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1
Read
• This week read Preface/ Introduction-Schlesinger and Bernhardt
• This week Introduction to Kean
• Chpt 1-Kean (discuss Sept 20)/Schlesinger (start on next week)
• Read the 3 papers for assignment due Sept 20 Weart paper/Vistousek paper/Sherwood paper
• Check Web of Science
First discussion and papers Due Sept 20• Read Weart. Sherwood, and Vistousek paper. Find a recent paper
(>2013) that addresses the major topic of one of these papers (email the citation to me by Sept 6)
• For written assignment
– Summarize the major points of each paper you have chosen (1 old one and 1 new)
– Describe how your paper adds to the major topic of discussion in the older paper you chose.
– Describe any limitations you feel exist in your more recent paper
– Give complete citations
• For class 10 minute presentation – I will pick 4 students to do this
– Summarize how this paper adds to the major discussion in one of the 3 assigned papers
– Pick a major graph or figure out of the paper you are going to discuss to share with the class-
– Give complete citations
2
Things to think about
• Weart/Sherwood– Major topic -Paradigm shifts
– What does it take for a shift to occur?
• Vistousek– Humans impact on every surface of the Earth
Introduce periodic table here remind them
3
• Science is an adventure of the human spirit. It is essentially an artistic enterprise, stimulated largely by curiosity, served largely by disciplined imagination & based largely on faith in the reasonableness, order, & beauty of the universe.–Warren Weaver
• Scientific knowledge is a body of statements of varying degrees of certainty –– some most unsure, some nearly sure, & none absolutely certain.
Richard Feynman
• “We have to remember that what we observe is not nature herself but nature exposed to our method of questioning”
– Werner Heisenberg
• Principle of uniformitarianism-”the past history of our globe must be explained by what can be seen to be happening now.” James Hutton, Charles Lyell and William Whewell
• Interpretations can only go as far as the data we have to make them
4
Considerations
• We can’t solve problems by using the standards of thinking we used when we created them.
• Life is a tragedy for those who feel and a comedy for those who think.Jean Bruyere
BiogeochemistryInterdisciplinary science of the 21st century
• Introduction “nightmare to a traditional laboratory chemist” S and B
• Definitions• Biogeochemical cycles
– Need for– Limitations
• Origins– Elements– Earth– Life
• Tools– Isotopes– Models Read pg 4 S and B– Measuring fluxes
5
• Earth is “materially a closed dynamic system.”
• But not closed to energy resulting in constant cycling of elements (actually some elements come in from outer space).
• Biogeochemical cycles “description of the transport and transformation of chemical substances through the earth “spheres”
Important scholars• James Hutton 1789
– Superorganism
• Darwin 1881
• Arrhenius 1886
– CO2 and climate
• Vernadsky “true father” 1926
– All geochemical processes that occur at the surface of the earth are affected by life
• Hutchinson 1950
– Birds and N and P cycling
• Lovelock 1972-feedbacks in biosphere climatic system lead to homeostasis of basic earth processes
• Schlesinger
6
Integrating science from diverse disciplines
• Ways to understand– Thermodynamics-equilibrium?
– Stoichiometry-are constituents available for reactions
– Experiments
– Isotopes
– Models
GAIA Hypothesis/Paradigm
• Unique chemistry of of earth’s atmosphere created by life
• “life is the tiller of environmental control.” (Toby Tyrell 2013)
• Physical and chemical characteristics of earth’s surface are actively made fit and comfortable for life by the presence of life.
• Earth as self regulating system
Vanishing face of Gaia
the “Gaian system”. Westbrook 2000 Alternate or exacerbating hypothesis
GeologicCo-evolutionary (coupled metabolism)
7
Dead planets versus live planets S and B Table 2.1
Dead planets versus live planets
• Dead-Thermodynamic equilibrium
• Live-Thermodynamic disequilibrium– O2, N2, H2O in the air maintained by life
– O2 coexisting with combustible biomass
8
Table 3.5 Schlesinger and B
Concentrations changedhttp://www.csiro.au/greenhouse-gases/
1788
327
GAIA Hypothesis/Paradigm
• Unique chemistry of of Earth’s atmosphere created by life
• Physical and chemical characteristics of earth’s surface are actively made fit and comfortable for life by the presence of life.
• Earth as self regulating system
Vanishing face of Gaia
the “Gaian system”. Westbrook 2000
9
http://earthobservatory.nasa.gov/GlobalMaps/
Terra satellite--http://terra.nasa.gov/About/
EOS NetworkGLOBAL VIEWSBuilding biogeochemical cycles
RIM Fire
Figure 1.1 from Jacobson et al
Bio-geo-chemistry
Biogeochemical cycles-
Humans ..
