Atmospheric Natural Disasters Flashcards
What is the difference between High and Low Pressure?
H: pushes air down + anticyclone + hot/dry
L: Air rises up + cyclone + wet
What weather is caused by High Pressure?
heat waves + droughts (hot/dry events)
What weather is caused by Low Pressure?
Wet events
What influences high temperatures?
Insolation, albedo, humidity, heat waves
What is the most deadly meteorological natural disaster?
heat waves
Where is the Hadley Cell? Describe some of its characteristics.
around the equator, hot Air moves to the left, the equator become a band of LP, and the other end of the cells is a band of HP
Where is the Ferrel Cell? Describe some of its characteristics.
The middle cells (US is in this one)
Hot air moves to the right
Polar air sinks down
Where is the Polar Cell? Describe some of its characteristics.
Colder air sinks from the poles
What is the Coriolis Effect?
Spin of the earth causing wind to bend
What is a Temperature Inversion?
Descending cold air
Describe air in the Northern Hemisphere
Low pressure goes counterclockwise, curving to the right
High pressure goes clockwise, curving to the left
What causes a drought?
Lots of HP with little rainfall
What is a rainshadow? What causes it?
a patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather.
Describe the Anasazi Drought of 1267
23 year drought that led to the abandonment of Mesa Verde Pueblos
What caused the downfall of the Mayan Civilization? (760-910 CE)
Systemic ecological collapse due to deforestation, siltation, decline of biodiversity, and drought
Describe the Dust Bowl (1931-1939)
Affected 75% of the US
Poor agricultural practices, high temps, low rainfall, and high winds
How did the Sahara Desert form?
Cyclical change from tropical to desert due to periodic climate change
Describe the Atacama Desert
Oldest + driest hot desert in the world
Caused by a rainshadow, inversion layer, HP anticyclone, and is on the Hadley+Ferrel Cell boundary
How do deserts expand? How can that expansion be accelerated?
- When there are extended amounts of HP
- Rapid anthropogenic global warming
What is fire season?
combo of carbon, hydrogen, oxygen, and heat
What percentage of fires are caused by lightning? What percentage by humans?
L: 15%
H: 85%
What is fire?
Photosynthesis in reverse
What ecosystems are fires necessary in?
all but tropical rainforests and deserts
What contributes to fire weather?
Hot sunny days, topography, warm dry winds, drought conditions
Describe the Greek Forest Fires of 2007, 2018, and 2021
2007: 84 dead
2018: caused by a man and wind spread it, 102 dead
2021: Heat wave caused it, 3 dead
Describe the Australia drought & bushfires of 1939, 2009, and 2019-2020
1939: Black Friday bushfire (71 dead)
2009: Black Saturday bushfire (180 dead)
2019-2020: 33 humans dead, over 3 billion animal deaths
Describe California’s drought & wildfire history
accelerating
What percentage of people are killed in wet weather disasters?
66%
What atmospheric processes have to do with Temperature?
Insolation, albedo, circulation
What atmospheric processes have to do with Pressure?
LP: unstable air
HP: stable air
What atmospheric processes have to do with Water?
Humidity, precipitation, and dew point
Latent Heat of phase change
What is the difference between stable and unstable air?
Stable = HP
Unstable = LP
What is seasonal precipitation?
Temp dependent
What is fog?
A cloud touching the Earth
What is rain?
Drop of water with enough mass to reach the surface of the Earth
What is an ice storm?
Super-cooled rain that freezes when it touches a frozen surface
What is frost?
dew that freezes in air and deposits on surfaces
What is snow/hail/sleet?
a crystallized drop of water with enough mass to gravitationally fall to the earth while frozen
How does El Nino affect the Pacific Ocean temperature? The Western Americas? SE Asia and Australia?
PO: warms it
WA: LP
SE A & A: HP
How does La Nina affect the Pacific Ocean temperature? The Western Americas? SE Asia and Australia?
