Sev + Haz Midterm

When did the earth form?

4.6 billion years ago (BYR/GYR, never seen this abbreviation before but its what he uses)

Earth’s atmosphere’s evolution over time

• Original atmosphere was mostly Hydrogen, Helium, CO2, H20, CH4 (4.5 BYR)

• Earth lost most of the original atmosphere lost due to the sun(4.2 BYR)

• Secondary atmosphere forms (4 BYR)

  • H20, CO2, NH3

• Life forms on earth (3.5-3.8 BYR)

• Oxygen started forming from photosynthesis (2 BYR)

Current Makeup of atmosphere

• N2 (78%)

• O2 (21%)

• Argon (.8%)

• CO2 (.042%)

Pressure formula, and how it changes with altitude

• P=Force/Area, usually lbs per inch

• Pressure decreases exponentially with altitude

• At 18,000 ft: ½ atm is below, P=500 millibars

• At 20 miles (105,000 ft), 99% atm is below you and pressure is 10 millibars mb

What does the atmosphere mean to us?

• Protects against meteorites, X-UV radiation, cosmic rays, and air to breath (O2), N2 for plants, greenhouse warming (CO2, methane)

Temperature conversion (Kelvin, Celsius, and Farenheit)

K=C+273

C=(5/9)*(F-32)

F=(9/5*C)+32

I believe he’s giving us these formulas.

How does temperature decrease with altitude? Lapse rate

• Rate of cooling is variable but averages about 6.5 degrees celsius per km

  • Or 3.5 F/1000 ft moist air

  • Or 5.5 F/1000 ft dry air

• Stops decreasing at tropopause—9 km (abt 6 miles) at poles and ~16km (abt 10 miles) at the equator

Structure of atmosphere

1. Troposphere—lowest layer

   1. upper boundary called tropopause

2. Stratosphere—second layer

   1. upper boundary called stratopause

3. Mesosphere—third layer (upper boundary called mesopause)

4. Thermosphere—outermost layer

Average temp. increase from greenhouse effect, as a result of CO2 up 45%

From 1850-2022: +1.8F

Coriolis effect, know equation and where its the strongest

• The curving of the path of objects or fluids due to the earth's rotation

• Fc=2 Omega * Velocity * Sin (latitude)

  • Velocity=Distance/Time

  • Sin 90 (poles)=1, whereas Sin 0 (equator)=0

  • Omega in this case means angular rotation of earth, which idk what that is.

• Acts to right of motion in northern hemisphere and left in southern hemisphere

• Strongest at the poles

• Causes tropical disturbances to wind-up

Role played by friction in hurricane formation

• Near the Earth's surface, friction slows down the winds moving in a hurricane. This effect is strongest at the boundary layer, which is the part of the atmosphere in contact with the surface (land or ocean).

• As air moves inward toward the low-pressure center of a hurricane, friction slows it down. This reduction in speed allows the air to converge and rise, leading to the formation of clouds and thunderstorms that feed the hurricane.

• Over the ocean, where hurricanes generally form, the friction is less because water surfaces are smoother than land. This allows wind speeds to remain higher, fueling the storm.

Centrifugal force (idk if we need to know this)

Outward force: Fce= V2/distance from center

What makes the wind blow, and pressure gradient force formula

• Newtons second law, difference in pressure grade

• PGF= -(1/density)[DP/DX]. Dp/dx is change of pressure with horizontal distance x

• Bigger the difference, stronger the wind (very high diff in hurricane)

• Negative sign indicates the force is directed from high to low pressure

Inter-tropical convergence zone (ITCZ)

• A belt of low pressure that encircles the Earth near the equator, where the trade winds from the Northern and Southern Hemispheres converge. This region is characterized by high humidity, frequent thunderstorms, and significant cloud formation due to the intense solar heating and the convergence of moist air masses.

• Ideal conditions for hurricane formation and most typically form just north or south of it.

