Extreme Weather Test #4
Measuring El Nino: SST- look for warm pool to develop near dateline Atmospheric Pressure -SOI-Southern Oscillation Index -Pressure at Tahiti-Pressure at Darwin, Aust. -Strongly (+) Index=____ ______ -Strongly (-) Index=____ ______ -Strongly defined as relative to ____
(+) = LA NINA (-) = EL NINO MEAN
ex: Lake Chad Drought in Africa
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do the majority of climate scientists agree that the global climate has warmed over the last century?
YES!!!!
Sunspots: Sunspots are huge magnetic storms that extend from the Sun's surface deep into the interior. They are associated with the Sun's ejections of huge masses of particles that, upon reaching Earth's upper atmosphere interact with gases there. Sunspots and temperature? Sunspots and drought?
**sunspots have no correlation with increase in temperature**
Worst El Nino's on Record: 1. Forecasters expected the El Nino in the summer of 1997 to displace the paths of the subtropical jet and the polar jet streams. Which are responsible for steering much of the weather systems across the U.S. 2. As predicted the shift in the subtropical jet brought rain to the Gulf Coast. -Tampa received more than 3x its normal winter precipitation 3. The shift in the jet streams also caused HIGHER than normal temps EAST of the rockies
*1997/98 El Nino* (brought ton of wet weather S.E. USA, WET & COOL) (Philippines drier than normal, DRIER & WARMER)
*El Nino* SOI= Tahiti mslp - Darwin mslp = HIGH-LOW = slightly positive
*La Nina* SOI= Tahiti mslp - Darwin mslp = HIGH-LOW=strongly positive
Does climate change lead to more extreme weather events? hurricanes? tornadoes? severe thunderstorms? drought?
*break record higher temps (over 2x higher) than record low temps*
Defining the Tropics: -latitude ____N to ____S -Koeppen (1936) coldest month above 18C (64F) -____annual temperature ____ -axis of subtropical high pressure cells -ITCZ migrates thru tropics -areas where irrigation is ____ needed
-23.5 N to 23.5 S -Low, Range -not *not much variability, always hot*
Monsoon Mechanisms: -_______/_______ temperature contrast -____ humidity -___________ uplift -Differ from Land/Sea breezes -------spatially-___________ -------temporally-_________
-Land/Ocean -HIGH -OROGRAPHIC Spatially-occur over thousands of km Temporally-have an annual time scale
Normal Ocean Conditions: -During normal years the atmospheric circulation in the tropical pacific is dominated by ______ ________ _______. -These strong _______ _______ generate a strong equatorial current that flows westward from South America toward Australia. -The ___________ ________ Current causes a large upwelling of cold water along the WEST COAST of South America
-Strong trade winds - trade winds -Peruvian Ocean
**Normal Weather Conditions: WALKER CIRCULATION CELL: water flow in pacific *LOOK AT PICTURE/DIAGRAM pg236
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Cause of Death: -difficult to estimate heat mortality relationship because of health impacts of heat -Heat deaths often coded as something else -Heat related deaths often under reported -Need to use excess mortality
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Definition of a Heat Wave: -numerous definitions have been developed -ultimately varies by geographical location & level of population variability
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El Nino Conditions: Reversed water flow of pressure system West--------->>>East of Pacific pg 238 2 pictures
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GHG's & the Ozone Layer: 1. As a corollary to increased GHGs the STRATOSPHERE may COOL as GHGs trap heat in lower atmosphere 2. Lower temperatures catalyze reactions that destroy ozone in the stratosphere 3. Ozone is important for blocking harmful UV radiation
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Heat & Health: -CDC attributes 688 deaths per year directly to heat wave events. Greater than combo of other extreme events -# may be larger due to exacerbation of pre-existing conditions or co-morbidities -Heat places stress on susceptible populations -Lack of public awareness (silent killer)
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IPCC - intergovernmental panel on climate change --> best understanding of future climate change in a report
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Intro to Climate Change: -throughout time, the earth's climate has always been changing -We have seen the variations in climate patterns in ice cores, tree rings, etc. -Avg global temps are becoming warmer -The big question recently has been "Is there an anthropogenic influence on climate change?"
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La Nina: -opposite of el nino -researchers have come to recognize than when surface temps in the PACIFIC are COLDER than average, a La Nina event is triggered!
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Look at pg 265 "What we know about Climate Change"
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Mayan Civilization: -19 million people -converted forest to agriculture Christopher Columbus (~500): -brought diseases that killed large portion of native population -
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More moisture, more snowfall under global climate warming.
