The Changes in Categories Relative Humidity in Iraq

Abstract

The aim of this reaserch is study the change in relative humidity(R.H)categories,which is divided according to classification scientist Ravinshteen it is humidity high category 100%-80%,humidities 80%-65%humidity medium 65%-50%and humidity low category less than 50%. and applied this classification on the hours data period (1985-2010). It is show the R.H categories 100%-80%,80%-65%and65%-50% recored low frequency in second session comparison first session exception humidity low category which is record high frequency at the expense of other categories.concering frequency value high ten number100%-90%which is lowest frequency too in the second cycle the value 96% record hight diffrence in frequency between two cycle. And there are seasonal changes between two session. To determind the reasons of this changes in( R.H) categories its correlation with average temperature and rainfall and rate of wind speed. It has been found all the study station witness change increase in average temperature in the second session comparison first session and Rutba station record high difference in average reach 2.6C.and average of rainfall is also dropped in second session . the average frequency of wind speed , the low and medium speed is increase in second session comparison speed strong wind which dropped in second cycle .in addition there are another egology facts result to low value of (R.H) Key wordsRelative Humidity , Categories , Temperature , Rainfall