scholarly journals Fiber optic distributed temperature sensing for the determination of air temperature

2014 ◽  
Vol 7 (6) ◽  
pp. 6287-6298
Author(s):  
S. A. P. de Jong ◽  
J. D. Slingerland ◽  
N. C. van de Giesen

Abstract. This paper describes a method to correct for the effect of solar radiation in atmospheric Distributed Temperature Sensing (DTS) applications. By using two cables with different diameters, one can determine what temperature a zero diameter cable would have. Such virtual cable would not be affected by solar heating and would take on the temperature of the surrounding air. The results for a pair of black cables and a pair of white cables were very good. The correlations between standard air temperature measurements and air temperatures derived from both colors had a high correlation coefficient (r2 = 0.99). A thin white cable measured temperatures that were close to air temperature. The temperatures were measured along horizontal cables but the results are especially interesting for vertical atmospheric profiling.

2015 ◽  
Vol 8 (1) ◽  
pp. 335-339 ◽  
Author(s):  
S. A. P. de Jong ◽  
J. D. Slingerland ◽  
N. C. van de Giesen

Abstract. This paper describes a method to correct for the effect of solar radiation in atmospheric distributed temperature sensing (DTS) applications. By using two cables with different diameters, one can determine what temperature a zero diameter cable would have. Such a virtual cable would not be affected by solar heating and would take on the temperature of the surrounding air. With two unshielded cable pairs, one black pair and one white pair, good results were obtained given the general consensus that shielding is needed to avoid radiation errors (WMO, 2010). The correlations between standard air temperature measurements and air temperatures derived from both cables of colors had a high correlation coefficient (r2=0.99) and a RMSE of 0.38 °C, compared to a RMSE of 2.40 °C for a 3.0 mm uncorrected black cable. A thin white cable measured temperatures that were close to air temperature measured with a nearby shielded thermometer (RMSE of 0.61 °C). The temperatures were measured along horizontal cables with an eye to temperature measurements in urban areas, but the same method can be applied to any atmospheric DTS measurements, and for profile measurements along towers or with balloons and quadcopters.


2011 ◽  
Vol 4 (2) ◽  
pp. 143-149 ◽  
Author(s):  
C. A. Keller ◽  
H. Huwald ◽  
M. K. Vollmer ◽  
A. Wenger ◽  
M. Hill ◽  
...  

Abstract. A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS) with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in September 2009, providing evidence that DTS is well suited for this atmospheric application. Observed stable temperature profiles exhibit an exponential shape confirming similarity concepts of the temperature inversion close to the surface. The atmospheric mixing height (MH) was estimated to vary between 5 m and 50 m as a result of the nocturnal boundary layer evolution. This value is in good agreement with the MH derived from concurrent Radon-222 (222Rn) measurements and in previous studies.


2010 ◽  
Vol 3 (3) ◽  
pp. 2723-2741 ◽  
Author(s):  
C. A. Keller ◽  
H. Huwald ◽  
M. K. Vollmer ◽  
A. Wenger ◽  
M. Hill ◽  
...  

Abstract. A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS) with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in September 2009, providing evidence that DTS is well suited for this atmospheric application. Observed stable temperature profiles exhibit an exponential shape confirming similarity concepts of the temperature inversion close to the surface. The atmospheric mixing height (MH) was estimated to vary between 5 m and 50 m as a result of the nocturnal boundary layer evolution. This value is in good agreement to the MH derived from concurrent Radon-222 (222Rn) measurements and in previous studies.