PO: cools it
WA: HP
SE A & A: LP
What is the Polar Jet stream? Describe how it changes in Winter and in Summer.
The current of fast-moving air in the upper troposphere
Winter: winds at 125 km/hr, moves more south
Summer: winds at 60 km/hr, moves more north
What are the two types of moisture content?
continental (dry)
maritime (moist)
What are the three types of temperatures of air masses?
tropical (warm)
polar (cold)
arctic (extremely cold)
What are the source regions of the Continental Arctic (cA) air mass?
Highest latitudes in Asia, North America, Greenland, and Antarctica
What are the source regions of Continental Polar (cP) air mass?
High-latitude continental interiors
What are the source regions of Maritime Polar (mP) air mass?
High-latitude oceans
What are the source regions of Continental Tropical (cT) air mass?
Low-latitude oceans
What are the source regions of Maritime Tropical (mT) air mass?
subtopical oceans
What is a Warm Front?
Warm air pushes into area with cold air
Slow rise of warm air, causing thickening clouds and moderate rainfall
What is a Cold Front?
Cold air pushes beneath warm air
Fast rise of warm air causing the formation of cumulonimbus clouds, heavy rain, thunderstorms
What is an Occluded Front?
closure of front, cutting off warm air mass from the surface
Describe the Winter of Terror 1951
649 avalanches
265 dead
3-4.5 m of snow in 2-3 days
Steep topography
Describe the Blizzards of 1885-1888
Blizzard with 35 mph winds for 3+ hours
Nor’eassterly winds sunk ships
50 inches of snow from 1 storm
cattle froze
extreme flooding
Caused by Krakatoa
Deadliest Blizzard Iran 1972
Deadliest blizzard
26 feet of snow in 6 days
Buried 4000 people, trapped thousands
How does a thunderstorm happen?
warm humid air rises causing the formation of cumulonimbus clouds
What are the wind speed and hail size of a severe thunderstorm?
Wind: speed more than 58 mph
hail: more than 0.75 inches
What is a supercell?
single, extremely powerful storm cell
What do updrafts and downdrafts do?
bend and wrap around and amplify each
they form and carry hail
What is a downburst?
strong downdrafts with wind gusts of more than 270kph
What is a Gust Front?
when downdrafts reach the ground and surge forward
What are Mesoscale Convective Complexes (MCC)?
circular, organized systems of several thunderstorms
What are mesocyclones?
vortex of air around 2-10km in diameter
air rises and rotates around a vertical axis
-> rotating wall cloud protrudes down
What are Funnel Clouds?
narrow, rapidly rotating vortex does not touch down
How is Lightning generated?
charge separation
What is a tornado?
constricts mesocyclone to several hundred meters across & touches down -> extreme P chang over short timespan
What is a water spout? Where do they occur?
Smaller tornados that never reach land
occur over warm water
What scale is used to determine the intensity of a tornado?
Enhanced Fujita Scale (EF Scale) 0-5
Severe thunderstorm watch vs warning
Watch: situation conducive to tornado formation
Warning: severe thunderstorm has developed
Define Doppler radar
used to detect supercells
What is a Hook & vault formation?
often means tornado formation is imminent
Deadliest tornado Bangladesh 1989
F4 struck 2 large cities
1300 dead
around 80000 homeless
after 6 months of drought
What country has the most tornados? Why is that the case?
US
Clash of maritime tropical and continental polar air, midwest is flat land (no E-W mountain ranges)
Describe the Tri-State Tornado 1925
F5, deadliest in US history (695 dead)
Missouri, Illinois, Indiana
$16.5 million in damages
Describe the Joplin Tornado 2011
F5, more than a mile wide
Winds at 250 mph
158 dead
$2.8 million in damages and $2.2 insurance payout
What is the difference between hurricanes, cyclones, and typhoons?
Location
H: Atlantic
C: Indian Ocean and Australia
T: SE Asia and W Pacific
Where do hurricanes get most of their energy from?
