Transcript Document

Making the case for coupled
chemistry, climate,
biogeochemistry simulations
E.A. (Beth) Holland
Chemistry-Climate Workshop
Santa Fe, NM, Feb. 10-12
Thank you!
Roadmap
• Carbon cycle
• Carbon/Nitrogen Cycle
• CN Chemistry
• CN Chemistry Climate
• CN Chemistry Climate Biogeochemistry
Summary for Policymakers, IPCC 2001
Table 3.1: Global CO2 budgets (in Pg C/yr) based on
intra-decadal trends in atmospheric CO2 and O2.
IPCC 2001, Prentice et al, Chapter 3
Atmospheric increase
Emissions
(fossil fuel, cement)
Ocean-atmosphere flux
Land atmosphere flux*
Land use change
Residual terrestrial sink
1980s
1990s
3.3 ± 0.1
5.4 ± 0.3
3.2 ± 0.1
6.3 ± 0.4
-1.9 ± 0.6
-0.2±0.7
-1.7 ± 0.5
-1.4±0.7
1.7 (0.6 to 2.5)
NA
-1.9 (-3.8 to 0.3) NA
Positive values are fluxes to the atmosphere; negative values represent uptake from the atmosphere. The
fossil fuel emissions term for the 1980s (Marland et al., 2000) has been slightly revised downward since
the SAR. Error bars denote uncertainty (± 1s), not interannual variability, which is substantially greater.
photosynthesis
& respiration
Atmosphere
O2
NO2
CO2
H2O
N2 NO
x
NOy
O2
CO2
CO2 O2
NO, N2O
Pedosphere
Norg
NO3NH4+
Norg
soil (microbes, roots)
plants etc.
Biosphere
(C, H2O, N…)
Coupling C and N
Vegetation
Type
Tropical
rainforest
Fraction
wood
0.5
C:N
C:N
C:N
microbes leaves wood
14
50
150
Temperate
Evergreen
forest
0.5
14
70
300
Shrubland
0.5
14
60
180
Grassland
0
10
55
0
What are the implications of N deposition
for the global carbon cycle?
Table 6. Comparison of Terrestrial Net CO2 Flux Estimated by Inverse
Deconvolution and Our Perturbation Estimate of Terres trial Net CO2 Flux from N
Deposition
90°S–16°S
Equatorial
16°N–90°
Global
N
-0.1
+0.3
-0.6
-0.5
Keeling et al. [1989] a
-0.1
+0.5
-2.3
-1.9
Tans et al. [1994] a
-0.2
+0.8
-2.2
-1.5
Ciais et al. [1995] b
With Saturation
This work
-0.04
-0.11
-0.38
-0.53
IMAGES c
-0.05
-0.16
-0.41
-0.62
ECHAM c
-0.06
-0.13
-0.37
-0.56
GCTM c
-0.04
-0.11
-0.36
-0.51
GRANTOUR c
-0.05
-0.16
-0.40
-0.61
MOGUNTIA c
-0.10
-0.26
-0.73
-1.09
MOGUNTIA NH + NO d
x
y
Without Saturation
This work
IMAGES c
ECHAM c
GCTM c
GRANTOUR c
MOGUNTIA c
MOGUNTIA NHx + NOy
d
Values are in units of Gt C yr-1.
-0.04
-0.05
-0.07
-0.04
-0.06
-0.11
-0.12
-0.19
-0.15
-0.12
-0.20
-0.29
-0.57
-0.73
-0.73
-0.50
-0.64
-1.02
-0.73
-0.97
-0.95
-0.66
-0.90
-1.42
Wet deposition of NH4+
Dry deposition of particulate NH4+
Wet deposition of NO3-
Dry deposition of HNO3 (g)
Dry deposition of particulate NO3-
All units kg N ha-1 y-1
Holland, Braswell, Sulzman, Lamarque submitted
How does N retention vary with N
deposition?