Author(s):  
Olena P. Mitryasova ◽  
Anna S. Pryhodko

The purpose of research consists in definition and an estimation of climatic factors influence on disease incidence of Covid-19 on an example of Mykolaiv city. In research we used such scientific methods: theoretical methods: analysis, synthesis, monitoring, systematization, generalization. For research facility, were held by calculations based on software Microsoft Excel. The calculations were performed using the formula correlation. Results. The study examines the influence of climatic factors such as air temperature, humidity, solar radiation activity, wind speed, rainfall, and length of daylight. For the pair «Disease incidence – Temperature» the correlation coefficient is −0.74. For the pair «Disease incidence − Solar Radiation» correlation coefficient is −0.71. For the pair «Disease incidence – Daylight hours» correlation coefficient is −0.70. Humidity, as a derivative of air temperature, is evidenced by a comparison of decline periods and growth of these values. In the spring, along with the increase in temperature, the humidity dropped, and in the fall, when the air temperature dropped, the humidity increased. This factor also affected the spread of the virus in the second half of the year, when the humidity increased the virus began to spread faster. For the pair «Disease incidence – Humidity» correlation coefficient is +0.73 (average direct correlation). Other climatic factors, such as wind speed and rainfall, have not been shown to have a significant effect on the rate of disease spread. For the pair «Disease incidence − Wind speed» correlation coefficient is +0.32, which corresponds to a weak direct correlation. For the pair «Disease incidence − Rainfall» correlation coefficient is −0.30, which indicates a weak inverse correlation. Conclusion. The results of the study show that the reduction of disease incidence is observed at high temperatures, high activity of solar radiation, and prolonged daylight, which determines the conditions for the prevention of such diseases and will improve the quality of life to achieve sustainable development.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.


2021 ◽  
Vol 7 (20) ◽  
pp. eabe7136
Author(s):  
Robert Law ◽  
Poul Christoffersen ◽  
Bryn Hubbard ◽  
Samuel H. Doyle ◽  
Thomas R. Chudley ◽  
...  

Measurements of ice temperature provide crucial constraints on ice viscosity and the thermodynamic processes occurring within a glacier. However, such measurements are presently limited by a small number of relatively coarse-spatial-resolution borehole records, especially for ice sheets. Here, we advance our understanding of glacier thermodynamics with an exceptionally high-vertical-resolution (~0.65 m), distributed-fiber-optic temperature-sensing profile from a 1043-m borehole drilled to the base of Sermeq Kujalleq (Store Glacier), Greenland. We report substantial but isolated strain heating within interglacial-phase ice at 208 to 242 m depth together with strongly heterogeneous ice deformation in glacial-phase ice below 889 m. We also observe a high-strain interface between glacial- and interglacial-phase ice and a 73-m-thick temperate basal layer, interpreted as locally formed and important for the glacier’s fast motion. These findings demonstrate notable spatial heterogeneity, both vertically and at the catchment scale, in the conditions facilitating the fast motion of marine-terminating glaciers in Greenland.


Ground Water ◽  
2012 ◽  
Vol 51 (5) ◽  
pp. 670-678 ◽  
Author(s):  
Matthew W. Becker ◽  
Brian Bauer ◽  
Adam Hutchinson

1998 ◽  
Vol 123 (2) ◽  
pp. 208-214 ◽  
Author(s):  
James E. Faust ◽  
Royal D. Heins

An energy-balance model is described that predicts vinca (Catharanthus roseus L.) shoot-tip temperature using four environmental measurements: solar radiation and dry bulb, wet bulb, and glazing material temperature. The time and magnitude of the differences between shoot-tip and air temperature were determined in greenhouses maintained at air temperatures of 15, 20, 25, 30, or 35 °C. At night, shoot-tip temperature was always below air temperature. Shoot-tip temperature decreased from 0.5 to 5 °C below air temperature as greenhouse glass temperature decreased from 2 to 15 °C below air temperature. During the photoperiod under low vapor-pressure deficit (VPD) and low air temperature, shoot-tip temperature increased ≈4 °C as solar radiation increased from 0 to 600 W·m-2. Under high VPD and high air temperature, shoot-tip temperature initially decreased 1 to 2 °C at sunrise, then increased later in the morning as solar radiation increased. The model predicted shoot-tip temperatures within ±1 °C of 81% of the observed 1-hour average shoot-tip temperatures. The model was used to simulate shoot-tip temperatures under different VPD, solar radiation, and air temperatures. Since the rate of leaf and flower development are influenced by the temperature of the meristematic tissues, a model of shoot-tip temperature will be a valuable tool to predict plant development in greenhouses and to control the greenhouse environment based on a plant temperature setpoint.


Sign in / Sign up

Export Citation Format

Share Document