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Risk Factors for Hyperthermia: (individual to community) 1. Age/gender 2. Pre-existing medical conditions/mental illness 3. income & poverty status (SES) 4. Homelessness 5. Social Isolation 6. Access to health care & cooling technology/facilities 7. Neighborhood characteristics: land use/cover, crime rate, housing type, urban heat island
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Understanding Past Climates: 1. Ocean Floor Sediments 2. Oxygen Isotope Analysis 3. Dendrochronology 4. Ice Cores
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Volcanic Activity: -Explosive eruptions emit huge quantities of gases and fine-grained debris into the atmosphere. -The greatest eruptions are sufficiently powerful to inject material high into the stratosphere, where it spreads around the globe and remains for many months or years -Three major eruptions have provided considerable insight regarding the impact of volcanoes on global temperatures
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Worst La Nina's on Record: *Winter, 1989-90* 1. A world record snowfall for one season occurred in Washington State. 2. Also brought record breaking flooding to the Sudan, Bangladesh, & Thailand. 3. Australia had one of the driest winters on record which was sandwiched btwn two intensive rainfall events.
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pic on pg. 234 Winter vs. Summer Monsoon WINTER: Cold Continent, Dry air, High pressure arrows leaving continent SUMMER: Hot continent, Moist air, Low pressure arrows coming towards continent
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pic pg. 235 Summer Monsoon
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Sea-Level Rise Projections: a few inches to a few feet 1. 2ft: US would lose______square miles 2. 3ft: Would inundate______ 3. Affects _____, loss of ______, ______supplies 4. _____ of the world's population lives along coasts 5. Big question: ___ ______
1. 10,000 2. Miami 3. erosion, wetlands, freshwater 4. Half 5. ice sheets
Drought: 1. Remember: just because we see an increase in global temp in recent times DOES NOT mean that less precipitation is occurring globally. 2. There are regions around the world that are experiencing more precipitation as a result of climate change. 3. And some regions that are experiencing less precipitation because of the warmer conditions.
1. DOES NOT
Weather on Steroids!: 1. _______ ______ (primarily CO2) act like steroids for the climate system 2. _____ increase global mean temp & the probability of extreme heat 3. Not necessarily causing every extreme but certainly making extremes more likely. 4. Loaded dice example.
1. Greenhouse Gases 2. GHG's
Tornadoes: 1. ____systematic change in the frequency of tornadoes (Houghton 2001) 2. But the models and tornado records seem to tell a different story
1. NO
Oxygen Isotope Analysis: 1. Analysis is based on the ratio of ____ to ____. 2. A molecule of water can produce either of these isotopes 3. But the lighter isotope, ______, evaporates more readily from the oceans. This leaves a _____ concentration of the heavier isotope in the ocean water. 4. Hence, during a warm period, the relative amount of _____ will increase in the ocean waters since more ______ is evaporating.
1. O16 to O18 3. O16, greater 4. O18, O16 is evaporating
What we know but cannot quantify about climate change: 1. Deforestation will affect________rates 2. Climate change will ______ our vulnerability to extreme events 3. The distribution & frequency of _______ will change 4. The major ocean_______ will shift or breakdown 5. Mitigation and policy implementation will ____ a lot 6. Oceans play a major role in the ______cycle
1. PRECIPITATION 2. INCREASE 3. DISEASE 4. CURRENTS 5. COST 6. CARBON
Predicting El Nino & La Nina: 1. _________ -provide data on tropical rainfall, wind, and ocean temp patterns, as well as changes in conditions for hurricane formation. 2. ________ _______ -help to monitor sea-surface and upper ocean temps 3. __________ -balloon-borne instrument platforms with radio transmitting capabilities, help to monitor global weather and climate patterns 4. _________ ________ -gather all the weather data around the world and put it into useful formats used by scientists -Run models for future change
1. Satelites 2. Ocean Buoys 3. Radiosondes 4. Super Computers
2007 Conclusions: 1. Warming of the climate system is _______ . 2. Very HIGH CONFIDENCE that global average net effect of human activities since 1750 one of warming. 3. Human-caused warming over last 30 years has ______ had a visible influence on many physical and biological systems. 4. Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would ______ ______ be larger than those observed during the 20th century.
1. unequivocal (as certain as 99%) 2. very high confidence (at least 95%) 3. likely (human warming's affected physical and biological systems) 4. very likely (same emissions or more makes planet worse damage than what we've seen)
Severe Thunderstorms: 1. Climate change is affecting air quality to an ________extent, which may in turn increase the number of thunderstorms/supercell events 2. _______ activity is________correlated with _____ ______, and due to projections of a warmer climate in the future, one of the key questions that is yet to be answered is how will lightning and severe thunderstorms be affected.
1. unknown 2. lightning, positively, surface temps
Hurricanes: 1. Higher sea surface temperature ____ increase the number/intensity of hurricanes 2. Developed & underdeveloped countries are ______vulnerable to hurricane strikes due to an increase in coastal _______. 3. Category 6 hurricane?
