Post on 15-Dec-2015
Methane Emission to the Atmosphere
Bazhin N.M.
Institute of Chemical Kinetics and Combustion
Novosibirsk RUSSIA
Methane in Atmosphere – Concentration 1.8 ppm Content in Atmosphere 5000 Tg (1 Tg = 1012 g = 1 mln of tons)
Flux 500 Tg /year
-20 0 20 40 60 80 100 120 140
0.3
0.4
0.5
0.6
0.7M
etha
ne c
once
ntra
tion,
ppm
Time BC, 103 years
Methane concentration dependence on time
1600 1700 1800 1900 20000.6
0.8
1.0
1.2
1.4
1.6
1.8
Met
hane
con
cent
ratio
n, p
pm
Year
Methane concentration dependence on time
Methane concentration and world population
0 1 2 3 4 5 6 70.6
0.8
1.0
1.2
1.4
1.6
1.8
20001850M
etha
ne c
once
ntra
tion,
ppm
Population, 109 persons
Year1600
LandfillsLakes
Gas
Mines
Biomass burning
TermitsRice fields
Cattle
OceansMethanehydrates
Swamps
15%
2%1%
21%1%8%
8%
7%
10%
7% 20%
Methane sources
Emission from Swamps, Rice fields, Lakes and Oceans - 44%
Active layer
0.0 0.2 0.4 0.6 0.8 1.0
PlantAtmosphere
b
[N 2]
[CH4 ]h
Water column
Region II
Region I
Active layer
Active layer
0
Dep
th,
Z
Methane, nitrogen concentration, arb. units
ww DDKK 2,
- 1 0
- 2 0
D e p t h , m m
R o t h f u s s F . , C o n r a d R . , 1 9 9 8L i m n o l . O c e a n o g r . 4 3 , 1 5 1 1 - 1 5 1 8
- 1 0
- 2 0
D e p t h , m m
R o t h f u s s F . , C o n r a d R . , 1 9 9 8L i m n o l . O c e a n o g r . 4 3 , 1 5 1 1 - 1 5 1 8
-10
-20
D epth , m m
R othfuss F.,C onrad R ., 1998L im nol. O ceanogr. 43 , 1511-1518
Bubbles formation in rice field model
0 400 800 1200-60
-40
-20
0
20
Summer Winter
Chanton J.P., Martens C.S., Kelley C.A., 1989. Limnol. Oceanogr. 34, 807-819, fig 3
Dep
th, c
m
Methane concentration, M
Methane concentrations
0.0 0.2 0.4 0.6 0.8 1.0
10012
101
/)1(
/)(
WPKr
WhCC
)//1(
/)()(
000 zbzzP
KzCzPi
iii
i
)2/( 12 Dhh
Atmosphere
h
Region II
Region I
Active layer
Active layer
0
Dep
th,
Z
b Water
Upper border of bubbles position
Dimensionless unit of depth
10011 /WPDKl
lhh ~
100112 /)1(2 WPDKXh N
-1.6 -1.2 -0.8 -0.4 0.0-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
lnh
/ cm
ln(1-XN2)
lnh = 0.74 + 0.6 ln(1-XN2)
Artificial atmospheres: nitrogen - oxygen
Kuzmin et all, Limnology and Oceanology
1011114 /)()(~
0)(~~
CH WzWzWzWC
01~
1 C If W1(z) = W10 then
Transport in region I
Border conditions
10~1
~rC
z
)
~(
~~1~~1 hCC
hz
N2 0~
2 C
Transport in region II
jiji XXSS // Main idea:
0)()( zSzWCD iiii
- sink to the bubblesiS
iX - molar part in the bubbles
1/~~
221 uCC 122
~~CuC
221 quq
1
11 ~
1
~1~
Cq
CC
1
111 ~
1
~1
)~(~~
Cq
CzWC
0~
~~1 Hz
C )~
(~~
1~~1 hCChz
Border conditions
0 5 10 15 20 25 30 35 40 45
0
20
40
60
80
100
Y = 116*exp(-x/17)
T.J.Popp et all, Biogeochemistry,fig. 5, v.51, p.259-281 (2000)
CH
4 pro
duct
ion,
g
/g(p
eat)
d-1
Depth, cm
Exponential approximation to W(z) W1(z) = W10exp(-νz)
0 2 4 6 8 10 12 14
0.0
0.2
0.4
0.6
0.8
G.W.Kipphut, C.Martens, Geochimica et Cosmochimica Acta,1982, 46, p.2049-2060
40 cm
N2
CH4
Nu = 1.15
h = 0.932
CH
4, N
2 co
ncen
trat
ion,
arb
. un.
Depth, arb. un.
CH4 and N2 concentrations on depth,
W1(z) = W10exp(-νz)
1,5 2,0 2,5 3,0 3,5 4,040
50
60
70
80
- theory
- theory
- experiment
F.Rothfuss, R.ConradLimnol. Oceanogr. 43(7), 1998, 1511-1518
Me
tha
ne
co
nce
ntr
atio
n in
th
e b
ub
blts
, %
Depth, cm
Bubbles composition on depth
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
0
2
4
6
8
10M
eth
ane
bubb
le f
lux,
arb
.un.
Methane molar ratio in bubbles X1B
Points from Chanton et allLimnol.Oceanog.,34,p.807,1989
BJ1
~BJ1
~on X1B
Active layer
0.0 0.2 0.4 0.6 0.8 1.0
PlantAtmosphere
b
[N 2]
[CH4 ]h
Water column
Region II
Region I
Active layer
Active layer
0
Dep
th,
Z
Methane, nitrogen concentration, arb. units
ww DDKK 2,
M e t h a n e p l a n t s i n k s
)]0()()[()( 11 CzCzfzQ 1R
N i t r o g e n p l a n t s o u r c e
)]()0()[()( 22 zCCzfzQ 2R
D i f f e r e n t i a l e q u a t i o n
0])~(~
[~
1~
112''
1 rzCC
1012 /
~DPfK
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.00.0
0.2
0.4
0.6
0.8
1.0
C
C
= 0.428
= 0.644
= 1C
Po
sitio
n o
f b
ub
ble
s2
1
0C
H4 C
on
cen
tra
tion
, a
rb.
un
its
Depth, arb. units
Methane concentration on depth
2~
0 10 20 30 40 50 60
0.0
0.1
0.2
0.3
0.4
0.5
0.6
2~
Roots, = 4.5
Wilson J.O. et all, 1989Biogeochemistry , Vol. 8, pp. 55-712Bubbles - 22.5 % CH
4, theory - 28 % CH
4
Met
hane
con
cent
rati
on, a
rb.u
n.
Depth, cm
Methane concentration on depth
C O N C L U S I O N W E H A V E T O K N O W I N D E P E N D E N C E O N Z :
[ C H 4 ] , [ N 2 ] , [ C O 2 ] , [ A r ] ,
B u b b l e s C o m p o s i t i o n , V o l u m e o f B u b b l e s
iW pH,,Porosity,, TDK
ii
W E H A V E T O K N O W T H E D I F F U S I O N , B U B B L E S A N D P L A N T S F L U X E S F O R A L L C O M P O N E N T S