A.O. Langford1, C.J. Senff2, 1, R. J. Alvarez II1, R.M. Hardesty1, R. M. Banta1, W.A. Brewer1, S.P. Sandberg1, R.D. Marchbanks2,1, A.M.

Weickmann2,1, J. Brioude2,1, O R. Cooper2,1, B.J. Johnson3, S.J. Oltmans2,3

1. CSD, NOAA ESRL, Boulder, CO, United States 2. CIRES, U. of Colorado, Boulder, CO, United States

3. GMD, NOAA ESRL, Boulder, CO, United States

A.O. Langford1, C.J. Senff2, 1, R. J. Alvarez II1, R.M. Hardesty1, R. M. Banta1, W.A. Brewer1, S.P. Sandberg1, R.D. Marchbanks2,1, A.M.

Weickmann2,1, J. Brioude2,1, O R. Cooper2,1, B.J. Johnson3, S.J. Oltmans2,3

1. CSD, NOAA ESRL, Boulder, CO, United States 2. CIRES, U. of Colorado, Boulder, CO, United States

3. GMD, NOAA ESRL, Boulder, CO, United States

Stratosphere-Troposphere Transport (STT)in Southern California during CalNex

Did it happen and does it matter?

The proposed reduction in the 8-h NAAQS from 75 ppbv to 60-70 ppbv places greater importance on understanding the sources and processes that influence “policy relevant background” O3

PRB is O3 that would exist in the United States in the absence of anthropogenic emissions from the United States, Canada, and Mexico.

This includes O3 produced by photochemical reactions of NOx, VOCs, and carbon monoxide (CO) emitted from biogenic sources and wildfires, formed by lightning, transported across the Pacific from Asia and introduced into the troposphere from the stratosphere.

The proposed reduction in the 8-h NAAQS from 75 ppbv to 60-70 ppbv places greater importance on understanding the sources and processes that influence “policy relevant background” O3

PRB is O3 that would exist in the United States in the absence of anthropogenic emissions from the United States, Canada, and Mexico.

This includes O3 produced by photochemical reactions of NOx, VOCs, and carbon monoxide (CO) emitted from biogenic sources and wildfires, formed by lightning, transported across the Pacific from Asia and introduced into the troposphere from the stratosphere.

Motivation

Sprenger and Wernli, JGR, 108, D12, 8521, doi:10.1029/2002JD002636, 2003

Geographical distribution of mass flux associated with deep STT exchange events.

Geographical distribution of lower tropospheric ‘‘destinations’’ of deep STT.

Stratospheric intrusions on the West Coast (winter-spring)

Only “deep” (<3 km AGL) intrusions are likely to influence surface ozone

>>

TOPAZ Measurements of Stratospheric intrusions over LA Basin during CalNex

23 May 2010

29 May 2010

>300 ppbv

1736 UT 1824 UT

1748 UT 1836 UT

Stratospheric intrusion over LA Basin

29 May 2010

JTNP

Joshua Tree ozonesonde (IONS-2010)(Owen Cooper, Bryan Johnson, Sam Oltmans)

29 May 2010

35.0

34.5

34.0

33.5

-119.0 -118.0 -117.0 -116.0

Longitude (°E)

6

5

4

3

2

1

200150100500

Ozone (ppbv)

Sonde launch 22:01 UT TPZ: 675-679 19:37 UT

29 May 2010

Joshua Tree Ozonesondes IONS-2010(stratospheric intrusions)

200150100500O3 (ppbv), RH(%)

325320315310

theta (K)

5

4

3

2

1

014 June

RH O3

θ

2158 UT

200150100500O3 ( ), (%)ppbv RH

325320315310305

( )theta K

29 May

RH O3 θ

2201 UT

200150100500O3 ( ), (%)ppbv RH

325320315310

( )theta K

19 May

RH O3 θ

2150 UT

6

5

4

3

2

1

200150100500O3 ( ), (%)ppbv RH

320310300

( )theta K

11 May

RH O3 θ

1953 UT

EZ EZ

EZ

EZ

( )a ( )b ( )c ( )d

Particles transported by resolved winds and parameterized subgrid motions.