Holland, Braswell and Bossdorf
How does N deposition
impact C storage across a
range of vegetation types?
Do these simulations provide any evidence of N
saturation characterized by a non-linear increase in
outputs relative to inputs?
Coniferous Forests current N deposition
N losses
4.71
Deciduous Forests Current N deposition
5.21
10X
10X
Mixed Fo rests
Current N deposition
Shrublands
Current N deposition
Savannas
Current N deposition
Grasslands
Current N deposition
10X
10X
10X
10X
29.78
32.14
4.80
30.82
1.50
10.75
8.78
55.94
5.77
39.14
N losses=gaseous losses (NO + NH3 +N2O+ nitrate leaching, kg N ha-1 y-1
Holland, Braswell and Bossdorf, in prep.
NO!
What’s missing?
Figure 4: The correlation between NOy deposition and surface ozone concentrations
predicted by IMAGES, a 3-D chemical transport model. The correlation occurs because
both depend on the same sets of chemical reactions, precursors. (from Holland et al
1997, JGR Atmospheres 102:15,849-15,866).
Community Land Model
Dynamic Vegetation
Vegetation Dynamics
0 500 1000
PPFD
(molm-2s-1)
g CO2g-1s-1
Root
0.3
0
-10 25 60
Temperature (C)
0 15 30
0 -1 -2
0 1500 3000
0
-10 25 60
Temperature (C)
Autotrophic
Respiration
Temperature
(C)
Litterfall
0 500 1000
Heterotrophic
Respiration
Ambient
CO2 (ppm)
Foliage Water
Potential (MPa)
g CO2g-1s-1
0
-10 25 60
Temperature (C)
6
4
2
0
6
4
2
0
g CO2g-1s-1
Growth
Respiration
Sapwood
0.01
0
1
2
Vapor Pressure
Foliage
Deficit (Pa)
Nitrogen (%)
Bonan 2002
Nutrient
Uptake
8
1
0 15 30
Temperature
(C)
Relative Rate
6
4
2
0
Foliage
0.5
Relative Rate
g CO2g-1s-1
g CO2g-1s-1
Photosynthesis
g CO2g-1s-1
Ecosystem Carbon Balance
1
0
0
100
Soil Water
(% saturation)
Community Land Model
Climate
Chemistry
Temperature, Precipitation,
Radiation, Humidity, Wind
CO2, CH4, N2O
Ozone, Aerosols
Heat
Moisture
Momentum
CO2, CH4
N2O, Dust,
Volatile organic compounds
Element
Cycles
Canopy
Physiology
Soil
Processes
Biogeochemistry
Aerodynamics
Minutes-To-Hours
Biogeophysics
Water
Integrator
Of
Processes
And
Time-Scales
Energy
Surface Fluxes
Soil water, snowpack
Leaf area, leaf nutrition
Ecosystems
Watersheds
Days-To-Weeks
• Evapotranspiration
• Interception
• Infiltration
• Runoff
• Snowmelt
Physiology
Phenology
• Carbon uptake • Bud break
• Leaf drop
• Carbon loss
• Nutrient uptake
• Allocation
Ecosystems
• Litterfall
• Decomposition
• Mineralization
• Soil chemistry
Species composition
Ecosystem structure
Nutrient availability
Vegetation Dynamics
Years-To-Centuries
Plant
Ecosystem
Demography Processes
Open
Site
Bonan (2002) Ecological Climatology. Cambridge Univ. Press
Old-Growth
Forest
Disturbance
Fires
Hurricanes
Land use
Invasive species
BASE CASE EMISSIONS from MOZART 2
(JULY)
Isoprene
Flux
NO flux
Weidenmyer, C, XX Tie, S. Levis, A. Guenther, and EA Holland
What is the impact of land
use change on global O3
concentrations?
