Weather Exam 4 Draft 1

Which review topics are marked for both Exam 4 and the lab final?

Hurricanes, air pollutants, urban heat islands, and climate classification A–E. The lab final also includes the ten additional skills in this set.

Which details does the instructor say need less memorization?

Exact hurricane-category numbers, highland climate, desert names, and every climate-graph detail. Still understand the Saffir–Simpson scale and practice basic climographs; both remain on the lab review.

Are Climate Change Parts 1 and 2 confirmed for Exam 4 or the lab final?

Their placement is unconfirmed in the supplied review and lectures. A reference to a lab does not establish lab-final coverage. They are outside this focused set, but that does not mean they cannot be tested.

What regional names are used for strong tropical cyclones?

Hurricanes: Atlantic and eastern/central Pacific. Typhoons: western Pacific. Cyclones: Indian Ocean and South Pacific. These are the same storm family. The instructor explicitly says these regional names are important.

How does a disturbance develop into a hurricane?

A thunderstorm cluster gains low pressure and organized circulation as a depression, then strengthens into a named tropical storm and hurricane. Hint: disturbance → depression → tropical storm → hurricane.

What wind speeds define a depression, tropical storm, and hurricane?

Maximum sustained winds: depression 38 mph or less; tropical storm 39–73 mph; hurricane at least 74 mph. Naming starts at the tropical-storm stage.

Where does a hurricane get its energy?

Warm ocean water evaporates. Rising water vapor condenses and releases latent heat, supporting stronger circulation. Hint: warm water → evaporation → condensation → heat release.

What conditions favor hurricane formation?

An existing disturbance, deep warm ocean water (about 80°F/26.5°C), moisture, thunderstorms, enough Coriolis effect, and low vertical wind shear—little wind change with height. Warm water alone is insufficient.

Where do hurricanes usually form, and why not at the equator?

Usually roughly 5°–25° north or south, where warm water and enough Coriolis effect overlap. Coriolis is zero at the equator. These latitude ranges are typical, not absolute boundaries.

Why do cold water and strong wind shear limit hurricanes?

Cold water limits energy; strong vertical wind shear disrupts the storm's upright structure. Cool currents limit storms near the U.S. West Coast; strong shear usually inhibits South Atlantic formation. 

When is Atlantic hurricane season, and why does its peak lag behind summer heat?

June 1–November 30, peaking around September 10 during the busy mid-August–mid-October period. Ocean water warms slowly, so activity peaks after the hottest air temperatures. Storms can occur outside the official season.

How do tropical-cyclone seasons differ in other regions?

Eastern Pacific season begins May 15, with an earlier peak. Southern Hemisphere storms favor late summer/early fall, roughly January–March. Western Pacific typhoons can occur throughout the year.

What steers Atlantic hurricanes, and what is an easterly wave?

Trade winds often move disturbances west. The Bermuda High and surrounding winds steer or curve storms. An easterly wave is a disturbance moving west with the trade winds.

How do the eye, eyewall, and rainbands differ?

Eye: low-pressure center with sinking air and often calmer, clearer conditions. Eyewall: tall thunderstorms and strongest winds. Rainbands: curved thunderstorms with heavy rain and possible tornadoes.

How does air circulate through a hurricane?

Air converges near the surface, rises around the eyewall, spreads outward aloft, and sinks in the eye. Rotation is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

What happens as the eyewalls and eye pass over a place?

Rain and wind intensify toward the first eyewall. The eye brings a lull; the far eyewall brings violent winds from the opposite direction. Hint: the eye is not the all-clear.

How does pressure relate to hurricane wind strength?

A stronger pressure gradient supports stronger winds. Hurricane categories depend on maximum sustained wind, not central pressure.

How do sustained hurricane winds differ from gusts?

NHC sustained winds use a one-minute average; gusts are brief higher speeds. Example: 120 mph sustained winds may have 140–150 mph gusts.

How can a hurricane's forward motion affect winds on its two sides?

In an idealized Northern Hemisphere storm, right/left are relative to its track. Example: 100 mph rotation plus 20 mph motion gives 120 mph right and 80 mph left. Advisory winds already include motion; do not add again.

What does the Saffir–Simpson scale measure, and which categories are major?

Maximum sustained hurricane wind, in Categories 1–5. Categories 3–5 are major hurricanes. Storm surge and rainfall flooding are assessed separately; category does not describe every hazard.

How do hurricane and tornado scales differ, and what does he say about category numbers?