Geospheres
Transfers driven by sun energy and earth heat energy
Integration of disciplines
Recycling of material
11
6/28/2012Fine et al. 2015
Primary O3 Plume at 5000 to 6000 m aslBack Trajectory from 5500 m asl
Case Study 1: 6/28/2012Back Trajectories from Railroad Valley
Stratosphere
ASIA
Marine Boundary Layer
Los Angeles/San Diego etc
12
Box model• Steady state model used to understand Earth
conditions from year to year-Simple
• Can also be applied on smaller scales to conceptualize system complexities
• Starting point
Biogeochemical cycles Definitions
Reservoir/Pool/StockM
13
Chapter 8.10 Houghton Treatise on Geochemistry 2005
+5 S and B+4.1 ToG
825 ToG 2014
Definitions
Source Q Sink S
Flux (F) M/t
• Budget-– balance of all sources and sinks
– Steady state inputs=outputs
M
14
Definitions• Averaging history of all molecules results in
an average residence time
• All molecules- tells us on average how long an individual may last-however this can significantly vary
• Residence time- dM/dt= (Fin-Fout) + (introduction from sources-rate of removal) pg 56
pool of air over Nevada
15
Definitions
• Turnover time-time to empty reservoir in absence of sources if sinks remain constant
M/Fout some books equate TOT and RT
½ life- time for ½ of material to be removed
Response time- time scale for adjustment to change in ecosystem
Figure 4.2 Rhode
Coe
ffic
ient
of
va
riat
ion
Hg
Residence time
Figure 3.5 S and B
16
For biogeochemical cycles location in the atmosphere and ocean will influence residence time and distribution
Chapter 8.10 Houghton Treatise on Geochemistry
7.71.4
1.0
4.1 To G 5 S and B
17
Importance of spatial and temporal resolution
Concentration versus flux
6CO2 +6H2 O + light C6H12O6 + 6O2
6CO2 +6H2O C6H12O6 + 6O2
Cape Grimm
Moana Loa
18
Inter annual variability
Baldocchi et al 2001c
Spatial ecosystem variability
Baldocchi et al 2001
20
CO2 increase O2 decrease Holmen in Jacobson 2000
Vostok ice coreLong term linked biogeochemical cycles
Complex couplings
21
Long term geologic cycle??Earth’s orbital cycles
41 000
21 000
100 000 yrs
http://ossfoundation.us/projects/environment/global-warming/milankovitch-cycles
Vostok ice coreLong term linked biogeochemical cycles
Complex couplings
22
Long term geologic cycles-Urey cycle
Westbrook Box model
Figure 1.3 S and B
Systems thinking
• Component parts of a system can best be understood in the context of relationships with each other and other systems
• Holistic
• Positive and negative feedbacks
• Models
23
Long term geologic cycle of C• Remember fast cycling versus slow
• Long term cycles linked with temperature, climate, and weathering
• Negative feed back system-more weathering more CO2 sequestered
• Sea floor spreading as a control on climate– Volcanism Reading the Ridges Earth Magazine
– Uplift get more weathering
• Gaia hypothesis and human impacts.
• Although we may focus on 1 element or compound to simplify, we must keep in mind that the processes associated with one element may be strongly coupled with another – Things to consider
• Thermodynamics
• Living systems cause disequilibrium
• Coupling of elements and biological processes
24
August 2000 Whole cell fluxes
0
1000
2000
3000
4000
5000
6000
6.0 6.3 6.6 6.9 7.3 7.6 7.9 8.2
Day
Hg
flu
x, n
g/m
2h
-10
-5
0
5
10
15
20
25
CO
2 a
nd
H2
O f
lux
, u
mo
le/m
2s
Hg Cell1 Hg Cell2 Co2 H20
Abiotic and biotic gas fluxes
Just because there is a correlation does this tell you anything?
21 April 2005:
y = 0.012x - 0.935 (r2 = 0.914)
-10
-5
0
5
10
15
20
25
0 200 400 600 800 1000 1200 1400
Photon flux density (mol m-2 s-1)
bare
soi
l Hg
flux
(ng
m-2
h-1
)
22 April 2005:
y = 0.005x + 0.701 (r2 = 0.526)
-10
-5
0
5
10
15
20
25
0 200 400 600 800 1000 1200 1400
Photon flux density (mol m-2 s-1)
bare
soi
l Hg
flux
(ng
m-2
h-1
)
Five consecutive days (19-23 April 2005):
y = 0.006x + 0.662 (r2 = 0.395)
-10
-5
0
5
10
15
20
25
0 300 600 900 1200 1500
Photon flux density [mol m-2 s-1]
bare
soi
l Hg
flux
[ng
m-2
h-1
]
Stamenkovic and Gustin 2008
25
Hourly averaged data (n=218 days):
y = 0.003x + 0.518 (r2 = 0.116)
-10
-5
0
5
10
15
20
25
0 300 600 900 1200 1500
Photon flux density [mol m-2 h-1]
bare
soi
l Hg
flux
[ng
m-2
h-1
]
Daily averaged data (n=218):
y = 0.007x - 0.196 (r2 = 0.171)
-4
0
4
8
12
0 200 400 600
Photon flux density [mol m-2 h-1]
ba
re s
oil
Hg
flu
x [n
g m
-2 h
-1]
Monthly averaged data (n=12):
y = 0.016x - 1.871 (r2 = 0.714)
-4
0
4
8
12
0 200 400 600
Photon flux density [mol m-2 h-1]
ba
re s
oil
Hg
flu
x [n
g m
-2 h
-1]
Stamenkovic and Gustin 2008
0%
10%
20%
30%
40%
50%
60%
70%
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ALL
exp
lain
ed
va
ria
bili
ty (
SL
R r2 )
light intensity
air temperature
soil temperature
soil moisture
Stamenkovic and Gustin 2008
More complex than just a simple linear correlation
26
Understanding biogeochemical cycles-Limitations of laboratory
studies
Understanding biogeochemical cycles-Limitations of field
studies
28
Processes will influence cycling
• Mechanical / Physical- Phosphorus input to aquatic systems
• Chemical-precipitation, oxidation-reduction, adsorption, complexation
• Biological- nitrogen fixing plants, microbial processes
Importance of oxidation states
• Toxicity
• Mobility
• Bioavailability
• Oxidation reduction reactions-transfer of electrons