NCEP GFS winds: 0.5° x 0.5° horizontal, 26 vertical levels, 3-hour steps.Emanuel and Zivkovic-Rothman parameterization convection

Tracers Stratosphere: 25-55°N, 140-90°W, >2 PVU (60 ppbv/PVU), 10 days Free troposphere: 10-50°N, 140-90°W, 70-60 ppbv (PBL to 2 PVU), 10 days Asia: Asian sources (EDGAR 3.2) 0.33 CO (Heald et al.), 20 days Biomass burning : N. American and Asian sources 0.2 CO (McKeen et al.), 20 days

Target Domains

Santa Barbara: 34-35°N, 121-119°W 0-1, 0-3, 3-6 km AGL LA Basin: 33.5-34.5°N, 119-117°W 0-1, 0-3, 3-6 km AGL Mojave: 33.25-34.25°N, 117-115°W 0-1, 0-3, 3-6 km AGL

Particles transported by resolved winds and parameterized subgrid motions.

NCEP GFS winds: 0.5° x 0.5° horizontal, 26 vertical levels, 3-hour steps.Emanuel and Zivkovic-Rothman parameterization convection

Tracers Stratosphere: 25-55°N, 140-90°W, >2 PVU (60 ppbv/PVU), 10 days Free troposphere: 10-50°N, 140-90°W, 70-60 ppbv (PBL to 2 PVU), 10 days Asia: Asian sources (EDGAR 3.2) 0.33 CO (Heald et al.), 20 days Biomass burning : N. American and Asian sources 0.2 CO (McKeen et al.), 20 days

Target Domains

Santa Barbara: 34-35°N, 121-119°W 0-1, 0-3, 3-6 km AGL LA Basin: 33.5-34.5°N, 119-117°W 0-1, 0-3, 3-6 km AGL Mojave: 33.25-34.25°N, 117-115°W 0-1, 0-3, 3-6 km AGL

FLEXPART forward trajectory model(Jerome Brioude)

FLEXPART trajectories(Jerome Brioude)

18UT 23 May 2010

18UT 29 May 2010

4 km MSL

4 km MSL

FLEXPART Results: (3-6 km)

• 4 major STT events during IONS-2010 (3 on weekends)

•Excellent correlation with ozonesondes

(R=0.92)

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LAB

MD

40

30

20

10

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

Santa Barbara Los Angeles Mojave Desert

0-1 km ASL

100

80

60

40

20

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

Santa Barbara Los Angeles Mojave Desert

0-1 km ASL

40

30

20

10

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

STT AS BB

0-1 km ASLSanta Barbara

(a)

(b)

(c)

BB

Brad Pierce

ARB Ozone surface stations

UseUse

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

Use Maximum Daily 8-h average (MDA8) O3

Santa Barbara

LA Basin

Mojave Desert

100

80

60

40

May 9 May 16 May 23 May 30 June 6 June 13 June 20Date

Vandenberg Carpenteria

100

80

60

40

May 9 May 16 May 23 May 30 June 6 June 13 June 20Date

Vandenberg

Thousand Oaks

(a)

100

80

60

40

May 9 May 16 May 23 May 30 June 6 June 13 June 20Date

Vandenberg Glendora

100

80

60

40

May 9 May 16 May 23 May 30 June 6 June 13 June 20Date

Vandenberg Redlands

(b)

(c)

(d)

100

80

60

40

May 9 May 16 May 23 May 30 June 6 June 13 June 20Date

Vandenberg Indio

(e)

MDA8 O3 along NW-SE transect during IONS-2010 (9 May – 19 June)

• Subtropical airmass in early June • 5 Exceedance episodes in east Basin• Highest average O3 in Mojave Desert

