Climatology Flashcards
Name four layers in atmosphere
TSMTE
What is the atmosphere?
A layer of gases held by gravity that protects us from meteoroids and harmful sun rays, trapping heat and allowing life and liquid water to exist on Earth’s surface.
What is the composition of pure dry air?
N2 (78%) > O2 (21%) > Argon (0.93%) > CO2 (0.03%) > H2 > He > O3
What role does CO2 play in the atmosphere?
Contributes to the greenhouse effect and is emitted from burning fossil fuels.
What is the function of ozone in the atmosphere?
Filters out harmful UV rays.
Where is water vapor more prevalent in the atmosphere?
More in warm, wet tropics; less in dry, cold areas.
What are dust particles in the atmosphere sourced from?
Sea salts, fine soil, smoke-soot, ash, pollen, dust, meteor particles.
What is the troposphere?
The lowest layer of the atmosphere, 8-18 km high from ground, containing dust and water vapor, where all weather phenomena occur.
What is the normal lapse rate?
Temperature decreases with altitude.
What is the stratosphere and its significance?
Extends from the tropopause to 50 km, contains the ozone layer, and has a constant temperature up to 20 km.
What is lapse rate of mesosphere ?
Temperature decreases with altitude, reaching -100°C at 80 km.
What is the ionosphere?
A layer from 80-400 km containing charged particles that reflect radio waves back to Earth.
What characterizes the exosphere?
The uppermost layer with very little known about it and an extremely thin atmosphere.
What is the source of Earth’s energy balance?
The Sun through short wavelengths (insolation of solar radiation).
What is aphelion?
The farthest point from the Sun, occurring on July 4th.
What is perihelion?
The closest point to the Sun, occurring on January 3rd.
What are the main factors affecting variations in insolation?
- Earth’s rotation on its axis
- Length of day
- Transparency of atmosphere
- Angle of inclination of the sun’s rays
What is conduction in heat transfer?
Heat transfer by direct contact between objects.
What is convection?
Heat transfer via movement of a substance, occurring in liquids and gases.
What is advection?
Horizontal movement of air masses that transfers heat.
What is terrestrial radiation?
Direct heating of the body by transmission of heat waves.
What is the Earth’s heat budget?
The balance of incoming and outgoing heat that maintains a stable temperature.
What happens to heat losses after reaching the Earth’s surface?
Total Outgoing Heat: 65 units (17 from Earth + 48 from atmosphere).
What are the factors controlling temperature distribution?
- Latitude
- Altitude
- Distance from the sea
- Air masses and ocean currents
What is temperature inversion?
Cold air trapped below warm air, often causing fog and pollution buildup.
What is atmospheric pressure?
The weight of air pressing down on Earth’s surface, measured in millibars.
What causes wind movement?
Air moves from high pressure to low pressure.
What are the main pressure belts around the world?
- Equatorial Low
- Subtropical Highs
- Subpolar Lows
- Polar Highs
What is the Coriolis Force?
Deflects wind due to Earth’s rotation, affecting wind direction but not speed.
What is geostrophic wind?
Wind that flows parallel to isobars when pressure gradient and Coriolis force balance.
What is Hadley Cell?
A circulation pattern where rising air starts at the equator due to high insolation and low pressure.
What is the Hadley Cell?
A circulation pattern in the atmosphere where rising air at the equator leads to sinking air at approximately 30° N & S latitudes.
What initiates the rising air in the Hadley Cell?
High insolation and low pressure at the equator.
What phenomenon occurs at the convergence of trade winds?
Intertropical Convergence Zone (ITCZ).
What are the surface winds that flow as westerlies?
Winds flowing from the subtropical highs towards the equator.
What defines the Ferrel Cell?
Sinking cold air from the poles and rising warm air from subtropical highs.
What type of winds blow from the poles towards the middle latitudes?
Polar easterlies.
What are planetary winds?
Winds that are consistent throughout the year due to latitudinal differences in air pressure.
True or False: Trade winds blow from the poles towards the equator.
False.
What are monsoon winds?
Seasonal reversal of wind direction that modifies the planetary wind system.
What is a sea breeze?
A daytime phenomenon where land heats faster than water, creating a pressure gradient that pushes wind from sea to land.
Define land breeze.
A nighttime phenomenon where land cools faster than water, resulting in wind blowing from land to sea.
What are valley breezes?
Daytime winds that occur when mountain slopes heat up and air rises up the slope.
What is the definition of local winds?
Winds resulting from local temperature and pressure differences affecting small areas.
What is the jet stream?
High-speed winds in the mid-latitudes that blow from west to east near the tropopause.
What are the conditions for air mass formation?
Large landmass or water body, evenly distributed insolation, large scale subsidence of air.
List the five major air mass types.
- Maritime tropical (mT)
- Continental tropical (cT)
- Maritime polar (mP)
- Continental polar (cP)
- Continental arctic (cA)
What is frontogenesis?
The process of formation of fronts, occurring in mid-latitudes with steep gradients in pressure and temperature.
Describe a cold front.
Cold air moves towards warm air, often causing storms and a sharp drop in temperatures.
What characterizes a warm front?
Warm air mass moves towards cold air, leading to moderate precipitation and gradual temperature changes.
What is an occluded front?
A front where an air mass is fully lifted above the land surface, resulting in complex weather.
What are extra-tropical cyclones?
Cyclones that occur in mid and high latitudes, causing abrupt weather changes.
What is the central eye of a tropical cyclone?
The calm region at the center of the cyclone with subsiding air.
What are the necessary conditions for the formation of tropical cyclones?
- Large sea surface
- Temperature > 27°C
- Coriolis force
- Small variation in vertical wind
- Low pressure area
- Upper divergence above sea level
What distinguishes an extra-tropical cyclone from a tropical cyclone?
Extra-tropical cyclones have clear frontal systems, while tropical cyclones do not.
What are the three forms of water in the atmosphere?
- Gaseous (water vapor)
- Liquid
- Solid
What is evaporation?
The process where water transforms into water vapor, adding moisture to the atmosphere.
What is condensation?
The process where water vapor changes back into liquid water, withdrawing moisture from the atmosphere.
What are the four types of clouds based on height?
- Cirrus
- Cumulus
- Stratus
- Nimbus
What type of rainfall occurs due to rising heated air?
Convectional rain.
What is orographic rainfall?
Rainfall that occurs when a saturated air mass rises over a mountain, leading to condensation.
Where does rainfall typically decrease?
From the equator to the poles.
