Comparison of simple and advanced regional models in industrial regulation

Bernard Fisher

Risk Forecasting and Decision Science

Environment Agency

Examples of ozone prediction methods:

when to apply?

Difference field showing industrial plume contribution to daily maximum 1-hr O3 concentration for 24-27 June 2001

Horizontal particle distribution 43 hours after the SO2 release simulated by the model HYSPLIT (left) and FLEXPART (right). The colour code gives the heights of the particles in metres

Spectrum of Models Part 1

Example of ozone generation for industrial plumes

Complex NAME

Simple enclosing curves

Ozone formed in NOx plume (1500 mid afternoon)

Background: 20 ppb O3 and 50 ppb VOC

O3 maximum reached 106 ppb in domain.

constant wind direction and speed

travel timein hourspoint source

Scatter plot of hourly NO2 vs hourly NOx. hourly values with selected point sources. The background [O3] used for the enclosing curves was based on model results with all point sources removed.

NAME III enclosing curves, Models-3 and empirical curve comparisons

Spectrum of Models Part 2

Regional ozone

Complex CMAQ EMEP Eulerian

IDOP EMEP Lagrangian

Ozone from: A - Didcot A power station and B - Kingsnorth power station. Ozone creation downwind of A during daytime, while ozone depletion is dominant downwind of B. The background concentration of VOCs downwind of A is much higher than that downwind of source B.

The 24-h averaged O3 excess (left) and the daily maximum 1-hr ozone excess (right) on every simulation day for the June 2001 episode. The black dot is the location of the VOC source for IDOP comparison

Application of the Integrated Downwind Ozone Production approach to the assessment of the environmental impact of four processes operating at a large industrial complex. Emissions quoted are illustrative only

VOC species Emission IDOP Excess tonne hr-1 ppb per ozone ppb

tonne/ hr

Oil refining

acetylene 0.1 0.09 0.01benzene 0.1 0.27 0.03toluene 0.1 4.10 0.41

Total 0.3 0.45

EMEP Lagrangian model

The unit is 10ppb.h per 40% emission reduction

dAOT40c/dENOx

dAOT40c/dEVOC

EMEP Eulerian model country source-receptor relationships for 2003 meteorology and 2003 emissions are given. The changes in UK ozone for changes in UK emissions on UK ozone are:

ozone AOT40f at 3m-377 ppb.h per 15% emission reduction for NOx351 ppb.h per 15% emission reduction for VOC

SOMO35-103 ppb.d per 15% emission reduction for NOx55 ppb.d per 15% emission reduction for VOC

Spectrum of Models

Industrial plumes

Complex NAME

Simple enclosing curves

Regional ozone

Complex CMAQ EMEP Eulerian

OSPM EMEP Lagrangian

PTM

Simple IDOP RAINS

urban deficits ?????