South Coast Air Quality Management District

Air Quality Forecast Feedback:

Los Angeles Air Basin

NOAA Forecast Working Group Meeting

September 27-28, 2017

Marc Carreras-Sospedra, Ph.D and Sang-Mi Lee, Ph.D

South Coast Air Quality Management District 21865 Copley Dr, Diamond Bar, CA 92886

South Coast Air Quality Management District

Overview

• 12 UTC cycle Forecast Products

• Retrieved for Los Angeles Air Basin

• 2nd day forecast variables were evaluated:

– Daily Max 8-hour Ozone

– Average 24-hour PM2.5

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South Coast Air Quality Management District

Performance Evaluation Zone

3

Los Angeles Downtown

Pacific Ocean

Redlands

Crestline San Bernardino Fontana

Glendora

South Coast Air Quality Management District

Air Quality by Geographic Area

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0 10 20 30 40 50 60 70 80 90

Costa Mesa

LAX

Long Beach

Mission Viejo

West Los Angeles

Reseda

Santa Clarita

Azusa

Glendora

Pasadena

Anaheim

Central Los Angeles

La Habra

Pico Rivera

Pomona

Banning

Crestline

Fontana

Lake Elsinore

Mira Loma

Perris

Redlands

Rubidoux

San Bernardino

Upland

Co

asta

l

San

Fern

an

do

Foo

thill

sU

rban

So

urc

eU

rban

Re

cep

tor

Days over 75 ppb O3 standard

South Coast Air Quality Management District

Daily Max 8-hour Ozone

5 Period: April-August 15th

South Coast Air Quality Management District

Daily Max 8-hour Ozone at Glendora (FH)

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0

20

40

60

80

100

120

140

Observed 8hO3 Predicted 8hO3

South Coast Air Quality Management District

Daily Max 8-hour Ozone at Fontana (UR)

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0

20

40

60

80

100

120

140

Observed 8hO3 Predicted 8hO3

South Coast Air Quality Management District

Daily Max 8-hour Ozone at San Bernardino (UR)

8

0

20

40

60

80

100

120

140

Observed 8hO3 Predicted 8hO3

South Coast Air Quality Management District

Daily Max 8-hour Ozone at Crestline (UR)

9

0

20

40

60

80

100

120

140

Observed 8hO3 Predicted 8hO3

South Coast Air Quality Management District

Daily Max 8-hour Ozone at Redlands (UR)

10

0

20

40

60

80

100

120

140

Observed 8hO3 Predicted 8hO3

South Coast Air Quality Management District

Performance Statistics by Month

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Urban Receptor

-40

-20

0

20

40

60

80

100

Obs [ppb] Pred [ppb] Bias [ppb] Error [ppb] PPA [ppb] Bias [%] Error [%] PPA [%]

May Jun Jul Aug

South Coast Air Quality Management District

Geographical Variation

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-60

-40

-20

0

20

40

60

80

Obs [ppb] Pred [ppb] Bias [ppb] Error [ppb] PPA [ppb] Bias [%] Error [%] PPA [%]

Coastal Urb Source Urb Receptor Foothill

South Coast Air Quality Management District

Weekend Effect

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-60

-40

-20

0

20

40

60

80

Coastal Urb Source UrbReceptor

Foothill Coastal Urb Source UrbReceptor

Foothill

Weekday Weekend

Obs [ppb] Pred [ppb] Bias [ppb] Error [ppb]

PPA [ppb] Bias [%] Error [%] PPA [%]

South Coast Air Quality Management District

Average 24-hour PM2.5

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PM2.5 measurements were made with automated Beta Attenuation Method samplers

South Coast Air Quality Management District

Daily 24h PM2.5 at Riverside

15

0

10

20

30

40

50

60

24

h P

M2

.5(m

g/m

3) Observed 24hPM2.5 Predicted 24hPM2.5

South Coast Air Quality Management District

Quarterly Average 24-hour PM2.5

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South Coast Air Quality Management District

PM2.5 Performance Statistics by Quarter

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-20

-10

0

10

20

30

40

50

60

Obs [ug/m3] Pred [ug/m3] Bias [ug/m3] Error [ug/m3] Bias [%] Error [%]

Q1 Q2 Q3 Q4

South Coast Air Quality Management District

FUTURE IMPROVEMENTS

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South Coast Air Quality Management District

Future Improvements: On-Road Emissions Inventory

• The 2016 AQMP inventory was developed based on traffic sensor measurements data

• Further improvement specifically in heavy-duty vehicle category will be

introduced in MATES V and next AQMP

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Light & Medium Duty Traffic Volume near Los Angeles downtown in 2012

South Coast Air Quality Management District

Future Improvements: Marine Traffic Data

• The automatic identification system (AIS) is an automatic tracking system used for collision avoidance on ships and by vessel traffic services (VTS).

• Provides vessel type, size, position, course, and speed.

• Ocean Going Vessels’ emission amount and distribution will be evaluated with the AIS data

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South Coast Air Quality Management District

Example of ship data near Port of LA

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South Coast Air Quality Management District

Future Improvements: Aloft Aircraft Emissions

• Currently aircraft emissions

are treated as ground level

release

• Take-off and landing

emissions will be revised to

have gradual release with

altitude.

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( Source: www.flickr.com)

South Coast Air Quality Management District

Future Improvements: Assimilating Satellite Data

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• Assimilating Satellite Data into Global Chemical Transport model, GEOS-CHEM to evaluate inter-continental scale transport

• Collaboration with NASA JPL and UC Riverside

South Coast Air Quality Management District

Summary and Conclusions

• NOAA forecast still tends to under-predict high ozone episodes in the Basin

especially urban receptor and foothill areas where the peak concentrations are

recorded

• The ozone bias peaks in July-August, when ozone concentrations are the highest

• NOAA forecast under-predicted PM2.5 in spring and summer, and slightly over-

predicted PM2.5 in fall and winter

• SCAQMD is continuously working in improving modeling capabilities: emissions

modeling and background ozone

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