Nitrogen deposition in Nitrogen deposition in Rocky MountainRocky MountainNational ParkNational Park

NPS, USDA-FS, EPA, NSF, UniversitiesColorado DPHE & local partners

Nitrogen deposition in RockyNitrogen deposition in Rocky

• Overall nitrogen deposition is increasing.

• NO3 (combustion sources) makes up >50%.

• NH4 (agricultural sources) is increasing rapidly.

• Local and regional sources contribute to both.

• Local sources may contribute more during spring and summer.

Nitrogen in atmospheric depositionNitrogen in atmospheric depositionSource >>> Emissions >>> Wet Deposition

Combustion:VehiclesEnergy developmentEnergy production

NONOxx

(Nitrogen (Nitrogen oxidesoxides--gases)gases)

NONO33--

(Nitrate(Nitrate--dissolved + dissolved + particulate)particulate)

AgricultureLivestock productionCrop production

NHNH33

(Ammonia gas)(Ammonia gas)

NHNH44++

(Ammonium(Ammonium--dissolved + dissolved + particulate)particulate)

Total Total NONOxx emissions emissions

-- includes mobile and non-point sources

NO3 animationNO3 animation

End of NO3 animationEnd of NO3 animation

Percent change in NOPercent change in NO33-- in in wetfallwetfall

LehmannLehmann et al., et al., Environmental PollutionEnvironmental Pollution 20052005

Improving Trend, p<=0.05

Improving Trend, 0.05<p<=0.15

Degrading Trend, 0.05<p<=0.15

Degrading Trend, p<=0.05

No Trend

Trends in NO3 Concentrations in Precipitation, 1994-2003FY2004 Annual Performance Report for NPS Government Performance and Results Act (GPRA)

Air Quality Goal Ia3

02/03/2005

Acadia

Bandelier

Big Bend

Bryce Canyon

Buffalo

Canyonlands

Capulin Volcano

Craters of the Moon

Everglades

Gila Cliff

Glacier

Great Basin

Grand CanyonGreat Smoky Mtns

Guadalupe Mtns

Indiana Dunes

Isle Royale

Little Bighorn

Mesa Verde

Mount Rainier

North CascadesOlympic

Organ Pipe

Rocky Mountain

Sequoia

Shenandoah

Yellowstone

Yosemite

Denali

Downward pointing arrows denote trends toward decreasing nitrate (NO3) concentrations and improving air quality. Similarly, the up arrows correspond to trends toward higher nitrate concentrations and hence worsening air quality.

Total NHTotal NH33 emissionsemissions

-- includes mobile and non-point sources

End of NH4 animationEnd of NH4 animation

Percent change in NH4+ in Percent change in NH4+ in wetfallwetfall

LehmannLehmann et al., et al., Environmental PollutionEnvironmental Pollution 20052005

Improving Trend, p<=0.05

Improving Trend, 0.05<p<=0.15

Degrading Trend, 0.05<p<=0.15

Degrading Trend, p<=0.05

No Trend

Trends in NH4 Concentrations in Precipitation, 1994-2003FY2004 Annual Performance Report for NPS Government Performance and Results Act (GPRA)

Air Quality Goal Ia3

02/03/2005

Acadia

Bandelier

Big Bend

Bryce Canyon

Buffalo

Canyonlands

Capulin Volcano

Craters of the Moon

Everglades

Gila Cliff

Glacier

Great Basin

Grand CanyonGreat Smoky Mtns

Guadalupe Mtns

Indiana Dunes

Isle Royale

Little Bighorn

Mesa Verde

Mount Rainier

North CascadesOlympic

Organ Pipe

Rocky Mountain

Sequoia

Shenandoah

Yellowstone

Yosemite

Denali

Snowpack Snowpack chemistrychemistry

••Major ionsMajor ions••NutrientsNutrients••Trace metalsTrace metals••3434S, S, 1515N isotopesN isotopes

- G.P. Ingersoll and others, USGS

Nitrate in Nitrate in Rocky Rocky

Mountain Mountain snowpack snowpack

(average, (average, 19931993--2000)2000)

- G.P. Ingersoll and others, USGS

Annual VWM Inorganic N conc. in Annual VWM Inorganic N conc. in wetfall wetfall

10-year mean DIN concentration (NO3 + NH4)

NADP sites in Colorado and Wyoming > 2400m elevation

05

10152025303540

Sunlig

ht Pea

kFou

r Mile

Park

Wolf Cree

k Pas

sMola

s Pas

s

Buffalo

Pas

s - D

ry La

ke

Buffalo

Pas

s - Sum

mit Lak

eSug

arloa

fNiwot

Saddle

RMNP Bea

ver M

eado

ws

RMNP Loch V

aleSno

wy Ran

geBroo

klyn L

ake

South

Pass C

ityGyp

sum C

reek

DIN

Con

cent

ratio

n in

µ

eq/L

Wyo.Wyo.ZirkelZirkelSW Co.SW Co.W Co.W Co. Front RangeFront Range

0

5

10

15

20

25

30

Nitr

ogen

con

c., M

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Inorganic Nitrogen Concentration in Wetfall, Loch Vale NADP site.

NONO33

NHNH44

- from NADP/NTN database

Nitrogen concentrations in Nitrogen concentrations in wetfallwetfallby seasonby season

RMNP Loch Vale NADP 1994-2003 mean concentrations

0

5

10

15

20

25

30

35

1. Fall 2. Winter 3. Spring 4. Summer

Season

Inor

gani

c N

conc

., M

NO3-

NH4+

Airflow into ColoradoAirflow into Colorado

-- Nolan Nolan DoeskenDoesken, state climatologist, state climatologist

Bear Lake, Rocky Mt. Natl. ParkBear Lake, Rocky Mt. Natl. ParkBulk precipitation event samplesBulk precipitation event samples

23 April 19995.7 cm precip

10.1 µmol/l DIN (NH4+ + NO3-)

29 April 19994.2 cm precip

32.5 µmol/l DIN (NH4+ + NO3-)

- Campbell and others, USGS

Sources of nitrogen emissions in ColoradoSources of nitrogen emissions in Colorado

Colorado Natural Gas Marketed Production

0

200000

400000

600000

800000

1000000

1200000

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

Pro

duct

ion

(MM

cf)

Source attribution using naturally occurring, Source attribution using naturally occurring, stable isotopes of nitrogen compounds.stable isotopes of nitrogen compounds.

Provide capability of distinguishing between major source categories of emissions.

3 isotopes in NO3: 15N, 18O, 17O15N in NH4

+

Recent advances in methodology expand possibilities.

d15N of Seasonal Snowpack 1994-2001

Campbell and Kendall, unpub. data

Nitrogen deposition in RockyNitrogen deposition in Rocky

• Overall nitrogen deposition is increasing.

• NO3 (combustion sources) makes up >50%.

• NH4 (agricultural sources) is increasing rapidly.

• Local and regional sources contribute to both.

• Local sources may contribute more during spring and summer.

• Next steps?- Integrated modeling and monitoring studies of air

quality + deposition, incorporating natural tracers to identify source categories.