- Québec, Canada
- McGill University, Geography, Department Memberadd
Historical data provides observational information crucial to our understanding of the evolution of geophysical processes. However, there is a gap between predigi-tal age observations, which are typically handwritten, and data that is... more
Historical data provides observational information crucial to our understanding of the evolution of geophysical processes. However, there is a gap between predigi-tal age observations, which are typically handwritten, and data that is discoverable and analysable. The data rescue protocols here address this gap, covering the information lifecycle from handwritten register pages to transcription-ready content , describing the historical data, the database design for the data rescue, and the development of an application design to transcribe the meteorological information directly from an image file to the database. The preparatory steps necessary to organize, curate, image, and structure the meteorological information, prior to transcribing the historical data, are outlined here in an integrated methodology. The initial organization, the development of an image file nomenclature to link the rescued data to the original source, and the description of a metadata schema to optimize the transcription application are all vital to the process of ensuring traceability and transparency in the data rescue process. Taken together, these steps describe best practices guidelines for similar projects. Although we designed the methodology and application to be used in any data rescue context, our particular concern was to accommodate the needs of citizen scientists. We thus focused on making our application easily maintained, flexible, direct to database, clear, and simple to use. KEYWORDS citizen science, data rescue, database, historical climatology, historical meteorology
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Daily observations of weather and climate for the province of Quebec, Canada, start in the 18th century and continue to the pres-ent day. Daily temperature observations from 12 observers ranging from 1742 to 1873 are described here. The... more
Daily observations of weather and climate for the province of Quebec, Canada, start in the 18th century and continue to the pres-ent day. Daily temperature observations from 12 observers ranging from 1742 to 1873 are described here. The frequency distri-butions of the temperature observations from each of the historical weather journals are examined for data quality and consistency. Adjustments for differing types of exposures, particularly north wall exposures, are developed. It is shown that examination of the daily data distribution can be used to infer information concerning the instruments used and likely exposure in the absence of metadata. Comparisons of the relative frequency distributions of historical and modern hourly observations are usedto assess the reliability of the daily historical temperature data, and are able to detect problems with instrument exposure or sampling biases. Historical observations of temperature from the 18th and 19th centuries are shown to be comparable to modern temperature data. These daily observations will be used in further studies to analyse changes in climate and extreme conditions on a decadal to centennial time frame, and will form part of international data sets for the reconstruction and analysis of past climate events.
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Climatological and meteorological observations in Canada begin in the first half of the 18th century. Continuous daily observations of the weather and climate for the province of Quebec start in the late 18th century. Estimates of daily... more
Climatological and meteorological observations in Canada begin in the first half of the 18th century. Continuous daily observations of the weather and climate for the province of Quebec start in the late 18th century. Estimates of daily minimum and maximum temperatures from historical fixed hour observations are provided from regression models basedon hourly data from the modern period. Observations of temperature from different locations and observers are compared and regressions models are used to compile a single series of daily minimum and maximum temperatures extending back to1742, with nearly continuous observations from 1798. Mean, absolute minimum and maximum values suggest considerable variability in the climate over the past two centuries. Based on a variety of climate indicators, exceptionally warm years include 1808, 1848, 1870, 1953 and 1998, while cold years include 1809, 1816, 1818, 1875 and 1904. Analysis of frost days and growing season length suggest a reduction in cold temperatures over past 200 years, while the incidence of cold spells and heat waves has decreased
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Jean-Franc ̧ois Gaultier was a physician in the French colony of Que ́bec in New France from 1742 to 1756. During that period, he recorded daily readings of temperature and observations of the weather, although only the observations for... more
Jean-Franc ̧ois Gaultier was a physician in the French colony of Que ́bec in New France from 1742 to 1756. During that period, he recorded daily readings of temperature and observations of the weather, although only the observations for 1742–46, 1747–48, and 1754 have been located to date. Daily instrumental temperature data from Que ́bec for the 1740s provide a glimpse of climate variability in eastern North America, upstream of the North Atlantic. During the 1740s, winters appear to have been milder than during most of the twentieth century with the exception of the 1950s and early 1980s, and summers warmer than those of the twentieth century, with the exception of the 1970s and 1990s. Autumns and springs appear to have been cool relative to the twentieth century, suggesting that, while winters may have been milder, the winter season lasted longer, with a consequently shorter growing season. The cool springs and autumns, combined with warm winters and summers, give these few years in the 1740s annual average temperatures comparable to those averaged over the twentieth century; the annual average temperatures mask marked seasonal differences. There is also some evidence that the climate was drier than in recent times, with fewer precipitation days than during the 1970–2000 period.
