MacKay Data

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MacKay Modeling Group

Contents

MacKay Data

Temperature Data

Vincent, et al. (2012)

@article {JGRD:JGRD18070,
author = {Vincent, Lucie A. and Wang, Xiaolan L. and Milewska, Ewa J. and Wan, Hui and Yang, Feng and Swail, Val},
title = {A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis},
journal = {Journal of Geophysical Research: Atmospheres},
volume = {117},
number = {D18},
issn = {2156-2202},
url = {http://dx.doi.org/10.1029/2012JD017859},
doi = {10.1029/2012JD017859},
pages = {n/a--n/a},
keywords = {Climate change and variability, Climatology, General or miscellaneous, Canada, adjustment, discontinuity, homogeneity, temperature, trends},
year = {2012},
note = {D18110},
}

This study presents a second generation of homogenized monthly mean surface air temperature data set for Canadian climate trend analysis. Monthly means of daily maximum and of daily minimum temperatures were examined at 338 Canadian locations. Data from co-located observing sites were sometimes combined to create longer time series for use in trend analysis. Time series of observations were then adjusted to account for nation-wide change in observing time in July 1961, affecting daily minimum temperatures recorded at 120 synoptic stations; these were adjusted using hourly temperatures at the same sites. Next, homogeneity testing was performed to detect and adjust for other discontinuities. Two techniques were used to detect non-climatic shifts in de-seasonalized monthly mean temperatures: a multiple linear regression based test and a penalized maximal t test. These discontinuities were adjusted using a recently developed quantile-matching algorithm: the adjustments were estimated with the use of a reference series. Based on this new homogenized temperature data set, annual and seasonal temperature trends were estimated for Canada for 1950–2010 and Southern Canada for 1900–2010. Overall, temperature has increased at most locations. For 1950–2010, the annual mean temperature averaged over the country shows a positive trend of 1.5�C for the past 61 years. This warming is slightly more pronounced in the minimum temperature than in the maximum temperature; seasonally, the greatest warming occurs in winter and spring. The results are similar for Southern Canada although the warming is considerably greater in the minimum temperature compared to the maximum temperature over the period 1900–2010.


Vincent and Gullet (1998)

@article {JOC:JOC427,
author = {Vincent, Lucie A. and Gullett, D.W.},
title = {Canadian historical and homogeneous temperature datasets for climate change analyses},
journal = {International Journal of Climatology},
volume = {19},
number = {12},
publisher = {John Wiley & Sons, Ltd.},
issn = {1097-0088},
url = {http://dx.doi.org/10.1002/(SICI)1097-0088(199910)19:12<1375::AID-JOC427>3.0.CO;2-0},
doi = {10.1002/(SICI)1097-0088(199910)19:12<1375::AID-JOC427>3.0.CO;2-0},
pages = {1375--1388},
keywords = {Canada, homogeneity, trends, time series, temperature, database},
year = {1999},
}

Abstract

The Canadian Historical Temperature Database (CHTD) was developed to meet the need for detailed individual station datasets and to produce an improved historical climate change database. It contains datasets of monthly mean maximum and minimum temperatures for 210 Canadian stations. Stations were selected on the basis of length of record, data completeness, and spatial distribution across the country. Records from separate stations were sometimes joined to temporally extend their series backward. Missing data gaps were estimated using highly correlated neighbour stations. Relative homogeneity was assessed using a Canadian developed technique based on regression models. Nonclimatic steps resulting from station or site relocations were identified and quantified. Data adjustments were performed for large steps (greater than 0.6°C) with or without metadata and for medium steps (0.4–0.6°C) with support. A bias in minimum temperatures was also identified and adjusted at principal stations located in eastern Canada. The bias results from a change in observing procedure in 1961 throughout the country, and it typically produces a decreasing step of about 0.6–0.8°C in the annual series in the eastern part of the country. Although also detectable in western Canada, it appears to be small there and no bias adjustments were performed in the western part of the country. Large temporal and spatial differences in data availability exist between areas north and south of 60°N latitude making national analyses possible for only the latest 50 years of data. Spatial presentation of the linear trends before and after adjustments shows overall improvement to the regional and national trends in terms of spatial consistency. The CHTD contains the best available monthly temperature data in Canada and these datasets are now available to the climate change research community. Copyright © 1999 Royal Meteorological Society


Ice Data

http://www.norsemathology.org/longa/research/MacKay/data/Hill


Snow

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