Saffir–Simpson rates hurricanes in Categories 1–5; Enhanced Fujita rates tornadoes EF0–EF5. The instructor contrasts the scales and says exact hurricane-category wind ranges need not be memorized. 

What are the main hurricane hazards, and what else affects damage?

Wind, storm surge, rainfall flooding, tornadoes, destructive waves, and rip currents. Damage also depends on storm size, track, approach angle, and exposed people and property—not wind category alone.

What is storm surge?

An abnormal coastal water rise driven mainly by onshore wind, with a smaller pressure contribution. Waves ride on top; it is not a tsunami. Hint: wind pushes water shoreward.

Why can a lower-category hurricane cause dangerous coastal flooding?

Storm size, water depth, coastline shape, and track affect surge. It can flood low coasts, barrier islands, and areas miles inland. Wind category alone cannot describe the complete water hazard.

Why can tropical systems cause dangerous flooding far inland?

Slow-moving storms bring prolonged rain, and mountains concentrate runoff. Even tropical depressions can cause severe flooding. Inland areas also face wind and tornadoes.

What is air pollution, and why does it matter?

Harmful or unwanted gases and particles from natural or human sources. Pollution reduces visibility, harms plants and animals, and can damage respiratory and cardiovascular health.

Which five pollutant groups does the lecture emphasize?

Carbon monoxide (CO), sulfur oxides, nitrogen oxides (NOx), volatile organic compounds (VOCs), and particulate matter (PM).

Why does the instructor say there is no single solution to air pollution?

Different pollutants come from different sources, so different controls are needed. Stopping one activity cannot solve every air-pollution problem.

How do primary and secondary pollutants differ?

Primary pollutants enter the air directly, such as exhaust. Secondary pollutants form through atmospheric reactions, such as ground-level ozone. Hint: primary = emitted; secondary = formed in the air. 

Which pollutant–source matches did the instructor explicitly use as exam examples?

Transportation and fuel-burning engines → carbon monoxide (CO). Coal burning, especially electricity production → sulfur dioxide (SO₂). Hint: CO → car exhaust; SO₂ → sulfur in coal.

How do CO and CO₂ differ?

CO has one oxygen atom; CO₂ has two. Carbon monoxide is colorless and odorless and reduces oxygen delivery in blood. Odor added to household fuel gas does not make CO detectable. 

Where does dangerous carbon monoxide build up, and what affects its harm?

Combustion in enclosed or poorly ventilated spaces, such as an engine running in a closed garage. Higher concentrations and longer exposure increase risk: headache, nausea, dizziness, confusion, unconsciousness, or death.

What are particulate matter, PM₁₀, and PM₂.₅?

Airborne solid particles or liquid droplets from industrial combustion, other human/natural sources, or formation in the air. PM₁₀ is generally 10 micrometers or smaller; PM₂.₅ is 2.5 or smaller. Finer particles penetrate deeper into lungs.

How can aerosols affect sunlight and climate?

Aerosols are particles/droplets suspended in air. They change sunset colors. Some reduce sunlight reaching the surface and cause cooling; others absorb energy and warm the atmosphere. Hint: aerosol climate effects vary.

What should you remember about sulfur oxides and SO₂?

Sulfur oxides include SO₂ and SO₃. Coal-related SO₂ is a colorless primary pollutant with an irritating odor; it harms lungs and materials. Rotten-egg odor is H₂S, not SO₂.

Where do nitrogen oxides come from, and what do they do?

Coal and petroleum combustion produce nitrogen oxides. NO₂ causes yellow-brown haze. Nitrogen oxides contribute to health problems, material damage, nitric-acid formation, and ground-level ozone.

What are VOCs, and where do they come from?

Volatile organic compounds come from industry, transportation, and natural sources such as vegetation. They participate in reactions that form secondary pollutants, including ground-level ozone.

What is photochemical smog, and what produces it?

Sunlight drives NOx–VOC reactions that produce a mixture including ground-level ozone. Smog reduces visibility and irritates eyes/lungs; mountains and weak mixing restrict dispersion. Strong summer sunlight favors afternoon buildup. Hint: photo = light.

Why is ozone helpful high up but harmful near the ground?

Stratospheric ozone absorbs harmful ultraviolet radiation. Tropospheric or ground-level ozone irritates the respiratory system and can reduce lung function. Hint: high ozone protects; low ozone pollutes.

How does acid deposition form, and what does pH mean?

Sulfur oxides help form sulfuric acid; nitrogen oxides help form nitric acid. Acids enter precipitation or fog. Lower pH means more acidic; neutral is 7, while natural rain is roughly pH 5–6.