An evaluation of the interaction of morning residual layer and afternoon mixed layer ozone in houston using ozonesonde data
The Tropospheric Ozone Pollution Project (TOPP) launched >220 ozonesondes in Houston (July 2004– June 2008) providing examples of pollution transported into, re-circulated within, and exported from the Houston area. Fifty-one launches occurred during the Texas Air Quality Study (TexAQS) II and the summer portion of IONS-06 (INTEX [Intercontinental Transport Experiment] Ozonesonde Network Study). On 11 days during TexAQS II and on 8 other occasions, ozonesondes were launched both at dawn and in the afternoon. Analysis of these ‘‘intensive’’ launch sequences shows that morning residual layer (RL) ozone concentrations ([O3]) explained 60–70% of the variability found in the afternoon mixed layer (ML). Furthermore, maximum RL [O3] is nearly identical to the mean ML [O3] from the previous afternoon (morning minus afternoon ¼ =-1.6 +/- 8.4 ppbv). During TexAQS II, mean [O3] below 1.3 km (the mean ML height from ozonesonde data) increased from 37 +/- 22 ppbv in the morning to 74 +/- 18 ppbv in the afternoon, suggesting an average net local daily O3 production of w500–900 tons over the metropolitan Houston area.
Morris, G. A., Ford, B., Rappenglück, B., Thompson, A. M., Mefferd, A., Ngan, F., and Lefer, B. (2010). An evaluation of the interaction of morning residual layer and afternoon mixed layer ozone in houston using ozonesonde data. Atmospheric Environment, 44(33):4024-4034.