CAM-chem model evaluation of the emissions and distributions of VSLS using TOGA VOC observations

CAM-chem model evaluation of the emissions and distributions of VSLS using TOGA VOC observationsfrom CONTRAST and TORERO(in the lower and free troposphere over the eastern and western Pacific)

TOGA and AWAS observations: Rebecca Hornbrook, Eric Apel, Alan Hills, Dan Riemer, Nicola Blake, Stacey Hughes, Elliot Atlas, Valeria Donets, Sue Schauffler, Rich LuebCAM-chem modeling: Jean-Francois Lamarque, Doug Kinnison, Simone Tilmes

CONTRAST-ATTREX-CAST Science Meeting22-Oct-2014

Photo: ITCZ convection during RF10

VOC tracers from several sources/types:• Biogenic VOCs and oxidation products• Anthropogenic VOCs• Oil and Gas Tracers• Long-lived Halogenated VOCs• Short-lived Halogenated VOCs• OVOCs, including HCHO• DMS• Alkyl Nitrates• Biomass burning tracers (HCN, CH3CN)

TOGA: Trace Organic Gas Analyzer

TOGA Installed on the G-V

NCAR/ACD TOGA group CONTRAST-CAST-ATTREX science meeting

For more information, see these posters this afternoon:

• TOGA and AWAS measurements during CONTRAST

• Inter-comparisons of TOGA and AWAS measurements during CONTRAST

CAM-Chem with VSL Chemistry

Ordoñez et al., ACP, 2012; Saiz-Lopez et al., ACP, 2012, Fernandez et al., ACP, 2014

Tropospheric Halogen Chemistry

Halogenated sources from the ocean.

• Emissions following Chl-a over tropics

• Catalytic release from sea-salt

• Do NOT have polar emission processes

Chemical Processes

• Photochemistry (Cl, Br, and I)

• Dry / wet deposition

• 9 Additional vsl Organic species included.

• 160 species, 427 reactions

CESM CAM-CHEM

• Global Chemistry-Climate Model

• ~1.0° horizontal resolution

• Specified Dynamics Version (GEOS5)

• 56 vertical levels (surface to ~ 2 hPa)

Lamarque et al., Geosci. Mod. Dev., 2012

CHBr3 Flux in CAM-Chem

Total Bromine: 632 Gg Br yr-1

Total Iodine: 600 Gg I yr-1

CHBr3

17 daysCH2Br2

130 daysCH2ICl

8 h

Data Coverage: Western and Eastern Tropical Pacific


All CONTRAST Flights, Jan - Feb 2014 All TORERO Flights, Jan - Feb 2012

16

14

12

10

8

6

4

2

0A

ltitu

de

, km

150010005000

TOGA CAM-chem

DMS

16

14

12

10

8

6

4

2

0

Alti

tud

e,

km

150010005000

TOGA CAM-chem

DMS

16

14

12

10

8

6

4

2

0

Alti

tud

e,

km

1 10 100 1000

TOGA CAM-chem

DMS

16

14

12

10

8

6

4

2

0A

ltitu

de

, km

1 10 100 1000

TOGA CAM-chem

DMS

Spatial Distribution: DMS (Dimethyl sulfide, CH3SCH3)


-40

-30

-20

-10

0

10

-100 -90 -80 -70Longitude, deg

-40

-30

-20

-10

0

10

La

titu

de

, d

eg


25

20

15

10

5

0

-5

170160150140130Longitude, deg

25

20

15

10

5

0

-5

Latit

ude,

deg


200150100500DMS, pptv

CAM-chem

CAM-chemTOGA obs.

TOGA obs.

CONTRAST

TORERO

16

14

12

10

8

6

4

2

0A

ltitu

de

, km

3.02.52.01.51.00.50.0

TOGA CAM-chem

CH2Br2

16

14

12

10

8

6

4

2

0

Alti

tud

e,

km

3.02.52.01.51.00.50.0

TOGA CAM-chem

CH2Br2

Spatial Distribution of VSLS: Dibromomethane (CH2Br2)


-40

-30

-20

-10

0

10


-40

-30

-20

-10

0

10

La

titu

de

, d

eg


CAM-chemTOGA obs.

25

20

15

10

5

0

-5


25

20

15

10

5

0

-5

Latit

ude,

deg


2.52.01.51.00.5CH2Br2, pptv

CAM-chemTOGA obs.

CONTRAST

TORERO

16

14

12

10

8

6

4

2

0A

ltitu

de

, km

6420

TOGA CAM-chem

CHBr3

16

14

12

10

8

6

4

2

0

Alti

tud

e,

km

6420

TOGA CAM-chem

CHBr3

Spatial Distribution of VSLS: Bromoform (CHBr3)


CONTRAST

TORERO

CAM-chem-40

-30

-20

-10

0

10


TOGA obs.-40

-30

-20

-10

0

10

Lat

itud

e,

deg


TOGA obs.

