Long-Range Transport of Agricultural Smoke to OD Houston ...

1
Conclusions & Future Work Transported smoke measured during four flights (Sept. 4, 6, 13 and 14) No smoke measured at ground level AOD-to-PM higher than expected Aerosol was aged agricultural smoke from the Mississippi River Valley Aerosol aging increases smoke hygroscopicity by 36% f(RH) of 1.5 for aged smoke / 1.1 for fresh smoke and thus increases AOD more than fresh smoke would Future work will look at AERONET and ground-based PM 2.5 measurements in order to study: the frequency of these long-range transport events the spatial extent of smoke transport in the southeast U.S. DISCOVER-AQ DISCOVER-AQ was funded by NASA’s Earth Venture-1 Program through the Earth System Science Pathfinder (ESSP) Program Office. We wish to thank the ESSP Program Office for the support, the NASA Wallops Flight Facility, the pilots, flight crew, and the entire DISCOVER-AQ Science Team. We also wish to thank the entire SEAC4RS science team. Long-Range Transport of Agricultural Smoke to Houston, TX: Effects on Aerosol Optical Depths A.J. Beyersdorf ([email protected]) 1 , S. Burton 1 , G. Chen 1 , J. Lin 2 , R. Martin 1 , R. Moore 1 , A. Nenes 2 , K.L. Thornhill 1 , E.L. Winstead 1 , L.D. Ziemba 1 & B.E. Anderson 1 1 NASA Langley Research Center, 2 Georgia Institute of Technology Vertical profiles of extinction during DISCOVER-AQ-Texas varied amongst flights Boundary layer low loadings of 30-70/Mm 2,500-10,000 ft transported smoke caused increased aerosol loadings for September 13-14 September 13 th Smoke measured by both the HSRL and in situ measurements Highest loadings in the north of the flight region Back trajectory for layer aloft from a region of agricultural fires Differences in Back Trajectories Boundary layer low loadings of 30-70/Mm 2,500-10,000 ft transported smoke caused increased aerosol loadings for September 13-14 Smoke Transport 2.AQ.1 Measuring surface level particulate concentrations remains a challenge for Earth- observing satellites due to: 1) variability in aerosol vertical distribution, and 2) the effects of aerosol composition and hygroscopicity on optical properties. DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) is a multi-year project aimed at understanding the variables that affect remote sensing measurements in U.S. urban areas. Four campaigns were performed in regions with differing aerosol composition and meteorology: Baltimore & Washington, DC, Summer 2011 San Joaquin Valley, CA, Winter 2012 Houston, TX, Summer 2012 Denver, CO, Summer 2013 Results from Previous Campaigns Maryland aerosol was composed of a mixture of organics and ammonium sulfate aerosol present in a well-mixed deep haze layer (~ 7500 ft) California primarily ammonium nitrate aerosol contained in a very shallow boundary layer (~ 2000 ft) except for the last two flights AOD-to-PM The AOD-to-PM correlation is dependent on the height of the haze layer (boundary + residual) with Maryland having a higher ratio than measured during California. 0 0 0 0 0 0 0 Normalized Extinction RF01-09 RF11-12 15000 12500 10000 7500 5000 2500 0 Altitude (ft) 400 300 200 100 0 Extinction (Amb. RH at 532nm) 0 0 0 0 0 0 0 Normalized Extinction 15000 12500 10000 7500 5000 2500 0 Altitude (ft) 400 300 200 100 0 Extinction (Amb. RH at 532nm) Maryland California 9 Flights between Sept. 4 th and 26 th , 2013 P-3B aircraft 24 spirals (1,000-15,000 ft above ground levels) over 8 ground sites In situ measurements of aerosols & trace gases Aerosol number concentration, scattering, absorption, size & composition (by SP2 and PILS; particle into liquid sampler) B-200 aircraft (30,000 ft) High Resolution Spectral Lidar (HSRL) Sampling of agricultural fires during transit