Dissertations / Theses on the topic 'Synoptic maps'

The bulk of synoptic weather type research related to urban climate focuses on human health impacts; however, recent studies have begun to quantify urban heat island (UHI) magnitudes by weather type, or air mass classification. This study presents an analysis of UHI intensity through synoptic-scale air mass persistence during the spring season for four UHI-prone United States cities. Historical daily weather types for Birmingham, Alabama; Charlotte, North Carolina; Louisville, Kentucky; and St. Louis, Missouri were extracted from the Spatial Synoptic Classification database for 40 years from 1980 through 2019. Daily minimum surface air temperature data were downloaded from the Global Historical Climate Network to compute UHI. The historical daily weather type data were converted into a record of persistence, or the length of consecutive days that a synoptic weather type was in place at each location. A descriptive climatology of SSC weather types and UHI at each location was constructed before UHI magnitudes were segregated by day of persistence and examined for differences in intensity. Climatologically, the four urban areas experienced an increase in warm weather types at the expense of cool weather types throughout the study period. Specifically, the persistence of moist tropical weather types increased at a statistically significant rate at Birmingham, Charlotte, and Louisville, consistent with the theorized northward migration of the mid-latitude jet stream. Also evident is a statistically significant increase in UHI frequency and intensity at Birmingham, Charlotte, and Louisville during the study period. Results show that the moisture character of a weather type is an important differentiating factor in UHI intensification, as the mean UHI was found to increase with the persistence of dry weather types and decrease with the persistence of moist weather types, presumably reflecting differences in radiational heating and cooling with atmospheric moisture content. The most intense UHIs and the largest UHI magnitude increase by day of persistence are associated with dry weather types, which have become more frequent since 1980. The findings suggest that larger magnitude UHIs may become more common in the future should dry weather type persistence continue to increase. Higher urban temperatures put human health at risk due to a well-linked relationship between heat and mortality and morbidity rates. The effects of heat are cumulative; the more common persistent, oppressive days become, the larger the impact.
Master of Science
Most of the research related to variation in the warmth of an urban area relative to the surrounding rural area, or the urban heat island (UHI) effect, under varying air mass conditions (temperature and humidity) has focused on human health impacts. This study examines UHI intensity through regional-scale air mass persistence during the spring season in four UHI-prone United States cities. Historical daily air mass conditions in the form of weather types for Birmingham, Alabama; Charlotte, North Carolina; Louisville, Kentucky; and St. Louis, Missouri were downloaded from the Spatial Synoptic Classification database for the 40 years from 1980 to 2019. UHI values for each urban location were calculated using daily minimum air temperature data from the Global Historical Climate Network. A descriptive climatology of weather types and UHI magnitude at each of the four urban locations established long-term means and trends before analysis of UHI intensity through varying weather type residence times, or persistence. Time series analyses align with previous indications of an increasing persistence of weather types and an increase in the frequency of warm weather types at the expense of cool weather types during the spring season. An increase in both UHI frequency and intensity occurred through the study period at Birmingham, Charlotte, and Louisville. The mean intensity of the UHI was found to increase with the persistence of weather types of low humidity and to decrease with the persistence of moist weather types. The largest mean UHI and the largest UHI magnitude increase by day of persistence are associated with low humidity weather types, which have become more frequent since 1980. The impacts of heat are cumulative; persistently elevated temperatures are detrimental to human health.

