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Observed changes in relative humidity and dew point temperature in coastal regions of Iran

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Abstract

The analysis of trends in hydroclimatic parameters and assessment of their statistical significance have recently received a great concern to clarify whether or not there is an obvious climate change. In the current study, parametric linear regression and nonparametric Mann–Kendall tests were applied for detecting annual and seasonal trends in the relative humidity (RH) and dew point temperature (T dew) time series at ten coastal weather stations in Iran during 1966–2005. The serial structure of the data was considered, and the significant serial correlations were eliminated using the trend-free pre-whitening method. The results showed that annual RH increased by 1.03 and 0.28 %/decade at the northern and southern coastal regions of the country, respectively, while annual T dew increased by 0.29 and 0.15°C per decade at the northern and southern regions, respectively. The significant trends were frequent in the T dew series, but they were observed only at 2 out of the 50 RH series. The results showed that the difference between the results of the parametric and nonparametric tests was small, although the parametric test detected larger significant trends in the RH and T dew time series. Furthermore, the differences between the results of the trend tests were not related to the normality of the statistical distribution.

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References

  • Abu-Taleb AA, Alawneh AJ, Smadi MM (2007) Statistical analysis of recent changes in relative humidity in Jordan. Am J Environ Sci 3(2):75–77

    Article  Google Scholar 

  • Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B et al (2006) Global observed changes in daily climate extremes of temperature and precipitation. J Geophys Res 111:D05109. doi:10.1029/2005JD006290

    Article  Google Scholar 

  • Croitoru AE, Holobaca IH, Lazar C, Moldovan F, Imbroane A (2011) Air temperature trend and the impact on winter wheat phenology in Romania. Climate Chang. doi:10.1007/s10584-011-0133-6

  • Dai A (2006) Recent climatology, variability, and trends in global surface humidity. J Climate 19:3589–3606

    Article  Google Scholar 

  • Elliott WP, Angell JK (1997) Variations of cloudiness, precipitable water and relative humidity over the United States: 1973–1993. Geophys Res Lett 24:41–44

    Article  Google Scholar 

  • Feidas H, Noulopoulou Ch, Makrogiannis T, Bora-Senta E (2007) Trend analysis of precipitation time series in Greece and their relationship with circulation using surface and satellite data: 1955–2001. Theor Appl Climatol 87:155–177

    Article  Google Scholar 

  • Gaffen DJ, Ross RJ (1999) Climatology and trends of U.S. surface humidity and temperature. J Climate 12:811–828

    Article  Google Scholar 

  • Hamed KH, Rao AR (1998) A modified Mann–Kendall test for autocorrelated data. J Hydrol 204:182–196

    Article  Google Scholar 

  • Hulme M (1996) Recent climatic change in the world’s drylands. Geophys Res Lett 23:61–64

    Article  Google Scholar 

  • Huth R, Pokorna L (2004) Parametric versus nonparametric estimates of climatic trends. Theor Appl Climatol 77:107–112

    Article  Google Scholar 

  • Jaagus J (2006) Climatic changes in Estonia during the second half of the 20th century in relationship with changes in large-scale atmospheric circulation. Theor Appl Climatol 83:77–88

    Article  Google Scholar 

  • Khaliq MN, Ouarda TBMJ, Gachon P (2009) Identification of temporal trends in annual and seasonal low flows occurring in Canadian rivers: the effect of short- and long-term persistence. J Hydrol 369:183–197

    Article  Google Scholar 

  • Liu X, Xu Z, Yu R (2011) Trend of climate variability in China during the past decades. Climate Chang 109(3–4):503–516

    Article  Google Scholar 

  • Pal I, Al-Tabbaa A (2011) Assessing seasonal precipitation trends in India using parametric and non-parametric statistical techniques. Theor Appl Climatol 103:1–11

    Article  Google Scholar 

  • Robinson PJ (2000) Temporal trends in United States dew point temperatures. Int J Climatol 20(9):985–1002

    Article  Google Scholar 

  • Salmi T, Määttä A, Anttila P, Ruoho-Airola T, Amnell T (2002) Detecting trends of annual values of atmospheric pollutants by the Mann–Kendall test and Sen’s slope estimates—the Excel template application MAKESENS. Publications on Air Quality No. 31, Report code FMI-AQ-31 http://www.fmi.fi/kuvat/MAKESENS_MANUAL.pdf. Accessed 10 Jan 2008

  • Seidel TM, Grant AN, Pszenny AAP, Allman DJ (2007) Dewpoint and humidity measurements and trends at the Summit of Mount Washington, New Hampshire, 1935–2004. J Climate 20:5629–5641

    Article  Google Scholar 

  • Sen PK (1968) Estimates of the regression coefficient based on Kendall’s tau. J Am Stat Assoc 63:1379–1389

    Article  Google Scholar 

  • Tabari H, Aghajanloo M-B (2012) Temporal pattern of monthly aridity index in Iran with considering precipitation and evapotranspiration trends. Int J Climatol. doi:10.1002/joc.3432