flight No correlation between ambient AOD and particulate mass during DAQ-TX Ambient AOD (measured by the P3) varied between 0.06 (Sept 26 th ) & 0.32 (Sept. 14 th ) Flight day particulate mass was less variable (6-11 mg/m 3 ) DISCOVER-AQ Texas Downtown Houston Galveston Conroe 0.6 0.4 0.2 0.0 AOD 40 30 20 10 0 PM(mg/m 3 ) Measured by PILS below 1000 ft 15000 12500 10000 7500 5000 2500 125 100 75 50 25 0 Extinction (Amb, 532nm) RF07 (9-24) RF08 (9-25) RF09 (9-26) 15000 12500 10000 125 100 75 50 25 0 Extinction (Amb, 532nm) RF03 (9-11) RF04 (9-12) RF05 (9-13) RF06 (9-14) 15000 12500 10000 7500 5000 2500 0 125 100 75 50 25 0 Extinction (Amb, 532nm) RF01 (9-4) RF02 (9-6) 15000 12500 10000 7500 5000 2500 0 Altitude (ft) 125 100 75 50 25 0 Extinction (Amb, 532nm) Normalized Extinction West Houston 80 60 40 20 0 LIDAR In Situ Measurements 4 0 Extinction 29.2 29.6 30.0 30.4 Latitude 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Pressure Altitude 80 60 40 20 0 Scattering & Absorption (/Mm, green) Aerosol Size smoke was larger than fresher aerosol measured in the boundary layer Single Scattering Albedo smoke had a higher SSA than the boundary layer and fresh agricultural fires indicating secondary aerosol formation Hygroscopicity fresh smoke had an average f(RH) of 1.1 while the aged smoke averaged 1.5 Smoke Properties 4000 3000 2000 1000 0 Number (dNdlogDp) 10 2 4 6 8 100 2 4 6 8 1000 Diameter Frequency 2.8 2.6 2.4 2.2 2.0 Scat. Ang. Exp. Boundary Layer Elevated Layer Frequency 2.0 1.8 1.6 1.4 1.2 1.0 f(RH) Boundary Layer Elevated Layer Fresh. Ag. Fire Frequency 1.00 0.95 0.90 0.85 SSA Boundary Layer Elevated Layer Frequency 1.00 0.95 0.90 0.85 SSA Elevated Layer Ag. Fire Period 1 Period 2 Period 3 Aerosol Size Single Scattering Albedo Hygroscopicity 70 60 50 40 30 20 280 270 260 250 240 230 220 210 200 SEAC 4 RS & ARCTAS Biomass Burning SEAC 4 RS Fire Plumes Preliminary identification by Bob Yokelson including western U.S. wildfires and agricultural fires in the southeast. Additional identification to follow for more aged plumes downwind of the Rim fire. ARCTAS Fire Plumes 495 plumes identified by Hecobian et al. (ACP, 2011) Aged Asian wildfires sampled over Alaska Fresh Canadian and California wildfires Aged Asian Wildfires (ARCTAS) Fresh Canadian Wildfires (ARCTAS) SEAC4RS Wildfires SEAC4RS Ag. Fires Fresh California Wildfires (ARCTAS) Agricultural Fires (in comparison to wildfires) lower modified combustion efficiencies → smoldering fires MCE = (ΔCO 2 )/(ΔCO+ΔCO 2 ) high particulate emissions & lower single scattering albedo Western Wildfires (in comparison to ARCTAS fires) highest single scattering albedos f(RH) less than 1 indicative of soot restructuring 2.8 2.6 2.4 2.2 2.0 1.8 Scat. Ang. Exponent 1.00 0.95 0.90 0.85 Modified Combustion Efficiency Agricultural Fires 4.0 3.5 3.0 2.5 2.0 1.5 Abs. Ang. Exponent 1.00 0.95 0.90 0.85 Modified Combustion Efficiency 1.00 0.95 0.90 0.85 Single Scat. Albedo 1.00 0.95 0.90 0.85 Modified Combustion Efficiency Changes in aerosol intensive properties with flame conditions (MCE) Flaming conditions (high MCE) gives: higher scattering angstrom exponent (smaller aerosol) lower absorption angstrom exponent (less organic coating) lower single scattering albedo (darker smoke) 0.5 0.4 0.3 0.2 0.1 0.0 AOD 20 15 10 5 0 PM from PILS (<1000 ft) All Profiles Flight Averages colored by altitude of max. extinction (black is highest) 0.6 0.4 0.2 0.0 AOD 40 30 20 10 0 PM(mg/m 3 ) Measured by PILS below 1000 ft Maryland Slope = 0.027 California Slope = 0.006 20 15 10 5 0 PM 30 25 20 15 10 5 0 Day in September PILS Mass (below 1000 ft) PM2.5 (9am - 5pm) Galveston Conroe Deer Park 0.4 0.3 0.2 0.1 0.0 P3-B AOD (Amb, 532nm) 30 25 20 15 10 5 0 Day in September

