%0 Journal Article
%T Suspended Particulates Concentration (PM10) under Unstable Atmospheric Conditions over Subtropical Urban Area (Qena, Egypt)
%A M. El-Nouby Adam
%J Advances in Meteorology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/457181
%X The main purpose of this study is to evaluate the suspended particulates (PM10) in the atmosphere under unstable atmospheric conditions. The variation of PM10 was investigated and primary statistics were employed. The results show that, the PM10 concentrations values ranged from 6.00 to 646.74£¿¦Ìg£¿m£¿3. The average value of PM10 is equal to 114.32£¿¦Ìg£¿m£¿3. The high values were recorded in April and May (155.17£¿¦Ìg£¿m£¿3 and 171.82£¿¦Ìg£¿m£¿3, respectively) and the low values were noted in February and December (73.86£¿¦Ìg£¿m£¿3 and 74.05£¿¦Ìg£¿m£¿3, respectively). The average value of PM10 of the hot season (125.35 ¡Á 10£¿6£¿g£¿m£¿3) was higher than its value for the cold season (89.27£¿¦Ìg£¿m£¿3). In addition, the effect of weather elements (air temperature, humidity and wind) on the concentration of PM10 was determined. The multiple R between PM10 and these elements ranged from 0.05 to 0.47 and its value increased to reach 0.73 for the monthly average of the database used. Finally, the PM10 concentrations were grouped depending on their associated atmospheric stability class. These average values were equal to 122.80£¿¡À£¿9£¿¦Ìg£¿m£¿3 (highly unstable or convective), 109.37£¿¡À£¿12£¿¦Ìg£¿m£¿3 (moderately unstable) and 104.42£¿¡À£¿15£¿¦Ìg£¿m£¿3 (slightly unstable). 1. Introduction Adam [1] reviewed that the diurnal variation of temperature near the ground is one of the key characteristics of the atmospheric boundary layer (ABL) over land. The convective atmosphere constitutes the daytime unstable ABL. It consists of thermal plumes, that is, updrafts surrounded by large downdrafts. They grow in the morning with the solar heating of the surface of the earth. In the ABL, the air flow is turbulent because of two different mechanisms: friction with the surface and surface heating by the sun. Adam and El Shazly [2] evaluated the atmospheric stability at Qena and studied its diurnal variation which define the turbulent state of the atmosphere and also reflect its dispersion capabilities through the period from 2001 to 2004. They found that there are transitional hours in which the stability conditions change from the stable nighttime period to the unstable daytime hours (6:00 and 7:00 LST). During the daytime hours (8:00¨C15:00 LST), the atmosphere tends to be primarily unstable with some neutral condition. In addition, no occurrences of stable conditions were found in this period of time. This study is to assess the level of air pollution under unstable conditions after the transitional hours at midmorning hours (9:00¨C11:00 LST). This time is chosen because it is usually a period of a high traffic and
%U http://www.hindawi.com/journals/amete/2013/457181/