Abstract
Nitrate (NO 3 − ) levels in Lake Superior have increased from historic levels of about 5 μM to its current concentration of about 25 μM. The atmosphere makes a substantial contribution to the nitrogen budgets for Lake Superior and Lake Michigan. This study provides a more well-defined estimate of nitrogen dry deposition rates derived from the measurement of over-water concentrations, and in situ meteorological measurements, which were input into the Resistance Model. We obtained a nitrogen dry deposition rate of [(3.41 ± 2.26) × 10 7 kg N/yr; (5.90 ± 3.91) kg N/ha/yr] over Lake Michigan, and [(1.54 ± 1.06) × 10 7 kg N/yr; (1.87 ± 1.27) kg N/ha/yr] over Lake Superior. Nitric acid (HNO 3 ), which originates from the combustion of fossil fuels, contributes 84% of the total nitrogen dry deposition to Lake Michigan; and 66% to Lake Superior. Ammonia (NH 3 ), which originates from agricultural activities and gasoline combustion, is the second highest contributor of nitrogen dry deposition to both lakes: contributing 13% to Lake Michigan and 32% to Lake Superior. The nitrogen dry deposition is approximately 68% of the nitrogen wet deposition over Lake Superior, and approximately 80% of wet deposition over Lake Michigan. The over-water dry deposition velocity of HNO 3 and NH 3 were also evaluated. We obtained morning deposition velocities of 0.099 cm/s for NH 3 and 0.095 cm/s for HNO 3 ; and afternoon values of 0.137 cm/s for NH 3 and 0.132 cm/s for HNO 3 . Another key finding is that the atmospheric concentrations of nitrogen compounds near Lake Michigan and Lake Superior have decreased since 2003.
| Original language | English (US) |
|---|---|
| Journal | Journal of Great Lakes Research |
| DOIs | |
| State | Published - Jan 1 2019 |
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Keywords
- Air quality
- Deposition velocity
- Lake Michigan
- Lake Superior
- Nitrogen dry deposition
- Resistance model
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science
- Ecology
Cite this
Nitrogen dry deposition to Lake Superior and Lake Michigan. / Foley, Theresa A.; Betterton, Eric.
In: Journal of Great Lakes Research, 01.01.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nitrogen dry deposition to Lake Superior and Lake Michigan
AU - Foley, Theresa A.
AU - Betterton, Eric
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Nitrate (NO 3 − ) levels in Lake Superior have increased from historic levels of about 5 μM to its current concentration of about 25 μM. The atmosphere makes a substantial contribution to the nitrogen budgets for Lake Superior and Lake Michigan. This study provides a more well-defined estimate of nitrogen dry deposition rates derived from the measurement of over-water concentrations, and in situ meteorological measurements, which were input into the Resistance Model. We obtained a nitrogen dry deposition rate of [(3.41 ± 2.26) × 10 7 kg N/yr; (5.90 ± 3.91) kg N/ha/yr] over Lake Michigan, and [(1.54 ± 1.06) × 10 7 kg N/yr; (1.87 ± 1.27) kg N/ha/yr] over Lake Superior. Nitric acid (HNO 3 ), which originates from the combustion of fossil fuels, contributes 84% of the total nitrogen dry deposition to Lake Michigan; and 66% to Lake Superior. Ammonia (NH 3 ), which originates from agricultural activities and gasoline combustion, is the second highest contributor of nitrogen dry deposition to both lakes: contributing 13% to Lake Michigan and 32% to Lake Superior. The nitrogen dry deposition is approximately 68% of the nitrogen wet deposition over Lake Superior, and approximately 80% of wet deposition over Lake Michigan. The over-water dry deposition velocity of HNO 3 and NH 3 were also evaluated. We obtained morning deposition velocities of 0.099 cm/s for NH 3 and 0.095 cm/s for HNO 3 ; and afternoon values of 0.137 cm/s for NH 3 and 0.132 cm/s for HNO 3 . Another key finding is that the atmospheric concentrations of nitrogen compounds near Lake Michigan and Lake Superior have decreased since 2003.
AB - Nitrate (NO 3 − ) levels in Lake Superior have increased from historic levels of about 5 μM to its current concentration of about 25 μM. The atmosphere makes a substantial contribution to the nitrogen budgets for Lake Superior and Lake Michigan. This study provides a more well-defined estimate of nitrogen dry deposition rates derived from the measurement of over-water concentrations, and in situ meteorological measurements, which were input into the Resistance Model. We obtained a nitrogen dry deposition rate of [(3.41 ± 2.26) × 10 7 kg N/yr; (5.90 ± 3.91) kg N/ha/yr] over Lake Michigan, and [(1.54 ± 1.06) × 10 7 kg N/yr; (1.87 ± 1.27) kg N/ha/yr] over Lake Superior. Nitric acid (HNO 3 ), which originates from the combustion of fossil fuels, contributes 84% of the total nitrogen dry deposition to Lake Michigan; and 66% to Lake Superior. Ammonia (NH 3 ), which originates from agricultural activities and gasoline combustion, is the second highest contributor of nitrogen dry deposition to both lakes: contributing 13% to Lake Michigan and 32% to Lake Superior. The nitrogen dry deposition is approximately 68% of the nitrogen wet deposition over Lake Superior, and approximately 80% of wet deposition over Lake Michigan. The over-water dry deposition velocity of HNO 3 and NH 3 were also evaluated. We obtained morning deposition velocities of 0.099 cm/s for NH 3 and 0.095 cm/s for HNO 3 ; and afternoon values of 0.137 cm/s for NH 3 and 0.132 cm/s for HNO 3 . Another key finding is that the atmospheric concentrations of nitrogen compounds near Lake Michigan and Lake Superior have decreased since 2003.
KW - Air quality
KW - Deposition velocity
KW - Lake Michigan
KW - Lake Superior
KW - Nitrogen dry deposition
KW - Resistance model
UR - http://www.scopus.com/inward/record.url?scp=85061347401&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85061347401&partnerID=8YFLogxK
U2 - 10.1016/j.jglr.2018.12.003
DO - 10.1016/j.jglr.2018.12.003
M3 - Article
AN - SCOPUS:85061347401
JO - Journal of Great Lakes Research
JF - Journal of Great Lakes Research
SN - 0380-1330
ER -