25

20

15

10

5

0

-5

La

titu

de

, d

eg


6420CHBr3, pptv

CAM-chem

25

20

15

10

5

0

-5



Case Study: Smaller scale convective region north of Guam – CONTRAST RF05, Jan 22

Flight plan and active convection Actual Flight Track

Guam

Guam

Palau

Papua New Guinea

05:00profile

06:30profile

70

60

50

40

30

20

10

0

Be

nze

ne

, pp

tv

01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00CONTRAST RF05, 1/22/14

80

60

40

20

0

O3 , p

pb

v

16x103

12

8

4

0

altitu

de

, m

GV Altitude Benzene O3

VSLS behavior during CONTRAST RF05 – Localized Convection Region

Convection

With only localized convection, CHBr3 increases slightly in aged convection (see acetone). Shorter-lived species are not observed aloft, so the convection is not very recent. This region is less impacted by wide-spread convection, hence no clear C-shapes in the altitude profiles.

CAM-chem predicts moreCHBr3 and DMS than is observed aloft and in the MBL.


14x103

12

10

8

6

4

2

Alti

tud

e,

m

2.01.51.00.50.0[VOC], pptv

CHBr314x103

12

10

8

6

4

2A

ltitu

de,

m

1.20.80.40.0[VOC], pptv

CH2Br2

TOGA AWAS CC

500

400

300

200

100

0

Aceto

ne, pp

tv

01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00CONTRAST RF05, 1/22/14

3.0

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, CH

Br 3

, pp

tv

30

25

20

15

10

5

0

DM

S, pp

tv

16x103

14

12

10

8

6

4

2

0

altitude, m

CH2Br2 (TOGA) CHBr3 (TOGA) DMS (TOGA) Acetone (TOGA) GV Altitude

500

400

300

200

100

0

Aceto

ne, pp

tv

01:00 02:00 03:00 04:00 05:00 06:00 07:00 08:00CONTRAST RF05, 1/22/14

3.0

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, CH

Br 3

, pp

tv

30

25

20

15

10

5

0

DM

S, pp

tv

16x103

14

12

10

8

6

4

2

0

altitude, m

CH2Br2 (TOGA) CHBr3 (TOGA) DMS (TOGA) Acetone (TOGA) CH2Br2 (CC) CHBr3 (CC) DMS (CC) GV Altitude

16x103

14

12

10

8

6

4

2

0

Alti

tud

e,

m

100806040200[VOC], pptv

DMS


Case Study: Large scale convective region south of Guam – CONTRAST RF12, Feb 17

Guam

Papua New Guinea

Palau

RF12

Flight plan and active convection Actual Flight Track

40

30

20

10

0

Be

nze

ne

, pp

tv

00:00 01:00 02:00 03:00 04:00 05:00CONTRAST RF12, 2/17/14

16x103

12

8

4

0

Altitu

de

, m

80

60

40

20

0

O3 , p

pb

v

GV Altitude Benzene O3

Guam

Palau

VSLS behavior during CONTRAST RF12 – Sustained Convection Region

Recent convection

In regions with wide-spread convection, CHBr3 and CH2Br2 are unaffected by local updrafts. However, in the entire region they are elevated compared to the profiles near Guam, hence the C-shapes in the flight altitude profiles.

CAM-chem predicts moreCHBr3 and DMS than is observed aloft and more DMS at the surface near Guam.


3.0

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, C

HB

r 3,

pp

tv

00:00 00:30 01:00 01:30 02:00 02:30 03:00 03:30 04:00 04:30 05:00 05:30CONTRAST RF12, 2/17/14

16x103

14

12

10

8

6

4

2

0

altitu

de

, m

8

6

4

2

0

DM

S, p

ptv

CH2Br2 (TOGA) DMS (TOGA) CHBr3 (TOGA) GV Altitude3.0

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, C

HB

r 3,

pp

tv

00:00 00:30 01:00 01:30 02:00 02:30 03:00 03:30 04:00 04:30 05:00 05:30CONTRAST RF12, 2/17/14

16x103

14

12

10

8

6

4

2

0

altitu

de

, m

40

30

20

10

0

DM

S, p

ptv

CH2Br2 (TOGA) DMS (TOGA) CHBr3 (TOGA) GV Altitude CH2Br2 (CC) DMS (CC) CHBr3 (CC)

16x103

14

12

10

8

6

4

2

0

Alti

tude

, m

1.51.00.50.0[VOC], pptv

CHBr316x10

3

14

12

10

8

6

4

2

0

Alti

tude

, m

1.20.80.40.0[VOC], pptv

CH2Br2

TOGA AWAS CC

16x103

14

12

10

8

6

4

2

0

Alti

tud

e,

m

3020100[VOC], pptv

DMS

CAM-chem convection during CONTRAST RF05 and RF12 - DMS

CONTRAST-CAST-ATTREX science meeting

Altit

ude,

km

Altit

ude,

km

RF05

RF12

NCAR/ACD TOGA group

DMS, pptvTime, UTC

(DMS – lifetime ~ 1 day)

RF05 - no DMS obs in the UT.• convection present in CAM-chem in

region where convection was observed (in acetone, etc.)

