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Application of the Least Squares Method in the Adjustment of Chlorodifluoromethane (HCFC-142b) Regression Models

Authors: L. J. de Bessa Neto, V. S. Filho, J. V. Ferreira Nunes, G. C. Bergamo


There are many situations in which human activities have significant effects on the environment. Damage to the ozone layer is one of them. The objective of this work is to use the Least Squares Method, considering the linear, exponential, logarithmic, power and polynomial models of the second degree, to analyze through the coefficient of determination (R²), which model best fits the behavior of the chlorodifluoromethane (HCFC-142b) in parts per trillion between 1992 and 2018, as well as estimates of future concentrations between 5 and 10 periods, i.e. the concentration of this pollutant in the years 2023 and 2028 in each of the adjustments. A total of 809 observations of the concentration of HCFC-142b in one of the monitoring stations of gases precursors of the deterioration of the ozone layer during the period of time studied were selected and, using these data, the statistical software Excel was used for make the scatter plots of each of the adjustment models. With the development of the present study, it was observed that the logarithmic fit was the model that best fit the data set, since besides having a significant R² its adjusted curve was compatible with the natural trend curve of the phenomenon.

Keywords: Chlorodifluoromethane (HCFC-142b), ozone (O3), least squares method, regression models.

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[1] United Nations Development Programmem – UNDP, “Protecting the Ozone Layer and Reducing Global Warming”, Results, Case Studies and Lessons Learned from UNDP’s Montreal Protocol Programme, 2010.
[2] S. Solomon, D. Wuebbles, “Ozone Depletion Potentials, Global Warming Potentials, and Future Chlorine/Bromine Loading”, Earth System Research Laboratory (ESRL), chapter 13, 2012.
[3] Earth System Research Laboratory – ESRL, “Chlorodifluoromethane HCFC-142b”, Available in em: . Access in: december 12, 2018.
[4] Montzka, S. A., R. C. Myers, J. H. Butler, and J. W. Elkins, “Early trends in the global tropospheric abundance of hydrochlorofluorocarbon-141b and -142b”, Geophys. Res. Lett., 21, 2483-2486, 1994.
[5] United Nations Environment Programme, “Environmen- tal Effects Assessment Panel, Environmental Effects of Ozone Depletion and Its Interactions with Climate Change,” Progress Report, 2010.
[6] A. Aggarwal, R. Kumari, N. Mehla, Deepali, and R. P. Singh, “Depletion of the Ozone Layer and Its Consequences: A Review”, American Journal of Plant Sciences, october 2013, vol. 4, pp. 1990-1997.
[7] D. Moreira, T. Tirabassi, “Mathematical Model of Pollutant Dispersion in the Atmosphere: a technical instrument for environmental management”, Magazine Environment and Society, vol. 2, 2004.
[8] Calm, A. Jain, D. J. Wuebbles, “Impacts on Global Ozone and Climate from Use and Emission of 2,2-Dichloro-1,1,1-Trifluoroethane (HCFC-123)” Climatic Change, january 1999, pp. 3-6.
[9] S. J. Miller, “The Method of Least Squares”, Mathematics Department, Brown University, 2012, pp. 2-7.
[10] R. Custodio, J. C. Andrade, F. Augusto, “The Adjustment of Mathematical Functions to Experimental Data”, Institute of Chemistry, State University of Campinas – UNICAMP, São Paulo, Brazil, 1996.
[11] R. N. Almeida, “The Least Squares Methods: Study and Applications for High School”, (Master's Dissertation in Mathematics) - Center of Science and Technology, Northern Fluminense State University, Rio de Janeiro, Brazi, 2015, 65p.