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Research Interests: Environmental Engineering, Civil Engineering, Climatology, Time series analysis, Quality Control, and 15 moreHomogenization, Seasonality, Atmospheric sciences, Statistical Significance, Temperature, Atmospheric Pressure, Atmospheric Circulation, Air Temperature, Empirical Orthogonal Functions, Seasonal Variations, Surface Pressure, Degree of Freedom, Observations, Atmospheric Temperature, and surface temperature
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The relationship between Arctic sea‐ice concentration anomalies, particularly those associated with the “Great Salinity Anomaly” of 1968–1982, and atmospheric circulation anomalies north of 45°N is investigated. Empirical orthogonal... more
The relationship between Arctic sea‐ice concentration anomalies, particularly those associated with the “Great Salinity Anomaly” of 1968–1982, and atmospheric circulation anomalies north of 45°N is investigated. Empirical orthogonal function (EOF) analyses are performed on winter Arctic ice concentration from 1954 to 1990, sea level pressure and 500‐hPa heights from 1947 to 1994, and 850‐hPa temperatures from 1963 to 1994. Variability on both interannual and decadal timescales is apparent in the time series of the leading winter EOFs of all variables. The first EOF of winter sea‐ice concentration was found to characterize the patterns of ice variability associated with the Great Salinity Anomaly in the northern North Atlantic from 1968–82. Spatial maps of temporal correlation coefficients between the time series of the first EOF of winter sea‐ice concentration and the winter atmospheric anomaly fields are calculated at lags of 0 and ±7 year. Maximum correlations were found to exist when the time‐series of this ice EOF 1 leads the atmospheric anomaly fields by one year. A particularly interesting result is the connection between the presence of ice anomalies in the Greenland and Barents Seas and subsequent pressure anomalies of the same sign over the Irminger Basin and the Canadian Arctic. The main emphasis of the paper is to identify connections between Arctic sea‐ice and atmospheric circulation anomalies at interannual time‐scales.Cette étude vise à déterminer s'il existe une relation entre les anomalies de la concentration de glace marine arctique, en particulier celles reliées à la grande anomalie de salinité de la période 1968–1982, et les anomalies de la circulation au nord de 45°N. Des analyses en terme de Fonctions Empiriques Orthogonales (FEO) sont effectuées sur la concentration hivernale de glace arctique entre 1954 et 1990, la pression au niveau de la mer et les hauteurs géopotentielles au niveau 500 hPa de 1947 à 1994, et les températures au niveau 850 hPa de 1963 à 1994. D'une année à l'autre et à l'échelle décennale, la variabilité est apparente dans la série chronologique de la principale analyse FEO hivernale de toutes les variables. La première analyse FEO de la concentration hivernale de glace marine représente les caractéristiques de la variabilité de la glace, associées à la grande anomalie de salinité dans le nord de l'Atlantique Nord entre 1968 et 1982. Des cartes de coefficient de corrélations temporelles, entre la série chronologique de la première analyse FEO de la concentration hivernale de glace marine et les champs des anomalies atmosphériques hivernales, sont établies en déphasage de 0 et ± 1 année. Des corrélations maximales sont observées lorsque la série chronologique de cette analyse FEO 1 de glace mène les champs des anomalies atmosphériques par une année. Un résultat particulièrement intéressant est la relation entre les anomalies de glace dans les mers du Groenland et de Barents, et les anomalies subséquentes de pression du même signe sur le bassin Irminger et l'Arctique canadien. Cet article met l'accent sur l'identification des relations, d'une année à l'autre, entre la glace marine arctique et les anomalies de la circulation atmosphérique.
