Recent Anthropogenic Increases in Sulfur Dioxide from Asia Have - - PowerPoint PPT Presentation

Recent Anthropogenic Increases in Sulfur Dioxide from Asia Have Minimal Impact on Stratospheric Aerosol

Ryan R. Neely III, O. Brian Toon, Susan Solomon, J. P . Vernier, C. Alvarez,

• J. M. English, K. H. Rosenlof, M. J. Mills,C. G. Bardeen, John S. Daniel,

Jeffrey P . Thayer Acknowledgments: P . Yu, H. L. Miller, J. E. Barnes

1

Neely et al. (2013), Recent anthropogenic increases in SO2 from Asia have minimal impact on stratospheric aerosol, GRL, 40, doi:10.1002/grl.50263.

2000 to 2010 is an unprecedented “background” period

Fuego

T r a n s m i s s i

• n

Clear Sky Transmission At Mauna Loa, HI indicates “background” stratospheric aerosol conditions since 1998.

t

+4.8%/yr +6.3%/yr

Mauna Loa, HI Boulder, CO

Adapted from Hofmann at al. (2009)

GMD Lidar observations reveal variability in “background” stratospheric aerosol

20 to 25 km 20 to 25 km

A “Trend” In Global Stratospheric Aerosol?

Trends 4-7%/yr

Adapted from Vernier, J. P. et al. Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade.

• Geophys. Res. Lett 38, L12807– (2011).

Northern Mid-Latitudes Southern Mid-Latitudes Tropics

Variability in stratospheric aerosol impacts global radiative forcing

Adapted from Solomon et al. (2011), The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change, Science.

Bern 2.5cc

5

Greenhouse gas forcing increased continuously throughout period. Stratospheric aerosol only slowed increase by ~0.2W/m2

Adapted from Solomon et al. (2011), The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change, Science.

Total Radiative Forcing

1980 1990 2000 2010 2020 0.0 0.5 1.0 1.5 2.0 W/m2

"Background" GISS Projections No strat. aerosols GISS + no strat. aerosols after 2000 Satellite

El Chichon Pinatubo Greenhouse Gases and Tropospheric Aerosols only “Background” Stratospheric Aerosol (No Volcanoes) Observed Stratospheric Aerosol Record after Pinatubo

Possible Theories for “Trends”: Asian Emissions?

0.6% of Global Emissions must make it to stratosphere to maintain sulfur burden (Hofmann et al. 2009)

0! 20,000! 40,000! 60,000! 80,000! 100,000! 120,000! 140,000! 160,000! 1850! 1875! 1900! 1925! 1950! 1975! 2000! Gg SO2! Year!

Global SO2 Emissions!

0! 5,000! 10,000! 15,000! 20,000! 25,000! 30,000! 35,000! 40,000! 1900! 1925! 1950! 1975! 2000! Gg SO2! Year!

China SO2 Emissions!

Adapted from Smith, S. J., J. van Aardenne, Z. Klimont, R. J. Andres, A. Volke, and S. Delgado Arias (2011), Anthropogenic sulfur dioxide emissions: 1850–2005, Atmos. Chem. Phys, 11(3), 1101–1116, doi:10.5194/acp-11-1101-2011.

Possible Theories for “Trends”: Moderate Volcanoes?

Adapted from Vernier, J. P. et al. Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade. GRL 38, L12807– (2011).

Current observations cannot partition the observed variability to sources

The Model

CARMA

4 x 36 Bins 0.2 nm to 1100 nm

Meteoritic Smoke, Pure Sulfates, Mixed Sulfates

Adapted from English et al. (2011)

9

Neely, R. R., III, J. M. English, O. B. Toon, S. Solomon, M. Mills, and J. P. Thayer (2011), Implications of extinction due to meteoritic smoke in the upper stratosphere, Geophys. Res. Lett, 38(24), doi:10.1029/2011GL049865.

Model Experiment Setup: SO2 Schemes

5 model years

Base: 2000 Repeating Volcanic Anthropogenic

10 model years

“1995” “2000”

“2010”

Spin-Up

10

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 x 10

−3

Month AOD 525nm 20 S − 20 N, 20 to 30 km Base Model Run 1 Base Model Run 2 Base Model Run 3 Anthropogenic Emissions Run 1 Anthropogenic Emissions Run 2 10x Anthropogenic Emissions Volcanic Emissions SAGE II and Calipso AOD Volcanic Eruptions

Ul RuRa At Ma Si So Ta Jb ChOkKa Sa

Volcanoes drive stratospheric aerosol variability

Tropics

20 N to 20 S, 20 to 30 km

AOD (525 nm)

