Climate

1
Climate

• Fall 2006

2
OVERVIEW
http//www.environment-agency.gov.uk/commondata/fi
gurethumbnails/138184
3
What is climate?

• The general weather conditions of an area or
  region, such as temperature, precipitation, air
  pressure, humidity, winds, sunshine and
  cloudiness throughout the year, averaged for
  several years.
• The general weather conditions averaged over
  decades for example.
• On a long time scale.

http//www.unep-wcmc.org/climate/I/drought.jpg
4
What is weather?

• The atmospheric state in terms of temperature,
  wind, pressure, moisture and cloudiness for
  example.
• On a short time scale.

http//www.hpc.ncep.noaa.gov/noaa/noaa.gif
5
Different kinds of climate

• Temperate
• Subtropical
• Tropical
• Arid
• Semiarid
• Subarctic or Boreal
• Polar
• Alpine

6
http//www.eere.energy.gov/consumer/images/climati
c_region_map.gif
7
http//www.climatescience.gov/Library/stratplan200
3/vision/VisionFig1.jpg
8
(No Transcript)
9
pubs.usgs.gov/fs/fs-0071-97/
10
Mechanism
http//www.ncdc.noaa.gov/paleo/abrupt/images/ball1
.gif
11
Cuffey and Clow (1997) and Alley (2000).
http//www.ncdc.noaa.gov/paleo/abrupt/story3.html
12
Deposits/Rocks

• Till unsorted glacial deposit that ranges from
  clay to sand, gravel and boulders
• Limestone
• Shale
• Sandstone
• Etc.

13
Facies

• A facies is a body of rock with specific
  characteristics
• Walther's Law of Facies
• Johannes Walther
• The vertical succession of facies reflects
  lateral changes in environment. On the other
  hand, when a depositional environment "migrates"
  laterally, sediments of one come to lie on top of
  another.
• Paleosols - fossil soils important in analyzing
  facies in continental strata
• Paleoenvironmental indicators
• Sedimentation rate indicators for areas where the
  sedimentation has temporarily stopped or have
  been largely decreased

Reading, H.G. (Editor), 1996. Sedimentary
Environments. Processes, Facies and Stratigraphy.
Blackwell, Oxford, 688 pp.
14
Reading, H.G. (Editor), 1996. Sedimentary
Environments. Processes, Facies and Stratigraphy.
Blackwell, Oxford, 688 pp.
15
Reading, H.G. (Editor), 1996. Sedimentary
Environments. Processes, Facies and Stratigraphy.
Blackwell, Oxford, 688 pp.
16
Reading, H.G. (Editor), 1996. Sedimentary
Environments. Processes, Facies and Stratigraphy.
Blackwell, Oxford, 688 pp.
17
(No Transcript)
18
Thermohaline Circulation
http//www.ncdc.noaa.gov/paleo/abrupt/story3.htm l
19
Cycles Tend to Influence Climate

• 1st order cycles
• 2nd order cycles
• 3rd order cycles
• 4th and 5th order cycles within 3rd order cycles,
• or Milankovitch cycles.
• Precession Cycle
• Obliquity Cycle
• Eccentricity cycle

20
Milankovitch cycles

• Precession Cycle cyclic wobbling of the
  earth on its axis.
• - occurs about every 23,000 years.
• Obliquity Cycle cyclic changes in the tilt
  of the Earth on its axis, from 21.2 to 24.5.
• - occurs about every 41,000 years.
• Eccentricity cycle cyclic changes in the
  shape of the Earths orbit around the Sun --
  how elliptical or circular the Earths orbit
  is.
• - occurs about every 100,000 years.

21
http//www.searchanddiscovery.com/documents/2005/g
reen02/images/10.jpg
22
There is evidence for climate change

• Oceanic sediment cores
• Cores from estuaries
• Ice cores
• Foramifera, phytoplankton, corals, diatoms and
  other marine organisms in cores
• Forams usually have CaCO3 shells, while diatoms
  have silica shells
• By analyzing different ratios, such as the
  oxygen- 16/oxygen-18 ratio

23
Investigation
http//www.ncdc.noaa.gov/paleo/paleo.html
24
Forams
http//www.nmnh.si.edu/paleo/blast_images/k_forams
.jpg
25
Drilling for cores
From http//www.spacedaily.com/images/ocean-drilli
ng-bg.jpg
26
CORES
http//www.aip.org/history/climate/images/hzcore.j
pg
27
Ice Cores

• Ice cores contain gases, or snapshots of what
  past atmospheres were like, and thus past climates

http//www.ccrc.sr.unh.edu/cpw/Nepaltravel/nepal_
fig2.jpg
28
Interactions
www.climatechange.gc.ca/.../what_is/maps_graphs.sh
tml
29
http//earthobservatory.nasa.gov/Library/CarbonCyc
le/Images/carbon_cycle_diagram.jpg
30
Greenhouse Effect
31
E n e r g y
www.newscientist.com/hottopics/climate/climatefaq.
jsp
32
Kealing Curve

• http//en.wikipedia.org/wiki/Keeling_Curve

33
Pollution
From http//www.usaid.gov/environment/images/clima
te2.jpg
34
Several sources have pointed out that the global
mean temperature has increased/ is increasing
35
www.aps.org/public_affairs/popa/reports/popaiv-1.h
tml
36
www.ucar.edu/learn/1_4_1.htm
37
OVERVIEW
http//www.nasa.gov/images/content/105582main_Glob
alWarming_2060_lg.jpg
38
From www.ngdc.noaa.gov/news/ gc-intro.html
39
Saltwater Intrusion saltwater going into
freshwater areas

• Lose of freshwater wetlands occurs because of
  sea-level rise.
• There is more seawater nearby, like what occurs
  with wells, as the diagram shows.

www.epa.gov
40
To Conclude

• The climate has changed in the past and will
  change in the future.
• The future climate is uncertain due to the
  complexity and controversy associated with
  related issues.

41
www.oneworld.net/penguin/global_warming/
climate_home.html