Heat waves (definition, causes, and common time of year)

• In Northeast USA: 3 days of 90F or higher temperatures

  • In arizona its 100

• Causes:

  • strong sun

  • clear skies

  • high pressures and subsiding dry air

• Most common type of year mid july-early september

What ultimately drives hurricanes

Latent heat from the Sun

Most damage and loss of life of major hurricanes arise from:

Flooding from heavy rains and storm surges

The strongest winds of typical hurricane moving north in the Gulf of Mexico are typically on what side of the eye?

On the east (right) side of the eye. East side=dirty side

Heat effects/disorders on human body

• Hyperthermia (Leading weather related death in the US)

• Heat stroke

• Heat exhaustion

• Heat cramps

• Heat rash

• Effects on the body:

  • Reduced blood flow to brain

  • Reduced blood flow to active muscles

  • Increased sweating

  • If heat gain exceeds heat loss, body core temperature rises and heat disorders occur

• Treatment:

  • drink fluids/electrolytes (he recommends pedialyte)

Heat index (apparent temperature)

• Be able to compute using the table

  • Air temperature and Relative humidity on scale

• Real temperature feel

Who wrote the first book on meteorology?

Aristotle wrote Meteorologica ~350 BCE-the start of meterology science

Timeline of meteorology after Aristotle

• 300 BCE: Book of signs by Nino Parmenides, weather forecasts based on phenoma (red sky at night…)

• 200-100 BCE: Tower of the winds in Athens

• 1442: rain gauges in Korea

• 1450: Cardinal Nicholas de Cusa invents the crude hygrometer which measures moisture in the air.

Thermometer and Barometer Inventions

• Thermometer

  • Invented by Galileo in 1590s

  • measured the temperature=kinetic energy of air

• Barometer

  • invented by Torricelli in 1643

  • measure air pressure

Importance of the telegraph

• Invented in the 1850s, allowed for weather information to be transported rapidly, very important

• Allowed for tracking of weather systems (played a major part in the civil war)

Modern weather technology innovations (especially radars and satellites)

• Rawinsonde (1930s+): measure wind speed and direction along with pressure, altitute, geographic position, temperature, and relative humidity

• US national weather bureau founded in 1870

• Radar invented in 1935

  • important in WWII

  • and doplar radar important today for tracking storm movements

• Weather satellites in 1960s, first TIROS and then NIMBUS

• Super computers since 1990s used to quickly analyze weather elements

Classifications of tropical storms

• Easterly wave (0-23 MPH)

• Tropical depression (23-39 MPH)

• Tropical storm (39-74 MPH)

• Tropical cyclone (winds > 74 MPH)

Hurricane Categories —Saffir-Simpson scale (know wind speed and surge)

• Anything less than 74 MPH is tropical storm

• Cat 1

  • 74-95 MPH

  • 4-5 FT

• Cat 2

  • 96-110 MPH

  • 6-8 FT

• Cat 3

  • 111-130 MPH

  • 9-12 FT

• Cat 4

  • 131-155 MPH

  • 13-18 FT

• Cat 5

  • > 155 MPH

  • 19+ ft

Energy released by hurricanes equation

E=(Amt of H20 liquid condensed)*(Latent Heat)

=10^11 gm/s (rainfall) * 600 cal/gm=6 *10^13 cal/s=360 X 10^13 cal/min

Which is also equal to 3 megatron bombs or something like that

Conservation of angular momentum

R1 V1 = R2 * V2

Angular momentum question: The winds in the outer region of hurricane at 50 miles from the center are 20 mph, assuming conservation of angular momentum what would its speed at 10 miles from the center be?