Transcript of Long-Range Transport of Agricultural Smoke to OD Houston ...

Conclusions & Future WorkTransported smoke measured during four flights (Sept. 4, 6, 13

and 14)

• No smoke measured at ground level

• AOD-to-PM higher than expected

• Aerosol was aged agricultural smoke from the Mississippi

River Valley

• Aerosol aging increases smoke hygroscopicity by 36%

• f(RH) of 1.5 for aged smoke / 1.1 for fresh smoke

• and thus increases AOD more than fresh smoke would

Future work will look at AERONET and ground-based PM2.5

measurements in order to study:

• the frequency of these long-range transport events

• the spatial extent of smoke transport in the southeast U.S.

DISCOVER-AQ

DISCOVER-AQ was funded by NASA’s Earth Venture-1 Program through the Earth System Science

Pathfinder (ESSP) Program Office. We wish to thank the ESSP Program Office for the support, the

NASA Wallops Flight Facility, the pilots, flight crew, and the entire DISCOVER-AQ Science Team.

We also wish to thank the entire SEAC4RS science team.

Long-Range Transport of Agricultural Smoke to

Houston, TX: Effects on Aerosol Optical DepthsA.J. Beyersdorf ([email protected])1, S. Burton1, G. Chen1, J. Lin2, R. Martin1, R. Moore1,

A. Nenes2, K.L. Thornhill1, E.L. Winstead1, L.D. Ziemba1 & B.E. Anderson1

1NASA Langley Research Center, 2Georgia Institute of Technology

Vertical profiles of extinction during DISCOVER-AQ-Texas varied amongst flights

• Boundary layer – low loadings of 30-70/Mm

• 2,500-10,000 ft – transported smoke caused increased aerosol loadings for

September 13-14

September 13th

• Smoke measured by both the HSRL

and in situ measurements

• Highest loadings in the north of the

flight region

• Back trajectory for layer aloft from a

region of agricultural fires

Differences in Back Trajectories

• Boundary layer – low loadings of 30-70/Mm

• 2,500-10,000 ft – transported smoke caused increased aerosol loadings for

September 13-14

Smoke Transport

2.AQ.1

Measuring surface level particulate concentrations remains a challenge for Earth-

observing satellites due to:

1) variability in aerosol vertical distribution, and

2) the effects of aerosol composition and hygroscopicity on optical properties.

DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically

Resolved Observations Relevant to Air Quality) is a multi-year project aimed at

understanding the variables that affect remote sensing measurements in U.S. urban

areas. Four campaigns were performed in regions with differing aerosol composition

and meteorology:

Baltimore & Washington, DC, Summer 2011

San Joaquin Valley, CA, Winter 2012

Houston, TX, Summer 2012

Denver, CO, Summer 2013

Results from Previous Campaigns

Maryland

• aerosol was composed of a mixture of organics and ammonium sulfate

• aerosol present in a well-mixed deep haze layer (~ 7500 ft)

California

• primarily ammonium nitrate aerosol

• contained in a very shallow boundary layer (~ 2000 ft) except for the last two flights

AOD-to-PM

• The AOD-to-PM correlation is dependent on the height of the haze layer (boundary +

residual) with Maryland having a higher ratio than measured during California.

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

NormalizedExtinction

RF01-09

RF11-12

15000

12500

10000

7500

5000

2500

0

Alt

itu

de (

ft)

4003002001000

Extinction (Amb. RH at 532nm)

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

NormalizedExtinction

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

4003002001000

Extinction (Amb. RH at 532nm)

Maryland California

9 Flights between Sept. 4th and 26th, 2013

• P-3B aircraft

• 24 spirals (1,000-15,000 ft above ground levels)

over 8 ground sites

• In situ measurements of aerosols & trace gases

• Aerosol number concentration, scattering,

absorption, size & composition (by SP2 and

PILS; particle into liquid sampler)

• B-200 aircraft (30,000 ft)

• High Resolution Spectral Lidar (HSRL)

Sampling of agricultural fires during transit flight

No correlation between ambient AOD and

particulate mass during DAQ-TX

• Ambient AOD (measured by the P3) varied

between 0.06 (Sept 26th) & 0.32 (Sept. 14th)

• Flight day particulate mass was less variable

(6-11 mg/m3)

DISCOVER-AQ Texas

Downtown

Houston

Galveston

Conroe

0.6

0.4

0.2

0.0

AO

D

403020100

PM(mg/m3)

Measured by PILS below 1000 ft

Texas (colored by altitude of maximum extinction) fit_Over_MD_AOD fit_Over_CA_AOD_without_highs

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

1251007550250

Extinction (Amb, 532nm)

RF07 (9-24) RF08 (9-25) RF09 (9-26)

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

1251007550250

Extinction (Amb, 532nm)

RF03 (9-11) RF04 (9-12) RF05 (9-13) RF06 (9-14)

15000

12500

10000

7500

5000

2500

0

Alt

itu

de

(ft

)

