## Operational and diagnostic evaluations of ozone **forecasts by the Eta**  **- CMAQ model suite during the 2002**  **new E**  **ngland air quality study** **( NEAQS)** 
**Shaocai Yu**  $, 

### Rohit Mathur + 

### , Daiwen Kang $ 

### , Kenneth Schere + 

### ,

Brian Eder + 

### , Jonathan Pleim + 

### , Atmospheric Sciences Modeling Division NERL, U.S. EP

A, R TP , NC 2771 1. $ 

### On assignment from Science and Te chnology Corporation + 

### On assignment from Air Resources Laboratory , NOAA

# Introduction 

# In **troduction** 

#  **O 3**  

## forecast  **Necessary**  

### O **3** 

### : a **secondary pollutant,**   **pr oduc**  **ed by**  **polluti on from**  **nat ur**  **al and hu ma**  **n acti**  **vities.**  

### Warn the public:  **unhe althy air**   **vol unt**  **arily reduce**  **em issi**  **on -**  **pr od**  **ucing acti vities**  

###  **Forecasting m ethods (EPA,**  **1999 ):**   **Persistence, cli ma**  **tol ogy, regression equation et**  **c.** 

###  **3 -**  **D air quality mod**  **els** 

###  **Advantages of 3**  **- D air quali**  **ty m**  **odels**  **Spatial and tem poral**  **dist ributi**  **ons of O**  **3 an**  **d its precursors** 

###  **Underst an**  **d che mi**  **cal -**  **physical pr**  **oces ses**  **co nt**  **rolling O 3**  **for mat**  **ion**

# CMAQ **C ommunity**  

# M **ultiscale** 

# A **ir** 

# Q **uality** 

# M **odel**

 

### Community

**Model**  

### Multiscale

– 

### consistent model structures for interaction of urban through Continental scales  

### Multi **- pollutant** 

– 

### ozone, speciated particulate matter , visibility , acid deposition and air toxics 

# Objective  **Evaluate 3 -**  **D Eta**  **- CMAQ**  **mo del**  **perform ance o**  **n the spatial and tem**  **poral variations of O**  **3** 

## with AIRNOW **Obs over the NE US**  

#  **Diagnostically exam**  **ine the ability of Eta**  **- CMA**  **Q in representing chem**  **ic al**  **- physical processes for O**  **3** 

## form **ation with 2002 NEAQS data**

# Mo **del Description**  **Eta -**  **CMAQ mo**  **del suite: (R. Ma**  **thur et al. Talk)**   **Period: August 6 to Augu**  **st 17, 2002**

**August 6 to August 17, 2002**  **Using results: 12 UTC run**  **an d** 

**target period for**  **nex t day forecast (**  **04 UTC to 03 UTC )** 

## NE Model domain and site locations AIRMAP sites

#  **Results 1.**  **O 3**  

### episode after 8/11 0 5 10

0 5 10

0.0 0.2 0.4 0.6 0.8 1.0 1.2 (b) SO 2 /NO y

ratio (CS) 0 2 4 6 8 (a) SO 2 (CS) ppb

0 0.7 1.4

0 0.7 1.4

0 12 24

0 12 24

0 1.3 2.6

0 1.3 2.6

Ti me (EST) ObsModel

Obs Model

50.0 100.0 150.0 200.0 250.0 300.0 350.0 (c) CO (CS) ppb

0 180 360

0 180 360

0 5 10 15 20 ppb (d) SO 2 (TF)

0.0 0.5 1.0 1.5 2.0 2.5 (e) SO 2 /NO y

ratio (TF)

0 250 500

0 250 500 0.0 100.0 200.0 300.0 400.0

8/6 8/8 8/10 8/12 8/14 8/16 8/18

(f) CO (TF) ppb 

##  Parrish et al., 1991: • Mobile source: CO, NOx • Point source (power plants): SO 2 

## , NOx

• SO2/NOy<1: mobile source • SO2/NOy>1: point source 

##  Sites were significantly influenced by polluted plume after 8/1 1:  mobile and point sources SO2 (CS)

SO2 (TF) CO (CS)

CO (TF) 8/1 1

#  Results 1. **O3 episode (8/6 -**  **8/17/2002)**

Modeled and observed (diamond) O 3 

## (ppb)

~45 ppbv O 3 

## ~1 10 ppbv O 3

#  **Results 2.**  **Operational ev aluation at A**  **IRNOW sites**

Max 8hr Max 1hr



### AQS O 3 

### (ppb)ModelO3 

## NMB (max 8 - hr)

-92 -90 -88 -86 -84 -82 -80 -78 -76 -74 -72 -70 -68 34 36 38 40 42 44 46 48

-33.3 to -20 -20 to 0 0 to 25 25 to 50 50 to 75

#  Results **3. Ti**  **me -**  **series eval.** 

Time (EST)Concentrations(ppb) 0.0 50.0 100.0 150.0 O3(Ob s)

O3 (Model) 0 80 160

0 80 160 Ha rvar d Forest

0.0 0.5 1.0 1.5 2.0 NO(Obs)

NO (Model) 0 1 2

0 1 2

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 NO2(Obs)

NO2 (Model) 0 4 8

0 4 8

0.0 1.0 2.0 3.0 PAN(Obs)

