What is the Uncertainty Caused by IC/BCs in the Regional/Urban Ozone Simulations?Linking CMAQ with GEOS-CHEM

Global/Regional/Urban Multiscale Study

Nan-Kyoung Moon and Daewon ByunInstitute for Multidimensional Air Quality Studies

(IMAQS)University of Houston

Rokjin Park and Daniel JacobHarvard University

- Current usage; mostly rely on “climatological” fixed profiles

- Could be different at each side of domain reflecting certain regional differences

- Work best when outside the boundary of the domain does not have much direct emissions and no high concentration blobs already existing

- Need to study sensitivity of the model simulations to the different IC/BCs

- In reality fixed profiles are never accurate!

Regional air quality modeling requires prescription of IC/BCs

O

Ozonesonde observation shows multiday and vertical

variations in the troposphere (Newchurch and Ayoub, 2000)

The reality provided by ozonesonde observation

- Intermittent data in space and time

-Mostly ozone is the only parameter available

- There are many other important photochemical precursor species that must be prescribed

- The intra-relations among the species must be consistent

- Need a systematic IC/BC methods that can address above problems

- Let’s try to link global tropospheric model results with regional air quality model

Even with ozonesonde or other measurements….

This is a global 3-D model of atmospheric chemistry driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS) of the NASA Data Assimilation Office (DAO).

It is being developed by groups at Harvard, Duke, NASA/GSFC, U. Washington, Rutgers U., JPL, EPFL/Lausanne, CNRS/Toulouse, and the University of L'Aquila, Italy, as a versatile tool for application to a wide range of atmospheric chemistry problems.

           First Look 4.0            Late Look 4.0

Conventional Final Dump - NCEP Conventional CDAS Dump - NCEP

SSM/I (TPW only) Wentz SSM/I (TPW only) 

Operational Sea Ice Operational Sea Ice

Interactive TOVS retrievals Interactive TOVS retrievals

QuickSCAT  QuickSCAT

SBUV Ozone SBUV Ozone

SST - Downstream Average Reynolds SST - Centered Average

  ---- GADS  (Passive)

NASA GEOS DAO Products

Harvard GEOS-CHEM model

Air Quality Modeling with US EPA’s Models-3 CMAQ

CMAQChemistry Transport Model

Aerosol

Plumein

Grid

Gas-phaseChemistry

Diffusion

Photolysis rates

J PROC

WRFRAMSMM5

MeteorologicalModel Ouput

MCIPSMOKE

EmissionsProcessing

ECIP*

MEPPS*

Advection

CloudAqueousProcess

PDM

ICON/ BCONInit ial/ boundaryconditions

Processanalysis

Models-3Computational

Framework

Photolysis

SMOKE Tool

* Used in versions of CMAQ released before 2001

CommunityMulti-pollutantMulti-scaleAir QualityModelingSystem

First, Horizontal & Vertical Interpolations needed

LAT-LON 2 degree X 2.5 degree

20 layers in Sigma P

LAMBERT CONFORMAL

108 km X 108 km

23 layers in Sigma Z (Po)

Initial & Boundary Condition

in IO/API Format in 108km resolution

GEOS-CHEM (Goddard Earth Observing System-CHEMisrty)

MODEL3 CMAQ(Community Multi-scale/pollutant Air Quality model)

To link GEOS_CHEM with EPA’s CMAQ ……

O3-NOX-Hydrocarbon chemistry : 24 species24 species

CMAQ

CB4O3-NOx-Hydrocarbon

chemistry

[NO2 ] [NOx ]

[O3 ] [Ox ] - [NOx ]

[N2O5] [N2O5]

[HNO3] [HNO3]

[PNA ] [HNO4]

[H2O2] [H2O2]

[CO ] [CO ]

[PAN ] [PAN ] + [PMN ] + [PPN ]

[MGLY] [MP ]

[ISPD] [MVK ] + [MACR]

[NTR ] [R4N2]

[FORM] [CH2O]

[ALD2] [ALD2] + [RCHO]

[PAR ] [ALK4] + [C3H8] + [C2H6]

[OLE ] [PRPE]

[ISOP] [ISOP]

GEOS-CHEM

CB4 : 16 species16 species

Un-used species : ACET

Second, develop procedures matching GEOSCHEM and CMAQ chemistry mechanism

CB-4 example

GEOS2CMAQGEOS2CMAQGEOS2CMAQGEOS2CMAQ

LAT-LON 2O X 2.5O

w/ GEOSCHEM vertical coordinate

Chemistry Mapping

CB4 & SAPRC

IC/BC Process

IC/BC for

CMAQ resolution

The diagram of linkage between GEOSCHEM and CAMQ

LAMBERT CONFORMAL

w/ 108 km I/OAPI on CMAQ/MM5

vertical coordinate

• Possible inconsistencies between the global and regional scale dynamics

- inflow conditions at the boundary

- differences in the evolution of dynamics with time

• Remedy (yet to be tested)

