A Model to Determine Atmospheric Stability and its Correlation with CO Concentration
Atmospheric stability plays the most important role in
the transport and dispersion of air pollutants. Different methods are
used for stability determination with varying degrees of complexity.
Most of these methods are based on the relative magnitude of
convective and mechanical turbulence in atmospheric motions.
Richardson number, Monin-Obukhov length, Pasquill-Gifford
stability classification and Pasquill–Turner stability classification, are
the most common parameters and methods. The Pasquill–Turner
Method (PTM), which is employed in this study, makes use of
observations of wind speed, insolation and the time of day to classify
atmospheric stability with distinguishable indices. In this study, a
model is presented to determination of atmospheric stability
conditions using PTM. As a case study, meteorological data of
Mehrabad station in Tehran from 2000 to 2005 is applied to model.
Here, three different categories are considered to deduce the pattern
of stability conditions. First, the total pattern of stability classification
is obtained and results show that atmosphere is 38.77%, 27.26%,
33.97%, at stable, neutral and unstable condition, respectively. It is
also observed that days are mostly unstable (66.50%) while nights are
mostly stable (72.55%). Second, monthly and seasonal patterns are
derived and results indicate that relative frequency of stable
conditions decrease during January to June and increase during June
to December, while results for unstable conditions are exactly in
opposite manner. Autumn is the most stable season with relative
frequency of 50.69% for stable condition, whilst, it is 42.79%,
34.38% and 27.08% for winter, summer and spring, respectively.
Hourly stability pattern is the third category that points out that
unstable condition is dominant from approximately 03-15 GTM and
04-12 GTM for warm and cold seasons, respectively. Finally,
correlation between atmospheric stability and CO concentration is
achieved.
[1] Zoras, S., Triantafyllou, A.G, Deligiorgi, D., "Atmospheric stability and
PM10 concentrations at far distance from elevated point sources in
complex terrain: Worst-case episode study". J. of Environmental
Management, 80, pp. 295-302, 2006.
[2] Pal Arya, "Air pollution meteorology and dispersion". Oxford University
Press, Oxford. 1999.
[3] Wark, K., Warner, C.F., Davis, W.T., "Air pollution: Its Origin and
Control". Addison-Wesley, 1998.
[4] Muhan M., Siddiqui T.A., "Analysis of various schemes for the
estimation of atmospheric stability classification". Atmospheric
Environment, Vol. 32, pp. 3775-3781, 1998.
[5] Schenelle, K.B, Dey, P.R., "Atmospheric dispersion modeling
compliance guide". McGraw-Hill companies, 2000.
[6] Ludwig, F.L., "Comparison of two practical atmospheric stability
classification schemes in an urban application", J. Appl. Meteor., 15, pp.
1172-1176, 1976.
[7] Turner, D.B., "A diffusion model for an urban area". J. Appl. Meteor., 3,
pp. 83-91, 1964.
[8] Pasquill, F., "The estimation of the dispersion of windborne material".
Meteorological Magazine, 90, pp. 33-49, 1961.
[9] Seinfeld.J.H, Pandis.S.N, "Atmospheric chemistry and physics: from air
pollution to climate change", 1998.
[10] Jacobson, M.Z.," Fundamentals of atmospheric modeling", Cambridge
University Press, 2005.
[11] Iqbal, M., "An Introduction to Solar Radiation". Academic Press,
Toronto. 1983.
[12] Perez-Roa, R., Castro, J., Jorquera, H., Perez-Correa, J.R., Vesovic, V.,
2006. "Air-pollution modelling in an urban area: Correlating turbulent
diffusion coefficients by means of an artificial neural network
approach". Atmospheric Environment, 40, pp. 109-125, 2006.
[1] Zoras, S., Triantafyllou, A.G, Deligiorgi, D., "Atmospheric stability and
PM10 concentrations at far distance from elevated point sources in
complex terrain: Worst-case episode study". J. of Environmental
Management, 80, pp. 295-302, 2006.
[2] Pal Arya, "Air pollution meteorology and dispersion". Oxford University
Press, Oxford. 1999.
[3] Wark, K., Warner, C.F., Davis, W.T., "Air pollution: Its Origin and
Control". Addison-Wesley, 1998.
[4] Muhan M., Siddiqui T.A., "Analysis of various schemes for the
estimation of atmospheric stability classification". Atmospheric
Environment, Vol. 32, pp. 3775-3781, 1998.
[5] Schenelle, K.B, Dey, P.R., "Atmospheric dispersion modeling
compliance guide". McGraw-Hill companies, 2000.
[6] Ludwig, F.L., "Comparison of two practical atmospheric stability
classification schemes in an urban application", J. Appl. Meteor., 15, pp.
1172-1176, 1976.
[7] Turner, D.B., "A diffusion model for an urban area". J. Appl. Meteor., 3,
pp. 83-91, 1964.
[8] Pasquill, F., "The estimation of the dispersion of windborne material".
Meteorological Magazine, 90, pp. 33-49, 1961.
[9] Seinfeld.J.H, Pandis.S.N, "Atmospheric chemistry and physics: from air
pollution to climate change", 1998.
[10] Jacobson, M.Z.," Fundamentals of atmospheric modeling", Cambridge
University Press, 2005.
[11] Iqbal, M., "An Introduction to Solar Radiation". Academic Press,
Toronto. 1983.
[12] Perez-Roa, R., Castro, J., Jorquera, H., Perez-Correa, J.R., Vesovic, V.,
2006. "Air-pollution modelling in an urban area: Correlating turbulent
diffusion coefficients by means of an artificial neural network
approach". Atmospheric Environment, 40, pp. 109-125, 2006.
@article{"International Journal of Earth, Energy and Environmental Sciences:58079", author = "Kh. Ashrafi and Gh. A. Hoshyaripour", title = "A Model to Determine Atmospheric Stability and its Correlation with CO Concentration", abstract = "Atmospheric stability plays the most important role in
the transport and dispersion of air pollutants. Different methods are
used for stability determination with varying degrees of complexity.
Most of these methods are based on the relative magnitude of
convective and mechanical turbulence in atmospheric motions.
Richardson number, Monin-Obukhov length, Pasquill-Gifford
stability classification and Pasquill–Turner stability classification, are
the most common parameters and methods. The Pasquill–Turner
Method (PTM), which is employed in this study, makes use of
observations of wind speed, insolation and the time of day to classify
atmospheric stability with distinguishable indices. In this study, a
model is presented to determination of atmospheric stability
conditions using PTM. As a case study, meteorological data of
Mehrabad station in Tehran from 2000 to 2005 is applied to model.
Here, three different categories are considered to deduce the pattern
of stability conditions. First, the total pattern of stability classification
is obtained and results show that atmosphere is 38.77%, 27.26%,
33.97%, at stable, neutral and unstable condition, respectively. It is
also observed that days are mostly unstable (66.50%) while nights are
mostly stable (72.55%). Second, monthly and seasonal patterns are
derived and results indicate that relative frequency of stable
conditions decrease during January to June and increase during June
to December, while results for unstable conditions are exactly in
opposite manner. Autumn is the most stable season with relative
frequency of 50.69% for stable condition, whilst, it is 42.79%,
34.38% and 27.08% for winter, summer and spring, respectively.
Hourly stability pattern is the third category that points out that
unstable condition is dominant from approximately 03-15 GTM and
04-12 GTM for warm and cold seasons, respectively. Finally,
correlation between atmospheric stability and CO concentration is
achieved.", keywords = "Atmospheric stability, Pasquill-Turner classification,convective turbulence, mechanical turbulence, Tehran.", volume = "2", number = "8", pages = "97-6", }