Impact of Aligning Climatological Day on Gridding Daily Maximum-Minimum Temperature and Precipitation over Canada

Date

2011

Authors

Hopkinson, Ron F.
McKenney, Daniel
Milewska, Ewa
Hutchinson, Michael
Papadopol, Pia
Vincent, Lucie A.

Journal Title

Journal ISSN

Volume Title

Publisher

American Meteorological Society

Abstract

On 1 July 1961, the climatological day was redefined to end at 0600 UTC at all principal climate stations in Canada. Prior to that, the climatological day at principal stations ended at 1200 UTC for maximum temperature and precipitation and 0000 UTC for minimum temperature and was similar to the climatological day at ordinary stations. Hutchinson et al. reported occasional larger-than-expected residuals at 50 withheld stations when the Australian National University Spline (ANUSPLIN) interpolation scheme was applied to daily data for 1961-2003, and it was suggested that these larger residuals were in part due to the existence of different climatological days. In this study, daily minimum and maximum temperatures at principal stations were estimated using hourly temperatures for the same climatological day as local ordinary climate stations for the period 1953-2007. Daily precipitation was estimated at principal stations using synoptic precipitation data for the climatological day ending at 1200 UTC, which, for much of the country, was close to the time of the morning observation at ordinary climate stations. At withheld principal stations, the climatological-day adjustments led to the virtual elimination of large residuals in maximum and minimum temperature and a marked reduction in precipitation residuals. Across all 50 withheld stations the climatological day adjustments led to significant reductions, by around 12% for daily maximum temperature, 15% for daily minimum temperature, and 22% for precipitation, in the residuals reported by Hutchinson et al.

Description

Keywords

Keywords: Australian National University; Climate record; Climate stations; Gridding; Interpolation schemes; Maximum temperature; North America; Precipitation data; Interpolation; Data handling; air temperature; climatology; data processing; interpolation; precipit Climate records; Data processing; North America; Precipitation; Temperature

Citation

Source

Journal of Applied Meteorology and Climatology

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

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