Transcript Tornado Frequency by Decade - Student Research Libraries

Tornados and Climate Change
Michael Pateman
And
Drew Vankat
Introduction
• Investigation of tornadic frequency and
magnitude in the United States in relation to
the El Nino/Southern Oscillation and US
climate change
Hypothesis
• Global warming, along with increased El Nino
and La Nina cycles mean more plentiful and
powerful tornadoes
• But…What role does technology play in
increased detection?
Research Relevance
• If a relationship with climate cycles can be found, perhaps emergency
funding can be set aside in advance for victims
• Findings can be translated to other weather phenomena such as
thunderstorms, flooding, or hurricanes
• Authorities can take necessary precautions to minimize economic and
human losses
• Provide a more convincing argument for the need to rethink the way
we treat our environment.
What is a tornado?
• An intense, rotating column of air extending from the base
of a thunderstorm cloud to the ground.
www.spc.noaa.gov
ENSO
• The ENSO (El Nino/
Southern Oscillation) cycle
refers to the coherent, largescale fluctuation of ocean
temperatures, rainfall,
atmospheric circulation,
vertical motion and air
pressure across the tropical
Pacific.
http://www.cpc.ncep.noaa.gov/
What is El Nino?
• A disruption of the ocean-atmosphere system in
the Tropical Pacific
• Development of abnormally warm sea surface
temperatures across the eastern tropical Pacific
• Consequences can include increased rainfall in
some areas and extreme drought in others
What is La Nina?
• Characterized by unusually cold ocean temperatures
in the Equatorial Pacific
• USA: warmer southwest winters, colder Northwest
Materials and methods
• Data retrieved on tornado and ENSO
activity
• Downloaded into Excel, Statview, and
Cricket Graph
Tornado Frequency by Decade
Spearman Rank Correlation p-values:
Texas-Nebraska p=.1096
Texas-Ohio p=.0719
Nebraska-Ohio p=.0719
Frequency of Tornadoes in El-Nino Years
Spearman Rank Correlation p-values:
Texas-Nebraska p=.4902
Texas-Ohio p=.1837
Texas-USA p=.0170
Nebraska-Ohio p=1983
Nebraska-USA p=.0785
Ohio-USA p=.1223
Tornado Frequency in non-El-Nino Years
Spearman Rank Correlation p-values:
Texas-Nebraska p=.1096
Texas-Ohio p=.1615
Texas-USA p=.0719
Nebraska-Ohio p=.3173
Nebraska-USA p=.2301
Ohio-USA p=.0719
Tornado Frequency in La Nina Years
Spearman Rank Correlation p-values:
Texas-Nebraska p=.0422
Texas-Ohio p=.1474
Texas-USA p=.0376
Nebraska-Ohio p=.1117
Nebraska-USA p=.0751
Ohio-USA p=.0438
Tornado Frequency in
non-La-Nina Years
Spearman Rank Correlation p-values:
Texas-Nebraska p=.0719
Texas-Ohio p=.0719
Texas-USA p=.0455
Nebraska-Ohio p=.1096
Nebraska-USA p=.0719
Ohio-USA p=.0719
Texas Tornado Frequency
350
300
Count
250
200
150
100
50
0
1950
1960
1970
1980
Year
1990
2000
Nebraska Tornado Frequency
120
100
Count
80
60
40
20
0
1950
1960
1970
1980
Year
1990
2000
Ohio Tornado Frequency
70
60
Count
50
40
30
20
10
0
1950
1960
1970
1980
year
1990
2000
Data
• http://www4.ncdc.noaa.gov/cgiwin/wwcgi.dll?wwEvent~Storms
• All Tornado Data downloaded from this
site.
Tentative conclusions
• Overall increase in tornado frequency
• P-values indicate little relationship in
frequency for El-Nino years
• P-Values indicate a relationship in
frequency for La-Nina years
Still To Come…
• Spearman Rank Correlations for tornado
frequency per year in each state
• Analyze magnitude
Future Research
• Incorporate climate change and global
warming
• Any questions or suggestions?