Vorlesung "Umweltphysik I“ - Institut für Umweltphysik

Master Course „Environmental Physics“ (MKEP4)
http://www.iup.uni-heidelberg.de/institut/studium/lehre/MKEP4/
1. Introduction
Winter Term
Ulrich Platt
2011/12
Institut für Umweltphysik
1

Master Course „Environmental Physics“ (MKEP4)
Lecture
Web-page:
http://www.iup.uni-heidelberg.de/institut/studium/lehre/MKEP4/
Lecture: Tue and Thur 14:00 - 16:00
Institute for Environmental Physics, Institut für Umweltphysik,
INF 229, Seminarraum 108/110, 1.OG
Exercises: K. Roth, D. Wagenbach and G. Balschbach

Lecture Program of MKEP4
Part 1: Introduction and Fundamentals (4 sessions)
1.Introduction to Environmental Physics and the Earth System
2.Global energy balance and structure of the atmosphere
3.Stratification and convection in air and water
4.Transport processes
Part 2: Geophysical Fluid Dynamics (7 sessions)
5.Introduction to Geophysical Fluid Dynamics
6.Flow on large scales, geostrophic approximation
7.Rotating Flow: Vorticity
8.Turbulence
9.Turbulent transport and flow near boundaries
10.Global circulation of the atmosphere
11.Global circulation of the ocean
Part 3: Other Compartments and Fields (4 sessions)
12.Gas and heat transfer between air and water
13.Atmospheric Physical Chemistry
14.Freshwater systems, Soil and Groundwater
15.The cryosphere
3

Lecture Program of MKEP4
Part 4: Methods and Models (7 sessions)
16.Fundamentals of isotope methods
17.Isotopes and tracers in environmental physics
18.Measurement methods of environmental physics
19.Remote sensing methods
20.Model concepts, box models
21.Lumped-parameter models, complex box models
22.Continuous models, numerical and inversion techniques
Part 5: Climate (6 sessions)
22.The carbon cycle
23.Radiative transfer
24.Aerosols and clouds
25.Climate sensitivity, feedbacks, and predictions
26.Climate variability and palaeoclimate reconstruction
27.Climate Engineering
Last week: Written
Exam
(Feb. 2012)
4

Main resource for parts 1, 2, 5:
Marshall, J. and R. A. Plumb:
Atmosphere, Ocean, and Climate
Dynamics. An introductory Text.
Elsevier Academic Press, 2008.
Companion
website:
Literature
http://www.elsevierdirect.com/companion.
jsp?ISBN=9780125586917
Available in IUP-Library (INF 229, 4 th
floor), IUP-Nr. 1993
5

Literature
Other Textbooks:
1) Roedel, W. amd Wagner T., 2011. Physik unserer Umwelt, Die Atmosphäre.
Springer Verlag, Heidelberg, 4th Edition. (IUP 1780).
2) Wells, N., 1997. Atmosphere and Ocean - A Physical Introduction. John Wiley &
Sons, 2nd Edition. (IUP 1723).
3) Pedlosky, J., 1987. Geophysical Fluid Dynamics. Springer Verlag, Heidelberg, 2nd Edition. (IUP 720)
4) Bergmann-Schäfer, 1997. Lehrbuch der Experimentalphysik, Bd.7, Erde und
Planeten. de Gruyter, Berlin. (IUP 1862)
5) Peixoto J.P., Oort A.H., 1993. Physics of Climate. American Institute of Physics,
New York. (IUP 1409).
Online Resources:
1) Stewart, R. H., 2003. Introduction to Physical Oceanography. Online textbook,
http://oceanworld.tamu.edu/home/course_book.htm
2) Mook, W.G. (ed.), 2001. Environmental Isotopes in the Hydrological Cycle
http://www-naweb.iaea.org/napc/ih/IHS_resources_publication_hydroCycle_en.html
3) Goosse H. et al., 2010. Introduction to climate dynamics and climate modeling.
Online textbook, http://www.climate.be/textbook
4) Stocker, T., 2009. Introduction to Climate Modelling. Lecture Notes, Univ. of Bern.
http://www.climate.unibe.ch/main/courses/klimamodellierung_hs09/stocker09climmod.pdf
6

Contents of Today's Lecture
Introduction to Environmental Physics
and the Earth System
• Definition and history of environmental physics
• Big issues (climate, ozone, water, soil, energy,..)
• The Earth System and its compartments
• Properties of Earth's fluids
7

