The Rain Forest Canopy Reduction

Effect on NO Emission from Soils*

* results shown here are from the "EUropean Studies on Trace Gases and Atmospheric CHemistry"-project to the "Large-Scale Biosphere-Atmosphere Experiment in Amazonia"

Franz X. Meixner (1), Christof Ammann (2), Udo Rummel (1), Urs Andreas Gut (3), and Meinrat O. Andreae (1)

10th Scientific Conference of the International Association of Meteorology of Atmospheric Sciences (IAMAS) Commission for Atmospheric Chemistry and Global Pollution (CACGP) and 7th Scientific Conference of the International Global Atmospheric Chemistry Project (IGAC)

Creta Maris, Hersonissos, Crete, Greece,18-25 September 2002

(1) Max-Planck-Institut für Chemie, Abteilung Biogeochemie, Postfach 3060, D-55020 Mainz, Germany(2) Eidgenössische Forschungsanstalt für Agrarökologie und Landbau, CH -8046 Zürich, Switzerland

(3) Bundesamt für Energie (BFE), Monbijoustrasse 72, CH-3003 Bern, Switzerland

background

remote regions

(USA)

urban (USA)

maritime

(Pacific)

tropical rainforest

wet season

ambi

ent m

ixin

g ra

tio (

NO

+N

O2)

in p

pb

VOC as propylene (normalized by reactivity) in ppb

isolines = ozone production rate in ppb/h

Chameides et al., JGR, 97: 6037-6055, 1992.

ABLE campaignsend of the 80's

tropical NOx sources anthropogenic (traffic) biomass burning (deforestation) biogenic emission from soils

background

(tropical) NO soil emission inventories based on chamber measurements

there are only a few NO, NO2 (NOx, NOy) flux measurements

over tall vegetation (forests) at all

(global) atmospheric chemistry models need reliable NOx

fluxes as a lower boundary condition

mostly a constant or LAI parameterized NOx canopy reduction

factor (CRF) is used (e.g. Yienger & Levy, 1995)

very recently (!) : Ganzeveld et al. (JGR, September 2002) multilayer trace gas exchange sub-model (in a chemistry

general circulation model) to explicitly calculate NOx emissions

from forests

biogenic NO emssion from soils (Brazil)

Bakwin et al. (1990)Neill et al. (1995, 1997) ?

Bakwin et al. (1990)

1 : 10

FNOx, out = 0.25 FNOsoil

Jacob & Wofsy (1990)

Neill et al. (1999)Verchot et al. (1999)Garcia-Montiel et al. (2001)van Dijk et al. (2002)Gut et al. (2002)Kirkman et al. (2002)

4 -104 -10 ng NO-N mng NO-N m-2-2ss-1-1< 1 ng NO-N m-2s-1

3NO, NO , O , VOC2

VOC

VOC emissionfrom leaves

NO + O 3 NO2 + O2

NO2 + O2 NO + O 3hv

’RO’2 + NO RO + NO 22

O3

deposition toleaf surface

O3 (and NO )2

NO2

O3

O3 and NO2deposition to

stomata

NO emission from soil

NO

O3

NONO + O 3 NO2 + O2

2NO

NO2

chemistry vs. biology vs. transport

time scales ?

LBA-EUSTACH, Reserva Biologica Jarú, Rondônia/Brazil

"missing"

fluxes : NO2, NOy

conductanceconductance : NO2

vertical profile (8 levels) NO, NO2, O3, CO2, H2O, VOC, aerosols, Rn ( Kbulk) T, j(NO2), Rnet, glob rad

conductance / emissionconductance / emission O3, CO2, H2O, VOC

emission / deposition soil profile NO, NO2, O3, CO2, Rn

eddy covariance fluxes NO, O3, CO2, H2O, sensible

heat (H), momentum (u*, w)

F(NO)F(NO)in ng N m-2s-1

eddy covariance(4 days)

range (min - max)dynamic chambers (4)

average (21 days)

-5

0

5

10

15

20

Bereich der Bodenkammern Mittelwert: Bodenkammern Eddy Kovarianz

NO

Flu

ss

(n

g N

m-2

s-1)

11 m11 min-canopyin-canopy

20

15

10

5

0

53 m53 mabove canopyabove canopy

15

10

5

0

1 m1 m"forest floor""forest floor"

00:00 04:00 08:00 12:00 16:00 20:00 24:00

12

8

4

0

00:00 06:00 12:00 18:00 24:000

10

20

30

40

50

O3 [ppb]he

ight

abo

ve g

roun

d [m

] 36 -- 40 32 -- 36 28 -- 32 24 -- 28 20 -- 24 16 -- 20 12 -- 16 8 -- 12 4 -- 8 0 -- 4

