Midterm Flashcards
tornado
- a violently rotating column of air associated with extreme horizontal winds
latent heat
- the amount of heat that is either absorbed or released when a substance changes phases
conduction
- the transfer of heat through a substance by means of atomic or molecular interactions
- Relies on temperature differences, causing heat to flow through a substance from an area of greater temperature to an area of lesser temperature
convection
- the transfer of heat by the mass movement of a fluid, such as water or air
- important process for the transfer of atmospheric heat in thunderstorms and in the large-scale circulation of warm air away from the equator
radiation
- refers to wave-like energy that is emitted by any substance that possesses heat
atmosphere
- the thin gaseous envelope that
surrounds Earth - made up of gas molecules, suspended particles of solid and liquid, and falling precipitation
relative humidity
- the ratio of the water vapor present in the atmosphere to the maximum amount of water vapor that could be there for a given temperature
troposphere
- lowest layer of the atmosphere
- where we are
- boundary to the next layer is the tropopause
jet streams
- westerly winds (flowing from
west to east) that encircle the globe and play an important role in creating severe weather and controlling the
path of storms
Coriolis effect
- the apparent deflection of moving objects due to the Earth’s rotation
- happens because Earth, our frame of reference, rotates beneath the flowing air masses, causing a deflection of the wind to
the right or to the left - winds in the Northern Hemisphere are deflected to the right and blow in a
counterclockwise rotation around the low-pressure center
front
- the boundary between a cooler and warmer air mass
- called a cold front when cold air is moving into a mass of warm air and a warm front when the opposite occurs
Vertical wind shear
- produced by an increase in wind velocity with altitude, or change in the horizontal direction of wind with altitude, which causes a rolling motion—horizontal axis rotation—of the air in the lower troposphere
supercell storm
- The most damaging of all severe thunderstorms
- defined by the presence of an upward spiraling columnnof air—vertical axis rotation—known as a mesocyclone
lightening
- consists of flashes of light produced by
the discharge of millions of joules of electricity
hail-stones
- hard, rounded, or irregular pieces of ice
- produced by large thunderstorms
EF scale
- Enhanced Fujita
- assigns values to tornados based on a post-storm damage survey
blizzards
- severe winter storms in which large
amounts of falling or blowing snow are driven by high winds to create low visibilities for an extended period of time
ice storms
- prolonged periods of freezing rain, can
be more damaging than blizzards and just as dangerous
drought
- An extended period of unusually low precipitation that produces a temporary shortage of water for people, other animals, and plants
dust storms
- strong windstorms in which suspended dust that is carried by the wind reduces visibility for a significant period of time
heat waves
- prolonged periods of extreme heat that are both longer and hotter than normal
heat index
- measures the body’s perception of air temperature, which is greatly influenced by humidity
Urban heat island effect
- a local climatic condition in which a metropolitan area may become as much as 12°C (~22°F) warmer than the surrounding countryside
warning
- indicates that the area affected is in
danger, and people should take immediate action to protect themselves and others
wildfire
- a self-sustaining, rapid, high-temperature
biochemical oxidation reaction that releases heat, light, and other product
pyrolysis
- literally means “heat divided”
- a group of processes that chemically degrade the fuel
- ex: takes place when you scorch a piece of toast and turn it black
combustion
- begins with ignition
- marks the start of a set of processes
completely different from those related to preignition
hydrophobic layer
- a water repellant layer in the soil that is caused by an extremely hot fire
dry ravel
- the process where sediment moves downslope in dry weather following a wildfire
- moves sediments like sand, gravel, and organic material
sediment flushing
- sediment is flushed from the channel, leaving it much as it was before the fire
vegetation fire
- effects on vegetation are numerous, varied, and complex
wildland–urban interface
- the fringes of wetland
- more people are living here as human population increases
- Homes are built in undeveloped canyons and on wooded slopes susceptible to fire
fire regime
- includes (1) the types of fuel that are found in plant communities; (2) typical fire behavior as described by fire size,
intensity, and amount of biomass removed; and (3) the overall fire history of the area, including fire frequency and recurrence interval
prescribed burns
- a controlled fire that is intentionally set to manage land and resources
- counters the dangerous build up of fuel
red flag warnings
- issued by National Weather Service forecast offices when extreme fire conditions either are occurring or will take place in less than 24 hours
- alert people
cyclone
- an area or center of low atmospheric pressure characterized by rotating winds
- ex: Hurricane Sandy
tropical cyclones
- form over warm tropical or subtropical ocean water, typically between 5° and 20° latitude
- not associated with fronts
extratropical cyclones
- develop over land or water in temperate regions, typically between 30° and 70° latitude
- generally associated with fronts
and have cool central core
cyclone intensity
- usually indicated by their sustained wind speeds and lowest atmospheric pressure
hurricanes
- ## strong tropical cyclones
typhoons