What is Environmental Physics (EP)?
Definition of Environmental Physics
Research on physical processes in the environment using the
methods of physics.
Environment: Earth surface systems affecting human life
directly and indirectly.
Environmental Physics in relation to other sciences
EP is a comparatively young* branch of research in physics.
In terms of studied systems, EP overlaps with Earth Sciences (e.g.
Geophysics, Geochemistry, Meteorology, Hydrology).
The description of the processes and systems is mostly based on
classical physics (e.g. mechanics, thermodynamics).
The analytical techniques applied in EP mostly originate from
modern physics (e.g. nuclear, atomic, molecular physics).
*or old(!)
8

Environmental Physics as an old Branch of Science
Environmental Physics (before it was called Environmental
Physics) explained many phenomena in our environment
that were unexplained (or attributed to acts of god(s)), like:
•
•
•
•
•
•
Tides
Weather
in the
Lightning
The
Shape
...
colour
ocean
phenomena
and thunder
of the
of the
(precipitation, clouds, wind)
sky, El Mirage effects
landscape

Definition Umweltphysik
Arbeitsgebiet der Umweltphysik sind die klassischen Systeme Wasser,
Boden, Luft und Ökosysteme, die die menschliche Umwelt bilden. Hierzu
gehören auch die Flüsse von Energie und von Stoffen sowohl innerhalb
dieser Kompartimente wie auch zwischen ihnen.
Wichtige Ansätze sind die Untersuchungen von Transportvorgängen mittels
Spurenstoffen und die Entwicklung von Modellen, die die Umwelt
systemisch nachbilden. Daneben geht es auch um die Entwicklung
hochspezialisierter Messverfahren, was ja eine klassische Aufgabe der
Physik ist.
Umweltphysik ist ein Teilgebiet der Physik, sie hebt sich aber von anderen
Bereichen der Physik ab durch ihre systemorientierte Sichtweise und durch
spezielle Methoden, mit denen Fragestellungen angegangen werden. Mit
den klassischen Fachdisziplinen (z. B. der Meteorologie) gibt es deutliche
Überlappungen. Die Umweltphysik ist aber physikalischer und eher auf
Grundlagenforschung hin ausgerichtet.
10

Contributions of Environmental Physics
The results of research in environmental physics contribute in many ways
to fundamental research in science.
Examples:
• The development of the theoretical foundations for the origin of 'chaos‘
in conjunction with research on turbulence.
• Determination of predictability of weakly causal, non-linear systems,
which frequently occur in environmental sciences (e.g. the weather).
In addition the development of new measurement techniques and their
refinement is prominently influenced by environmental physics.
Examples:
• New methods of image processing
• New methods in optical spectroscopy (e.g. DOAS)
• Radiometry and accelerator mass spectrometry (e.g. for 14 C-dating)
• Supercomputers for weather prediction and climate simulation.
11

•
•
•
Highlights of "Environmental Physics"
1896: Greenhouse
warming
due
to CO 2
increase
Svante Arrhenius (1859 – 1927)
Swedish physicist and chemist
Nobel Prize in Chemistry 1903 (electrolytic conductivity)
1930: Astronomical
theory
of the
Milutin Milanković (1879 – 1958)
Serbian geophysicist and civil engineer
1949: Development
ice
of radiocarbon
Willard Frank Libby (1908 – 1980)
American physical chemist
Nobel Prize in Chemistry 1960
ages
( 14 C) dating
12

•
•
•
Highlights of "Environmental Physics"
1958: Start of CO 2
time series
in Hawaii
Charles David Keeling (1928 – 2005)
American geochemist
Tyler Prize for Environmental Achievement 2005
1961: Systematics
of stable
isotopes
of water
Harmon Craig (1926 – 2003)
American geochemist
Balzan Prize for Geochemistry 1998
Also: Willi Dansgaard (1922 – 2011), Danish Geophysicist
1969: First coupled
ocean-atmosphere
Syukuro Manabe (1931)
Japanese meteorologist and climatologist
Revelle Medal 1993
models
13

