Trends and periodicity of daily temperature and precipitation extremes during 1960–2013 in Hunan Province, central south China
In this study, the trends and periodicity in climate extremes are examined in Hunan Province over the period 1960–2013 on the basis of 27 extreme climate indices calculated from daily temperature and precipitation records at 89 meteorological stations. The results show that in the whole province, temperature extremes exhibit a warming trend with more than 50% stations being statistically significant for 7 out of 16 temperature indices, and the nighttime temperature increases faster than the daytime temperature at the annual scale. The changes in most extreme temperature indices show strongly coherent spatial patterns. Moreover, the change rates of almost all temperature indices in north Hunan are greater than those of other regions. However, the statistically significant changes in indices of extreme precipitation are observed at fewer stations than in extreme temperature indices, forming less spatially coherent patterns. Positive trends in indices of extreme precipitation show that the amount and intensity of extreme precipitation events are generally increasing in both annual and seasonal scales, whereas the significant downward trend in consecutive wet days indicates that the precipitation becomes more even over the study period. Analysis of changes in probability distributions of extreme indices for 1960–1986 and 1987–2013 also demonstrates a remarkable shift toward warmer condition and increasing tendency in the amount and intensity of extreme precipitation during the past decades. The variations in extreme climate indices exhibit inconstant frequencies in the wavelet power spectrum. Among the 16 temperature indices, 2 of them show significant 1-year periodic oscillation and 7 of them exhibit significant 4-year cycle during some certain periods. However, significant periodic oscillations can be found in all of the precipitation indices. Wet-day precipitation and three absolute precipitation indices show significant 1-year cycle and other seven provide significant power at the 4-year period, which are mainly found during 1970–1980 and after 1992.
KeywordsTemperature extremes Precipitation extremes Trends Periodicity
We thank the anonymous reviewers for their careful reading and constructive comments that improved the paper. Funding for this study was provided by the National Natural Science Foundation of China under grant 41472238, the Construct Program of the Key Discipline in Hunan Province of China under grant 20110001, Scientific Research Fund of Hunan Provincial Education Department of China under grant 14A097, and Hunan Provincial Innovation Foundation for Postgraduate under grant CX2016B211.
- Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B, Tank A, Haylock M, Collins D, Trewin B, Rahimzadeh F, Tagipour A, Kumar KR, Revadekar J, Griffiths G, Vincent L, Stephenson DB, Burn J, Aguilar E, Brunet M, Taylor M, New M, Zhai P, Rusticucci M, Vazquez-Aguirre JL (2006) Global observed changes in daily climate extremes of temperature and precipitation. J Geophys Res-Atmos 111(D5). doi: 10.1029/2005jd006290
- IPCC (2013) Climate change 2013: the physical science basis. Contribution of working group I to the fifth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, p 1535Google Scholar
- Kendall MG (1975) Rank correlation methods. Griffin, LondonGoogle Scholar
- Peterson TC, Folland C, Gruza G, Hogg W, Mokssit A, Plummer N (2001) Report of the activities of the working group on climate change detection and related rapporteurs. Tech. Doc. 1071, 146 pp, World Meteorological Organization, GenevaGoogle Scholar
- Peterson TC (2005) The workshop on enhancing south and central Asian climate monitoring and indices. Pune, India, February: 14–19Google Scholar
- Soltani M, Laux P, Kunstmann H, Stan K, Sohrabi MM, Molanejad M, Sabziparvar AA, Ranjbar Saadat Abadi A, Ranjbar F, Rousta I, Zawar-Reza P, Khoshakhlagh E, Soltanzadeh I, Badu CA, Azizi GH (2015) Assessment of climate variations in temperature and precipitation extreme events over Iran. Theor Appl Climatol: 1–21Google Scholar
- Zhang X, Yang F (2013) RClimDex (1.1) user manual. (Available at http: // cccma. Seos. Uvic. Ca /ETCCDI/software.shtml)Google Scholar