A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis

Abstract

[1] 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.Citation: Vincent, L. A., X. L. Wang, E. J. Milewska, H. Wan, F. Yang, and V. Swail (2012), A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis,

Increasing Winter Baseflow in Response to Permafrost Thaw and Precipitation Regime Shifts in Northeastern China

“…These differences likely arise because (1) the watersheds in the present study span discontinuous, sporadic, and isolated permafrost systems that are more sensitive to climate warming than continuous permafrost environments [6,66] and (2) [68] and in Alaska (with the highest increases in winter in the interior region of 0.22 • C·decade −1 from 1949 to 1998) [69]. The spatial distribution of our results also points to the importance of permafrost thaw as a driver of hydrologic change.…”

Evaluation of CORDEX-Arctic daily precipitation and temperature-based climate indices over Canadian Arctic land areas

“…ec.gc.ca/index.php?page=download-obs) that have at least 15 valid years in the 1980-2004 validation period of GCM-driven RCM simulations. Where stations were adjusted and corrected for known systematic errors, we used the corrected station data from the Adjusted Historical Canadian Climate Data set (AHCCD; Vincent et al 2002Vincent et al , 2012Mekis and Vincent 2011). The AHCCD takes account of systematic errors from changes in observing programs, instrumentation and station moves (the latter for temperature data only), and also includes station joining to produce longer records.…”

Climatic Trends in the Temperature of Çanakkale City, Turkey

“…Long-term temporal trends in time series of the temperature have been studied in America (DeGaetano, 1996;Stafford et al, 2000;Zhang et al, 2000;Vincent et al, 2012), Europe (Klein Tank et al, 2002;Klein Tank & Können, 2003;Wijngaard et al, 2003;Feidas et al, 2004;del Río et al, 2007;Mohsin & Gough, 2009), Asia (Shrestha et al, 1999Su et al, 2006;Dhorde et al, 2009;Jain & Kumar, 2012). In Turkey, Türkeş et al (1996) investigated mean seasonal daily temperature during the period 1930-1993.…”