•
•
•
Highlights of "Environmental Physics"
1970/74: Mechanisms
of ozone
depletion
Paul J. Crutzen (1933), Dutch atmospheric chemist
Mario J. Molina (1943), Mexican chemist
Frank Sherwood Rowland (1927), American chemist
Nobel Prize in Chemistry 1995
1979: CO 2
and paleoclimate
from
ice
cores
Hans Oeschger (1927 – 1998)
Swiss physicist. Founder of the Division of Climate and
Environmental Physics at the University of Bern (1963)
Tyler Prize 1996, Revelle Medal 1997
Also: Willi Dansgaard (1922 – 2011)
1989: Ocean circulation
& abrupt climate
Wallace (Wally) Broecker (1931)
American geochemist
Tyler Prize 2002, Revelle Medal 1995, etc.
change
14

•
Highlights of "Environmental Physics"
1988: IPCC established
by
WMO/UNEP
Intergovernmental Panel on Climate Change
Reports in 1990, 1995, 2001, 2007
Nobel Peace Prize 2007
Thomas Stocker, Climate and
Environmental Physics, Univ.
Bern
Co-Chair Working Group I, IPCC
4th Assessment Report 2007:
996 Pages
152 Lead authors
~ 450 Contributing authors
available at: http://www.ipcc.ch
15

•
•
Environmental Physics in HD/Germany
1960s: Application of methods of nuclear
to environmental research in Heidelberg
Otto Haxel (1909-1998), German nuclear physicist
Otto Hahn Prize of the City of Frankfurt a. M. 1980
1975: Foundation
of the
IUP Heidelberg
physics
Karl-Otto Münnich (1925 – 2003), German physicist
14C dating of groundwater, bomb-radioisotopes as tracers,
biogeochemical cycles, etc.
• 1988: Environmental Physics at ETH Zurich
• 1993: Foundation of IUP Bremen
• 1998: Fachverband Umweltphysik in the DPG
• 2000-2006: Environmental Physics at TU Ilmenau
• 2003: Environmental Physics at Univ. Konstanz
• 2008: Environmental Physics at Univ. Koblenz-Landau
16

•
•
•
•
Big Issues in Environmental Physics
Water and Soils: Food security
Air pollution, ozone depletion
Energy: Resources and impacts
Climate and climate change
17

Irrigated
•
•
•
agriculture
produces 40 % of the
world's food on 20% of
the agricultural area
accounts for 70% of the
water withdrawals (3.000
of the available 13.000
km3 /a)
regionally overutilises
surface and ground water
Hidden
problem:
non-sustainability
Food Security: Irrigation
18

Non-Sustainability: Groundwater Depletion
Central Valley, CA, USA
San Francisco
Groundwater Atlas of the US
http://capp.water.usgs.gov/gwa/
North China Plain, China
Beijing
Foster et al., 2004. Hydrogeol. J. 12: 81-93
19
19

Land (soil) degradation
•
•
•
•
•
erosion
nutrient
salinization
depletion
desertification
etc.
Salinization:
Frequently a
consequence
of irrigation
Food Security: Soils
due
to
20

Air Pollution: Global View
Remote Sensing: Global Distribution of NO2 from Spectra of the
SCIAMACHY-Satellite Instrument on ENVISAT
Mean tropospheric NO2 – column density (in 1015 molecules/cm2 ), Jan. 2003 – June
2004, S. Beirle, U. Platt, T. Wagner
Further gases measured: Methane, Formaldehyde, SO2 , BrO, OClO, H2O, ...
21

Depletion of the Ozone Layer
WMO (World Meteorological Organization),
Scientific Assessment of Ozone Depletion:
2006, Global Ozone Research and Monitoring
Project, Report No. 50, 572 pp., 2007.
October
August
O3 profiles in August (Antarctic winter)
and October (Antarctic spring) of 1996
and 1997, [Nardi et al. 1999]
22

Origin
especially
of ozone
Depletion of the Ozone Layer
strong
depletion: Catalytic
in the
presence
cycle
with
Cl (also Br),
of polar stratospheric
WMO Scientific Assessment of Ozone Depletion, 2007.
clouds
(PSC)
Rowland-Molina hypothesis 1975, Nobel Prize 1995 Susan Solomon, 1986
23

Antarctic
Ozone, September 2010
http://ozonewatch.gsfc.nasa.gov/
The "Ozone Hole"
Discovery in 1985, British Antarctic
Survey
1987 (in force 1989)
Montreal Protocol:
Phasing out production of substances
responsible for ozone depletion.
24

Predicted Recovery of the Ozone Layer
Montreal Protocol
WMO Scientific Assessment of Ozone Depletion, 2007. 25