5 June30 May

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LA

MD

FLEXPART Results: (0-1 km)

• Three major STT episodes

• No free tropospheric source for peaks

•No Asian transport or biomass burning

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LAB

MD

40

30

20

10

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

Santa Barbara Los Angeles Mojave Desert

0-1 km ASL

100

80

60

40

20

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

Santa Barbara Los Angeles Mojave Desert

0-1 km ASL

40

30

20

10

0

May 9 May 16 May 23 May 30 June 6 June 13 June 20

Date

STT AS BB

0-1 km ASLSanta Barbara

(a)

(b)

(c)

5 June30 May

•PCA is non-parametric technique used to identify patterns of common variance in large datasets.

•Requires no assumptions about the data distribution.

•Principal components (PCs) are linear combinations of original variables weighted by coefficients (or loadings) ranging from -1 to +1.

•PCA is non-parametric technique used to identify patterns of common variance in large datasets.

•Requires no assumptions about the data distribution.

•Principal components (PCs) are linear combinations of original variables weighted by coefficients (or loadings) ranging from -1 to +1.

Principal Component Analysis

PCA Results

(a)

(b)

(c)

(d)35

34

33

-121 -120 -119 -118 -117 -116

Longitude (°E)

PC2 (IONS)

35

34

33

-121 -120 -119 -118 -117 -116

Longitude (°E)

PC1 (IONS)

-1.0 -0.5 0.0 0.5 1.0

-3

-2

-1

0

1

2

3

May 9 May 16 May 23 May 30 Jun 6 Jun 13 Jun 20

Date

30

20

10

0 T PC1T: 32.5-35°N, 119.5-117°W

R=0.74, P<0.001

-3

-2

-1

0

1

2

3

May 9 May 16 May 23 May 30 Jun 6 Jun 13 Jun 20

Date

120

100

80

60 ABSV PC2ABSV: 30-35°N, 122 -117°W

R=0.48, P<0.001

5 June30 May

59%

16%

AmplitudesLoadings

-20

0

20

May 25 June 1 June 8Date

PC1 PC2

Carpenteria

-20

0

20

May 25 June 1 June 8Date

PC1 PC2

Thousand Oaks

-40

-20

0

20

40

May 25 June 1 June 8Date

PC1 PC2

Glendora

(a)

(b)

(c)

-40

-20

0

20

40

May 25 June 1 June 8Date

PC1 PC2

Redlands

-20

0

20

May 25 June 1 June 8Date

PC1 PC2

Indio

(d)

(e)

5 June30 May MDA8 O3 along NW-SE transect resolved into PC1 (photochemistry) and PC2 (transport) contributions

• PC1 only contributes to 5 June peak• PC2 increases O3 >10 ppbv in Santa

Barbara on 30 May • PC2 decreases O3 >10 ppbv in Mojave

Desert on 30 May

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LA

MD

Marine 40 ppbv O3

High VOC High NOx

Marine 40 ppbv O3

High VOC High NOx

UT/LS 80 ppbv O3

Low VOC, Low NOx

60 ppbv O3

Med-High VOC Med-High NOx

60 ppbv O3

Med-High VOC Med-High NOx+20 ppbv

Urban 80 ppbv O3

High VOC High NOx

Urban 80 ppbv O3

High VOC High NOx

UT/LS 80 ppbv O3

Low VOC, Low NOx

80 ppbv O3

Med-High VOC Med-High NOx

80 ppbv O3

Med-High VOC Med-High NOx +0 ppbv

Polluted 100 ppbv O3

High VOC High NOx

Polluted 100 ppbv O3

High VOC High NOx

UT/LS 80 ppbv O3

Low VOC, Low NOx

90 ppbv O3

Med-High VOC Med-High NOx

90 ppbv O3

Med-High VOC Med-High NOx-10 ppbv

• STT did affect surface O3 in LA Area during CalNex.

• 29-30 May event increased surface O3 in Santa Barbara,Orange, Ventura and parts of Los Angeles counties.

