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Rainfall trend analysis is essential for managing water resources, agriculture, disaster management, and climate change research. The current study aims to examine annual rainfall variability and trend over 38 meteorological stations in Iraq during the period (1980-2021) using three tests: linear regression analysis (LRA), Mann-Kendall (MK), and the innovative trend analysis (ITA). The results of the three different tests showed that most stations recorded a decreasing trend except for four stations in ITA, six stations in MK, and seven stations in the LRA test, which exhibit a positive trend. However, three stations, Emaidyah, Rabiah, and Biji, showed an increasing trend for all three tests. The ITA test recorded more significant results (14 stations) than the other two tests. The larger significant result appeared in the significance level of 95 % (nine in LRA, eight in MK, and five in ITA). The outcomes of the three trend-detection approaches by assessing the statistical significance levels, 90 %, 95 %, and 99 %, revealed no significant trend in 16 stations dispersed throughout the various climatic zones of Iraq. Only Emadiayah station indicated a positive trend at the significance of 99 %. The overall results showed that the ITA test outperformed the MK and LRA tests since it produced more significant results. [ABSTRACT FROM AUTHOR]

Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m³ was situated to face the geographical south. The test room is thermally insulated and connected to a solar chimney which generates a convection current to draw the air out of the room through a heat exchanger. The heat exchanger was submerged in a water tank of 2 m length, 1 m width and 1 m height. It was also covered with a layer of soil mixture with a thickness of 10 cm. The experiment simulates the natural conditions of a shallow water surface, connected to the room from the other side. The study results revealed that the air temperature inside the test room was lower than that of the ambient air outside. Pearson correlation coefficient showed that there was a strong direct relationship between solar radiation, temperature and wind speed from one side and the cooling efficiency from the other side. Also, there was a negative correlation between relative humidity and cooling efficiency. [ABSTRACT FROM AUTHOR]

Tropospheric nitrogen dioxide (NO2) is a trace gas with important impact on atmospheric chemistry, human health and a key pollutant in particular cities, measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. This study present ten years (monthly and yearly averaged) dataset from Ozone Monitoring Instrument (OMI) used to investigate tropospheric NO2 characteristics and variations over Iraq during 2005-2014. Annual NO2 shows an elevation from the northern to the southern and highest values was at central parts of Iraq. Monthly distributions revels higher values NO2 in winter and summer than spring and autumn seasons, and rising NO2 throughout study period over industrial and crowded urban zones. The trend analysis over Baghdad shows a linear growth rate 9.8% per year with an annual average (5.6·1015 molecules per 1 cm2). The air mass trajectory analysis as hotspot regions shows seasonal fl uctuations between winter and summer seasons depend on weather conditions and topography. The increased NO2 values in winter are due to anthropogenic emissions and subsequent plumes from Europe. In addition, in summer because of hot weather and large paddy fi elds emissions. The lowest NO2 value was at monsoon period mostly linked to the rains. The OMI data and satellite information are able to observe the troposphere NO2 elevation at different regions. [ABSTRACT FROM AUTHOR]

In present paper, an artificial neural network (ANN) model is developed for estimating monthly mean daily global solar radiation of Baghdad city, Iraq. The results of the ANN models have been compared with measured data on the basis of root mean square error (RMSE), mean absolute error (MAE) and determination coefficient (R2). It is found that the solar radiation estimations by ANN are in good agreement with the measured values .Results obtained indicate that the ANN model can successfully be used for the estimation of monthly mean daily global solar radiation for Baghdad city. These results testify the generalization capability of the ANN model and its ability to produce accurate estimates in Baghdad. [ABSTRACT FROM AUTHOR]

Total Ozone Column (TOC) measured by Total Ozone Mapping Spectrometer (TOMS) broad on Earth probe (EP) for Baghdad city (Lat 33.35 N°, Long 44.45 E°) has been analyzed. The results give the estimate means and variability of temporal scale. Using linear regression, results shows that TOC has a trend of - 0.333 DU per year. The maximum and minimum day to day variation of TOC were 40.9% (121DU) and 22.4%(-66.3DU) respectively. A spectral analysis on daily values shows that the dominating oscillation periods are between 2.8 and 5.4 days. Solar activity has a weak effect on total ozone production with correlation coefficient (0.22). [ABSTRACT FROM AUTHOR]

The use of solar radiation measurements on various solar systems design needs knowledge on its spatial and temporal variations. Such knowledge can be acquired by employing interpolation ground measured solar radiation collected by ground radiometric stations. More reliable information could be obtained by analyzing satellite images. The aim of this work is to evaluate the measurements of daily global solar radiation extracted from Meteosat-8 images using Heliosat-2 method. Ground measurements from two Iraqi stations were used in the evaluation processes. The results indicated that the mean RMSE and MAE for Baghdad were 0.621 kWh/m² and 0.024 kWh/m² and for Mosul were 0.458 kWh/m² and 0.012 kWh/m² respectively. These results are very satisfactory for monitoring the temporal and spatial variation of solar radiation for places which suffer from shortage of ground solar radiation measurements. [ABSTRACT FROM AUTHOR]