4 4.5 5 5.5 6

−

− Base Model Run 1 Base Model Run 2 Base Model Run 3 Anthropogenic Emissions Run 1 Anthropogenic Emissions Run 2 10x Anthropogenic Emissions Volcanic Emissions SAGE II and Calipso AOD Volcanic Eruptions

Year 11

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2 3 4 5 6 7 8 9 10 x 10

−3

Year AOD 525nm 30 N − 50 N, 15 to 30 km Base Model Run 1 Base Model Run 2 Base Model Run 3 Anthropogenic Emissions Run 1 Anthropogenic Emissions Run 2 10x Anthropogenic Emissions Volcanic Emissions SAGE II and Calipso AOD Volcanic Eruptions

Ul RuRa At Ma Si So Ta Jb ChOkKa Sa

Anthropogenic emissions may have some influence

Northern Midlatitudes

30 N to 50 N, 15 to 30 km

AOD (525 nm)

4 4.5 5 5.5 6

−

− Base Model Run 1 Base Model Run 2 Base Model Run 3 Anthropogenic Emissions Run 1 Anthropogenic Emissions Run 2 10x Anthropogenic Emissions Volcanic Emissions SAGE II and Calipso AOD Volcanic Eruptions

Year 12

Anthropogenic Influence: The Asian Tropical Aerosol Layer (ATAL)

13

Median 1020 nm Extinction Ratio Observed by SAGE II from 15N to 45N, June thru August

Plot adapted from Thomason, L. W. and Vernier, J.-P .: Improved SAGE II cloud/aerosol categorization and observations of the asian tropopause aerosol layer: 1989–2005, Atmos. Chem. Phys. Discuss., 12, 27521-27554, doi:10.5194/acpd-12-27521-2012, 2012.

Anthropogenic Influence: The ATAL

14 With Global Anthropogenic Sulfur Emissions Without Chinese and Indian Anthropogenic Sulfur Emissions

Altitude (km) Longitude Longitude

Modeled Mean 1020 nm Extinction Ratio from 14N to 46N, June thru August

ATAL reduced by ~60%and “Background” Layer is similar

Conclusions

Anthropogenic

Terrestrial

OCS S O

2

S O

2

Marine

S O

2

Volcanic 15 Stratospheric Aerosol Layer

Volcanoes are the major source variability Anthropogenic SO2 may be responsible for ATAL

D M S

16

Back Up Slides

Anthropogenic Influence: The ATAL

17 With Global Anthropogenic Sulfur Emissions Without Global Anthropogenic Sulfur Emissions

Altitude (km) Longitude Longitude No ATAL present and “Background” Layer has 10% less extinction and

Modeled Mean 1020 nm Extinction Ratio from 14N to 46N, June thru August

“Trends”: Volcanic or Anthropogenic?

Troposphere Stratosphere Surface

Anthropogenic

Biomass Burning Terrestrial

OCS S O

2

OCS S O

2

Marine

S O

2

Volcanic 18

Aerosol Layer

Increases in Asian Anthropogenic Emissions since 2000

19

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 5 10 15 20 25 Year SO2 (Tg, Above 2000 Emissions ) Observed India Emissions Observed Chinese Emissions

Data source: Lu, Z., Zhang, Q. & Streets, D. G. Sulfur dioxide and primary carbonaceous aerosol emissions in China and India. 1996–2010, Atmospheric Chemistry and Physics 11, 9839–9864 (2011).

2000 Emissions totaled 25 Tg ~50 Increase

Aura/OMI - 01/28/2005 04:12-04:16 UT - Orbit 02867 SO2 column STL [DU]

1 2 3 4 5 6 7 8 9 10

OMI SO2 Andrew Tupper at the Darwin Volcanic Ash Advisory Centre "The eruption...clearly penetrated into the stratosphere...based on the warmth of the central umbrella cloud, and the subsequent dispersion of the ice-cloud..."

Eruption height: ~20 km

Modeling volcanic emissions as plumes of SO2

Manam (Ma) shown as an example

20

WACCM SO2 Mixing Ratio at 19 km

0.01 0.02 5 10 15 20 25 30 35 40

Monthly Averaged SO 2 Profile After Manam Eruption

SO 2 (Tg) Altitude (km)

WACCM SO2 Profile

Modeling volcanic emissions as plumes of SO2

Manam (Ma) shown as an example

21

2000 to 2010 is an unprecedented “background” period

Global Aerosol Optical Depth

1995 2000 2005 2010 Year 0.000 0.005 0.010 0.015 0.020 Optical Depth 0.000 0.005 0.010 0.015 0.020

Satellite (Global, >15 km) Satellite (Tropics, >15 km) GISS Ammann et al.