Western Antarctica has been experiencing significant warming for at least the past fifty years. While higher Net Surface Mass Balance (SMB) over West Antarctica during this period of warming is expected, SMB reconstructions from ice cores reveal a more complex pattern during the period of warming. The mechanisms giving rise to SMB variability over the West Antarctic Ice Sheet (WAIS) are not well understood due to lack of instrumental data. The Southern Annular Mode (SAM) and El Niño Southern Oscillation (ENSO) are believed to contribute to WAIS SMB variability but the assumption has not been rigorously tested. SMB during years where SAM and ENSO are in extreme phases is compared to average SMB from the period 1979-2010. Additionally, atmospheric circulation anomalies are used to assess what circulation patterns accompany extreme modes of climate during the same period. The results suggest that significantly lower SMB occurs when SAM is in an extremely positive phase or ENSO is in an extremely negative phase. Additionally, atmospheric circulation anomalies show that certain circulation patterns accompany extreme modes of climate, which contribute to SMB variability over the WAIS. Ultimately, the location of low and high pressure cells is the best predictor for extreme accumulation events over the WAIS. These results are verified by assessing observed net SMB trends from a network of firn cores located from the central WAIS. Seven new firn cores are added to improve the spatial network of regional net SMB measurements. Reconstructed net SMB is calculated from new firn core records, and compared to the existing cores. The new suite of preliminary firn core records show the same significant decreasing trend that is observed in existing cores. This represents a negative region-wide SMB trend that is likely in part due to trends in SAM and ENSO.

An updated silvics text for British Columbia. The need for an effective learning tool for silvics - one of the basic required courses in forestry - has been recognized by intructors as well as students across the province. The text prepared 18 years ago by Krajina et al. (1982) specifically for western Canada has become outdated. The silvics text by Burns and Honkala (1990) represents an up-to-date compendium but it is not an effective learning tool, particularly lacking in the linkage of silvics to ecological classification. Consequently, we revised and expanded “Distribution and Ecological Characteristics of Trees and Shrubs of British Columbia” (Krajina et al. 1982) using the available information on silvics, with some modification for BC and the results of recent silvics research done in BC. This material has been consolidated into a format that will help students understand the silvical attributes of tree species as well as the relationships between trees and their environments. To enhance learning, we have selected a series of slides illustrating the salient characteristics for each species and present this visual component on a CD-ROM included with the text. Also included is a large biogeoclimatic zone map of BC. The text, together with the CD-ROM, is intended to facilitate learning of silvics emphasizing its application to silviculture.

Since their development in the 1990s, gridded reanalysis data sets have proven quite useful for a broad range of synoptic climatological analyses, especially those utilizing a map pattern classification approach. However, their use in broad-scale, surface weather typing classifications and applications have not yet been explored. This research details the development of such a gridded weather typing classification (GWTC) scheme using North American Regional Reanalysis data for 1979-2010 for the continental United States.

Utilizing eight-times daily observations of temperature, dew point, pressure, cloud cover, u-wind and v-wind components, the GWTC categorizes the daily surface weather of 2,070 locations into one of 11 discrete weather types, nine core types and two transitional types, that remain consistent throughout the domain. Due to the use of an automated deseasonalized z-score initial typing procedure, the character of each type is both geographically and seasonally relative, allowing each core weather type to occur at every location, at any time of the year. Diagnostic statistics reveal a high degree of spatial cohesion among the weather types classified at neighboring locations, along with an effective partitioning of the climate variability of individual locations (via a Variability Skill Score metric) into these 11 weather types. Daily maps of the spatial distribution of GWTC weather types across the United States correspond well to traditional surface weather maps, and comparisons of the GWTC with the Spatial Synoptic Classification are also favorable.

While the potential future utility of the classification is expected to be primarily for the resultant calendars of daily weather types at specific locations, the automation of the methodology allows the classification to be easily repeatable, and therefore, easily transportable to other locations, atmospheric levels, and data sets (including output from gridded general circulation models). Further, the enhanced spatial resolution of the GWTC may also allow for new applications of surface weather typing classifications in mountainous and rural areas not well represented by airport weather stations.

碩士
國立中央大學
太空科學研究所
104
Synoptic maps are approximations of the full surface of the sun. We construct synoptic maps from CR2099 to CR2158 to study the dark regions on the EUV image called coronal holes. The data are retrieved from Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager onboard Solar Dynamics Obervatory. Each synoptic map contains 48 central meridian images arranged in time series. Dark regions are extracted by the thresholding routines. A dark region is identified as a coronal hole if its magnetic field skewness exceeds 0.35. The sun is divided into north-polar (65° to 90°), mid-low latitude (-65° to 65°) and south-polar (-90° to -65°) region. Each region the area and unsigned flux of coronal holes are calculated and discussed. The result shows that mid-low latitude holes occupy 5% the area of mid-low latitude region, with unsigned flux 0.8×10^22 Mx. South-polar holes occupy 30% the area of the south polar region, with unsigned flux 0.4×10^22 Mx. Since south-polar region is much smaller than the mid-low latitude region, the magnetic field is stronger in south-polar holes than in mid-low latitude holes. In addition, we combine synoptic maps with Real-Time Solar Wind measurements on Advanced Composition Explorer, and try to trace fast solar wind particles from 1 AU back to the solar surface. The result shows that 48% of fast solar wind sources are close to the center of coronal holes.