Deep layer of warm water that is more than 27C/81F that fuels latent heat of condensation
Describe the Northern vs. Southern hemisphere hurricane season
N: Primarily Aug and Sept
S: Primarily Jan to Mar
Define tropical disturbances
disorganized groups of thunderstorms with weak P gradients and little to no rotation
Define Easterly waves
The origin of most W Atlantic tropical disturbances that become hurricanes.
Large undulations/ripples in the normal trade wind pattern
Define Tropical depression
a tropical disturbance develops so that there is 1 or more closed isobar on a weather map
Define tropical storm
depression that intensifies further and maintains wind speeds above 60 km/hr
How is the Coriolis effect involved with hurricane formation?
it is required for hurricanes to form
This is why no hurricanes form at the equator
What is the sea level pressure of a normal hurricane?
950mb
For each millibar of pressure decrease, there is 1 cm of sea level rise
Describe the eye of a hurrricane
average 20 miles in diameter
region of HP that lasts 1-2 hrs
Describe the eye wall
margin of the eye
zone of most intense storm activity with the strongest winds, thickest clouds, and most intense precipitation
Define hot towers
located in some eye walls
localized portions of the eye wall that rise up to 7 mi high
indicate that the storm will intensify within 6 hrs
What can be inferred from a shrinking eye?
An intensifying storm that is reaching its max strength
What is emerging land?
tectonic uplift or falling sea level (erosion -> mass wasting)
What is submerging land?
tectonic subsidence or rising sea level (deposition -> flooding)
What is subsidence?
land decreasing in elevation tectonically
What causes Sea Level Rise?
atmospheric warming, ocean warming, melting land ice + permafrost, and tectonic divergence rate
What causes land subsidence?
withdrawl of groundwater, oil, natural gas, magma, and lava
permafrost melt
freeze-thaw and shrink-swell cycles
mine collapse
cave formation and collapse
drought
What are storm surges?
a rise in water level due to a hurricane moving landward, in the N hemisphere on the E side, winds are in the same direction as the movement of the storm, so storm surge is greater
What other disaster is associated with hurricanes?
tornados
What are the benefits of hurricanes?
major source of water
carry life forms long distances
stir up nutrients
regenerate ecosystems
What are the hazards of hurricanes?
extreme flooding
hazardous flying debris
water contamination
coastal erosion
How do you end a hurricane?
eliminate its energy source
Hurricane watch vs warning
Watch: a prediction that an approaching hurricane will approach land in more than 24 hours
Warning: it is expected to make landfall over the US within 24 hours
What is the Saffir-Simpson scale?
classifies hurricanes into 5 categories
Describe the 1900 Galveston TX Hurricane
Deadliest US hurricane (around 8000 dead)
Storm surge was 8-12 ft
Category 4
Describe the deadliest hurricane: Bhola Cyclone 1970
Category 4
500,000 dead
115 mph winds
gusts of 150 mph
storm surge flooded Gages Delta
Describe Hurricane Mitch 1998
Category 5
180 mph winds
around 19,000 (Honduras had 7,000 of those deaths)
Describe Typhoon Yunya 1991
Category 3
At the same time that V6 Mount Pinatubo erupted
Describe Hurricane Katrina 2005
Category 5
1836 dead
$125 billion in damage
flooded 80% of New Orleans
What is Karst topography?
sinkholes and caves form as acidic groundwater erodes subsurface rocks and soil
What is a sinkhole?
cave roof collapses
What percentage of the US land is coastal?
10%
What percentage of the US population lives on the coast?