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Research Interests: Environmental Engineering, Civil Engineering, Climate Change, Climatology, Climate variability, and 12 moreSea Ice, Seasonality, Atmospheric sciences, Historical Climatology, North Atlantic, Little Ice Age, Canonical Correlation Analysis, Air Temperature, European regions, Statistical Model, Indexation, and Regression equation
... The year 1740 is recognized as being one of the coldest in Europe in over 300 years (Luterbacher et al. 2002), and both 1740 and 1742 rank among the 30 coldest Northern Hemisphere summers of the past 600 years, based on tree-ring data... more
... The year 1740 is recognized as being one of the coldest in Europe in over 300 years (Luterbacher et al. 2002), and both 1740 and 1742 rank among the 30 coldest Northern Hemisphere summers of the past 600 years, based on tree-ring data (Briffa et al. ...
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A set of 71 station series of surface pressure from Canada and Greenland have been examined for quality control and homogeneity. These records range in length from 50 to 130 years. The object of this exercise was to investigate... more
A set of 71 station series of surface pressure from Canada and Greenland have been examined for quality control and homogeneity. These records range in length from 50 to 130 years. The object of this exercise was to investigate station-based surface pressure series and atmospheric circulation on a decadal time scale, and to examine the effects of the atmospheric circulation on climate. The data considered here are monthly means.Several major inhomogeneities were discovered during the course of this exercise, the most serious of which relates to a Canadian-wide change in reporting practice which took place in 1977. This type of inhomogeneity is almost impossible to uncover using conventional homogenization techniques based upon reference series. The final homogenized series show appreciable differences in regional trends of atmospheric pressure compared with the unhomogenized series, particularly in southern Canada.Empirical orthogonal function (EOF) analyses on the station series revealed three main modes of circulation over Canada and Greenland; these patterns were compared with results from the UK Hadley Centre's gridded pressure dataset. There are appreciable differences between the leading EOF modes of the two datasets, which may be due to an artificially enhanced number of degrees of freedom in the gridded dataset. Trends in atmospheric pressure were also calculated; these suggest an intensification of zonal flow during winter over the period 1950–98, but these variations appear to be much less pronounced and not statistically significant when considered over the whole of the 20th century.The new station database was also compared with a gridded surface temperature dataset. There are strong correlations between the various circulation indices and temperature anomalies. Some of the trends of temperature in Canada during the period 1950–98 can be attributed to these changes of atmospheric circulation. The regional atmospheric circulation indices described here are shown to have considerable influence on the surface temperature variability and trends for all seasons of the year. Copyright © 2005 Royal Meteorological Society
Research Interests: Environmental Engineering, Civil Engineering, Climatology, Time series analysis, Quality Control, and 15 moreHomogenization, Seasonality, Atmospheric sciences, Statistical Significance, Temperature, Land Surface Temperature, Atmospheric Pressure, Atmospheric Circulation, Air Temperature, Empirical Orthogonal Functions, Seasonal Variations, Surface Pressure, Degree of Freedom, Observations, and Atmospheric Temperature
Research Interests: Oceanography, Climate Change, Time Series, Principal Component Analysis, North Atlantic Oscillation, and 12 moreClimate Dynamics, Atmospheric sciences, North Atlantic, Land Surface Temperature, Fluctuations, Atmospheric Circulation, European regions, Indexation, Flow Pattern, Surface Pressure, Regional Analysis, and Atmospheric Temperature
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Daily pressure observations recorded by William Derham (1657–1735) at Upminster, Essex (near London), from 1697 to 1706 and 1708 have been corrected, converted to modern units and the Gregorian calendar, and adjusted for homogeneity.... more