- name for hurricanes n the Pacific Ocean west of the International
Dateline (180° longitude) and north of the equator
tropical cyclone
- general term for large thunderstorm complex with winds that circulate inward toward an area of atmospheric low pressure that has formed over warm tropical ocean water
tropical disturbance
- what most hurricanes start out as
- a large area of unsettled weather that is typically 200 to 600 km (~120 to 370 mi.) in diameter and has an organized mass of thunderstorms that persists for more than 24 hours
easterly waves
- North–south elongatated troughs that form over west Africa and migrate
westward across the Atlantic Ocean with the trade winds at a rate of 15–30 km (~10–20 mi.) per hour
tropical depression
- what a tropical disturbance may become if winds increase and spiral around the area of disturbed weather to form a low-pressure center
tropical storm
- what the depression is upgraded to once maximum sustained wind speeds increase to 63 km (~39 mi.) per hour
rains band
- The clouds that spiral around a hurricane
- contain numerous thunderstorms
eyewall
- innermost band of clouds that the most rainfall and winds happen in
North Atlantic Oscillation (NAO)
- A fluctuating atmospheric pressure
phenomenon in the North Atlantic Ocean that affects the flow of westerly winds in the midlatitudes primarily during winter months
overwash
- deposits that are formed by sand eroded from the beach and coastal sand dunes
that gets carried landward by the storm surge - form as broad fans or deltas at the end of
channels as the storm surge cuts through the beach and dunes perpendicular to the shoreline
sea cliff
- The landward extent of the beach that is a cliff
- called this along the seashore, but a bluff along a lakeshore
relative sea level
- the position of the sea at seashore
- Influenced by both the movement of the land and the movement of the water
eustatic sea level
- also called global sea level
- Controlled by processes that affect the overall volume of water in the ocean and
the shape of the ocean basins
rip currents
- Ppowerful currents form that carry large amounts of water away from the shore
- develop when a series of large waves
piles up water between the longshore bar and the swash zone
beach budget
- An easy way to visualize erosion at a
particular beach is to take a beach budget approach - we can analyze a beach in terms of input, storage, and output of the sand or gravel that makes up the beach
- Most input of sediment to a beach is caused by the coastal processes that move the sediment along the shore or by local wave erosion
seawalls
- Structures built on land parallel to the coastline to help slow erosion and protect buildings from damage
beach nourishment
- The process of adding sand, gravel, or other sediment to a beach to compensate for erosion
- requires extracting sand from the ocean floor and placing it onto the beach
breakwater
- Designed to intercept waves and
provide a protected area or harbor for mooring boats or ships
Jetties
- Usually built in pairs, perpendicular to
the shore at the mouth of a river or at the entrance of an inlet to a bay or lagoon
weather
- condition of the atmosphere at a certain time and place
- short term
climate
- weather that is observed and measured over a long period of time
external energy
- Weather disasters are fueled by the Sun
- Weather drives hydrologic cycle which in turn drives erosion
- Sun heats earth unevenly – this causes our patterns of weather & climate
greenhouse effect
- a natural process that traps heat in the Earth’s atmosphere, making the planet warmer than it would be without it
- Allows visible light, inhibits outgoing
radiation
specific heat
- water has a high specific heat
- heats up and cools down slowly
relative humidity
- the amount of water vapor present in air
- how close the air is to being fully saturated
- 100%= in a cloud or fully raining
- based on air’s water content and capacity
dew point
- the temperature to which air would have to be cooled for saturation to occur
- the higher it is, the higher the water vapor content
air
- easily compressed, denser closer to Earth’s surface, high pressure at surface, held by gravity
- flows from higher pressure to lower pressure
adiabatic cooling/warming
- expansion causes cooling, which is when the temperature decreases without the loss of heat energy
- compression causes warming, which when the temperature increases without gain in heat energy
air mass
- chunk of air that is based on some type of moisture and temperature property
- Ex: cool moist air mass
high pressure systems
- sinking air at at the surface, the air is moving out
- sunny, dry, calm days
low pressure systems
- air converges and rises
- makes thunderstorms, winter storms, etc
- unstable air
cold fronts
- more commonly seen
- cold air mass moves in and under warm air mass, lifting it up
warm fronts
- widespread light precipitation
- warm air flows up and over cold air mass
dry line
- neither warm nor cold front
- Steep change in moisture
- Can produce cumulus clouds or thunderstorms
rain
- Above freezing diameter of 0.5mm or larger
- If smaller than 0.5mm—-drizzle
snow
- Most of our precip starts as snow
- Snow reaching the ground depends on the freezing level in the atmosphere
dry snow
- small powdery snow that is good to ski in
wet snow
- about at the freezing line
- clumpy snowflakes
- good for making snowmen
sleet vs freezing rain
- falling snowflake melts as it goes through warm layer
- if it falls through layer of below freezing air near the surface, it will freeze into an ice pelet= sleet
- if that same cold layer is too shallow to freeze a pellet, drops will be supercooled=freezing rain
types of winter storms
- heavy snow-snow squall
- alberta clippers
- Nor’easters
- blizzards
- ice storms
- lake effect snow
how do winter storms form?