1. will 2. more, populations
Characteristics of Monsoon Regions: -prevailing wind direction shift minimum ______ degrees btwn January and July - average frequency of prevailing directions in January and July exceeds 40% (aka________) -Mean resultant winds in at least one month exceeds 3 m/s = 7mph
120 degrees aka winds constantly coming from the same direction
________-> year without a SUMMER
1816
Ice Cores:(look @ CO2 in atmosphere) 1. Cores are extracted from oil type drilling rigs 2. Cores can reach up to ______ meters (6500ft) in length and may represent more than _______ years of climate history. 3. Air bubbles are trapped in the ice record variations in ___________ ____________ 4. These cores can detect changes to _____ ______, _______, & ________ _______
2. 2000 meters; 200,000 years 3. ATMOSPHERIC COMPOSITION 4. AIR TEMPERATURE, METHANE, CARBON DIOXIDE
Ocean Floor Sediments: 1. Research vessels produce sediment profiles from the bottom of the ocean 2. The sediment contains ______ __________shells from living organisms that have lived near the earth's surface in the past. 3. The type of _________ _________ shell can tell you something about the __________ since these organisms live only within _______ temp ranges.
2. CALCIUM CARBONATE 3. CALCIUM CARBONATE, TEMPERATURE, NARROW
Variations in Earth's Orbit: 1. Eccentricity 2. Precession- 3. Obliquity-
2. how we're sitting on axis 3. angle of tilt on axis 23.5
"__________ Global Warming" : predicted temps would increase gradually (was right) predictions vs. observations
BROECKER'S
What changes climate?
Changes in: 1. Suns output 2. Earth's output 3. Drifting continents 4. Volcanic eruptions 5. Greenhouse gases
Effects of El Nino: -the effects of El Nino are somewhat variable depending on the temp and size of the warm countercurrent.
Consistent Effects of El Nino Include: 1. Warmer than normal winters in the Northern US & Canada 2. Cooler than normal winters in the Southwest & Southeast US 3. The Eastern US, Peru, Chile and Western Europe experience wetter-than normal conditions 4. Drought conditions are generally observed in Indonesia, Australia, Africa, Central Americas and the Philippines 5. Suppression of the number of Atlantic Hurricanes
_______________: 1. Each year a tree produces one ring (growth ring) 2. The distance btwn each tree ring can tell you something about the _______ & _________ patterns. 3. Not all trees are suitable for dendro! ________ ring=DRY _______ ring = WET
Dendochronology 2. Temperature & Moisture SMALLER BIGGER
Southern Oscillation: no longer Walker Oscillation Researchers now typically call El Nino events: _____ _____ ______ ____ (ENSO)
El Nino Southern Oscillation
Hurricanes: 1. ___ _____ contributes to ______ eastern Pacific hurricanes and _______ Atlantic hurricanes. 2. ___ ______ contributes to _____ eastern Pacific hurricanes and _____ Atlantic Hurricanes
El Nino, more eastern Pacific, FEWER ATLANTIC La Nina, fewer eastern Pacific, MORE ATLANTIC
Typical Weather Events: El Nino- jet streams aren't stopped La Nina- atmospheric block, jet stream is curved
El Nino: Low pressure ----------->>> La Nina: High pressure (Curved jet stream)
True or False. The Larsen-B ice shelf, Greenland, and Patagonia are starting to recover some of the sea ice they have lost in the last 20 years.
False
_______ _______: climate plays a major role in vegetation distribution. By analyzing pollen from fossils, it is possible to obtain high-resolution records of vegetation changes in an area. _________: Corals build their hard skeletons from calcium carbonate extracted from sea water. The carbonate contains isotopes of oxygen can be used to determine the temp of the water in which the coral grew. _____ _______: Writing, art work, architecture Climate Patterns: _______, _______,& _______ ______
Fossil Pollen Coral Historic Data Climate Patterns: precipitation, temperature, & greenhouse gases
______ suffer more than _____ from heat wave. Till 65 even.
Guys, girls
Spread of Cholera has _______ through time because of ________ & _______.
INCREASED, drought & flooding
__ _______ -> less wind shear Gulf of Mexico
La Nina
Regional Circulations in the Tropics: Seasonal (regular):_________(happens every year) Non-Seasonal (irregular): _______Circulation (ENSO) (not every year, ex: EL NINO every 3-7 yr)
MONSOON-yearly WALKER CIRCULATION - not every year
what is obliquity?
