolute temperatures, are important for thermal mapping, a low pass filter to remove or reduce high‐frequency errors or ‘noise’ is required. This paper examines the required features of such a filter and tests the applicability of one such filter with a thermal mapping data set. The results show that high‐frequency noise may be reduced without losing the spatial resolution necessary to detect cold spots in the road network. It is also demonstrated that in order to achieve this goal, a sufficiently high spatial resolution of raw observations is required.
The weather sensitivity of the UK food retail and distribution industry
Authors: Agnew Maureen D , Thornes John E 
Published: June 2010

AbstractThis paper focuses attention on the weather sensitivity of the food and drinks sector within the UK retail and distribution industry. The potential benefits to accrue from the application of meteorological knowledge are evaluated in light of current advances in retail information systems and management. Subsequently, the viability of using weather forecasts in operational decision‐making is discussed from both the meteorological and industrial standpoints.
Monthly characterisation of the tropical weather combining satellite and raingauge data
Authors: Hidalgo L G 
Published: June 2010

AbstractA computerised procedure has been developed for helping meteorologists produce a monthly characterisation of tropical weather. Inputs are a regional value of outgoing longwave radiation (OLR) from the TIROS/NOAA satellites and a rainfall amount from a local raingauge within the region, both for a given month and year. OLR has been incorporated to help complete information conveyed by the rainfall because this is influenced by short‐period episodes responsible for tropical rainfall. The main output is a category for the month. Analyses of anomalies and weather spell are also included. Meteorologists may apply the procedure on a near‐real‐time basis since OLR and rainfall data are available via the Internet (ftp). When raingauge data are missing the satellite estimates of rainfall can be used.
Automated measurements of snow temperature profiles in the Cairngorm mountains, Scotland
Authors: Purves R S , Barton J S , Wright D S B 
Published: June 2010

AbstractA programme to measure snow temperature profiles using thermistors with automatic data logging and telemetry is described for sites in the Cairngorm mountains, Scotland. The data for 1992/93 and 1993/94 are discussed in terms of snow metamorphic processes. Equilibrium forms and melt‐freeze dominate, but temperature gradients high enough to produce faceting can occur. These data have been utilised in the successful adaptation of the NXD (Nearest Day) avalanche forecasting model to the Northern Cairngorms.
Tropical cyclones in the south‐west Indian Ocean: Track prediction and verification of the UKMO model for 1991–92
Authors: Vermeulen Jan H 
Published: June 2010

AbstractThe aim of this paper is to evaluate tropical cyclone (TC) track forecasts of the United Kingdom Meteorological Office model in the south‐west Indian Ocean for 1991–92. These results are then compared with similar results for 1989–90 and 1990–91. Displacement errors are used for the evaluation of TC track predictions of individual TCs for forecast days 1 to 5. The Dvorak‐number is used to determine TC intensity. The skill of the numerical weather prediction model of the UKMO varies from high for the intense TCs to low for the weak TCs. Similar results were found for the western North Pacific by other researchers and is probably caused by deficiencies in the bogussing techniques. The weak TCs Davilia, Bryna and Celesta were forecast by only 18% of the model runs. For days 1, 2 and 3 the seasonal mean TC track forecast errors of 1991–92 compare well with those from 1989–90 and 1990–91.
Diagnosis of a rapidly deepening depression: 16/17 January 1995
Authors: Carroll Edward B 
Published: June 2010

AbstractThe development of a vigorous mid‐latitude depression as simulated in the UK Met. Office operational limited area model is examined. Water vapour imagery is compared with forecast fields, and it is shown that such imagery can be used to visualise the distribution of absolute vorticity and also to verify the model forecast. It is suggested that the similarity between the water vapour imagery and the absolute vorticity fields is greater than that previously noted between the water vapour imagery and the potential vorticity fields.
Radiosonde balloon drift — does it matter for data assimilation?
Authors: MacPherson Bruce 
Published: June 2010

AbstractOperational data assimilation systems for numerical weather prediction (NWP) neglect the space‐time drift of radiosonde balloons during their ascent. The validity of this assumption is assessed by reference to the equations of motion and a sensitivity experiment with a mesoscale NWP model. In the experiment, balloon drift is explicitly accounted for in the case of one key ascent which had a significant impact on a short‐period forecast of small‐scale baroclinic development. It is found in this case that, while the impact of balloon drift can indeed be detected, it is small compared with the impact from the observation when assimilated with neglect of balloon drift.
Weather, air quality and health
Authors: Collier C G , Hardaker P J 
Published: June 2010

AbstractRelationships between weather and health have been studied throughout recorded history. This century, air quality has been recognised as an important complicating feature in many urban and industrial locations. In this paper, having defined the difference between climate and weather, we outline some of the relationships which have been defined between both climate and weather conditions, air quality and human health. Links between conditions ranging from mental illness, respiratory and heart disease to flu have been reported. Unfortunately, much of the published work over the years has lacked scientific credibility or has used widely differing analysis tools. However, increased availability of data, and an understanding of the need to follow good scientific practice, are offering the opportunity to place some of the relationships on a more sound foundation. Recent studies identifying susceptible genetic conditions may lead to understanding of previously unexplained linkages. The need for research collaboration between the meteorological, atmospheric chemistry, epidemiology and, most importantly, the medical communities to investigate sometimes complex trigger mechanisms, is highlighted.
A statistical method for predictions of mean monthly precipitation in Cuba
Authors: Naranjo‐Díaz Lino R , Centella Abel , Cardenas Pedro 
Published: June 2010

