Environmental Engineering Reference
In-Depth Information
underestimated in both inventories. Other oil and gas sources may be under-
estimated, have temporal allocation profiles which are not well-represented in
the model, or are simply not present in currently available emission inventories
(e.g., evaporation from produced water ponds).
Comment:
The WDEQ campaign was ended earlier this year. Bob Baxter et al.
was showing real-time measurements of the Wyoming monitors. A few monitors
showed 120 ppb peak ozone. So no doubt it was widespread. But between
February 15 and 28 (when campaign ended on February 28) no such high
readings at the monitors. So looked like the high ozone reading at the monitors
did reflect sporadic occurrence. A very specific set of conditions must con-
currently happening in order to produce such a scenario.
Conditions associated with high winter ozone in Southwest Wyoming during
the WDEQ 2007-8 field study are noted above on page 3. When the model
inputs reflect these conditions, CAMx simulates these high winter ozone events.
Comment:
The low bias of CAMx not capturing the surface ozone peaks are
perhaps due to (a) strong albedo that added to photolytic rates were not accounted
for and (b) dry depositional velocity over different kind of snow may not be
well captured by the model. Comments 4 and 5 by Pius Lee (NOAA ARL).
Snow albedo effects and their feedbacks on photolysis rates are accounted
for in CAMx, as are the effects of snow on the dry deposition velocity.