Change in
Concentration
(ppbv)
•For 25% of each grid cell in the Amazon basic, isoprene flux is
increased by a factor of 8, replacement with oil palm
plantations
•For 25% of each grid cell in the northwest U.S., isoprene flux
is increased by a factor of 30, replacement with Poplar
plantations
% Change
Weidenmyer, C, XX Tie, S. Levis, A. Guenther, and EA Holland
The GLOBAL N CYCLE
Putting the pieces together
Stomatal conductance
Sellers et al 1997, Science
N interactions
• Dickinson, R.E., J. A. Berry, G. B.Bonan, G. J. Collatz, C.
B. Field, I. Y. Fung, M. Goulden, W. A. Hoffman, R. B.
Jackson, R. Myneni, P. J. Sellers and M. Shaikh, 2001:
Nitrogen Controls on Climate Model Evapotranspiration. J
Clim., 15, No. 3, 278-295.
RESULT: Improvements in
models ability to capture the
seasonal cycle of temperature.
What if?
We included N, CO2 and O3 feedbacks on stomatal conductance and
the influence of stomatal conductance on dry deposition?
Comparison of the five models: dry deposition velocities
cm s-1
1
ECHAM1
GCTM2
GRANTOUR3
IMAGES4
MOGUNTIA5
O3
0.4
n/a
0.6
0.4 grasslands
0.5 savannah
1 tropical forests
0.6 other forests
0.35
NO
0.04
0.25
0.10
0.6 * Vd for O3
0.40
NO2
0.25
0.25
0.50
0.6 * Vd for O3
0.25
HNO3
2.0
1.5
1.0
2.0
2.0
Roelofs and Lelieveld 1995
Kasibhalta et al. 1991, 1993; Levy et al. 1996 a & b; Moxim et al. 1996
3
Penner et al. 1991; 1993
4
Müller 1992; Müller and Brasseur 1995; Lamarque pers. comm.
5
Dentener and Crutzen 1993
2
Deposition Velocity Calculation
Fc = Vd * C
Fc- flux, Vd- deposition velocity, Cconcentration
Vd =(Ra + Rb + Rs) –1
Ra-aerodyamic resistance, from CLM
Rb-quasi-boundary layer resistance, from CLM
Rs-surface resistance
approach of Ganzeveld (1995, 1999) + Wesley and Hicks 2000
HNO3 dry
deposition
(kg N ha-1 y-1)
Holland, EA, JF Lamarque, J
Sulzman, R. Braswell, submitted,
Global Biogeochemical Cycles
.0
0.0
0.30
0.61
0.75
1.51
QuickTime™ and a YUV420 codec decompressor are needed to see this picture.
conterminous United States,
total measured N deposition= 4.54 Tg N y -1
22%
28%
NO3-(aq)
NO3-(aq)
NOy (g+particulate)
NOy(g+particulate)
+
NH4 (aq)
NH4+(aq)
NH4+(particulate)
NH4+(particulate)
Global NOy deposition budget, from TM3,
total N deposition=46.4 Tg N y-1
24%
26%
8%
5%
NOx (aq)
NOx(g)
HNO3(g)
HNO3 (g)
14%
6%
HNO3(aq)
HNO
3 (aq)
organic nitrates (g)
Organic Nitrates (g)
PAN (g)
23%
Western Europe,
total measured N deposition= 10.83 Tg N y -1
44%
PAN (g)
organic nitrates (aq)
Organic Nitrates (aq)
NO3-(aq)
NO3-(aq)
-
12%
HNO3 (g)+NO3 (particulate)
HNO3(g)+NO3(particulate)
NO2 (g)
NO2(g)
21%
+
NH4 (aq)
NH4+(aq)
36%
+
20%
11%
NH4 (particulate)
NH4+(particulate)
N deposition partitioning for two
measurement compilations (Holland et al.
submitted) and one model compilation
(Neff et al. 2002)
Wet deposition of NH4+
Dry deposition of particulate NH4+
Wet deposition of NO3-
Dry deposition of HNO3 (g)
Dry deposition of particulate NO3-
All units kg N ha-1 y-1
Holland, Braswell, Sulzman, Lamarque submitted
photosynthesis
& respiration
Atmosphere
O2
NO2
CO2
H2O
N2 NO
x
NOy
O2
CO2
CO2 O2
NO, N2O
Pedosphere
Norg
NO3NH4+
Norg
soil (microbes, roots)
plants etc.
