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PATTERNS OF DIURNAL VARIATION OF GROWING SEASON PRECIPITATION ON THE CANADIAN PRAIRIES: A HARMONIC ANALYSIS
Author(s) -
CHAKRAVARTI A.K.,
ARCHIBOLD O.W.
Publication year - 1993
Publication title -
canadian geographer / le géographe canadien
Language(s) - French
Resource type - Journals
SCImago Journal Rank - 0.35
H-Index - 46
eISSN - 1541-0064
pISSN - 0008-3658
DOI - 10.1111/j.1541-0064.1993.tb01537.x
Subject(s) - precipitation , forestry , geography , morning , diurnal temperature variation , dry season , climatology , cartography , meteorology , geology , biology , botany
We analyze the spatial variation in diurnal daytime‐nighttime precipitation amounts and event frequency, using 24 years (1965‐88) of hourly growing season precipitation records for 24 stations on the Canadian Prairies. Harmonic analysis indicates that both maximum amount of precipitation and maximum frequency of precipitation events occur during late night to early morning throughout the agricultural areas. Comparison of drier and wetter season precipitation patterns indicates further that the nocturnal maximum is weak in the drier and strong in the wetter growing seasons. Identification of these patterns might be helpful for more reliable forecasting of not onlyprecipitation probabilities for various times of day during the growing season in general, but also those for drier vs. wetter seasons in particular. Nous analysons la variation spatiale de la frequence et de la quantitk depre'cipitations diurnales utilisant des observationsCchelonne'essurunepe'riode de24 anne'es (I 965‐ 88) et recueillies toutes les heures durant la saison de croissance pour 24 stations des prairies Canadiennes. Une analyse harmonique rnontre qu'ti travers ces re'gions agricoles, la quantite' rnaxirnale de pre'cipitations ainsi que la frkquence rnaxirnale de ces evhernents seproduisent tard la nuit jusqu'ti t8t le rnatin. De plus, la cornparaison des rnoddes de prtkipitations recueillis durant les saisons les plus sPches et les plus hurnides rnontre que le rnaxirnurn nocturne est faible durant les saisons les plus seches et Clev6 durant les saisons les plus hurnides. L'identification de ces tendences devrait aider ti I'elaboration de predictions plus exactes concernant non seulernent les probabilite's de prkcipitations ti toute heuredu jour et de la nuit durant la saison de croissance, mais aussi, et plus particulisrernent, les probabilite's de precipitations attache'es ti I'identification des saisons les plus seches et des saisons les plus hurnides.