Daily pressure observations recorded by William Derham (1657–1735) at Upminster, Essex (near London), from 1697 to 1706 and 1708 have been corrected, converted to modern units and the Gregorian calendar, and adjusted for homogeneity. These pressure readings have been compared with previously published contemporary observations from Paris, and the two sets of early instrumental data used to calculate a daily series of the pressure difference between Paris and London. Frequency analysis of the daily series reveals that reversals of the south–north pressure gradient and easterly winds were more common from 1697 to 1708 than during the 1990s. Monthly mean values of Paris–London pressure differences have been compared with previously published monthly mean reconstructed surface pressure maps and to a reconstructed North Atlantic Oscillation (NAO) index. There is a good agreement between the strength and direction of monthly mean flow between London and Paris estimated from the circulation maps and the sign and magnitude of the Paris–London westerly flow index, but the correlation between the Paris–London index, known to be a good proxy for European zonal circulation, and the reconstructed NAO index, is low (0.2). Correlations between the monthly mean Paris–London zonal circulation index and central England temperatures suggest a strong relationship during winter and late summer from 1697 to 1708. The meticulous daily instrumental observations and the monthly and seasonal climate descriptions of Derham, his collection of instrumental observations and climatic descriptions from contemporary observers throughout Europe, and his early theories on the causes of climate change make his publications a valuable source of information for studies on climate during the early instrumental period. It is hoped that more of Derham's papers related to weather and climate may eventually come to light. Copyright © 2001 Royal Meteorological Society.
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The quality of 51 series of surface pressure (extending back to between 1780 and 1871) over Europe is assessed using three different homogenization techniques. A new technique introduced here based on an iteration of multiple qualitative... more
The quality of 51 series of surface pressure (extending back to between 1780 and 1871) over Europe is assessed using three different homogenization techniques. A new technique introduced here based on an iteration of multiple qualitative comparisons and adjustments (MCAs), and the Caussinus and Mestre technique, based on multiple decision rules and Bayesian statistics, are two methods that do not require a homogeneous reference series for the detection and adjustment of inhomogeneities. The third technique, the standard normal homogeneity test, does require a homogeneous reference series for the homogenization procedure, and has been used only on the last 100 yr of each station series. The results of the three methods, as well as the original, unadjusted data, are compared for differences in the variance of the individual series and in their interstation correlations. Empirical orthogonal function analysis is also used to assess differences in the results of the adjustment methods. The comparisons suggest that surface pressure in this geographical domain may be considered as being stationary over periods ranging from decades to centuries, and thus homogeneous parts of a surface pressure record can be used to adjust for inhomogeneities, as is done using MCA. It is also seen that EOF analysis can be an effective tool to assess the homogeneity of a dataset. The results of the EOF analysis show that inhomogeneities and poorly adjusted series can have undue influence on subsequent analyses.
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Long series of monthly surface pressure observations are analysed from the 1770s to 1995, using empirical orthogonal function (EOF) analysis and circulation indices. Analyses of the associated principal components show that the... more
Long series of monthly surface pressure observations are analysed from the 1770s to 1995, using empirical orthogonal function (EOF) analysis and circulation indices. Analyses of the associated principal components show that the variability of surface atmospheric circulation over Europe (35°-70°N and 30°W-40°E) is well captured, using only 20 stations. The first three EOF patterns of the study are the central tendency of European pressure (EOF 1), a zonal flow pattern over Europe (EOF 2), and a blocking/cyclonic pattern in the eastern North Atlantic (EOF 3). EOF analyses on sub-periods of the station records suggest episodes of more intense meridional circulation (EOF 3) from 1822 to 1870, and stronger zonal westerlies from 1947 to 1995. Simple zonal circulation indices were also constructed for a North Atlantic Oscillation (NAO) index using Gibraltar and Reykjavik (1821-1995), a western European zonal index using Madrid, Barcelona, Trondheim and Lund (1786-1995), and a Paris-London index (1774-1995). Correlation analysis suggests that the NAO may be a better indicator of eastern North Atlantic blocking or cyclonicity (EOF 3) than of European zonal flow, especially outside the winter months. Both the western European and Paris-London zonal indices were highly correlated with the time series principal components (PCs) of EOF 2, extending the construction of a reliable monthly index of European surface westerlies to 1774. The zonal flow indicated by these circulation indices appears to have been considerably more variable, with more extreme values, in the late 18th and early 19th centuries than in the 20th century. From the 200-year perspective presented here, the recent positive trend in the NAO does not appear unusual.