AbstractStatistical methods for predicting the mean monthly precipitation in Cuba have been developed. Two different approaches have been used: multiple linear regression (MLR) and an adaptive scheme using a LVQ algorithm. Three main climatic divisions were defined over the Cuban territory using 180 observation points with a nearly homogeneous geographical distribution. A 50‐year (1941–1990) period was considered. Three types of variable were used as predictors: The Southern Oscillation Index and the Sea Surface Temperature anomaly in the central equatorial Pacific as the ENSO related variables, the Wolf Sunspot Index as a solar activity related variable and variables related to seasonality and persistence. The last of these was found to be the most important in producing high skill. A cross‐validation approach was used to test the prediction quality. This indicated that the LVQ algorithm provided a greater number of correct forecasts but the MLR method showed a slightly higher level of skill. The feasibility of using a LVQ algorithm for predicting mean monthly precipitation is established. However, the high skills found for the MLR method suggest that it should be used as a complementary tool in the decision‐making process.
A mesoscale vortex diagnosed from combined satellite and model data
Authors: Browning K A , Roberts N M , Sim C S 
Published: June 2010

AbstractMesoscale vortices originating as tropopause folds can lead to cyclogenesis, cloud formation and/or convective overturning. The presence of such mesoscale vortices can often be inferred from the nature and behaviour of dry zones in Meteosat water vapour imagery. Diagnostics from an operational limited‐area forecast model are presented for one such dry zone, which appeared to rotate in the water vapour imagery. Model and imagery show that a vortex‐induced combination of potential instability and ascent led to the development of a small band of cloud and thundery rain.
Investigating a SSM/I microwave algorithm to calibrate Meteosat infrared instantaneous rainrate estimates
Authors: Levizzani V , Porcú F , Marzano F S , Mugnai A , Smith E A , Prodi F 
Published: June 2010

AbstractSimultaneous rainfall analyses using Special Sensor Microwave/Imager (SSM/I) passive microwave measurements and thermal infrared measurements from Meteosat are presented for two storms over northern Italy that caused damaging floods. Upwelling brightness temperatures over precipitating clouds in the mm‐cm spectrum are directly associated with precipitation microphysics throughout the cloud column down into the rain layer. In contrast, brightness temperatures in the thermal infrared window, which arise from emission near cloud top, are not directly responsive to precipitation processes. However, because of the diffraction‐limited nature of passive microwave detectors, microwave radiometer ground footprints are considerably larger than those characteristic of infrared sensors, even those flown at geosynchronous altitude. Furthermore, passive microwave radiometers are flown on low‐earth orbiters, which produce less than ideal sampling rates, whereas optical‐infrared radiometers flown on geosynchronous orbiters produce high frequency sampling concomitant with precipitation time scales. In this study, we investigate how these two types of measuring systems could be used in a complementary fashion to improve rainfall estimation. A physically based microwave algorithm is used to estimate rainfall with SSM/I measurements, whereas a two‐threshold statistical technique is used for corresponding estimates from Meteosat. Results suggest that an infrared‐based analysis of rainfall derived from half‐hourly geosynchronous images can be improved with a calibration‐transfer approach using a microwave algorithm sensitive to vertical cloud structure.
Cyclogenesis over the Aegean Sea: Identification and synoptic categories
Authors: Flocas Helena A , Karacostas Theodore S 
Published: June 2010

AbstractAn attempt is made to identify and investigate the structure, behaviour and synoptic characteristics of cyclogenesis over the Aegean Sea. A simple, realistic and easily used methodology of identification, in an analytical form, was established. This combines two types of criteria: synoptic and dynamic/thermodynamic. Six synoptic categories that could favour cyclogenesis over the Aegean Sea are distinguished according to the synoptic criteria. Grid‐point values of geopotential height and temperature are used to calculate the dynamic/thermodynamic criteria, which are used to identify potential cases of cyclogenesis with respect to the thermodynamic prerequisites and the time continuance. It is demonstrated that cyclogenesis over the Aegean Sea is not as rare as was believed. The majority of cases result from the prevalence of a south‐westerly flow, a long‐wave trough and a closed system over the Aegean Sea. The cyclogenesis appears to occur primarily in the cold period of the year, mainly from October to May, and to have a small intensity and lifetime.
The quality and accuracy of a sample of public and commercial weather forecasts in the UK
Authors: Thornes John E 
Published: June 2010

AbstractAt a time when the commercialisation of weather forecasting is proceeding at an alarming rate around the world, it is essential to review the quality and accuracy of weather forecasts to ensure that current standards are at least maintained. The privatisation of meteorological services in some countries (e.g. New Zealand) and the vigorous commercialisation of established Met. Offices such as in the United Kingdom, France and Sweden suggests that customer satisfaction, increased income and reduced expenditure will dominate the weather forecasting scene over the next decade. It is important that the quality of weather forecasts is closely monitored before and after commercialisation to ensure that the accuracy of weather forecasts continues to improve and that public weather forecasting does not suffer. The improved technologies for data collection such as weather satellites, weather radar, wind profilers, road weather information systems, sferics, etc. should make it easier to assess forecast accuracy ‐ but with the exception of road weather forecasts there is little sign that the new technology has been used for this purpose. The current accuracy of a sample of weather forecasts in the UK is discussed and a framework for publishing future weather forecast verification statistics is presented.