Layer became stable only in 2000. Previous observations will be influenced by 1991 Pinatubo eruption.

Adapted from Solomon et al. (2011), The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change, Science Niwano et al. (2009), Seasonal cycles of Stratospheric Aerosol and Gas Experiment II near- background aerosol in the lower stratosphere, J. Geophys. Res, 114(D14), D14306.

Anthropogenic Influence: The Asian Tropical Aerosol Layer (ATAL) Mean Scattering Ratio (SR) from CALIPSO at 532 nm between 15–17 km

23

Jun-Aug 2006 Jun-Aug 2007 Jun-Aug 2008 Jun-Aug 2009

Adapted from: Vernier, J. P ., L. W. Thomason, and J. Kar (2011), CALIPSO detection of an Asian tropopause aerosol layer, Geophys. Res. Lett, 38(7), doi:10.1029/2010GL046614.

Anthropogenic emissions transported to the stratosphere via the Asian Monsoon

Plot from Randel et al. (2010), Asian Monsoon Transport of Pollution to the Stratosphere, Science.

2000 to 2010 is an unprecedented “background” period

Mauna Loa Apparent Transmission

1960 1970 1980 1990 2000 2010 0.91 0.92 0.93 0.94 0.95 Transmission 1960 1970 1980 1990 2000 2010 0.91 0.92 0.93 0.94 0.95

Empirical Clean Value

Monthly Maximum Annual High Average

Mauna Loa Aerosol Optical Depth

1995 2000 2005 2010 0.000 0.005 0.010 0.015 0.020 Optical Depth 0.944 0.939 0.934 0.929 0.924 Transmission

Satellite (Tropics, >15 km) Lidar (Stratospheric) Lidar (Stratospheric, Annual Average) PFR Transmission

Global Aerosol Optical Depth

1995 2000 2005 2010 Year 0.000 0.005 0.010 0.015 0.020 Optical Depth 0.000 0.005 0.010 0.015 0.020

Satellite (Global, >15 km) Satellite (Tropics, >15 km) GISS Ammann et al.

Variability in stratospheric aerosol impacts global radiative forcing

Adapted from Solomon et al. (2011), The Persistently Variable “Background” Stratospheric Aerosol Layer and Global Climate Change, Science.

Bern 2.5cc

Total Radiative Forcing

1980 1990 2000 2010 2020 0.0 0.5 1.0 1.5 2.0 W/m2

"Background" GISS Projections No strat. aerosols GISS + no strat. aerosols after 2000 Satellite

El Chichon Pinatubo Greenhouse Gases and Tropospheric Aerosols only “Background” Stratospheric Aerosol (No Volcanoes) Observed Stratospheric Aerosol Record after Pinatubo

Radiative forcing is a measure of the imbalance in the radiative budget caused by an external factor on the Earth-atmosphere system 26

Impacts on global temperature

Total Radiative Forcing

1980 1990 2000 2010 2020 0.0 0.5 1.0 1.5 2.0 W/m2

Temperature Change

1980 1990 2000 2010 2020 Year 0.0 0.2 0.4 0.6 0.8 1.0 Deg C

"Background" GISS Projections No strat. aerosols GISS + no strat. aerosols after 2000 Satellite

El Chichon Pinatubo

• Fig. 4. Radiative forcing for six stratospheric aerosol forcing scenarios (top, also see Fig. 3) and the

Trends are largely due to episodic injections from volcanic eruptions

Extinction Ratio (Aerosol over Molecular) from 15 to 35 km, 20 S to 20 N

15 20 25 30 35

Altitude (km) Year

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 15 20 25 30 35 0.2 0.4 0.6 0.8 1 1.2 1.4

Ul RuRa At Ma Si So Ta Jb Ka ChOk Sa

Altitude (km) a) b)

Observed Modeled

Adapted from Vernier, et al. (2011). Lu et al. (2010), Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000, Atmos. Chem. Phys, 10(13)

Anthropogenic vs Volcanic emissions

Year China Volcano 2006 0.2 TgS Soufrière Hills 0.17 TgS Estimated Emission to Stratosphere (0.6% of Global Emissions must make it to stratosphere to maintain sulfur burden (Hofmann et al. 2009))

Chinese SO2 Emissions

33 TgS

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1 2 3 4 5 6 7 Particle radius (microns)

Vfa

fall

(m (mm/s) Ma Mass ss sc scatt ttering ef efficiency (m (m2/g /g)

Pinatubo 10Tg 10Tg/yr Continuos

Effective Radius

Plots adapted from English, J. M., O. B. Toon, and M. J. Mills (2011), Microphysical simulations of stratospheric sulfur geoengineering, J. Geophys. Res., under review.