• increase of ≈10-20 ppbv in Santa Barbara County (68 ppbv)

• decrease of ≈10 ppbv in eastern San Bernardino County.

•STT may lead to spring exceedances with lower standard.

• STT did affect surface O3 in LA Area during CalNex.

• 29-30 May event increased surface O3 in Santa Barbara,Orange, Ventura and parts of Los Angeles counties.

• increase of ≈10-20 ppbv in Santa Barbara County (68 ppbv)

• decrease of ≈10 ppbv in eastern San Bernardino County.

•STT may lead to spring exceedances with lower standard.

Summary

NOAA AOC Twin Otter crewNOAA Health of the Atmosphere Program

CA Air Resources BoardJoshua Tree National Park

NOAA AOC Twin Otter crewNOAA Health of the Atmosphere Program

CA Air Resources BoardJoshua Tree National Park

Acknowledgements

County-high MDA8 O3 during 2010

• Spring and Fall maxima in Santa Barbara• Summertime increase across Basin• Exceedances in east Basin April-Sept.• Highest MDA8 on June 5 (Crestline)• Less variability in High Desert

120

100

80

60

40

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Ventura Santa Barbara

120

100

80

60

40

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Los Angeles Santa Barbara

120

100

80

60

40

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

San Bernardino Santa Barbara

120

100

80

60

40

20

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Santa Barbara Riverside

(b)

(c)

(d)

(a)

IONS-2010

NAAQS

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LA

MD

County-high MDA8 O3 during 2010

• Summertime increase across Basin• Highest summer O3 in east Basin

• Episodic transport to Santa Barbara from Central Valley in Fall

60

40

20

0

-20

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Ventura

16.8 ppbv

60

40

20

0

-20

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Los Angeles

38.5 ppbv

60

40

20

0

-20

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

San Bernardino

43.0 ppbv

( )a

( )b

( )c

60

40

20

0

-20

1/1/10 4/1/10 7/1/10 10/1/10 1/1/11Day

Riverside

40.3 ppbv

( )d

IONS-2010

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

SB

LA

MD

County-high MDA8 O3 during 2010 (less Santa Barbara)

Joshua Tree Ozonesondes IONS-2010(stratospheric intrusions)

200150100500O3 (ppbv), RH(%)

325320315310

theta (K)

5

4

3

2

1

014 June

RH O3

θ

2158 UT

200150100500O3 ( ), (%)ppbv RH

325320315310305

( )theta K

29 May

RH O3 θ

2201 UT

200150100500O3 ( ), (%)ppbv RH

325320315310

( )theta K

19 May

RH O3 θ

2150 UT

6

5

4

3

2

1

200150100500O3 ( ), (%)ppbv RH

320310300

( )theta K

11 May

RH O3 θ

1953 UT

EZ EZ

EZ

EZ

( )a ( )b ( )c ( )d

MDA8 along NW-SE transect during 5 high O3 episodes

• Little or no O3 increase on 23 May

• Largest increase in west on 30 May

• Similar trends on all other days

35.0

34.5

34.0

33.5

-121.0 -120.0 -119.0 -118.0 -117.0 -116.0 -115.0Longitude (°E)

JTCL

VBG

mean wind SN

120

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(16 May)

(23 May)

120

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(30 May)

(23 May)

120

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(5 June)

(23 May)

120

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(23 May)

(13 June)

120

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(17 June)

(23 May)

(b)

(c)

(a)

(d)

(e)

SB LAB MD

SB

LAB

MD

Joshua Tree Ozonesondes

12080400O3 (ppbv), RH(%)

325320315310

theta (K)

