Statistical modeling of the association between pervasive precipitation anomalies in Southern Alburz and global ocean-atmospheric patterns

Document Type : Case Report


Scientific Faculty Member of Iranian Research Organization for Science and Technology (IROST), Tehran, Iran


Precipitation patterns are influenced by many factors, such as global atmospheric circulations to name but one. Precipitation patterns in Iran have always had great fluctuations even in a smaller scale like the Alburz Mountain Range. The present research has tried to find the relationship between global atmospheric patterns and the pervasive precipitation ones in Alburz. For doing so, 17 climate indices have been chosen with the correlation between these indices and the precipitation data calculated in different lag times, using a backward correlation method (from the present time to 3 months earlier). Based on the obtained correlation results, a regression modeling has been conducted that employs a backward method. As for each lag time, one equation has been offered to estimate the amount of precipitation for every single region. Results have shown that the Bivariate ENSO Time Series (BEST) and the East Pacific Oscillation (EPO) provide the highest correlation with the pervasive precipitation time series. Also, it has been demonstrated that in multivariate correlation, the efficient index to model the relation among these indices as well as precipitation in southern Alburz alters in each lag time. Both MBE and RMSE, employed to evaluate the modeling, show relatively acceptable values, implying that the equations are acceptably capable of predicting the amount of precipitation in both northern and southern Alburz.


Alijani, B. (2002). Variations of 500 hPa flow patterns over Iran and surrounding areas and their relationship with the climate of Iran. Theor. Appl. Climatol., 72, 41-54.
Allen, R.G., Periera, L.S., Raes, D. and Smith, M. (1998). Crop evapotranspiration: guideline for computing crop water requirement. FAO Irrigation and drainage paper 56. Food and Agriculture Organization, Rome. Italy.
Bannayan, M., Sanjani, S., Alizadeh, A., Sadeghi-Lotfabadi, S. and Mohamadian, A. (2010). Association between climate indices, aridity index, and rainfed crop yield in northeast of Iran. Field Crop Res., 118, 105–114.
Cai, J., Liu, Y., Lei, T. and Pereira, L.S. (2007). Estimating reference evapotranspiration with the FAO Penman–Monteith equation using daily weather forecast messages. Agric. For. Meteorol., 145(1), 22-35.
Frei, C., Schar, C., Luthi, D. and Davies, H.C. (1998). Heavy precipitation processes in the warmer climate. Geophys. Res. Lett., 25, 1431-1434.
Ghahraman, B. (2006). Time trend in the mean annual temperature of Iran. Turk. J. Agric. For., 30, 439-448.
Ghasemi, A.R. and Khalili, D. (2008a). The association between regional and global atmospheric patterns and winter precipitation in Iran. Atmos. Res., 88, 116-133.
Ghasemi A.R. and Khalili, D. (2008b). The Effect of the North Sea- Caspian Pattern on winter temperatures in Iran Theor. Appl. Climatol., 12, 59-74
Ghasemi, A.R. and Khalili, D. (2006). The influence of the Arctic Oscillation on winter temperatures in Iran. Theor. Appl. Climatol., 85, 149-164.
Gocic, M. and Trajkovic, S. (2010). Software for estimating reference evapotranspiration using limited weather data. Comput. Electron. Agric., 71, 158-162.
Goodess, C.M. and Jones, P.D. (2002). Link between circulation and changes in the characteristics of Iberian rainfall. Int. J. Climatol., 22, 1593-1615.
Javanmard, S., Babaeian, I., Bodaghjamali, J., Shahabfar, A.R. and Khazanedari, L. (2004). The correlation between the variability of Kazakhstan–Oman Gulf and precipitation changes in Iran. Geogr. Res., 71, 134-150. [in Persian]
Karbassi, A.R. and Amirnezhad, R. (2004). Geochemistry of heavy metals and sedimentation rate in a bay adjacent to the Caspian Sea. Int J. of Environ. Sci. Tech., 1(3), 191-198.
Masih, I., Uhlenbrook, S., Maskey, S. and Smakhtin, V. (2011). Streamflow trends and climate linkages in the Zagros Mountains, Iran. Clim. Chang., 104, 317-338.
Modarres, R. and Sarhadi, A. (2009). Rainfall trends analysis of Iran in the last half of the twentieth century. J. Geophys. Res., 114, D03101.
Modarres, R. and da Silva, V.P.R. (2007). Rainfall trends in arid and semi-arid regions of Iran. J. Arid Environ., 70, 344-355.
Moradi, H.R. (2004). The effects of NAO index on climate of Iran. Geogr. Res., 48, 17-30. [in Persian with English abstract]
Nazemosadat, M.J. and Cordery, I. (2000). On the relationships between ENSO and autumn rainfall in Iran. Int. J. Climatol., 20, 47-61.
Nazemosadat, M.J. and Ghasemi, A.R. (2004). Quantifying the ENSO-related shifts in the intensity and probability of drought and wet periods in Iran. J. Clim., 17, 4005-4018.
Popova, Z., Kercheva, M. and Pereira, L. (2006). Validation of the FAO methodology for computing ET with limited data. Application to south Bulgaria. Irrig. Drain., 55, 201-215.
Sabziparvar, A.A., Mirmasoudi, S.H., Tabari, H., Nazemosadat, M.J. and Maryanaji, Z. (2011). ENSO teleconnection impacts on reference evapotranspiration variability in some warm climates of Iran. Int. J. Climatol., 31(11), 1710-1723.
Sharmad, T., Bidhendi, GRN., Karbassi, AR., Moatar, F. and Adabi M.H. (2012). Historical changes in distribution and partitioning of natural and anthropogenic shares of heavy metals in sediment core from the southern Caspian SeaEnv. Earth Sci., 67(3), 799-811.
Tabari, H. and Hosseinzadeh -Talaee, P. (2011a). Analysis of trends in temperature data in arid and semi-arid regions of Iran. Glob. Planet. Chang., 79, 1-10.
Tabari, H. and Hosseinzadeh-Talaee, P. (2011b). Recent trends of mean maximum and minimum air temperatures in the western half of Iran. Meteorog. Atmos. Phys., 111, 121–131.
Tabari, H. and Hosseinzadeh-Talaee, P. (2011c). Temporal variability of precipitation over Iran: 1966-2005. J. Hydrol., 396, 313-320.