Milankovitch Cycles cycle1: eccentricity or shape of Earth's orbit around sun. Over 100,000 years shape changes from nearly circular to elliptical and back. cycle2: precession of Earth on its axis, or "wobble." Like a spinning top. the axis turns with about a 26,000 year cycle. 11,000 years fro now, the southern hemisphere will be closer to the sun in July. cycle3: obliquity or angle of the axis to the ecliptic (now 23.5degrees) varies from 22 to 24.5 over a 40,000 year cycle. cycle 4: variation of time of aphelion and perihelion cycle over 18,000 years. all of these change isolation- seasonality - coooler summers= more ice accumulation
what is occuring if the SOI is strongly positive?
SOI=TahitiMSLP-DarwinMSLP=high-low=positive See chart
Is there an anthropogenic influence on climate change?
See Graph
Potential Effects of Climate Change: to numerous to talk about them all.
These effects include: 1. impact to human health (disease, respiratory illness) 2. Ecological impacts (changes to thickness, type and distribution of vegetation. Also changes to home range of animal) 3. Changes in Sea Level 4. Change to temperature and precipitation patterns 5. Increase economic and cultural vulnerability 6. Changes to glacial and sea ice distribution 7. Breakdown or shift in the THERMOHALINE
Is climate change human induced or a natural cycle? Facts: 1. **The industrialization era has resulted in greater concentrations of CARBON DIOXIDE and other greenhouse gases in the atmosphere** 2. The use of fire and overgrazing of marginal lands by domesticated animals have both reduced the abundance and distribution of vegetation. 3. This change in vegetation results in changes to ______, ________ rates, & _______ patterns.
This is a question that is NOT up for debate. People have been modifying the environment/ climate for THOUSANDS of years. 3. ALBEDO, EVAPORATION RATES, & WIND PATTERNS
Greenhouse Gases:
Water vapor Carbon Dioxide Methane Nitrous Oxide Sulfur Hexafluoride
what have scientists used to determine past climate fluctuations?
artwork architecture fossilized pollen ocean sediments tree cores (dendrochronology) lake sediments oxygen isotopes
Origins of El Nino: -During the 19th century locals along the Peru coast named the warm countercurrent El Nino -Means the ____ _____ due to its origin around Christmas
boy child
Melting Permafrost: What's permafrost? -permanent frozen ground -24% of land in NH -As deep as 1400m -Holds massive amounts of _____ -2009 estimation: 1400-1700GT Carbon (more than currently exists in all living things & 2x as much carbon as in atmosphere) -increased GHG emissions: mainly METHANE (CH4) - over 80X more effective in trapping heat than CO2
carbon
Does the impact of heat waves vary?
chart
how often do strong ENSO conditions occurs?
every 3-7 years
El Nino: -near the end of each year a warm countercurrent, which flows eastward along the equator develops. Resulting in warm water accumulations along the coasts of Ecuador and Peru -Lasts only a ____ _____ -At irregular intervals of __ to ___ yrs, these warm countercurrents become unusually strong and replace the normally cold waters offshore of South America -Today the term El Nino Southern Oscillation is used by scientists to mark unusually strong warm ocean countercurrents and a reversal of pressure systems.
few weeks 3 to 7 yrs
Increasing greenhouse gases trap more ______.
heat
Greenhouse gases are outgoing ________ radiation. _______ methane leads to ______ warming.
longwave increased, increased
El Nino contributes to ______ eastern Pacific hurricanes. La Nina Contributes to ______ eastern Pacific hurricanes.
more fewer
what physical changes occur in the Pacific under ENSO conditions?
pressure patterns reverse and warm ocean counter currents develop CHARTS
How do greenhouse gases heat the planet?
see chart
T/F Records of past climate indicate that carbon dioxide levels have been as high as current levels.
see chart
explain the mechanisms behind the Monsoon?
see chart
what is the name of the circulation pattern associated with ENSO?
see chart
how do changes in temperature means and variance affect extremes?
see charts
Tornado Activity: -Depends on the location of the polar jet stream (and thus the location and movement of mid-latitude cyclones) -El Nino: more to the _______ -La Nina: more to the _____
south north
What physical conditions are generally present during the heat wave?
summertime (high insolation) high pressure (little rain or cloud) high humidity movement of warm and moist air masses into area Urban location (UHI)
Solar Variability: -among the most persistent hypotheses of climate change have been those based on the idea that the SUN is a variable star and that its output of energy VARIES through time -Seems Logical: increases in SOLAR OUTPUT would cause the atmosphere to _______, and reductions would result in ______ -However, no major long term variations in total intensity have ever been recorded
warm, cooling
What are the effects of El Nino on weather around the globe?
warmer than normal winters in the Northern US and Canada cooler than normal winters in the Southwest and Southeast US The Eastern US, Peru, Chile and Western Europe experience wetter-than normal conditions drought conditions are generally observed in Indonesia, Australia, Africa, Central America and the Philippines Suppression of the number of Atlantic Hurricanes
El Nino- ______ Aleutian High La Nina- ______ Aleutian High
weak strong