4

3

2

1

018 June

RH O3

θ

2155 UT

12080400O3 ( ), (%)ppbv RH

325320315

( )theta K

14 June

RH O3

θ

2158 UT

330325320315

( )theta K

12080400O3 ( ), (%)ppbv RH

5 June

RH O3 θ

2202 UT

( )a ( )b ( )c ( )e

12080400O3 ( ), (%)ppbv RH

325320315310305

( )theta K

29 May

RH O3

θ

2201 UT

6

5

4

3

2

1

12080400O3 ( ), (%)ppbv RH

325320315310305

( )theta K

15 May

RH O3

θ

2159 UT

( )d

1. 9-10 May (ozonesonde)2. 11-12 May (WP-3D, ozonesonde)3. 19 May (ozonesonde)4. 23 May (TOPAZ)5. 29 May (TOPAZ, ozonesonde)6. 11-12 June (ozonesonde)7. 16 June (ozonesonde)8. 26 June (TOPAZ)

Stratospheric intrusions during CalNex

MDA8 O3 during IONS-2010( 9 May – 20 June 2010)

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(30 May)

(23 May)

-20

-10

0

10

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(30 May)

100

80

60

40

20

-121 -120 -119 -118 -117 -116

Longitude (°E)

(30 May)

(23 May)

(a)

(b)

(c)

Surface impacts of stratospheric intrusions during CalNex

5000

4500

4000

3500

3000

2500

2000

1500

1000

500

34.334.234.134.033.933.8

Lat(°N)

(a) 29 May TOPAZ: 1933-1943 UT Ozonesonde: 2202 UT

CBL

120

100

80

60

5000

4500

4000

3500

3000

2500

2000

1500

1000

500

34.334.234.134.033.933.8

Lat(°N)

(b) 5 June

TOPAZ: 0127-0136 UT Ozonesonde: 2201 UT

CBL

•E•E

What are the surface impacts?

“Long range transport of ozone from ‐ the Los Angeles Basin: A case study”

Orographic Lifting

Langford et al., GRL, VOL. 37, L06807, doi:10.1029/2010GL042507, 2010

3-8 km MSL 300m AGL

Lifting of ozone plume above the San Gabriel Mountains by the Mountain Chimney Effect

Surface impacts of Asian transport during CalNex

80

70

60

50

40

30

20

10

6/11/10 6/21/10Day

Paradise

Sutter Buttes Shasta Lake

42

41

40

39

38

-124 -123 -122 -121 -120

Longitude (°E)

70605040

FLEXPART trajectories 01UT 3 July 2010 (3 km MSL)

Asia (CO)North America (CO)

Biomass Burning (CO)STT (O3)

Orographic lifting by San Gabriel Mountains during CalNex

2 July 2010

15 July 2010

ResiResi

“Increasing springtime ozone mixing ratios in the free troposphere over western North America”

Transport from Asia

Cooper et al., Nature, Vol 463| 21 January 2010| doi:10.1038/nature08708

3-8 km MSL 300m AGL

Residence times of FLEXPART back trajectories from highest 33% of 1984-2008 Western N.A. ozone measurements

Asia (CO)North America (CO)

Biomass Burning (CO)STT (O3)

FLEXPART trajectories 22UT 22 June 2010 (4 km MSL )

ReddingRedding

Asian transport layers during CalNex

22 June 2010

18 June 2010

Redding Sacramento(NASA B200)

Asian transport layers during CalNex

22 June 2010

FLEXPART trajectories 18UT 29 May 2010 (4 km MSL)

Asia (CO)North America (CO)

Biomass Burning (CO)STT (O3)

Stratospheric intrusion above SF Bay area on 26 June 2010

FLEXPART trajectories 22UT 26 June 2010 (4 km MSL)

Asia (CO)North America (CO)

Biomass Burning (CO)STT (O3)

FLEXPART trajectories 02UT 19 June 2010 (4 km MSL)

Asia (CO)North America (CO)

Biomass Burning (CO)STT (O3)

Examine daily ma 8-h ozone in Examine daily ma 8-h ozone in

Surface impacts of stratospheric intrusions during CalNex

Examine daily max 8-h ozone in 5 coastal air basins