The atmospheric drivers of winter and summer surface climate in western Canada are evaluated using a synoptic climatological approach. Winter snow accumulation provides the largest contribution to annual streamflow of the north-flowing Mackenzie and east-flowing Saskatchewan Rivers, while summer water availability is primarily a product of basin-wide precipitation and evapotranspiration. A catalogue of dominant synoptic types is produced for winter (Nov-Apr) and summer (May-Oct) using the method of Self-Organizing Maps. Water availability, quantified through high-resolution gridded temperature and precipitation data, associated with these synoptic types is then determined. The frequency of dominant types during positive/negative phases of the Southern Oscillation Index, Pacific Decadal Oscillation, and Arctic Oscillation reveal the atmospheric processes through which these teleconnections influence surface climate. Results from the winter analysis are more coherent than summer, with strong relationships found between synoptic types, teleconnections, and surface climate. Although not as strong, links between summer synoptic types and water availability also exist. Additionally, time-series analysis of synoptic type frequencies indicates a trend toward circulation patterns that produce warmer, drier winters as well as an earlier onset and extension of the summer season. This study increases our understanding of the atmospheric processes controlling the distribution of water resources in western Canada.
Graduate
0388
0725
0368
bwnewton@uvic.ca

Η συνοπτική ταξινόμηση των συστημάτων καιρού αφορά πληθώρα περιβαλλοντικών εφαρμογών. Προσφάτως, η γνωστική περιοχή για την οποία η συνοπτική ταξινόμηση έχει βαρύνουσα σημασία είναι αυτή της ατμοσφαιρικής ρύπανσης. Η γνώση της συνοπτικής κλιματολογίας μιας περιοχής, επιτρέπει την πρόγνωση και ενδεχομένως την αποφυγή επεισοδίων ρύπανσης, τα οποία οφείλονται είτε σε τοπικές πηγές είτε στην μεταφορά ρύπων. Η γνώση αυτή ενισχύεται σημαντικά μέσω της κατηγοριοποίησης (ταξινόμησης) των συνοπτικών καταστάσεων που επικρατούν σε μία δεδομένη περιοχή. Τα τελευταία χρόνια έχουν γίνει προσπάθειες «αυτόματης», μη εμπειρικής, ταξινόμησης με την χρήση Η/Υ. Οι μέχρι τώρα προσπάθειες επικεντρώνονται σε κλασικές στατιστικές μεθόδους. Σκοπός αυτής της διδακτορικής διατριβής είναι η ανάπτυξη μεθόδων και η υλοποίηση αλγορίθμων για την εξαγωγή και ψηφιακή επεξεργασία περιβαλλοντικών σημάτων και εικόνων. Η εφαρμογή των ανωτέρω οδηγεί στη δημιουργία έμπειρων συστημάτων συνοπτικής ταξινόμησης των συστημάτων καιρού, η οποία βασίζεται σε μεθόδους επεξεργασίας εικόνας, ανάλυσης και ομαδοποίησης δεδομένων, αναγνώρισης προτύπων και θεωρίας γράφων. Η σκοπιμότητα της παρούσης έρευνας διαφαίνεται από τη πρωτοτυπία που παρουσιάζει, η οποία έγκειται στο γεγονός ότι οι τεχνικές που παρουσιάζονται και που έχουν αντιμετωπίσει επιτυχώς σειρά προβλημάτων ταξινόμησης σε διάφορους γνωστικούς τομείς, εφαρμόζονται για πρώτη φορά στην Ελλάδα σε θέματα Μετεωρολογίας-Κλιματολογίας-Φυσικής του Περιβάλλοντος και συγκεκριμένα για την συνοπτική ταξινόμηση των συστημάτων καιρού. Τα χαρακτηριστικά των σύγχρονων μεθόδων επεξεργασίας εικόνας, θεωρίας γράφων και ανάλυσης δεδομένων, καθιστούν τις προτεινόμενες προσεγγίσεις αυτής της διατριβής ανταγωνιστικές τόσο σε επίπεδο ποιότητας ταξινόμησης όσο και σε υπολογιστικό χρόνο.
The synoptic classification of weather systems involves a variety of environmental applications. Recently, the synoptic classification has been found to be relevant with the cognitive area of air pollution. Knowing the synoptic climatology of a region, allows the prediction and possibly the prevention of pollution incidents, resulting in either local sources or in transport of pollutants. This knowledge is greatly enhanced by the categorization (classification) of the synoptic conditions in a given area. In recent years ‘automatic’, non-empirical, classification methods have been developed using computers. So far these efforts have been based on classical statistical methods. The aim of this PhD thesis is the development of methods and the implementation of algorithms to extract and process digital signals and environmental images. Consequently, expert systems for the synoptic classification of weather systems are created based on methods relative to image processing, data analysis and clustering, pattern recognition and graph theory. The objective of this research is demonstrated by its own originality which lies in the fact that the presented techniques have successfully addressed a number of classification problems in different topics. It is the first time that such methods have been applied on Meteorology-Climatology-Physics of the Environment in Greece, namely the synoptic classification of weather systems. The characteristics of the modern methods proposed in this PhD thesis are competitive both in classification quality and in computational time.

