Tree-ring based reconstructions of precipitation for the southern Canadian Cordillera

• Published in: Climatic change 2004-07, Vol.65 (1-2), p.209-241
• Main Authors: WATSON, Emma, LUCKMAN, Brian H
• Format: Article
• Language: English
• Subjects: Climate; Climate change; Drought; Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Pine trees; Precipitation; Trees; Water in the atmosphere (humidity, clouds, evaporation, precipitation)
• ISSN: 0165-0009; 1573-1480
• DOI: 10.1023/b:clim.0000037487.83308.02

This paper reconstructs precipitation variability in the southern Canadian Cordillera over the past 3-400 years using dendroclimatological techniques. Fifty-three total ring-width (RW) chronologies, 28 earlywood (EW) and 28 latewood (LW) chronologies were developed from open-grown, low-elevation stands of Pseudotsuga menziesii (Douglas-fir) and Pinusponderosa (ponderosa pine) across the southern Canadian Cordillera. RW, EW and LW chronologies from both species were used to develop 13 annual (prior July to current June) precipitation reconstructions across the region. The reconstructions range in length from 165 to 688 years, pass verification tests and capture 39-64% of the variancein the instrumental record. Coincident, prolonged intervals of dry conditions are estimated for the years: 1717-1732, 1839-1859, 1917-1941 and 1968-1979. Shorter dry intervals are identified between 1581-1586, 1626-1630,1641-1653 1701-1708, 1756-1761, 1768-1772, 1793-1800,1868-1875, 1889-1897 and 1985-1989. The historic drought of the 1920-1930s was the longest but not the most intense across this area in the last 300 years. Wet conditions occur in the majority of reconstructions for the years: 1689-1700, 1750-55,1778-1789, 1800-1830, 1880-1890, 1898-1916 and 1942-1960. Thesedata, in conjunction with data from adjacent areas, are used to provide the first maps of decadal precipitation anomalies for the region between 1700 and 1990. [PUBLICATION ABSTRACT]