1251007550250

Extinction (Amb, 532nm)

RF01 (9-4) RF02 (9-6)

15000

12500

10000

7500

5000

2500

0

Alt

itu

de (

ft)

1251007550250

Extinction (Amb, 532nm)

15000

12500

10000

7500

5000

2500

0

Alt

itu

de (

ft)

Normalized Extinction

West

Houston

4

3

2

1

0

Alt

itu

de (

km

)

30.430.230.029.829.629.429.2

Latitude

806040200

0913, Circuit 1 - Extinction

LIDAR

In Situ Measurements

4

0

Extinction

29.2 29.6 30.0 30.4Latitude

3.0

2.5

2.0

1.5

1.0

0.5

0.0

Pre

ss

ure

Alt

itu

de

806040200

Scattering & Absorption (/Mm, green)

Aerosol Size – smoke was larger than fresher aerosol

measured in the boundary layer

Single Scattering Albedo – smoke had a higher SSA than

the boundary layer and fresh agricultural fires indicating

secondary aerosol formation

Hygroscopicity – fresh smoke had an average f(RH) of

1.1 while the aged smoke averaged 1.5

Smoke Properties

4000

3000

2000

1000

0Nu

mb

er

(dN

dlo

gD

p)

102 4 6 8

1002 4 6 8

1000

Diameter

Fre

qu

en

cy

2.82.62.42.22.0

Scat. Ang. Exp.

Boundary LayerElevated Layer

Fre

qu

en

cy

2.01.81.61.41.21.0

f(RH)

Boundary LayerElevated LayerFresh. Ag. Fire

Fre

qu

en

cy

1.000.950.900.85

SSA

Boundary LayerElevated Layer

Fre

qu

en

cy

1.000.950.900.85

SSA

Elevated LayerAg. Fire

Period 1 Period 2 Period 3

Aerosol Size Single Scattering Albedo

Hyg

rosco

pic

ity

70

60

50

40

30

20

280270260250240230220210200

SEAC4RS & ARCTAS Biomass BurningSEAC4RS Fire Plumes

• Preliminary identification by Bob

Yokelson including western U.S.

wildfires and agricultural fires in

the southeast.

• Additional identification to follow

for more aged plumes downwind

of the Rim fire.

ARCTAS Fire Plumes

• 495 plumes identified by

Hecobian et al. (ACP, 2011)

• Aged Asian wildfires sampled

over Alaska

• Fresh Canadian and California

wildfires

Aged Asian

Wildfires

(ARCTAS)

Fresh Canadian

Wildfires

(ARCTAS)

SEAC4RS

Wildfires SEAC4RS

Ag. Fires

Fresh California

Wildfires

(ARCTAS)

Agricultural Fires (in comparison to wildfires)

• lower modified combustion efficiencies → smoldering fires

• MCE = (ΔCO2)/(ΔCO+ΔCO2)

• high particulate emissions & lower single scattering albedo

Western Wildfires (in comparison to ARCTAS fires)

• highest single scattering albedos

• f(RH) less than 1 → indicative of soot restructuring

2.8

2.6

2.4

2.2

2.0

1.8Scat.

An

g.

Exp

on

en

t1.000.950.900.85

Modified Combustion Efficiency

Agricultural Fires4.0

3.5

3.0

2.5

2.0

1.5Ab

s.

An

g.

Exp

on

en

t

1.000.950.900.85

Modified Combustion Efficiency

1.00

0.95

0.90

0.85Sin

gle

Scat.

Alb

ed

o

1.000.950.900.85

Modified Combustion Efficiency

Changes in aerosol intensive properties with flame conditions (MCE)

• Flaming conditions (high MCE) gives:

• higher scattering angstrom exponent (smaller aerosol)

• lower absorption angstrom exponent (less organic coating)

• lower single scattering albedo (darker smoke)

0.5

0.4

0.3

0.2

0.1

0.0

AO

D

20151050

PM from PILS (<1000 ft)All ProfilesFlight Averages colored by altitude

of max. extinction (black is highest)

0.6

0.4

0.2

0.0

AO

D

403020100

PM(mg/m3)

Measured by PILS below 1000 ft

Maryland California fit_Over_MD_AOD fit_Over_CA_AOD_without_highs

MarylandSlope = 0.027

CaliforniaSlope = 0.006

20

15

10

5

0

PM

302520151050

Day in September

PILS Mass (below 1000 ft)PM2.5 (9am - 5pm)

Galveston Conroe Deer Park

0.4

0.3

0.2

0.1

0.0P3-B

AO

D (

Am

b,

53

2n

m)

302520151050

Day in September