Why Are Volcanoes More Efficient at Making Aerosol?

All 2000 Anthropogenic SO2 No Anthropogenic SO2 Only Chinese and Indian Anthropogenic SO2 No Chinese and Indian Anthropogenic SO2

June-Aug. Mean Extinction Ratio at 1020 nm, 14N to 46N

Altitude (km) Altitude (km) Longitude Longitude

Transport in WACCM

WACCM, June, 65º E WACCM, June, 115º E

−100 100 −60 −40 −20 20 40 60

Longitude Latitude

WACCM CO 100 hPa

20 40 60 80 100

CO (ppbv) Longitude Latitude

MLS CO 100 hPa

−100 100 −60 −40 −20 20 40 60

20 40 60 80 100

CO (ppbv)

a) b)

Transport pathways of carbon monoxide in the Asian summer monsoon diagnosed from Model of Ozone and Related Tracers (MOZART)

Mijeong Park,1 William J. Randel,1 Louisa K. Emmons,1 and Nathaniel J. Livesey2

−20 20 40 60 80 2 4 6 8 10 12 14 16 18 20 22

Altitide (km) Latitude WACCM, June, 65º E

10 20 30 40 50 60 70 80 90 100

−20 20 40 60 80 2 4 6 8 10 12 14 16 18 20 22

Altitide (km) Latitude WACCM, June, 115º E

20 40 60 80 100

CO (ppbv)

c) d)

Longitude Longitude

Figure 7. Latitude-altitude cross-sections of monthly mean MOZART-4 CO at the (a) western (67.5E) and (b) eastern (112.5E) sides of the monsoon maximum in June 2005. Thermal tropopause derived from the model temperature profile is denoted as thick dashed lines. Thin solid lines are isentropes (320, 340, 360, 380, 450, and 500 K).

33

Scattering Calculations

x)n(r, z)=

36 Bins 0.2 nm to 1100 nm

) = π ⇥ ∞ r2Qπ( ˜ m, x)n(r, z)dr

!! !! ! ! !

Bohren and Huffman (1983)

10

−1

10 10

1

10

−3

10

−2

10

−1

10 10

1

Extinction Efficieny Used for Sulfate Aerosol Size Parameter(x=2π r/ λ) Qext m=1.412 m=1.462 m=1.512 Qext

Volcanoes

Table S1: Volcano Eruption Date Lat. Long. SO2 Injected (Tg)

• Max. Injection

Height (km) V E I Ulawun (Ul) 2000.74

• 5

151 0.0529 15 4 Ruang (Ru) 2002.73 2 125 0.05530 2030 16*31 4 Reventador (Ra) 2002.83

• 78

0.09632 17 4 Anatahan (At) 2004.28 16 146 0.06530 1530 3 Manam (Ma) 2005.07

• 4

145 0.1830 1933 4 Sierra Negra (Si) 2005.81 1 91 0.3634 1534,35 3 Soufrière Hills (So) 2006.38 16

• 62

0.230 2030 3 Tavurvur (Ta) 2006.76

• 4

152 0.12530 1730 4 Jebel at Tair (Jb) 2007.75 16 42 0.0832 1632 3 Chaiten (Ch) 2008.34

• 43
• 73

0.0132 19*32 4 Okmok (Ok) 2008.53 53

• 168

0.12236 1637 4 Kasatochi (Ka) 2008.60 52

• 176

1.738 14-1839 18*40 4 Sarychev (Sa) 2009.44 48 153 1.441 1741 4

SO2 Profiles

Figure S3:!

10

−4

10

−3

10

−2

5 10 15 20 25 30 SO 2 (Tg) Altitude (km) Anthropogenic Emissions 10x Anthropogenic Emissions Manam Eruption Base Model

Volcanic aerosol is also transported to the stratosphere via the Asian monsoon

Nabro erupted on 13 June, 2011 in NE Africa injecting 1.3 Tg of SO2 to 9 to 14 km (below tropopause).

Bourassa, A., A. Robock, W. Randel, and T. Deshler (2012), Large Volcanic Aerosol Load in the Stratosphere Linked to Asian Monsoon Transport, Science.

All 2000 Anthropogenic SO2 No Anthropogenic SO2 Only Chinese and Indian Anthropogenic SO2 No Chinese and Indian Anthropogenic SO2

June-Aug. Mean Extinction Ratio at 1020 nm, 14N to 46N

Altitude (km) Altitude (km) Longitude Longitude

Global July Model Surface SO2 Emissions

India China

New Experiment: Modulate Global Anthropogenic Emissions