Long-term climate change and surface versus underground temperature measurements in Paris

Abstract

Careful temperature measurements performed from 1783 to 1852 in underground galleries, 28 m below the Paris Observatory, are compared with current measurements performed in a limestone quarry, 20 m below ground surface, and with local and European surface temperature records. When averaged using a backward 11-year moving window, the surface temperature time series looks similar and exhibits the already well-known 1°C temperature increase over the last century. In addition, since about 1987, a steeper increase of about 0.07°C per year is noticed on all surface records. Underground temperatures, unaffected by surface fluctuations and averaging procedures, show a 0.9°C increase and thus confirm the trend indicated by the surface records. The averaged time series of the temperature in Paris and of the Wolf number, an indicator of sunspot activity, were reasonably well correlated till 1987 but deviated significantly from each other after that date. The long-term connection between surface temperature and solar cycles is further supported by a temporal analysis of the frequency content at 11 years and 5.5 years. Visual correlations between temperature and sunspot numbers, unconvincing when using recent records, appear more striking with underground data from 1783 to 1852. This analysis suggests that solar activity played an important role in temperature changes till the last century, but that different processes, possibly related to human-induced changes in the climate system, have been taking place lately with increasing intensity, especially since 1987.

Spatiotemporal variation of radon and carbon dioxide concentrations in an underground quarry: coupled processes of natural ventilation, barometric pumping and internal mixing

“…1), with pillars left in place to support the roof. About 4 m of the rock has been exploited, but most of the floor area is covered by about 2 m of filling from quarry waste, so that the mean distance between floor and ceiling is about 2 m. The average air temperature is 12.5 C, slowly increasing with time (Perrier et al, 2005a;Crouzeix et al, 2003), with an annual variation of the order of 0.04 C peak to peak. Relative humidity in the air ranges from 99.2 AE 0.1% to 99.8 AE 0.1% in most of the quarry.…”

Spatial and Temporal Dependence of Temperature Variations Induced by Atmospheric Pressure Variations in Shallow Underground Cavities

“…In winter, natural ventilation proceeds through the main vertical access pit (PERRIER et al, 2002;2005a). The average air temperature is 12.5°C, slowly increasing with time (PERRIER et al, 2005b), with an annual variation of the order of 0.04°C peak-to-peak. Relative humidity varies from 99.2 to 99.8% in most of the quarry.…”

“…The site is located 28 m below ground surface, in the same geological formation as the Vincennes quarry, in a cavity used in the XVIII th century for precise underground temperature measurements (Cassini, J.-D. manuscript AD5.22;PERRIER et al, 2005b). The cavity is now cemented and has a volume of 60 m 3 (width 2.5 m, depth 10 m, and height 2.4 m).…”

Analysis of urban effects on soil temperature in Ankara

“…In Paris, which has had a long-term urban environment and heavy water infiltration, it is revealed that the temperature increase closely matches the urban air temperature increase. Perrier et al (2005), using the deep-soil temperature in the underground quarry in Vincennes, near Paris, observed temperatures greater than eighteenth and nineteenth century extrapolated values below the Paris Observatory by 0.9 • C. This increase must include some contribution from the UHI. However, the agreement with the surface temperatures suggests that this contribution is not dominating.…”