Study of N2O Flux overCentral Amazon
Monica Tais Siqueira D'Amelio (IPEN/LQA) ([email protected])
Luciana Vanni Gatti (IPEN/LQA)John Bharat Miller (NOAA/ESRL)
Filipe Vaz (IPEN/LQA)Andrew Crottwell (NOAA/ESRL)
Pieter Tans (NOAA/ESRL)
N2O Sources and Sinks N2O is the 3rd most important
anthropogenic greenhouse gas. Life time: 120 years
Main sources: Nitrification and denitrification in soils: 9-31
TgN2Oyr-1
Ocean: 9-19 TgN2Oyr-1 Agricultural soil: 19.5 TgN2Oyr-1 (77% of
anthropogenic contribution) Main sinks
Decomposition in stratosphere by photodissociation (90%)
Reactions with excited oxygen (10%).
Measurement SitesCuieiras Biological Reserve – Manaus - AM
Tapajós National Forest – Santarém - PA
Flux CalculationBarbados
(RPB)
Ascension(ASC)
SANMAN FLOW
time
)O][N-O]([NF
4km
0zbg2site2
ON2
dz
Miller et al., 2007 method
Trajectories Study (Hysplit model)
“A Very Large Flux Chamber”
Back trajectories Used to calculate time air has been over land at 8 altitudes. Typically quite similar as a function of altitude.
Calculating the background
‘No’ Emissions
2x105
Step 1. Chose SF6 like a tracer transport
Calculating the background
Step 2. Calculate NHand SH contribution
ASC
RPB SF6 Time Series
4.44.64.85.05.25.45.65.86.06.26.46.6
9/11/2000 5/9/2001 1/4/2002 9/1/2002 4/29/2003 12/25/2003 8/21/2004 4/18/2005 12/14/2005 8/11/2006 4/8/2007
Con
cent
raçã
o (p
pt)
ASC RPB Flona Tapajós Cuieiras
(a)
Normalizing Profiles
0
500
1000
1500
2000
2500
3000
3500
4000
4500
314.0 316.0 318.0 320.0 322.0 324.0 326.0
N2O Minxing ratio (ppb)
Alti
tude
(m)
dry 20002001200220032004200520062007
0
500
1000
1500
2000
2500
3000
3500
4000
4500
314.0 316.0 318.0 320.0 322.0 324.0 326.0
N2O mixing ratio (ppb)
Alti
tude
(m)
wet
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-4.0 -2.0 0.0 2.0 4.0
N2O Minxing ratio (ppb)
Alti
tude
(m)
dry 20002001200220032004200520062007
4
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-4.0 -2.0 0.0 2.0 4.0
N2O mixing ratio (ppb)
Alti
tude
(m)
wet
Profiles Normalized
Integration of profiles
z
bgisiteibgisitei
timezONONONON 2/)}][]([)][]{([
F 221212ON2
04/24/2007
0
500
1000
1500
2000
2500
3000
3500
4000
4500
320.5 321 321.5 322 322.5 323 323.5 324
N2O mixing ratio (ppb)
Alti
tude
(m)
background 04/24/2007
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 0.5 1 1.5 2 2.5 3
N2O mixing ratio (ppb)
Alti
tude
(m)
Normalized
From Coast to Flona Tapajós
-4.0
-2.0
0.0
2.0
4.0
6.0
0 1 2 3 4 5 6 7 8 9 10 11 12
months
Flux
(mg/
m2 /d
ay)
2000 2001 2002 2003 2004 2005 2006
“Santarém” Fluxes
WET DRY
2005 Wet season enhancement – probably related to agriculture
From Coast to Cuieiras
-4.0
-2.0
0.0
2.0
4.0
6.0
0 1 2 3 4 5 6 7 8 9 10 11 12
months
Flux
(mg/
m2 /d
ay)
2004 2005 2006
“Manaus” Fluxes
WET DRY
Summary and Comparison with other estimates
Years/Site SAN MAN
Wet Dry Wet Dry
2001-2003 0.0 ± 1.2 -1.65 ± 2.2
2004-2006 2.1 ± 1.6 0.8 ± 0.6 1.9 ± 0.8 1.1 ± 0.7
•Comparison (mg N2O/m-2yr-1)1.9 – Primary Forest,
Rondônia, Brazil (Garcia-Montiel, et al., 2004)0.38 – Primary Forest, Manaus, Brazil (Coolman, 1994)0.44 – Young Pasture, Manaus, Brazil (Coolman, 1994)
Conclusions The normalized profiles show a clear
enhancement during wet season. SAN fluxes were enhanced until 2005.
In 2006 political programs decreased the N-fertilizer used in Para.
MAN fluxes are lower in 2006 for the same reason.
Fluxes calculated are similar other studies over near regions.
Question: What is the Forest Contribution?
Barbados(RPB)
Ascension(ASC)
SANMAN FLOW
Two Methods:1. Subtracting fluxes
sancoastmancoast FF forestF
2. Use SAN as the background for MAN3. Both methods: choose trajectories where air comes from SAN to MAN.
Preliminary Results Profiles considering: same trajectory,
close date
1. Subtracting2. SAN = BGD04/24/07 2.826 04/27/07 2.629 -0.197 0.38506/23/07 3.078 06/25/07 2.744 -0.335 0.44007/27/07 1.242 07/28/07 2.119 0.878 4.69908/03/07 1.096 08/06/07 1.035 -0.061 -3.108
Preliminaries Fluxes(mg/m2/day)
SAN MAN(mg/m2/day)
Uncertainty is large, but little evidence for large emissions in forest between SAN and MAN.
Conclusions The normalized profiles show a clear
enhancement during wet season. SAN fluxes were enhanced until 2005. In
2006 political programs decreased the N-fertilizer used in Para.
MAN fluxes are lower in 2006 for the same reason.
Coast to SAN present higher fluxes than coast to MAN.
Fluxes calculated are similar other studies over near regions.
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