Observations of Our Changing Planet: Weather EXTREMES

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Observations of Our Changing PlanetWeather
EXTREMES
Professor Menglin Jin METR112 Global Climate
Change
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The Weather Extremes and Climate ChangeVideo

• http//www.met.sjsu.edu/metr112-videos/MET201122
  0Video20Library-MP4/weather20extremes/
• Global Warming-1.mp4

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Meehl et al. 2005 Science
GCM simulated sea surface temperature and sea
Level rise under different CO2 conditions
Surface Air Temperature
Surface will keep warming
Sea level rise
Sea level will keep rise
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Definitions

• Climate Change
• Changes in climate of the past, present or
  future associated with natural or anthropogenic
  (human) factors
• Global Warming
• Warming of the 20th and 21st century associated
  with anthropogenic activities.

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Weather VS Climate

• Weather describes whatever is happening outdoors
  in a given place at a given time.
• Weather is what happens from minute to minute.
• can change a lot within a very short time
• Weather includes daily changes in precipitation,
  barometric pressure, temperature, and wind
  conditions in a given location.

• Climate describes the total of all weather
  occurring over a period of years in a given
  place.
• Climate tells us what it's usually like in the
  place where you live

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NASA Earth Satellite Provide tremendous
Observations
TRMM 11/27/97
Landsat 7 4/15/99
Aqua 5/4/02
Terra 12/18/99
Weather can be measured from space. Average of
weather can get climate
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Weather Extremes

• Hurricane
• Flood
• Snowfall
• Drought
• fire
• etc

what are the frequency and strength of extreme
weather events in a changing climate
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What does it mean by extreme?
Extreme value distributions are often used to
model the smallest or largest value among a
large set of independent, identically distributed
random values representing measurements or
observations.
frequency
Extremes
Climate value
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Where are the extremes here?
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NOAA Extreme Weather and Climate Events
http//www.ncdc.noaa.gov/oa/climate/severeweather/
extremes.html
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Landsat 7 Observes Flooding in New
OrleansHurricane Katrina
September 7, 2005
September 15, 2005
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TRMM Unprecedented Views of Hurricanes
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Hurricane Ike was the third most destructive
hurricane to ever make landfall in the United
States. It was the ninth named storm, fifth
hurricane and third major hurricane of the 2008
Atlantic hurricane season
Category 4
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Hurricane and SST Change
Webster et al. report that the number of
category 4 and 5 hurricanes has almost doubled
globally over the past three decades
(Webster et al, 2005, Science)
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Hurricane and SST Change
Emanuel, K. A. (2005), Nature
Emanuel, K. A. (2005) reports that a measure of
the power dissipated by tropical cyclones
(proportional to the cube of wind speeds
accumulated over the North Atlantic and western
North Pacific basins) has approximately doubled
since about 1950, with most of the increase
occurring over the past 30 years. According to
Emanuel, increases in both intensity and duration
of tropical cyclones have contributed to this
apparent increase. Emanuel's power dissipation
index (PDI) is strongly correlated with sea
surface temperatures in these basins, which have
increased markedly over the same period.
http//www.gfdl.noaa.gov/tk/glob_warm_hurr.html
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Be careful

• Hurricanes are natural events, and are not
  linearly related to climate change
• Climate change, by increase SST, indeed makes it
  more possible to have strong hurricane occur

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Saharan Dust Front - Ground View
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Saharan Dust Front - Algeria
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Arctic sea ice coverage, 1979 and 2003 NASA
http//www.learner.org/channel/courses/envsci/unit
/text.php?unit12secNum7
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(No Transcript)
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20-Year Trends in Arctic Sea Ice Coverage
Yearly and Seasonal Ice Coverage
Trends Yearly 2.8/decade Winter 2.2/decade
Spring 3.1/decade Summer 4.5/decade Autumn
1.9/decade

• 37,000 km2/year decrease of sea ice area
• over a 19.4 year period observed from satellite

Parkinson et al. (1999) and Vinnikov et al. (1999)
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Decreases in Arctic Sea Ice Coverage as Observed
from Satellite Observations
Year
Parkinson et al. (1999)
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Deviation of Monthly Arctic Sea Ice Area22 years
from Nimbus 7 to DMSP
Seasonal Cycle Removed
1.0
0.5
0.0
Sea Ice Area (106 km2)
-0.5
-1.0
-1.5
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83
85
87
89
91
93
95
97
99
Year
DMSP Defense Meteorological Satellite program
Parkinson et al. (1999)
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MODIS Flyby of the Himalayas Ganges Valley
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Glaciers as a Harbinger of Global Change

• Glacier National Park
• 110 glaciers have disappeared in the past 150
  years
• 37 remaining glaciers expected to disappear
  within 25 years
• Mt. Kilimanjaro
• All glaciers likely to disappear within 20 years
• 160,000 glaciers worldwide being monitored by
  satellites (especially Landsat 7/ETM and
  Terra/ASTER)

Gangotri Glacier, Himalaya
Bhutan-Himalaya
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Seasonal Snow Coverage from MODIS
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Flood
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Flood occurs all over the globe
China
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Land Cover Change in Florida1900 vs 1992

• Human influence has transformed southern Florida
• Land converted to cropland and cities
• Everglades transformed from deep-water sloughs
  and bog marsh into drier sawgrass marshes
• Mangroves have shrunk dramatically

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Crop and Property Damages from Natural
Hazards1960 June 2004
/Square mile
14.5-500
500-1,250
1,250-2,500
2,500-5,000
5,000-545,000

• San Francisco County (26.8 million/square mile)
• Los Alamos (16.5 million/square mile)

Hazards Research Lab, U of South Carolina
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Summary and Resources

• Satellites have played a crucial role in
  understanding and documenting global change
• sources and sinks of carbon in the oceans and
  land
• global surface and atmospheric temperature
• sea ice extent and change
• glacial retreat
• hurricanes
• Resource on Earth science, including news
  stories, images of the day, data sets, and
  natural hazards
• earthobservatory.nasa.gov

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The only way to have real success in science ...
is to describe the evidence very carefully
without regard to the way you feel it should be.
If you have a theory, you must try to explain
what's good about it and what's bad about it
equally. In science you learn a kind of standard
integrity and honesty. Richard Feynman
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What does it mean by extreme?
Extreme value distributions are often used to
model the smallest or largest value among a
large set of independent, identically distributed
random values representing measurements or
observations.
frequency
Extremes
Climate value
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Where are the extremes here?
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NOAA Extreme Weather and Climate Events
http//www.ncdc.noaa.gov/oa/climate/severeweather/
extremes.html