PAN (Model)
0 2.5 5

0 2.5 5

0.0 100.0 200.0 300.0 400.0 500.0 CO(Obs)

CO (Model)
0 300 600

0 300 600

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

8/6 8/8 8/10 8/12 8/14 8/16 8/18

NOy (Obs) NOy (Model)
0 20 40

0 20 40

ObsModel 

## O 3 

## NO NO 2 

## PA N CO NOy Harvard Forest

8/1 1

##  Hanna et al. (2001): • 50% uncertainty in JNO2 • 40 ppbv (or 20%) uncertainty in max O 3 

## • Model reproduces • 64 - 77% of observed JNO2 within a factor of 1.5 

##  Priority: more accurate determination of JNO2 in model 

#  Results **3. Ti**  **me -**  **series at**  **AIRMAP sites** 

#  Results **3. O 3**  

### Lidar vertical profiles 

## Obs
Model 

##  Extremely tough test: Te mporal and 3 - D field correctly

• Model reproduced obs at low altitude and more uniform

• Over predictions increase with altitude Ship Tr ack

#  Results **(diagnostic evaluation)**  

###  **NO x**  **- sensitive r**  **egimes: [O3]/[NOx],**  **Photochemical age: [NOz]/[NOy],**  **O3 pr oduction efficiency:**  **[NOz]/[O3]** 

##  Arnold et al., 2003: • **[O3]/[NOx]** <14: VOC - sensitive

>46: NOx - sensitive

 Both model and obs: three sites are mainly under strongly NOx sensitive conditions (>53%) 

##  **NOx -**  **sensitive re**  **gimes: [O3]/[NOx]** 

#  Results **Photochemical age:**  **[NOz]/[NOy]**  Arnold et al., 2003: • **[NO z**  

### ]/[NO **y** 

### ] >0.6: aged NOx plume

0.0 0.2 0.4 0.6 0.8 1.0 Obs

Model (a) CS

0.0 0.2 0.4 0.6 0.8 (b) TFNOz/NOyratio

0.0 0.2 0.4 0.6 0.8 (c) HF

0 2 4 6 8 10 12 14 16 18 20 22 Time (EST) 

##  For daytime (6 to 18 EST) hours: **NOz/NOy >0.6**  **CS TF**  **HF Obs**  **82% 72%**  **82% Mo**  **del 96%**  **56% 87%**  

##  Model and Obs: accumulating O 3



## aging the NOx in the similar way . CS
TF

HF

#  Results **O 3**  

## pr **oduction efficiency** 

#  **: O**  **3** 

## - **NO z**  

## slope

10 20 30 40 50 60 70 80 Ob s Model (a) CS

0 20 40 60 80 100 120 140 160[O3](ppb) (b) TF

0 20 40 60 80 100 120 140 160

0 2 4 6 8 10 12 14 16 NO z ( ppb) (c) HF 0 5 10

0 5 10

0 8 16

0 8 16Model
Ob s

NO z (ppb) 0 4 8

0 4 8 

##  Parrish et al., 1993 : • O 3 

### - NO z 

### slope:  upper limit of  : • Obs: 8.3 to 10.0 • Model: 4.2 to 5.1 N



# 

N 

#  N 

#  NOz  At rural sites in E US ( Olszyna et al., 1994) 

## : : 5 to 10 N 

#  NOzO3 

## CS TF HF

# Contacts: Brian K. Eder email: eder@hpcc.epa.gov

www .arl.noaa.gov/ www .epa.gov/asmdnerl 

# Conclusions  

### Model captured t

he buildup of O 3 

### an d its episode af te r August

11 and reproduce spatial distr. of O 3 

### for t he day time o ver the NE US very well with NMB<20% .  

### Fo r ope rational evaluation at AIRNOW sites, model reproduced mo st of obse rved max 8 - hrO 3 

### within factor of 1.5 with NM B= 9%.  

### Model captured 64 - 77% of observed JNO2 within a factor of 1.5  Model re pr od

uced the O 3 

### Lidar vertical profiles at lo w altitude ( 355 to 500 m ) well but tended t o overpre dict in high altitude .  

### Both model and Ob s sh owthe AIRMAP sites are mainly under str ongly NOx - se nsitive conditions (>53%) an d a re accumulating O3 and aging th e NOx in t

he similar way

in these sites  

### Th e mo deled up per limits ( 4. 3 t o 5.1 ) of estimated byO3 - NOz slopes a re about half of the observations ( 8. 3 t o 10.0 ) N 

# 

# Future research needed  For real tim e forec ast of O 3 

# , key is th e pr ognostic mo del for ecasts of meteorological fields:  Cold front patterns,  cloud cover  wind fields  

# Im prove photochem ic al m echanism and em ission  

# Im prove the m ode l perform ance f or JNO2 , especially dur in g th e cloudy

periods  

# More evaluation **wit h exten**  **sive data from the 2004 NEAQS field c**  **am paign**  **is unde rw**  **ay**Disclai me r Th e resear ch presented here was pe rformed under th e Mem orandum o f Understanding betw een the U.S. Environm ental Pr otection Agen cy ( EP A) and th e U .S. Departm ent of Commerce's National Oceanic and At mo spheric Ad mi nistration (NOAA ) and under agreem ent num

ber DW13921548. A lthough it has been review ed by E PA and NOAA and approved f

or publ ication, it does not necessaril y ref lect their policies or views.