40%
Tectonically passive vs active
Passive = subsiding
Active = uplift
What is the erosion rate influenced by?
type of bedrock
tidal range
wave exposure
weather
earthquakes
uplift + subsidence
Describe the Atlantic coast
wide tidal range
has the most coasts that are open to wave erosion (2.6 ft/yr)
varied bedrock (resistant and non-resistant)
barrier islands are common
sea level rise ~1 ft/century
Describe the Gulf of Mexico coast
narrow tidal range
low wave energy
non-resistant rocks
tectonic subsidence
Mississippi river delta dominates
6 ft/yr of erosion
Describe the Pacific coast
tectonic uplift
mostly non-resistant rock
high energy waves
mid-level tidal range
0.016 ft/yr of erosion
Describe the Great Lakes shorelines
7ft fluctuation since 1860
tectonic uplift
What causes sea coast flooding?
tsunami
high tide
wind
sea level rise
low barometric pressure
What is the tide range?
high minus low tide
What are spring tides?
Earth, moon, sun in alignment (new and full moons) = max high tides and wide tidal range
What are neap tides?
Earth, moon, sun at a right angle (1st and 3rd quarter moons) = min high tides and most restricted tidal range
What causes surface waves? What determines wave intensity?
wind
wind velocity
What is a rogue wave?
more than 2 times the size of surrounding waves
What are breaker waves?
When a wave touches the seafloor at 1/2 wavelength, bottom of the wave slows due to friction, wavelength begins to decrease, wave height begins to increase, top of wave falls over and breaks
What is a rip current?
move away from the shore to balance water moving towards the shore
What causes erosion on headlands?
wave refraction
What is beach drift?
the direction of sand flowing down current
What eventually happens to irregular coastlines?
smooth out over time with erosion
What are atolls?
a ring-shaped reef, island, or chain of islands formed of coral that act as a wave break
What happens when the rock grain is parallel to the coast?
protects the coast and forms long beaches
What happens when the rock grain is perpendicular to the coast?
more inland flooding
What does the longshore current direction determine?
where erosion and deposition occur
the movement of sand, oil, nutrients, and boats
used to prevent erosion, determine land use planning, promote ecosystem health
What are the differences between Bay Barriers, Tombolos, and Spits?
Bay Barrier: Coastal barriers that connect two headlands, and enclose a pond, marsh, or another aquatic habitat.
Tombolo: a deposition landform by which an island becomes attached to the mainland by a narrow piece of land
Spit: a deposition bar or beach landform off coasts or lake shores
Describe the Barrier Island system
Along the Atlantic coast, protects the land behind it
What is a rip rap?
large rocks too big for waves to move
protects terrace base
What is a seawall?
protect what’s behind them only
What is a beach groin?
Groins are shore perpendicular structures, used to maintain updrift beaches or to restrict longshore sediment transport.
What is a jettie?
A jetty is a long, narrow structure that protects a coastline from the currents and tides.
What is a breakwater?
a barrier built out into a body of water to protect a coast or harbor from the force of waves.
What can limit erosion?
natural and man-made dunes
What are the damages of beach nourishment?
Big ships would vacuum sand from the bottom of the ocean (including ecosystems down there) and just shoot it to fill in beaches. This is a flawed system because not only does it destroy ecosystems, but it is a temporary fix to a big problem. It’s just going to erode away anyway.
What administrations monitor the weather?
National Weather Service (NWS)
National Oceanic & Atmospheric Administration (NOAA)
What is a Drainage basin?
River tributaries propagate toward lower elevations linking together as a watershed that begins at the headwaters
What happens with tributaries as elevation decreases?
tributaries increase in width & depth & floodplain area
Describe high gradient rivers
steep slope
mostly erosional
lots of landslides & debris flow
Describe alluvial fans
when rivers transition from high to low gradient
distributaries distribute the water among multiple drainages
Describe floodplains (low-gradient rivers)
depositional area = loose sediment = more intense shaking during an earthquake
What types of channels form on floodplains?
meandering: erosion & deposition on bends
braided: lots of deposition
What is a distributary? What are the two types? Describe them
when a channel divides & distributes across a larger area. deposition dominates = flooding
Delta: a depositional landform
created by the entrance of a river into an ocean, sea, desert, estuary, lake, or another river
Estuary: a semi-closed coastal body of water with one or more streams flowing into it and a free connection into the open sea
What causes river floods?