00:00 06:00 12:00 18:00 24:000

10

20

30

40

50NO [ppb]

heig

ht a

bove

gro

und

[m] 1.8 -- 2.0

1.6 -- 1.8 1.4 -- 1.6 1.2 -- 1.4 1.0 -- 1.2 0.8 -- 1.0 0.6 -- 0.8 0.4 -- 0.6 0.2 -- 0.4 0 -- 0.2

canopy top

canopy top

LBA-EUSTACH, Reserva Biologica Jarú, drywet season transition

00:00 06:00 12:00 18:00 24:000

10

20

30

40

50

O3 [ppb]he

ight

abo

ve g

roun

d [m

]

36 -- 40 32 -- 36 28 -- 32 24 -- 28 20 -- 24 16 -- 20 12 -- 16 8 -- 12 4 -- 8 0 -- 4

00:00 06:00 12:00 18:00 24:000

10

20

30

40

50NO [ppb]

heig

ht a

bove

gro

und

[m]

1.8 -- 2.0 1.6 -- 1.8 1.4 -- 1.6 1.2 -- 1.4 1.0 -- 1.2 0.8 -- 1.0 0.6 -- 0.8 0.4 -- 0.6 0.2 -- 0.4 0 -- 0.2

canopy top

(average of 43 days Sept/Oct 1999)

characteristic chemical time scale

NO2 + h  NO + O3 , k' = jNO2 

NO + O3  NO2 + O2 , k = 2  10–12 exp(–1400/Tair)

characteristic turbulent time scale

determination of chemical & turbulent characteristic time scales

chem = 2 /{ jNO22 + k2 ( [O3] – [NO] )2 + 2 jNO2 k ( [O3] + [NO] + 2[NO2] ) }0.5

(Lenschow, 1982)

trunk space : "ramp patterns" in high frequency scalar time series coherent structures surface renewal model wavelet analysis "turbulent residence time"

Paw U et al., 1995;

above canopy :turb = k (zref + z0) (w2/u*)-1

(Villá-Guerrau & Duynkerke, 1992;

0 – 1m : Rn and CO2 flux / gradient approach (Kbulk)

Gut et al., 2002)

LBA-EUSTACH, Reserva Biologica Jarú, 1999

1

10

100

1000

10000

100000

00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:00

t i m e o f d a y [local]

c h

a r

a c

t e

r i

s t

i c

t i

m e

( )

[

s]

turb LBA-EUSTACH-2 chem LBA-EUSTACH-2turb LBA-EUSTACH-1 chem LBA-EUSTACH-1

53 m53 mabove canopyabove canopy

LBA-EUSTACH, Reserva Biologica Jarú, 18...22-MAY-1999

11 m11 min-canopyin-canopy

LBA-EUSTACH, Reserva Biologica Jarú, 18...22-MAY-1999

1 m1 m"forest floor""forest floor"

0

10

20

30

40

50

0,0 0,1 0,2 0,3 0,4

arbitrary units

heig

ht a

bove

gro

und

[m

]

pLAI model

pLAI fit to measurements8

7

6

5

432

1

j = NO, NO2, O3, RO2'

Fj,plant,7

Fj,gas phase,7

Fj,turb,6

Fj,turb,7

NO + O 3 NO2 + O2

NO2 + O2 NO + O 3hv

’RO’2 + NO RO + NO 22

Fj,plant,1Fj,gas phase,1

Fj,turb,1

F(NO)soil F(NO2)soil

F(O3)soil

[NO], [NO2], [O3] at 53m

R(O3)soil

R(NO2)soil

F(NO)soil

w/u*

j(NO2)

R(O3)plant

a simple, multilayer diagnostic model

0

10

20

30

40

50

0 2 4 6 8 10 12 14

eddy diffusion coefficient [m2 s-1]

he

igh

t a

bo

ve g

rou

nd

[

m]

LBA-EUSTACH, Reserva Biologica Jarú, drywet season transition

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

25 30 35

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

0

10

20

30

40

50

1,E-05 1,E-04 1,E-03 1,E-02 1,E-01 1,E+00 1,E+01 1,E+02

eddy diffusion coefficient [m2 s-1]

he

igh

t a

bo

ve g

rou

nd

[

m]

LBA-EUSTACH, Reserva Biologica Jarú, drywet season transition

0

10

20

30

40

50

0 1 2 3

eddy diffusion coefficient [m2 s-1]

he

igh

t a

bo

ve g

rou

nd

[

m]

LBA-EUSTACH, Reserva Biologica Jarú, drywet season transition

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

22 23 24

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

a simple, multilayer diagnostic model : first results

F(NO)

F(NO2)

F(O3)

F(NOx)