Biosphere
(C, H2O, N…)
Coupling C and N
Vegetation
Type
Tropical
rainforest
Fraction
wood
0.5
C:N
C:N
C:N
microbes leaves wood
14
50
150
Temperate
Evergreen
forest
0.5
14
70
300
Shrubland
0.5
14
60
180
Grassland
0
10
55
0
P. Thornton, NCAR/CGD, Sept. 2002
Soil NO flux Yienger and Levy
NOx flux
= Fw/d ( T, Aw/d) x P x CR (LAI, SAI)
(ng m-2 s-1)
T-soil temperature
A-biome dependent coefficient
w/d - distingushes between wet and dry soil fluxes
for wet soils, there are 3 temperature relationships:
cold ( 0-10 °C) :
= 0.28 x Aw x T
(a)
(0.103+0.04) x T
normal (10 -30 °C):
= Aw x e
(b)
optim al (>30 °C)
= 21.97 x Aw (30° substituted into b)
for dry soils, there are 2 temperature relationships:
cold (0-30 °)
=A d x T / 30°
optim al (> 30° C) = Ad
P- precipitation scalar factor to adjust the flux in event
of a flux depending on one of the following four states:
no rain:
P=1.0
sprinkle: 0.1 < rain < 0.5 cm day-1, 5 fold increase
P= 11.19 x e -0.805 [day-1] x t
(1< time (days) <3)
shower: 0.5 < rain < 1.5 cm day-1 10 fold increase
P= 14.68 x e -0.384 [day-1] x t
(1< time (days) <7)
heavy rain: 1.5 < rain cm day-1 15 fold increase
P= 18.46 x e -0.208 [day-1] x t
(1< time (days) <14)
pulse yield: 1.3 Tg NOx-N y-1
Soil N gas model
Model measurement
comparison
Parton,1, W.J., E.A. Holland,2 S.J. Del Grosso,1 M.D.
Hartman,1 R.E. Martin,3 A.R. Mosier,4 D.S. Ojima,1
and D.S. Schimel2. Generalized Model for NOx and
N2O Emissions from Soils. J. Geophys. Res .
106:17,403-17,419.
What is the acceleration of the N cycle?
How has the quantity and pattern of N deposition changed over the last 100
years?
N forcing
Summary for Policymakers, IPCC 2001
What does the future hold ?
Compound
Greenhouse gases
CO2-fossil fuel
CH4
N2O
O3 precursors
C: NMVOCs + CO
N: NO x
Sulfate aerosol
precursors
SO2
Average
Range
+167%
+62
+44
(-28 to +405)
(-24 to 137)
(-19 to 148)
+85%
+98%
(-59 to 202)
(-39 to 192)
-48
(-15 to Ğ72)
IPCC SRES scenario emissions: % increases
projected for 2100, relative to 2000
The NCAR Biogeosciences
Initiative:
Elisabeth Holland
(Program Leader)
Gordon Bonan
Alex Guenther
Natalie Mahowald
David Schimel
Britton Stephens
Jielun Sun
Peter Thornton
100
Net Nitrification/Net
Mineralization %
NO 3 -N ug/g
8
6
4
2
0
300 yr
4.1 million yr
80
60
40
20
0
300 yr
4.1 million yr
N Trace Gases
N2O-N and NO-N ng cm-2 h-1
Nitrate Concentration
Net Nitrification
(% Net Mineralization)
2.5
2
NO
N2O
1.5
1
0.5
0
300 yr
4.1 million yr
Abiotic controls on nitrification
Regulation
of NO:N2O
ratio