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The relationship between surface atmospheric circulation and temperature in Europe from the 1770s to 1995 is examined using correlation analysis. The atmospheric circulation is represented by six indices: the three leading principal... more
The relationship between surface atmospheric circulation and temperature in Europe from the 1770s to 1995 is examined using correlation analysis. The atmospheric circulation is represented by six indices: the three leading principal components (PCs) of an empirical orthogonal function (EOF) analysis of 20 European pressure series from 1822 to 1995, which represent the central tendency of European pressure (EOF 1), a zonal circulation pattern (EOF 2) and a meridional pattern (EOF 3), a North Atlantic zonal index constructed from Gibraltar and Reykjavik pressure series for 1821-1995; a Western European zonal index constructed from Madrid, Barcelona, Lund and Trondheim for 1786-1995; and an index constructed from Paris and London, 1774-1995. Eight long temperature series from northwestern and central Europe were correlated with these circulation indices. European temperatures in general had the highest correlations with the zonal circulation indices in winter, with almost 70% of the variability in the temperature records explained by variations in the zonal index. The correlation coefficients between PC 3 (representing meridional circulation) and temperatures were highest in spring and autumn, particularly for Scandinavia. Running correlation series calculated over 25-year windows reveal significant non-stationarities in the relationship between surface temperature and atmospheric circulation on decadal time scales, suggesting caution must be used in extrapolating current relationships between circulation and temperature for future climate predictions based on downscaling or past palaeoclimatic reconstructions.
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Daily pressure observations recorded by William Derham (1657-1735) at Upminster, Essex (near London), from 1697 to 1706 and 1708 have been corrected, converted to modern units and the Gregorian calendar, and adjusted for homogeneity.... more
Daily pressure observations recorded by William Derham (1657-1735) at Upminster, Essex (near London), from 1697 to 1706 and 1708 have been corrected, converted to modern units and the Gregorian calendar, and adjusted for homogeneity. These pressure readings have been compared with previously published contemporary observations from Paris, and the two sets of early instrumental data used to calculate a daily series of the pressure difference between Paris and London. Frequency analysis of the daily series reveals that reversals of the south-north pressure gradient and easterly winds were more common from 1697 to 1708 than during the 1990s. Monthly mean values of Paris-London pressure differences have been compared with previously published monthly mean reconstructed surface pressure maps and to a reconstructed North Atlantic Oscillation (NAO) index. There is a good agreement between the strength and direction of monthly mean flow between London and Paris estimated from the circulation maps and the sign and magnitude of the Paris-London westerly flow index, but the correlation between the Paris-London index, known to be a good proxy for European zonal circulation, and the reconstructed NAO index, is low (0.2). Correlations between the monthly mean Paris-London zonal circulation index and central England temperatures suggest a strong relationship during winter and late summer from 1697 to 1708. The meticulous daily instrumental observations and the monthly and seasonal climate descriptions of Derham, his collection of instrumental observations and climatic descriptions from contemporary observers throughout Europe, and his early theories on the causes of climate change make his publications a valuable source of information for studies on climate during the early instrumental period. It is hoped that more of Derham's papers related to weather and climate may eventually come to light.