- Cold, dry air interacts with warm, moist air
creates a lot of energy
alberta clippers
- light snow
- high winds (35-45 mph)
- sharp drop in temperature
Nor’Eastern
- originates neat southeast coast
- heavy rain or snow
- blizzard like conditions
blizzards
- Long lasting snowstorm with strong winds and intense snowfall
- Cold air at the surface
- Large amounts of moisture
- Lift (warm air must rise over cold air)
Criteria:
- Sustained winds or frequent gusts of 35mph or more
- Visibility less than ¼ mile
- Conditions prevailing for more than 3 hours
snow squalls
- high impacts
- flash freezes
ice storms
- Caused by freezing rain
- NWS- accumulation of at least 0.25 inches of ice on exposed surfaces
- Form when precipitation falls through a shallow layer of warm air, then freezing near the surface
lake effect snow
- cold air blows over a large relatively warm lake, and there is a build up of clouds, and snow dumps to the eastern shore of the lake
watch
- looking at the conditions, could happen or not
warning
- probably going to happen
advisory
- in between watch and warning
storm of the century 1993
- Formed of the Gulf of Mexico on March 12 1993
- Heavy snow stretching from Alabama (69 inches in TN)
- Hurricane force winds
- High Storm surge
- Scattered Tornadoes in the south
- Record cold temperatures across the south and east (-12F)
- 208 fatalities, 10 million without power
the blizzard of 2016 (Snowzilla)
- Up to 3 feet of snow in Mid-Atlantic and
Northeast - 12 States declared State of Emergency
- 13,000 flights cancelled
- At least 55 fatalities
- Low pressure over Texas
- New low pressure over Carolinas threw forecasters off
- Strengthened as it moved north
March 2017 North American Blizzard
- Up to 3 feet of snow
- Extratropical cyclone from North Pacific moved ashore and created new low
- Alberta Clipper
- Weak low from Gulf moved NE fed moisture into northern system
- New low near Georgia- Nor’easter
- Controversy in NYC
Jan 2018 Grayson
- Below average temps for East
- Low pressure system dropped pressure very quickly
- Historic “bombcyclone”
- 22 fatalities
- 300,000 without power
extreme cold
- ~1300 deaths per year
- Hypothermia
- Vulnerable subpopulations
- Homeless, elderly
polar vortex
- extreme cold air from Arctic region
- jet stream brings down extreme temperatures in the middle of the US every winter
health risks
- frost bites
- hypothermia
drainage basin
- The region drained by a single stream or river
- also called watershed or river basin
discharge
- The volume of water moving through a cross-section of a river per unit time
floodplain
- Relatively flat land adjacent
to a river that is produced by river processes - meanders migrate back and forth across this
flooding
- The natural process of overbank flow
flash floods
- Typically occur in the upper part of a
drainage basin (zone 1) and in some small drainage basins of tributaries to a larger river
downstream floods
- In zone 2
- often make national television and newspaper headlines
megafloods
- a high-magnatide, low-frequency, catastrophic flood that involves the sudden release of a large amount of water
Water–Energy–Food Nexus
- a concept that describes the interdependencies between water, energy, and food security
channelization
- a method of engineering that modifies rivers and roads to improve flow and reduce flooding