Analysis of Ozone Modeling for May – July 2006 in PNW using AIRPACT3 (CMAQ) and CAMx. Robert Kotchenruther, Ph.D. EPA Region 10 Nov CMAQ O 3 Prediction 7/22/ Z Current AIRPACT3 12km domain

Background: The basis of the Model Runs was WSU’s AIRPACT3 air quality forecast system. * Daily 24 hour prediction of air quality (gases and aerosols). * 95 x 95 grid at 12km resolution. * CMAQ v4.4 model with SPARC99 chemical mechanism. * MM5 12km meteorological forecasts from UW. * Uses the SMOKE emissions model with emissions files developed by WSU. For this retrospective run, AIRPACT3 was used as above except: * Archived MM5 forecasts were concatenated into a continuous meteorological dataset using hours from each UW run. * The CAMx (v4.31) model was also run by converting CMAQ IC, BC, and emissions files into CAMx input format. * CMAQ and CAMx were run for the period May 8 – July 31, * First 4 days of run were removed for model spin-up. Some CMAQ and CAMx differences: * CAMx uses SAPRC99, but does not include aerosol chemistry. * Differences in formulation of chemistry numerical solvers * Differences in treatment of vertical and horizontal advection and diffusion (minor) * Differences in treatment of plume rise from elevated point sources (minor) * CMAQ and CAMx user different MM5/met pre-processors.

Background(2): The motivation for this retrospective run of AIRPACT3 was that Washington & Oregon experienced exceedances of the 8 hour ozone standard at 5 sites this summer. Provided and opportunity to explore how well AIRPACT3 is performing for O 3 Max 8hr average O 3, WA & OR sites, 2006 (ppbv) Main purpose of presentation A snapshot of current AIRPACT3 ozone performance. A lead in to a discussion of where we should place efforts to improve - our understanding of model’s current performance - where best to place efforts at improving model performance DateEnumclaw (WA) Pack Forest (WA) Issaquah (WA) Carus (OR) Turner (OR) 16-May87 26-Jun Jul Jul

WA & OR O 3 monitoring sites available for analysis This analysis will focus on the five sites with 8hr O3 exceedances:(WA Sites) ISSLKSAM ENUMUDMT PAC_FOR (OR Sites) CARUS TURNER

The plots on the following slides show daily max (and min) ozone (and temperature). The maximum 1hr average was taken for both models and monitor, unpaired in time. This example is from Enumclaw, Mud Mountain Road. Daily Max O 3, 2006 Hourly Average O 3, 2006

ENUMUDMT (WA) – Enumclaw, Mud Mountain Road* = exceedance day Plots show daily max and min ozone, 1hr average, model and monitor unpaired in time. Daily Max O 3, 2006 Daily Min O 3, 2006 * * **

ENUMUDMT (WA) – Enumclaw, Mud Mountain Road* = exceedance day Plots show daily max ozone and temp, 1hr average, model and monitor unpaired in time. Daily Max O 3, 2006 * * ** Daily Max Temp., 2006

CARUS (OR) – Carus, Spangler Rd.* = exceedance day Plots show daily max ozone and temp, 1hr average, model and monitor unpaired in time. * Daily Max O 3, 2006 Daily Max Temp., 2006

TURNER (OR) – Turner Cascade Jr. High* = exceedance day Plots show daily max ozone and temp, 1hr average, model and monitor unpaired in time. * Daily Max O 3, 2006 Daily Max Temp., 2006

PAC_FOR (WA) – Pack Forest * = exceedance day Plots show daily max and min ozone, 1hr average, model and monitor unpaired in time. Daily Max O 3, 2006 * * * ISSLKSAM (WA) – Issaquah Lake Sammamish Daily Max O 3, 2006 **

Scatter plot comparing daily 1hr ozone maximum observations and model predictions, unpaired in time. Combined data from 5 sites reporting O 3 exceedances in OR & WA.

Scatter plot comparing daily 1hr ozone minimum observations and model predictions, unpaired in time. Combined data from 5 sites reporting O3 exceedances in OR & WA.

Discussion Ideas for where to look to understand model over prediction of ozone when ambient ozone is below ~ 80 ppb and under prediction when over ~ 80 ppb? - Biases in pbl or other met variables? - Emissions inventories? - Nesting to a finer resolution? - ???? Discuss above in two contexts: - Given current available measurements. - If we begin making measurements not currently available. i.e., mobile lab to be discussed later today