Influence of changes in the station location and measurement routine on the homogeneity of the temperature, wind speed and precipitation time series; pp. 302–313Full article in PDF format | doi: 10.3176/eng.2012.4.02
Changes in the location, instrumentation and measurement times are documented for three Estonian meteorological stations during the last century. These metadata were used to check if such changes have introduced significant discontinuities into the time series of daily and monthly mean temperature, average wind speed and daily and monthly precipitation sums. For this purpose, time periods of the length of at least ten years were separated before and after each change and average values of meteorological elements during these periods were compared by means of the t-test at the significance level of 0.05. On the daily basis, such changes introduced an increase in all parameters under consideration. On the monthly basis, only wind speed and precipitation sums were affected in some cases. Earlier climatological analyses have shown that in Estonia the temperature has risen and the precipitation sums have increased. Therefore, it is very difficult to separate natural trends from the artificial changes.
1. WMO. Guide to Meteorological Instruments and Methods of Observation (6th ed.). WMO, Geneva, 1996.
2. Davey, C. A. and Pielke, R. A. Sen. Microclimateexposures of surface-based weather stations. Bull. Amer. Meteorol. Soc., 2005, 86, 497–504.
3. Vose, R. S., Williams, C. N. Jnr., Peterson, T. C., Karl, T. R. and Easterling, D. R. An evaluation of the time of observation bias adjustment in the U.S. Historical Climatology Network. Geophys. Res. Lett., 2003, 30, Art. No. 2046.
4. Keevallik, S., Loitjärv, K., Rajasalu, R. and Russak, V. Meteorological regime of Lake Peipsi. In Lake Peipsi, Meteorology, Hydrology, Hydrochemistry (Nõges, T., ed.). Sulemees Publishers, Tartu, 2001, 18–37.
5. Ungersböck, M., Rubel, F., Fuchs, T. and Rudolf, B. Bias correction of global daily rain gauge measurements. Phys. Chem. Earth (B), 2001, 26, 411–414.
6. Keevallik, S., Männik, A. and Hinnov, J. Comparison of HIRLAM wind data with measurements at Estonian coastal meteorological stations. Estonian J. Earth Sci., 2010, 59, 90–99.
7. Ren, Y. Y. and Ren, G. Y. A remote sensing method of selecting reference stations for evaluating urbanization effect on surface air temperature trends. J. Climate, 2011, 24, 3179–3189.
8. Keevallik, S. and Russak, V. Changes in the amount of low clouds in Estonia (1955–1995). Int. J. Climatol., 2001, 21, 389–397.
9. Rosin, K. and Keevallik, S. Regional variation of hourly and daily totals of global radiation recorded at automatic weather stations in Estonia. Estonian J. Eng., 2012, 18, 76–86.
10. Peterson, T. C. Examination of potential biases in air temperature caused by poor station locations. Bull. Amer. Meteorol. Soc., 2006, 87, 1073–1089.
11. Pielke, R. Sr., Nielsen-Gammon, J., Davey, C., Angel, J., Bliss, O., Doesken, N., Cai, M., Fall, S., Niyogi, D., Gallo, K. et al. Documentation of uncertainties and biases associated with surface temperature measurement sites for climate change assessment. Bull. Amer. Meteorol. Soc., 2007, 88, 913–928.
12. Hung, C. Temperature discontinuity caused by relocation of meteorological stations in Taiwan. Terr. Atmos. Ocean. Sci., 2009, 20, 607–617.
13. Domonkos, P. and Štĕpánek, P. Statistical characteristics of detectable inhomogeneities in observed meteorological time series. Stud. Geophys. Geod., 2009, 53, 239–260.
14. Ducré-Robitaille, J.-F., Vincent, L. A. and Boulet, G. Comparison of techniques for detection of discontinuities in temperature series. Int. J. Climatol., 2003, 23, 1087–1101.
15. Brown, P. and DeGaetano, A. T. A method to detect inhomogeneities in historical dewpoint temperature series. J. Appl. Meteorol. Climatol., 2009, 48, 2362–2376.
16. Aguilar, E., Auer, I., Brunet, M., Peterson, T. C. and Wieringa, J. Guidelines on Climate Metadata and Homogenization. WCDMP-No. 53, WMO-TD No. 1186, WMO, Geneva, 2003.
17. Tarand, A. Tallinnas mõõdetud õhutemperatuuri aegrida. Publ. Geophys. Univ. Tartu., 2003, 93, 25–36.
18. Handbook of the Climate of the USSR, 4, Estonian SSR, Part II, Air and Ground Temperature. Gidrometeoizdat, Leningrad, 1965 (in Russian).
19. Handbook of the Climate of the USSR, 4, Estonian SSR, Part IV, Air Humidity, Precipitation and Snow Cover. Gidrometeoizdat, Leningrad, 1968 (in Russian).
20. Keevallik, S., Soomere, T., Pärg, R. and Žukova, V. Outlook for wind measurement at Estonian automatic weather stations. Proc. Estonian Acad. Sci. Eng., 2007, 13, 234–251.
21. Jaagus, J. Climatic changes in Estonia during the second half of the 20th century in relationship with changes in large-scale atmospheric circulation. Theor. Appl. Climatol., 2006, 83, 77–88.
22. Keevallik, S. and Soomere, T. Trends in wind speed over the Gulf on Finland 1961–2000. In Proc. 4th Study Conference on BALTEX. Gudhjem, Denmark, 2004. International BALTEX Secretariat, Geesthacht, Germany, 2004, 129–130.
23. Bryson, R. A. The paradigm of climatology: An essay. Bull. Amer. Meteorol. Soc., 1997, 78, 449–455.
24. Kärner, O. ARIMA representation for daily solar irradiance and surface air temperature time series. J. Atm. Sol-Terrest. Phys., 2009, 71, 841–847.25. Kärner, O. Tartu õhutemperatuuri tolerants ja kliima muutlikkus. Publ. Inst. Geogr. Univ. Tartu., 2011, 109, 58–75.
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