- Run regional scale model with global scale output as input for initialization and analysis nudging

cf: Currently most uses EDAS as basic input for MM5

Issues in linking GEOSCHEM and CMAQ (1)

GEOSCHEM ; DAO

Comparison of Wind FieldsComparison of Wind Fields

GEOSCHEN : W -NWesterly (inflow)

MM5 : Northerly (parallel to grid)

Let’s see how big the problem is:

GEOSCHEM ; DAO

GEOSCHEM : Easterly and northerlyMM5 : Clock wise rotation motion

GEOSCHEM : inflowMM5 : outflow

• Chemistry Issues:- coarse resolution concentration distribution in global scale move into fine scale regional grid

- differences in the evolution of concentration patterns with time

- different chemical mechanism representation

- different representation of atmospheric reactivity in the coarse scale

• Remedy

- use as much consistent chemistry mechanisms (TBD)

Issues of linking GEOSCHEM and CMAQ (2)

Mapping Table

SAPRACO3-NOx-Hydrocarbon

chemistry

[NO2 ] [NOx ] – [NO]

[PAN] [PAN]

[CO] [CO]

[ALK3] [ALK4]+[ALK5 [ALK4]

[ISOPRENE ] [ISOP]

[HNO3] [HNO3]

[H2O2] [H2O2]

[ACET ] [ACET]

[MEK] [MEK]

[CCHO] [ALD2]

[RCHO] [RCHO]

[MRTHACRO] [MACR]

[MA_PAN] [PMN]

[MVK] [MVK]

[PAN2] [PPN]

SAPRACO3-NOx-Hydrocarbon

chemistry

[RNO3] [R4N2]

[OLE1] + [OLE2] [PRPE]

[ALK2] [C3H8]

[HCHO] [CH2O]

[ALK1] [C2H6]

[N2O5] [N2O5]

[HNO4] [HNO4]

[COOH ] [MP]

CMAQ

GEOS-CHEM

SAPRAC-99

(yet to be simulated)

Horizontal distribution of O3 concentration from GEOS-CHEM global output at Layer 1

108km resolution2 X 2.5 degree resolution

Horizontal distribution of CO concentration from GEOS-CHEM global output at Layer 1

108km resolution2 X 2.5 degree resolution

1. GEOSCHEM vs. CMAQ CONUS

2. CMAQ CONUS vs. CMAQ Regional 36-km

3. Effects of using different IC/BCs- profile vs. GEOS-CHEM for CONUS domain

Comparative Study with CMAQ

The comparison of vertical cross section between GEOSCHEM and CONUS results

GEOSCHEM 108km CONUS 36km

O3.. August 16, 2000, 00UTC (First day of simulation)

GEOSCHEM CONUS

August 16, 2000 (First day of simulation)September 1, 2000 (Last day of simulation)

September 1, 2000. 09 & 21UTC

GEOSCHEM

CONUS

CO.. August 16, 2000, 00UTC

GEOSCHEM CONUS

September 1, 2000. 09 & 21UTC

GEOSCHEM

CONUS

NO2.. August 16, 2000, 00UTC

GEOSCHEM CONUS

September 1, 2000. 09 & 21UTC

GEOSCHEM

CONUS

The comparison of vertical cross section for O3, CO, FORM and NO2 between Regional vs CONUS 36-km CMAQ results.

ICBC from GEOSCHEM 108km data

O3, August 31, 2000. 09 & 21 UTCO3, August 31, 2000. 09 & 21 UTC

Comparison of horizontal distribution between CONUS and Regional 36kmComparison of horizontal distribution between CONUS and Regional 36km

CO, August 31, 2000. 09 & 21 UTCCO, August 31, 2000. 09 & 21 UTC

The comparison of vertical cross section between CONUS and regional domain results

CONUS 36km Regional 36km

August 31, 2000. 09 & 21UTC

C

O

N

U

S

Regional36km

August 31, 2000. 09 & 21UTC

C

O

N

U

S

Regional36km

The comparison for O3, CO and NO2

between

profile IC/BC vs. IC/BC from GEOSCHEM 108km data

Profile Data Case GEOS-CHEM Data Case

The comparison of CMAQ results in different IC and BC (2000.08.25. 09, 21UTC)

03AM CST

03PM CST

08/28/2000 03AM CST 09AM CST

12:00 CST 03PM CST

Profile Data Case GEOS-CHEM Data Case

Continued, now at 4-km resolution

(August, 26, 2000, 21UTC)

Conclusive Remarks

•Issues related with linking global tropospheric chemistry model with regional air quality model has been studied

•Problems with current fixed profile method identified

•Global tropospheric model provides needed dynamic evolution and concentration distribution realism not existing in profile method

•We observe significant changes in the atmospheric reactivity conditions depending on profile vs. GEOSCHEM IC/BC

•Global-regional scale linking is the best when outside the regional domain boundary does not have much direct emission sources; e.g., CONUS domain

•Need to study the issues of harmonization of chemical mechanisms further

•Need to quantify and minimize the effects of different dynamics between the global and regional meteorological data used