HR: 08:45h
AN: PP51G-04    [Abstracts]
TI: Measured vs. Simulated Transients of Temperature Logs - A Test of Borehole Climatology
AU: * Majorowicz, J
EM: majorowicz@shaw.ca
AF: Northern Geothermal, 105 Carlson Close, Edmonton, Alb T6R 2J8 Canada
AU: Skinner, W
EM: Walter.Skinner@ec.gc.ca
AF: Climate Research Branch, Environment Canada, 4905 Dufferin St., Toronto, Ont M3H 5T4 Canada
AU: Gosnold, W
EM: gosnold@badlands.nodak.edu
AF: Department of Geology and Geological Engineering, University of North Dakota, Grand Forks, ND 58202-8358 United States
AU: Safanda, J
EM: jsa@ig.cas.cz
AF: Geophysical Institute, Czech Academy of Science, Bocni II/1401, Spoilov, 141-31 Czech Republic
AB: Twenty-seven temperature-depth (T-z) profiles from shallow boreholes of less than 250 m in depth in mostly arid areas of the Canadian Prairie Provinces and northern U.S.A. Great Plains initially measured in the 1980's and early 1990's and repeated in the years 1995, 1999, 2000, 2004 and 2005 are compared with synthetic profiles based on the surface air temperature time series at nearby meteorological stations. Similar comparisons are currently being made for the northern U.S.A. Great Plains. The multiple T-z profiles of southwestern Canadian boreholes indicate a general agreement between ground surface temperature (GST) warming and warming observed in surface air temperature (SAT) series from meteorological stations. GST temperature changes of 0.1 - 0.2§ C and 0.4§ C are observed between the measurements for the shorter (decade) and longer (two decades) time spans, respectively. Temperature changes for the last 200 years derived from the FSI inversion of the deeper logs in southern Saskatchewan and southern-central Alberta in Canada are 2.5§ C. These changes correspond to those changes derived from synthetic profiles in which surface temperature time series are used as forcing signals. Repeated measurements in the U.S.A. northern Great Plains (North Dakota) show similar large relative temperature change as do the Saskatchewan wells. The comparison of changes from repeated temperature logs in the high warming areas of the Canadian Prairies and U.S.A. Great Plains with those simulated from SAT forcing shows that surface temperature forcing is responsible for the majority of the observed deviation of temperature with depth. In some cases however, differences higher than the error of measurements are observed between the model based on surface temperature forcing and observation. These are interpreted in terms of well hydrogeological conditions and the influence of snow cover.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 9350 North America
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005