Author name:
وسن عادل عبد الوهاب
Supervisor name:
سالار علي خضر الدزيي
Abstract:
The continental feature is a correlative feature in the climate of Iraq because of its geographic position which is characterize of being far away from the water bodies. Such water bodies may show their effect on the temperature ranges and other elements of the climate as far as many obvious differences are observed between one year and another and from one area to another. For this reason, the study of pressure systems and their influences in changing the degree of the continental feature of the Iraqi climate during the period of (1970 - 2012) is carried out and most basically depending on the temperature averages of January and July. These two months were chosen as far as the former is considered the coldest month in Iraq while the latter is considered as the hottest. Therefore these two months can distinguish the continental feature.The degree of the continental feature could be counted by conducting a collection of equations applied to the studied stations. In this way, Borisov's equation resulted in the highest average with the rate of (78.6%) and according to which the Iraqi climate is ranging between the intense continental to the highly intense continental climate. Further, Gorczynski equation resulted in the rate of ( 60.7%), which, accordingly, included the Iraqi climatic station within the continental climate. Other equations as Johnson's rectified (modified) equation resulted in the rate of (50.9%), and Khromov's 2 equation (26.1%) and Khromov's 1 equation (26%). While Wallen's equation recorded the lowest average with the rate of (22.7%). What is shown through carrying out these equations is that the degree of the continental feature increase towards southern parts of Iraq, while it decreases towards the north. There is only one exception of Kharamov's equation 1 and 2 according to which this continental feature increases towards the north while it decreases moving towards the south, Except Johnson amended where it appeared that the continental trend does not take a degree or a certain character in continental prevail recipe diversity among sections of IraqAs far as the general trend of the degree of the continental feature of the Iraqi climate is concerned, there appeared that some climatic stations tended to an increase in their continental feature while others tended to a decrease in that same feature. Forinstance, the climatic stations of Mousil, Sinjar and Sulaymaniyah, were more tending to the decrease in their continental feature. This result was in reverse to the other climate stations whose attitude was towards the increase in their continental feature as Kirkuk, Khaniqeen, Baghdad, Rutbah, Karbala', Hay, Umarah, Samawah Nasiriyah, and Basra. This means that the northern parts of Iraq witness a decrease in their continental feature in comparison to the middle and southern stations which witness an increase in their same feature.Also, there was noticed that this continental feature increased in certain years while other years witnessed a decrease in this feature. According to the study of the elements of the climate, it is shown that the temperature of January during the years that witnessed an increased continental feature at the average of (7.9 C°), was much colder than the years witnessing the decreased continental feature at the average of (10.8 C°) and thus was warmer. Reversely, in June during the years of the decreased continental feature, the temperature recorded its height with (36.3 C°), whereas, in the years witnessing a decreased continental feature, the temperature was rather lower recording (34.6 C°).Concerning the degree of relative humidity, its disparity average between one January and another was 2.2% and the disparity average between one June and another was (1.5%). This happens because July is well characterized by its dryness in comparison to January which is wetter than June. It is noteworthy that June usually witnesses an activation of the extensions of the law Indian Seasonal in addition to the overwhelming continental tropical air mass (cT) which is a dry and hot mass.The disparity of the rain rates between the increased continental feature years and the decreased continental feature years and during the months of January reached (1622.5 mm) and this rate is considered as a very large disparity rate when compared to other climate elements. As for the average of the wind speed in June during the increased continental feature years, it reached (3 - 8 m/sec.), while in the decreased continental featureyears, it reached the average of (4.2 m/sec.). Therefore, the disparity between the two was (0.4m/sec.) which is a rate that exceeded the disparity occurring between the months of January of the increasing and decreasing years as it rates to (0.1m/sec.).By analyzing the weather maps of the level (1000) mb during January, it is shown that the union law was characterized by a larger frequency in the years of decreased continental feature as the sum of redundancies reached (34) times. While in the years of increased continental feature, the sum of frequency reached 25 times. In this way, the disparity in the redundancy between the increasing and decreasing years reached 9 law and this disparity is considered as the most responsible reason in constructing the continental feature because the law is the reason behind decreasing the continental feature because it is a dump law and it remains wet for a longer time, let alone that it is very wide.Finally, as for the pressure level (500) mb, it appears that the ridge has an inverse relation with the continental feature. As it happens, the more its redundancy occurs, the less the continental feature is. That is to say, winter is to become warmer in the years during which the redundancy increases, while the less redundancy occurs, the more the continental feature is and the less warm and the colder winter will be and that is January.