Scientific Report on the Ozone Problem
WMO (World Meteorological Organization),
Scientific Assessment of Ozone Depletion:
2006, Global Ozone Research and Monitoring
Project, Report No. 50, 572 pp., 2007.
"Ozone Hole":
Example of swift and
successful global
environmental action
http://www.wmo.int/pages/prog/arep/gaw/ozone_2006/ozone_asst_report.html
26

Energy: Resources and Impacts
Environmental Physics does not develop energy technology,
but contributes in many ways to energy-related problems, e.g.
Nuclear Power
• Assessment of the safety of nuclear waste repositories
• Analysis of radioisotopes emitted by nuclear industry
Fossil Fuels
• Detection of greenhouse gas emissions
• Other emissions (NOx, SO2, aerosols, etc.)
Other energy sources/carriers
• Assessment of potentials of renewable resources
• Enironmental impact of a H2-economy • Water use and greenhouse impact of biofuels
27

Energy: Resources and Impacts
E.g. potential of renewable
Global distribution
of mean
T. Troendle, IUP Heidelberg
resources: Wind energy
wind speeds
28

Impact of Energy Use: CO 2 in Atmosphere
Charles Keeling
(1928-2005)
http://scrippsco2.ucsd.edu/
� Humanity causes global environmental change
29

CO 2 [ppm]
380
360
340
320
300
280
CO 2 -Rise in the Atmosphere
390
380
370
360
350
340
Atmospheric CO 2
330
Neumayer
320
310
South Pole
Schauinsland [UBA]
1970 1980 1990 2000
1750 1800 1850 1900 1950 2000
Year
South Pole [Keeling et al.]
Antarctica: Ice [Neftel et al., 1994;
Etheridge et al., 1998]
30

Global Warming of the Past 150 Years
IPCC, AR4, 2007
31

The Future Climate of Earth?
Stabilise emissions
at 2000-level
30GtC/a
in 2090
Reduction, back to
emissions of 2005
until 2070
32

The Earth System and its Compartments
"Environment" is a thin shell:
Atmosphere (at STP): 8.0 km
Ocean (mean depth): 3.8 km
Geological Spheres
Press, F. and R. Siever, 1986, Earth,
W. H. Freeman, New York.
33

Dynamics of the "Solid" Earth (Geophysics)
Heating
Cooling
from
through
Lithospheric
Convection
radioactive
heat
� plate
decay
and latent heat
mantle-convection, hot spots
flow
≈
0.087 Wm −2
tectonics
from
“freezing”
and conduction
Press, F. and R. Siever, 1986, Earth, W. H. Freeman, New York, 4. edition.
34

North-South
Ice sheets
(~ 3 km)
Topography of Earth's Surface
section
along
Air: horizontally mostly free
Water: horizontally
Greenwich meridian
confined
Oceans
(~ 5 km)
(0°
longitude)
Mountains
(few km)
35

Meridional Land/Sea Distribution
36

Atmosphere
Compartments and Interactions
Dynamics:
Navier-Stokes-
Equation
Solar Radiation
Oceans Cryosphere Biosphere
Groundwater
Hydrological
Cycle
37

Water and Air on Earth
All Water on Earth: Sphere, R�700km All Air on Earth: Sphere, R�1000km
(97 % saltwater) (standard conditions)
Source: Adam Nieman, http://www.adamnieman.co.uk/vos/index.html
38

Properties of Earth's Fluids
Composition of air
(dry air)
%: 10 -2 , ppm: 10 -6 ppb: 10 -9 , ppt: 10 -12
39

N2 O2 Noble Gases
H2O CO 2
CH4 H2 N2O CO
O 3
NM-VOC
NOX SO2 HO 2
OH
10 -19
Mixing Ratios of Atmospheric Trace Gases
?
Radon
10 -12 10 -9 10 -6 10 -3 1
100‘s-1000‘s
Xe
5-100‘s
ppt ppb ppm
Kr
He Ne Ar
5-6
3-4
No. of different species in conc. range

Properties of Air
R = 8.314 J mol -1 K -1
Molar mass of dry air:
= 0.029 kg mol-1 M d
41

Pressure Profile of the Atmosphere
Change of p with
z
�� � �
M Mp ,M MolarMass
V RT
z (vertical
Fp(z+�z) F g
Fp(z) coordinate, upwards):
Barometric
� �
equation:
Mg
� z
RT
0 0
z
�
z
s
p z �p �e �p �e Scale
Height:
RT
zs �
Mg
8.314 � 273.15
� �7980m
0.029 �9.81
H = Height of a hypothetical
atmosphere with p = p0 = const.
� �
dF � F(z�dz) �F(z) �F(z) �g��Adz �Fz�g�Adz �dV
dF Mp dp Mg
dp � �g� �
dz �g dz � � dz
A RT p RT
Mp
RT
dm
42