storm surges
heavy rain
rain on impermeable sufaces
snow and ice melt
failed levees and dams
What determines a flood probability?
a linear relationship between time and discharge
When do peak floods occur?
after peak rainfall
What is a Zone 1 flood?
steep: flash flooding, arid climates, dam/levee break
What is a Zone 2 flood?
downstream: storms inundate floodplain
What is a Zone 3 flood?
alluvial fans and deltas
What is a mega flood?
atmospheric rivers
What determines the damage and size of a flood?
length of storm, timing, infiltration conditions, topography, vegetation, humans
How do we decrease flood hazards?
create structures, reshape rivers, zoning/land use, preparation, evacuation
Describe 1800’s Worst flood: Johnstown PA 1889
South Fork Dam failure
2209 dead; 99 entire families
Describe the most destructive US flood: Great Mississippi flood of 1927
heavy rains
246 dead
led to the building of the largest system of levees and floodways
Describe the Deadliest flood in history: China 1931
4 million dead due to drowning, starvation, and disease
followed a 2 year drought and a bad winter with lots of snow, heavy rain made it melt
Describe Boulder CO 2013 flooding
extreme mass wasting and flooding
8 dead; 5 missing
on an alluvial fan
20+ inches of rain
Describe California mega flood Ark Storm 1862
worst storm to hit CA
Lots of damage to the point that CA declared bankruptcy
Recurrence interval of 100-200 years
Which part of a hurricane does the Department of Commerce propeller plane study to forecast hurricane development?
eye wall
Which organization decides evacuation orders during a US hurricane?
National Hurricane Center in Miami
Does land or water warm more quickly during the day, causing warm air to rise?
Land
In the northern hemisphere, winds are diverted to the __________.
Right
Describe Hurricane Sandy October 2012
95 mph winds and a record deluge flooded entire neighborhoods
How many people in the US are in harm’s way from hurricanes?
More than 47 million people from TX to MN
What are the conditions that allow clouds to form?
Impurities in the air known as cloud condensation nuclei are required to transform air into ice crystals forming clouds
What landform is the major source of atmospheric mineral dust?
Sahara Desert
How does the Sahara have the power to prevent hurricanes?
Arid air from the dust cuts off hurricane development
How often does Miami, FL experience large storms?
Every other year
How are buildings tested against hurricane winds?
They use 105 extremely powerful fans that blow air at 200 km/h that are at all angles
They add flaming winds and rain
How many people were killed by Hurricane Sandy? How much did the damage cost?
142 dead
50 billion dollars
Hurricanes are to ____________ what _______ are to winter.
Summer
Blizzards
Where do blizzards that impact Europe develop?
US
How are hurricanes & earthquakes connected? Which regions are most vulnerable to this connection?
Extreme precipitation can lead huge amounts of earth into the ocean, changing the pressure ratios in the ground and causing earthquakes
Haiti, Taiwan, Japan
How is Japan using technology to prevent typhoon destruction?
Huge pipes underground detur the flow of water underground and into the pacific ocean
When & where did the largest storm disaster occur on Earth?
1970 in eastern Pakistan
What was Project Storm Fury?
Tried to stop hurricanes by using silver iodide (spoiler alert, it didn’t work)
How does China modify the weather?
Tons of chemicals are sprayed into the air
How does Saharan dust affect the Amazon, ocean surface waters, and West African weather?
Trees thrive in the amazon with phosphorus and iron
Red tides that kill fish
Monsoons to Droughts in West Africa
How is lightning studied in Florida?
They launch a rocket with a spool of kevlar coated cooper wire to bring lightning to them
What major weather event threatens California?
The Arc Storm (big flood disaster with lots and lots of rain)
What weather changes are expected as a result of climate change?
Heat waves
Extreme rainfall
Storms
What is expected by the year 2070?
The world’s port cities will be more flooded