20 × 50 = 10 * X

10x=1000

x=100 mph

Hurricane Sandy

• 2012, deadliest most destructive of the 2012 hurricane season

• Hurricane Sandy merged with an extratropical cyclone off New Jersey and became a hybrid superstorm

• Nearly 70+ billion in damage and killed 233 ppl across eight countries

• most damage was done to NJ, NY, RI, and a little bit of CT

• Started in Caribbean, hit Jamaica and Cuba

• Largest Atlantic hurricane on record, as of 2019

Galveston Hurricane

• 1900, Killed nearly 10,000 people, deadliest hurricane to hit US

• 35.4 Mil in damage (abt 1 billion w inflation)

• Hit as a category 4 hurricane

• Could have been lessened, US ignored data from Cuba

• Started around Cape Verde, Africa

Hurricane Katrina

• 2005, destructive Cat 4-5 Atlantic Hurricane that hit New Orleans

• Over 1800 deaths, and 125+ billion in damage, costliest hurricane in US history

• Picked up water from Lake Pontchartrain and dumped it on city of New Orleans

• Much of the old city is at or below sea level

Hurricane Ian

• September 2022

• Hit as Cat 4, 150 deaths, and did 112 billion in damage

• costliest hurricane in FLs history

• Began off western coast of Africa, than gathered force crossing the Atlantic

Hurricane Helene

• September 2024

• Hit Florida as a Cat 4, damage all the way up through NC and TN

• Was stronger due to record temps in gulf of Mexico

• Devastating rain/floods in Georgia, SC, western, NC, TN, and Virginia

• Estimated 220+ dead and 35+ billion in damage

• More than 600 miles of destruction

Hurricane Milton

• Global warming, gulf of Mexico is record temperature at surface lvl and deep water.

• Eye is aimed right at Tampa Bay, relatively small eye, should go across Florida

• Maybe the largest most destructive hurricane to hit Florida in modern times

The Doppler effect, gonna be math question on this

Shift in wavelength/rest wavelength=velocity/speed of light

How does Doppler radar work?

• Measures/detects rainfall from reflectivity, motion, and circulation

• Shorter wavelength=motion towards observer

• Longer wavelength=motion away from observer

• most effective source of tornado detection

Common weather instruments (8) and what they measure

• Thermometers—measures temperature

• Barometers—measures air pressure

• Psychrometer—measures humidity

  • Hygrometers measure humidity based on absorption of water

• Anemometer—measures wind speed

• Windsocks/Wind Vane—measures wind direction

• Rain Gauge—Measures amount of rain-fall

• Weather balloon measures weather conditions higher in atmosphere

• Weather Satellite—photograph, track, and measure the conditions of large scale air movements.

Different types of thermometers and which one doesnt expand

• Bimetallic thermometer

• Expansion thermometers

• RTD, resistance temperature detector

• Thermocouple (doesnt expand)

Kinetic Energy equation (no math question on test)

KE=1/2mv²

Relative Humidity, and what relative humidity is when ambient (air) temperature and dew point temperature are the same?

• Use relative humidity table (in percent). Dry bulb on vertical axis and dry bulb minus wet bulb on horizontal axis.

• Relative humidity is 100% when they are the same.

Insect thermometers, below what temp. are all insects silent?

• Crickets: Number of chirps in 14 sec + 40

• Katydid threshold: About 55 degrees to 90 degrees, the faster the chirp the warmer it is

• Locusts sing above 83 degrees

• All insects are silent below 40 degrees and above 105

What causes seasons?

• Angular tilt of the earth, 23.5 degrees

• IF tilt was 0 degrees there would be no seasons

When are 4 equinoxes/solstices

• Vernal equinox: Mar 21/22

• Autumnal Equinox: Sept 21/22

• Summer solstice: June 21/22

• Winter solstice Dec 21/22

Station model (things to know and where they are)

• Middle Circle: Cloud cover

• Upper left: Temperature

• Middle Left: Any significant weather, and visibility

• Lower left: Dewpoint temp.

• Upper right: sea level pressure (042=1004.2, implied decimal point)

  • (985=998.5, starts at 900 ig)

• Middle right: Barometric trend (+19/)

• Bottom right: Precipitation

• Arrow from circle=wind direction

Common weather symbols on station models

• Rain: dots, more dots means heavier rain

• Snow: stars, more stars means heavier snow

• Drizzle: Comma thing

Different fronts and their symbols (Cold, Warm, and stationary)

• Warm front: Semicircles facing upwards

• Cold front: Triangles facing up

• Stationary front: Alternating triangles and semicircles