Pressure Profile of the Atmosphere
observed
H = 6.8 km
43

The
scale
Scale Height of the Atmosphere
height
depends
RT Air (Mair zs �
Mg T = 0°C: zs Different gases
on temperature
= 7980 m
T = 15 °C: zs = 8420 m
T = -20 °C: zs = 7400 m
at T = 0 °C
T and molar
= 29 g/mol) at different temperatures:
mass M:
44

Separation of Gases in the Atmosphere?
Are heavy
gases
Answer: No! Strong
enriched
close
turbulent mixing
to the
surface?
up to ~100 km altitude
45

Hydrosphere and Ocean
http://www.unep.org/vitalwater/index.htm
46

The Global Hydrological Cycle
Oceanography
Hydrology
Limnophysics
Soil Physics
Hydrogeology
Trenberth et al., 2007, J. Hydrometeor. 8: 758 - 769
47

Physical Properties of Water
Property Comparison Importance, consequences
Specific heat
4180 J kg ‐1 K ‐1
Heat of fusion
3.34 . 105 J kg ‐1
Heat of evaporation
2.25 . 106 J kg ‐1
�max at T > Tfreezing (~4 °C at 0%, 1 atm)
Highest of all solids and
liquids except liquid NH3 Highest except
(80K)
NH 3
Highest of all substances
(538K)
Heat transport by water movement,
heat buffering
Thermostatic effect at freezing point
Heat and water transfer in the
atmosphere
Anomalous Density stratification of lakes,
facilitates freezing
�solid < �liquid anomalous Ice floats on water, freezing only at
surface, weathering
Surface tension Highest of all liquids Drop formation, capillary forces, soil
water retention, cell physiology
Dissolving power Very high Transport of dissolved substances
Dielectric constant Highest of all liquids
except and HCN
Viscosity
�=0.001 Kgm ‐1 s ‐1
�=10 ‐6 m 2 s ‐1
H2O2 High dissociation of dissolved salts
Kinematic viscosity � higher than
that of air
48

Properties of Water
49

The Ocean
Seawater
Properties of Earth's Fluids
1.365 x
1.41 x
10 18 m 3
10 21 m 3
50

•
•
•
•
•
•
•
The Ocean's Role in the Earth System
Covers about
70% of the
Earth's
Largest reservoir of available
ca. 50 times more than in the
Increase in atmospheric
acidification
Plays a central role
global water)
Provides
in the
CO 2
meridional transport
Buffers heat, reduces
CO 2
surface
(in the form of HCO -
3 ),
atmosphere
will lead
hydrological
seasonal
of heat
to ocean
cycle
by
changes
ocean
(97.5% of
currents
of temperature
� Central system of the world climate machine
51

Pressure Profile in the Ocean
Water is in good approximation incompressible
� Density is approximately constant, independent of depth.
Hydrostatic
pressure
p�z��p0��gz profile
(z positive upwards):
Remark 1: From � ≈ 1000 kg m-3 and g ≈ 9.81 m s-2 folllows
�g ≈ 104 Pa m-1 = 0.1 bar m-1 = 1 dbar m-1 = 1 bar / 10 m
Pressure often given in dbar, nearly equal to depth in m.
Remark 2: In reality water is compressible
pressure profile therefore exponential.
and the
But the compressibility is so low that the scale height
about 230 km, much bigger than the ocean depth.
is
52

•
•
•
•
•
•
Summary
Environmental Physics: Research on physical processes in
the environment with the methods of physics.
Environmental Physics has roots in nuclear physics and has
contributed to research on e.g. the hydrological cycle and
ocean (isotope hydrology), atmosphere (ozone, trace gases),
and climate (paleoclimate, climate modeling, carbon cycle).
Current
big
issues: Global change
and resource
scarcity
Main subsystems of earth (compartments) studied in
Environmental Physics: Atmosphere (air), Hydrosphere
(liquid water), Cryosphere (ice), Lithosphere (earth crust).
Atmosphere and ocean: Similar volumes, different densities
Equations of state and pressure profiles:
� air is compressible � exponential pressure profile
� water is incompressible � linear pressure profile
53