scholarly journals Seasonal sensitivity to atmospheric and ground surface temperature changes of an open earth-air heat exchanger in Canadian climates

Geothermics ◽  
2021 ◽  
Vol 89 ◽  
pp. 101914
Author(s):  
Andrew Zajch ◽  
William A. Gough
Keyword(s):  
Heat Exchanger ◽  
Surface Temperature ◽  
Ground Surface ◽  
Temperature Changes ◽  
Ground Surface Temperature

scholarly journals Modeling the Temperature Field in the Ground with an Installed Slinky-Coil Heat Exchanger

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4010
Author(s):  
Monika Gwadera ◽  
Krzysztof Kupiec
Keyword(s):  
Temperature Field ◽  
Heat Exchanger ◽  
Surface Temperature ◽  
Ground Surface ◽  
Heat Sources ◽  
Ground Surface Temperature ◽  
Coil Heat Exchanger ◽  
The Relationship ◽  
Temperature Responses ◽  
Coil Heat

In order to find the temperature field in the ground with a heat exchanger, it is necessary to determine temperature responses of the ground caused by heat sources and the influence of the environment. To determine the latter, a new model of heat transfer in the ground under natural conditions was developed. The heat flux of the evaporation of moisture from the ground was described by the relationship taking into account the annual amount of rainfall. The analytical solution for the equations of this model is presented. Under the conditions for which the calculations were performed, the following data were obtained: the average ground surface temperature Tsm = 10.67 °C, the ground surface temperature amplitude As = 13.88 K, and the phase angle Ps = 0.202 rad. This method makes it possible to easily determine the undisturbed ground temperature at any depth and at any time. This solution was used to find the temperature field in the ground with an installed slinky-coil heat exchanger that consisted of 63 coils. The results of calculations according to the presented model were compared with the results of measurements from the literature. The 3D model for the ground with an installed heat exchanger enables the analysis of the influence of miscellaneous parameters of the process of extracting or supplying heat from/to the ground on its temperature field.

scholarly journals North American regional climate reconstruction from Ground Surface Temperature Histories

2016 ◽  
Author(s):  
Fernando Jaume-Santero ◽  
Carolyne Pickler ◽  
Hugo Beltrami ◽  
Jean-Claude Mareschal
Keyword(s):  
Surface Temperature ◽  
North American ◽  
Regional Climate ◽  
Regional Analysis ◽  
Ground Surface ◽  
Transient Temperature ◽  
Acceptable Error ◽  
Temperature Changes ◽  
Ground Surface Temperature ◽  
Recent Climate

Abstract. Within the framework of the PAGES NAm2k project, 510 North American borehole temperature-depth profiles were analyzed to infer recent climate changes. To facilitate comparisons and to study the same time period, the profiles were truncated at 300 meters. Ground surface temperature histories for the last 500 years were obtained for a model describing the temporal ground surface temperature changes. The model consists of a series of 10 time-intervals of variable duration. The evaluation of the model is done by inversion of the transient temperature perturbations using singular value decomposition. The long-term surface temperature (T0) and thermal gradient (Γ0) were retrieved by linear regression for the bottommost 100 meters. In addition, a Monte-Carlo approach was used to find the range of solutions within an acceptable error difference between the forward-modelled history and the data. The results within 95 % confidence interval suggest a warming between 1.0 °C to 2.5 °C during the last two centuries. A regional analysis of mean temperature changes over the last 500 years show that all regions experienced warming, but this warming is not spatially uniform and is more marked in northern regions.

scholarly journals North American regional climate reconstruction from ground surface temperature histories

2016 ◽  
Vol 12 (12) ◽  
pp. 2181-2194 ◽  
Author(s):  
Fernando Jaume-Santero ◽  
Carolyne Pickler ◽  
Hugo Beltrami ◽  
Jean-Claude Mareschal
Keyword(s):  
Surface Temperature ◽  
North American ◽  
Regional Climate ◽  
Regional Analysis ◽  
Ground Surface ◽  
Temperature Changes ◽  
Ground Surface Temperature ◽  
Recent Climate ◽  
Geographical Maps ◽  
Value Decomposition

Abstract. Within the framework of the PAGES NAm2k project, 510 North American borehole temperature–depth profiles were analyzed to infer recent climate changes. To facilitate comparisons and to study the same time period, the profiles were truncated at 300 m. Ground surface temperature histories for the last 500 years were obtained for a model describing temperature changes at the surface for several climate-differentiated regions in North America. The evaluation of the model is done by inversion of temperature perturbations using singular value decomposition and its solutions are assessed using a Monte Carlo approach. The results within 95 % confidence interval suggest a warming between 1.0 and 2.5 K during the last two centuries. A regional analysis, composed of mean temperature changes over the last 500 years and geographical maps of ground surface temperatures, show that all regions experienced warming, but this warming is not spatially uniform and is more marked in northern regions.

scholarly journals 30,000 Years of Ground Surface Temperature and Heat Flux Changes in Karelia Reconstructed from Borehole Temperature Data

2013 ◽  
Vol 6 (1) ◽  
pp. 7-25 ◽  
Author(s):  
Dmitry Yu. Demezhko ◽  
Anastasia A. Gornostaeva ◽  
Georgy V. Tarkhanov ◽  
Oleg A. Esipko
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Global Climate ◽  
Ground Surface ◽  
Ice Cores ◽  
High Amplitude ◽  
Temperature History ◽  
Temperature Changes ◽  
Ground Surface Temperature ◽  
North West

Abstract Analyses of temperature-depth profiles logged in deep boreholes (> 1 km) permit the reconstruction of ground surface temperature (GST) and surface heat flux (SHF) histories in the period of global climate change at the border of the Pleistocene and the Holocene. We reconstructed past GST and SHF histories using data obtained from the 3.5-km-deep Onega borehole (Karelia, north-west Russia). The resulting reconstructions include information on the basal thermal regime of the Scandinavian Ice Sheet, which covered the region in the Last Glacial Maximum (LGM). The surface temperature history reveals a high amplitude of Pleistocene/ Holocene warming equal to 18-20 K. The heat flux changes precede the surface temperature changes and are close to the variations of insolation at a latitude of 60°N. A comparison of the reconstructed GST and SHF histories with the records of carbon dioxide contents in Antarctic ice cores shows that CO2 changes are much closer to temperature changes than they are to heat flux changes.

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