0.01 ppb m s-1 = 5.7 ng N m-2s-1

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

25 30 35

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

22 23 24

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

potential NOx Canopy Reduction Factors

F(NO)soil = 6.3 ng N m-2s-1 = 100 % ; [NO]53m = [NO2]53m = 0 ppb

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [

m]

25 30 35

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

[O3]53m = 40 ppb [O3]53m = 6 ppb

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

22 23 24

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

73%

13%14%

73 %

F(NOx)out

F(NO2)soil F(NO2)plant

14 %13 %

66%

21% 13%

F(NOx)out

66 %

F(NO2)soil F(NO2)plant

21 %13 %

potential vs. actual NOx Canopy Reduction Factor

F(NO)soil = 6.3 ng N m-2s-1 = 100 %

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

25 30 35

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

[O3]53m = 40 ppb

[NO]53m = 0 ppb

[NO2]53m = 0 ppb

66%

21% 13%

F(NOx)out

66 %

F(NO2)soil F(NO2)plant

21 %13 %

0 1 2 3

0

10

20

30

40

50 NO NO

2

O3

height [m

]

25 30 35

0

10

20

30

40

50

leaf area index

pot. temp [°C]

0 1 2

0 10 20 30 40 50

NO/NO2

O3

mixing ratio [ppb]

[O3]53m = 40 ppb

[NO]53m = 0.06 ppb

[NO2]53m = 0.3 ppb

29%

22%

49%

F(NOx)out

F(NO2)soil

F(NO2)plant

49 %

22 % 29 %

conclusions rainforest NOx canopy reduction factor of soil emitted NO (daily average):

25 % Jacob & Wofsy (1990) 50 % Yienger & Levy (1995) 43 % this work (actual CRF) 40–50 % Ganzeveld et al. (September 2002) high vegetation canopies are ideal environments for important chemistry–turbulence–biology interactions

in the case of NO–NO2–O3 the main controllers are

(a) turbulence intensity over the canopy (b) ozone mixing ratio over the canopy (c) biogenic NO emission from soil (d) canopy structure

deciduous (Gao et al., 1993), spruce (Duyzer et al., 1995), pine (Joss & Graber, 1996), orchard (Walton et al., 1997); maize (Fehsenfeld & Williams, 2000)

future needs

– NO2 conductance / NO2 canopy compensation mixing ratio – effect of different canopy structures – fluxes / flux divergences of NO2 and NOy

– interactions with radicals (RO2•) and reactive VOC's

....vergelt'sgod !

Andreas Gut

Christof Ammann

Udo Rummel

0 600 1200 1800-2

0

2

[m s

-1]

time [s]

w'

0

1

[K]

T'

-2

-1

0

1

[pp

b]

O3'

-1

0

1

[mm

ol m

ol-1

] H2O'

-3

0

3

[mol

mol

-1] CO

2' above-canopyabove-canopy

ramp pattern in scalar time-series

COCO22''

HH22O'O'

OO33''

T'T'

w'w'

residence time

surface renewal model

coherent structures

...wavelet analysis

ramp patterns ....

z

t

X ( t )

dt

dX

mX zdt

dX

A

V

dt

dXF

2

10

z m

A u f e n t h a l t s z e i tresidence time

biogenic NO emission from forest floor : 5 different techniques

4 dynamic chambers : NO, NO2, O3 surface fluxes Gut et al., JGR, 2002b

(gas-phase reactions and absorption to walls considered by blank chamber)

soil air profile : NO and Radon fluxes Gut et al., JGR, 2002a ("closed cycle" flushing of semi-permeable tubings (3 layers); soil diffusion coefficient by Rn profile and Rn surface flux (static chamber))

"bulk exchange" approach: NO fluxes from concentration gradients of NO (0.09 - 1.00m, above forest floor) Gut et al., JGR, 2002a (bulk exchange cofficient by Rn and CO2 gradients & surface flux (static chamber))

eddy covariance : NO fluxes at 1 and 11 m above forest floor Rummel et al., JGR, 2002

laboratory studies on soil samples : NO fluxes from NO production and NO consumption rates van Dijk et al., JGR, 2002

background

denitrification (mostly anaerobic)

nitrification (mostly aerobic)

most important controllers: — soil moisture

— soil temperature

— soil nutrients (NO3–, NH4

+)

— soil texture

in soils, production and consumption of nitric oxide are always simultaneous microbiological processes (Conrad, 1996)

NO-exchange is basically bi-directional usually NO emission is observed

background

remote regions

(USA)

urban (USA)

maritime

(Pacific)

tropical rainforest

wet season

ambi

ent m

ixin

g ra

tio (

NO

+N

O2)

in p

pb

VOC as propylene (normalized by reactivity) in ppb

isolines = ozone production rate in ppb/h

Chameides et al., JGR, 97: 6037-6055, 1992.

ABLE campaignsend of the 80's