Total Deposition at Clingmans Dome, TN in the Great Smoky Mountains National Park Selma Isil, AMEC E&I, Inc. Chris Rogers, AMEC E&I, Inc. Kathie Weathers, Cary Institute Amanda Elliott, Cary Institute Tom Lavery, Fuss & O’Neill

2

• Ecosystems at these elevations subject to substantial levels of acid deposition from clouds that originate in polluted areas.

• Depositions enhanced by frequent cloud immersion, orographically increased precipitation, high wind speeds, and the large leaf areas typical of mountain tree species.

The CASTNET Mountain Acid Deposition Program (MADPRO):

• Monitors cloud water and its chemical constituents. • High-elevation sites (typically higher than 800 meters).

• Collecting at Clingmans Dome, TN (CLD303) in the Great Smoky Mountains National Park since 1994.

3

View of Radio and Cloud Water Sampling Towers

4

Ozone Inlet (NPS)

Meteorological sensors - WS,

WD, T, RH (NPS)

Cloud Water Collector (EPA)

AT&T cellular modem antenna

(EPA)

PVM-100 Particle Volume Monitor

(EPA)

5

Cloud Event

6

View of the PVM

7

Close-up of Cloud Water Collector

8

Cloud Water Collector

9

Minimum conditions for activation of cloud collector

LWC > or = 0.05 g/m3

Temperature = 2°C No precipitation

Cloud Definition

10

ETI Precipitation Monitor

11

Installation while Site in Cloud

12

Locations of Dry, Wet and Cloud Monitoring Sites in the Great Smoky Mountains National Park (GRSM)

GRS420

TN11

CLD303

13

Seasonal Cloud Water Nitrate Concentrations and Depositions, 2000-2010

Seasonal Cloud Water Sulfate Concentrations and Depositions, 2000-2010

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

0

50

100

150

200

250

kg/h

a

mic

roeq

uiva

lent

s/L

Nitrate ConcentrationNitrate Deposition

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

0

100

200

300

400

500

600

kg/h

a

mic

roeq

uiva

lent

s/L

Sulfate ConcentrationSulfate Deposition

49.3% decrease from 2007

60.4% decrease from 2007

14

Sulfur Dioxide and Nitrogen Oxides Emissions at TVA Power Plants

0

100

200

300

400

500

600

700

800

Thou

sand

s of

Tons

Sulfur DioxideNitrogen Oxide

46.9% reduction since 2007

70.5% reduction since 2007

15

Mean Seasonal Cloud Water versus Mean Seasonal Precipitation Sulfate Concentrations, 2000–2010

Mean Seasonal Cloud Water versus Mean Seasonal Precipitation Nitrate Concentrations, 2000–2010

0

2

4

6

8

10

12

14

16

18

20

0

50

100

150

200

250 Microequivalents/liter -Precipitation C

oncentration

Mic

roeq

uiva

lent

s/lit

er -C

loud

Wat

er C

once

ntra

tion

Cloud NitratePrecipitation Nitrate

0

10

20

30

40

50

60

0

50

100

150

200

250

300

350

400

450

500 Microequivalents/liter -Precipitation C

oncentrationMic

roeq

uiva

lent

s/lit

er -C

loud

Wat

er C

once

ntra

tion

Cloud SulfatePrecipitation Sulfate

60.4% decrease in CW Sulfate 64.3%decrease in precipitation sulfate

49.3% decrease in CW nitrate 52.2% decrease in precipitation nitrate

16

Cloud Water and Wet Sulfate Deposition Estimates (June through September), 2000-2010

Cloud Water and Wet Nitrate Deposition Estimates (June through September), 2000-2010

0

2

4

6

8

10

12

14

0

10

20

30

40

50

60

70

80

90

Wet D

eposition (kg/ha)

Clo

ud W

ater

Dep

ositi

on (k

g/ha

)

Cloud Water SulfateWet Sulfate

0

1

2

3

4

5

6

7

0

10

20

30

40

50

60

70

Wet D

eposition (kg/ha)

Clo

ud W

ater

Dep

ositi

on (k

g/ha

)

Cloud Water NitrateWet Nitrate

17

Seasonal CLD303 Total Nitrogen Deposition Components, 2000-2010

Seasonal CLD303 Total Sulfur Deposition Components, 2000-2010

0.0

5.0

10.0

15.0

20.0

25.0

30.0

kg/h

a

Dry NitrogenWet NitrogenCloud Nitrogen

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

kg/h

a

Dry Sulfur Wet Sulfur Cloud Sulfur

2001: Dry Dep 3.8% 2010: 8.3% Wet Dep 6.4% 2010: 23.5% Cloud Dep 89.8% 2010: 68.2%

2001: Dry Dep 2.9% 2010: 4.8% Wet Dep 8.5% 2010: 23.9% Cloud Dep 88.6% 2010: 71.3%

18

View from Top of Collection Tower

19

Spatial Distribution of Measured Deposition Indices for Forest-floor Lead Concentrations in GRSM (Weathers, et. al., 2006)

20

Seasonal Total Nitrogen Deposition: CLD303 versus LandMod, 2000-2010

Seasonal Total Sulfur Deposition: CLD303 versus LandMod, 2000-2010

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

kg/h

a

CLD Total NitrogenLandMod Total Nitrogen

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

kg/h

a

CLD Total SulfurLandMod Total Sulfur

21

CLD303 Total Seasonal Sulfur Deposition and Difference in kg/ha from LandMod Total Seasonal Sulfur

-5.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

kg/h

a

Diff Sulfur

22

View from Top of Tower • Cloud deposition is the largest contributor to total deposition at high

elevation sites that experience cloud impaction • LandMod is a good overall predictor of total deposition at CLD303 except for

when cloud deposition rates are very high (2000 and 2001) • LandMod may be over predicting at lower deposition rates or may not be as

responsive to quick changes in emissions • Model inputs should be updated at least once a

decade

Conclusions

23

• Continue monitoring at CLD303 to help refine predictability of models

• Update inputs to CLOUD and LandMod

• Install NADP precipitation collector and CASTNET filter pack to get improved total deposition estimate as site specific data are necessary for calculation of inputs to highly sensitive high elevation ecoregions

• www.epa.gov/CASTNET

Recommendations

24

A Murky Future

25

The End