  • Tabari H, Hosseinzadeh Talaee P (2011a) Analysis of trends in temperature data in arid and semi-arid regions of Iran. Glob Planet Chang 79:1–10

    Article  Google Scholar 

  • Tabari H, Hosseinzadeh Talaee P (2011b) Recent trends of mean maximum and minimum air temperatures in the western half of Iran. Meteor Atmos Phys 111:121–131

    Article  Google Scholar 

  • Tabari H, Hosseinzadeh Talaee P (2011c) Temporal variability of precipitation over Iran: 1966–2005. J Hydrol 396:313–320

    Article  Google Scholar 

  • Tabari H, Marofi S (2011) Changes of pan evaporation in the west of Iran. Water Resour Manag 25:97–111

    Article  Google Scholar 

  • Tabari H, Abghani H, Hosseinzadeh Talaee P (2011a) Temporal trends and spatial characteristics of drought and rainfall in arid and semi-arid regions of Iran. Hydrol Process. doi:10.1002/hyp.8460

  • Tabari H, Aeini A, Hosseinzadeh Talaee P, Shifteh Some’e B (2011b) Spatial distribution and temporal variation of reference evapotranspiration in arid and semi-arid regions of Iran. Hydrol Process. doi:10.1002/hyp.8146

  • Tabari H, Hosseinzadeh Talaee P, Ezani A, Shifteh Some’e B (2011c) Shift changes and monotonic trends in autocorrelated temperature series over Iran. Theor Appl Climatol. doi:10.1007/s00704-011-0568-8

  • Tabari H, Marofi S, Aeini A, Hosseinzadeh Talaee P, Mohammadi K (2011d) Trend analysis of reference evapotranspiration in the western half of Iran. Agric For Meteorol 151:128–136

    Article  Google Scholar 

  • Tabari H, Marofi S, Ahmadi M (2011e) Long-term variations of water quality parameters in the Maroon River, Iran. Environ Monitor Assess 177:273–287

    Article  Google Scholar 

  • Tabari H, Nikbakht J, Shifteh Somee B (2011f) Investigation of groundwater level fluctuations in the north of Iran. Environ Earth Sci. doi:10.1007/s12665-011-1229-z

  • Tabari H, Shifteh Somee B, Rezaian Zadeh M (2011g) Testing for long-term trends in climatic variables in Iran. Atmos Res 100:132–140

    Article  Google Scholar 

  • Theil H (1950) A rank-invariant method of linear and polynomial regression analysis, Part 3. Proc Koninalijke Nederlandse Akademie van Weinenschatpen A 53:1397–1412

    Google Scholar 

  • van Wijngaarden WA, Vincent LA (2003) Trends in relative humidity in Canada from 1953–2003. Report prepared for Climate Research Branch, Meteorological Service of Canada

  • von Storch H (1995) Misuses of statistical analysis in climate research. In: Storch HV, Navarra A (eds) Analysis of climate variability: applications of statistical techniques. Springer, Berlin, pp 11–26

    Google Scholar 

  • Wilcox RR (1998) A note on the Theil–Sen regression estimator when the regressor is random and the error term is heteroscedastic. Biom J 40:261–268

    Article  Google Scholar 

  • Willett KM, Gillett NP, Jones PD, Thorne PW (2007) Attribution of observed surface humidity changes to human influence. Nature 449:710–713

    Article  Google Scholar 

  • Yavuz H, ErdoÄŸan S (2011) Spatial analysis of monthly and annual precipitation trends in Turkey. Water Resour Manag. doi:10.1007/s11269-011-9935-6

  • Yue S, Hashino M (2003) Temperature trends in Japan: 1900–1996. Theor Appl Climatol 75:15–27

    Google Scholar 

  • Yue S, Pilon P, Phinney R, Cavadias G (2002) The influence of autocorrelation on the ability to detect trend in hydrological series. Hydrol Process 16:1807–1829

    Article  Google Scholar 

  • Yue S, Pilon P, Phinney B (2003) Canadian streamflow trend detection: impacts of serial and cross-correlation. Hydrol Sci J 48(1):51–63

    Article  Google Scholar 

  • Zhang Q, Xu C-Y, Zhang Z, Chen YD (2009) Changes of temperature extremes for 1960–2004 in Far-West China. Stoch Environ Res Risk Assess 23(6):721–735

    Article  Google Scholar 

Download references

Acknowledgments

We thank the Islamic Republic of Iran Meteorological Organization (IRIMO) for making available the meteorological data of the various synoptic stations.

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Correspondence to P. Hosseinzadeh Talaee.

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Hosseinzadeh Talaee, P., Sabziparvar, A.A. & Tabari, H. Observed changes in relative humidity and dew point temperature in coastal regions of Iran. Theor Appl Climatol 110, 385–393 (2012). https://doi.org/10.1007/s00704-012-0630-1

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  • DOI: https://doi.org/10.1007/s00704-012-0630-1

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