TY  - JOUR
T1  - The Investigation and Forecasting of Relative Humidity Variation of Pars Abad-e-Moghan, North-West of Iran by ARIMA Model
AU - Samadzadeh, Rasool AU - Shiri, Mohammadreza AU - Salahi, Bromand AU - Shiri, Ghita 
JO  - Research Journal of Applied Sciences
VL  - 5
IS  - 6
SP  - 459
EP  - 465
PY  - 2010
DA  - 2001/08/19
SN  - 1815-932x
DO  - rjasci.2010.459.465
UR  - https://makhillpublications.co/view-article.php?doi=rjasci.2010.459.465
KW  - Iran
KW  -ARIMA
KW  -forecasting
KW  -relative humidity
KW  -SARIMA
KW  -trend
AB  - The use of statistical methods to study and predict changes in climate parameters has found wide application. One of these is Autoregressive Integrated Moving Average (ARIMA) model. In this study, the average monthly relative humidity of Pars Abad-e-Moghan station investigated based on above-mentioned model in a 25 years statistical period (1984-2010). Time series plot was used to investigate whether the series is stationary or non-stationary. Because the series was not stationary, so it was converted to a stationary series by Differencing order 1 (D = 1). Functions such as Autocorrelation Function (ACF), Partial Autocorrelation Function (PACF), Root Mean Square Error (RMSE), Mean Absolute Deviation (MAD) and Akaikes Information Criterion (AIC) were calculated to determine the order of Autoregressive (AR (p)) and Moving Average (MA (q)) parameters (Q, q, P, p). With considering above-mentioned criteria, seasonal ARIMA (p = 1, d = 0, q = 1) (P = 1, D = 1, Q = 1) modal was chosen as best modal. So, it was used to predict future values of relative humidity. Before using the model for forecasting, it checked for adequacy based on plot of standardized residuals, ACF plot of residuals, PACF plot of residuals. The relative humidity of Pars Abad-e-Moghan station was forecasted based on selected modal up to 2014. The results of which indicate the relative humidity in May, June and September will be faced with an increasing trend while in the rest of months will be not observed any trend.
ER  -