The sources and sinks of energy for transient waves in the Martian atmosphere are investigated, applying diagnostic techniques developed for the analysis of terrestrial baroclinic waves to output from a Mars General Circulation Model. These diagnostic techniques include the vertically averaged eddy kinetic energy and regression analysis. The results suggest that the primary source of the kinetic energy of the waves is baroclinic energy conversion in localized regions. It is also shown that there exist preferred regions of baroclinic energy conversion. In addition, it is shown that downstream baroclinic development plays an important role in the evolution of the waves and in the baroclinic energy conversion process. This is the first time that evidence for downstream baroclinic development has been found for an atmosphere other than the terrestrial one.

碩士
國立雲林科技大學
文化資產維護系
105
This paper is to explore the depth map is a map of the occupation categories, also is to tell where people engage in what occupation of the map, this map is different from the general terrain features and the only way, read this type of map can be found in the crowd flow, the city's Economic Zone... Etc.. Especially about the design of the city, although unlike government departments of urban planning drawing so concise and to the point.But this type of surface map,The more realistic performance, let the people read it know the relationship between industry distribution. Although the map is only a number of pictures and text of the icon, but in fact these icons which contains a variety of elements needed to constitute the city. The biggest reason for studying the map is to look for the old buildings that were preserved in the Japanese colonial period from a professional point of view, because there are a lot of valuable old buildings that are silently disappearing. As for the location selection of fewer people survey is also the Japanese colonial period are one of the five, also in the Second World War by the United States army bombed the worst, the Japanese air force in Taiwan city of Hsinchu city as the research object, and know the building in the era of the torrent under the survival and sacrifice of the real.

碩士
國立東華大學
臺灣文化學系
106
During the colonial rule of Japan, Hualien City was a place that Japan plans for overseas immigrants. In the old city district of Hualien, there have gone through several City Renovating and Urban Planning in the Japanese period, each one made the City more similar to today's city. however, with the change of political power, the deep landscape that left behind is still standing on the land of Eastern Taiwan. In recent years, the redevelopment of cities has regarded the past urban fabric as a better vision, but however, there are still many inappropriate cases that cause by the government or the local communities. 'The Maps of Japanese Occupation Categories Information Synopsis' can be a tool to see through the local life. In this study, the author will use two different ages of Hualien's maps for GIS layer nesting and digital analysis of QGIS. The study concern the urban configuration and commercial utilization changes in the old city district of Hualien City through the late Japanese period to the post-war period.