• However MBL DMS was predicted to be relatively low.

RF12 - DMS observed in the UT.• MBL DMS predicted to be > 50 pptv• Max convection predicted in slightly

different region, DMS up to 40 pptv.

14

12

10

8

6

Latit

ude,

deg

154152150148146144Longitude, deg

54321DMS, pptv

MaxCAM-chemconvection


Altit

ude,

km

Altit

ude,

km

CHBr3, pptvTime, UTC

RF05

RF12

CAM-chem convection during CONTRAST RF05 and RF12 – CHBr3

(bromoform – lifetime ~ 17 days)

RF05• The intrusion of low VSLS air from

above was captured by the model.• In general, BL bromoform was too

high in the model, but the aged convection was seen.

RF12• Without sampling the boundary

layer, we can’t definitely state that the modeled bromoform was too high in the BL.

• The profiles near Guam were predicted really well by the model.


VSLS behavior during TORERO RF04 & RF05 – S. American Coast v. Oligotrophic Ocean

-40

-35

-30

-25

-20

Latit

ude,

deg

290285280275270265Longitude, deg

12840Altitude, km

RF05

RF04

16x103

12

8

4

0

altitu

de

, m

15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:0029-Jan-2012; TORERO RF05; Time, UTC

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, p

ptv

8

6

4

2

0

CH

Br3 , p

ptv

1.0

0.8

0.6

0.4

0.2

0.0

CH

2IC

l, p

ptv

CH2ICl (TOGA) CH2Br2 (TOGA) CHBr3 (TOGA) CH2ICl (CC) CH2Br2 (CC) CHBr3 (CC) GV altitude

1.0

0.8

0.6

0.4

0.2

0.0

CH

2IC

l, p

ptv

13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:0027-Jan-2014; TORERO RF04; Time, UTC

16x103

12

8

4

0

altitu

de

, m

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, p

ptv

10

8

6

4

2

0

CH

Br3 , p

ptv

GV altitude CH2Br2 (TOGA) CH2Br2 (CC) CHBr3 (TOGA) CHBr3 (CC) CH2ICl (TOGA) CH2ICl (CC)

16x103

12

8

4

0

altitu

de

, m

19:00 19:30 20:00 20:30 21:0027-Jan-2014; TORERO RF04; Time, UTC

2.5

2.0

1.5

1.0

0.5

0.0

CH

2Br 2

, p

ptv

10

8

6

4

2

0

CH

Br3 , p

ptv

1.0

0.8

0.6

0.4

0.2

0.0

CH

2IC

l, p

ptv

CH2ICl (TOGA) CH2Br2 (TOGA) CHBr3 (TOGA) CH2ICl (CC) CH2Br2 (CC) CHBr3 (CC) GV altitude


VSLS behavior during TORERO RF04 & RF05 – S. American Coast v. Oligotrophic Ocean


Altit

ude,

km

Altit

ude,

km

DMS, pptvTime, UTC

RF04

RF05

CAM-chem convection during TORERO RF04 and RF05 - DMS

14

12

10

8

6

4

2

0

Alti

tude

, km

3002001000[VOC], pptv

DMS

14

12

10

8

6

4

2

0

Alti

tude

, km

3002001000[VOC], pptv

DMS


Altit

ude,

km

Altit

ude,

km

CHBr3, pptvTime, UTC

RF04

RF05

CAM-chem convection during TORERO RF04 and RF05 – CHBr3

14

12

10

8

6

4

2

0

Alti

tud

e,

km

6420[VOC], pptv

CHBr3

14

12

10

8

6

4

2

0

Alti

tud

e,

km6420

[VOC], pptv

CHBr3


Summary

• Marine boundary layer VSLS concentrations in the CONTRAST study region were lower and less variable than in the eastern Pacific.

• Overall there is good agreement between the observations and CAM-chem. For many HCs and OVOCs (not shown), the agreement is excellent.

• For the VSLs, CAM-chem tends to predict higher bromoform and DMS in both the Eastern and Western Tropical Pacific, although the general spatial and vertical trends agree with the observations.

Moving forward:• Continue to compare model and observations from the other

CONTRAST and TORERO flights to better understand the horizontal and vertical distributions of VSLs throughout the Tropical Pacific.

• Use these findings to better constrain the impact of VSLS convection on the UT/LS, and contribute feedback to the model emissions.

• Compare different model resolutions on the convective scale to see what, if any, improvement we can see on the convective modeling.

CAM-chem model evaluation of the emissions and distributions of VSLS using TOGA VOC observations

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