Review Sheet for Exam 2
Geography 1401 – Weather and Climate Review for Exam #2
This review sheet lists terms and concepts necessary for the second exam.
Exam Format: Multiple-choice, true-false questions, and a few short answer questions.
Review material from lectures and PowerPoint slides, as well as any related textbook material.
Remember to purchase a scantron sheet for the exam.
Contact information: axf011@shsu.edu for any questions.
Atmospheric Pressure
Definition: Force exerted by the weight of air molecules above a surface.
Instrument to Measure: Barometer.
Normal Range: Typically measured in millibars (mb), with standard atmospheric pressure at sea level being around 1013.25 mb.
Isobars: Lines on a map connecting points of equal atmospheric pressure.
Winds – Global Forces Affecting Wind Movement
Pressure Gradient Force: Difference in pressure between two areas causing wind to move from high to low pressure.
Centripetal Force: Force that acts on objects moving in a circular path, influencing wind movement near high and low-pressure systems.
Coriolis Force: Effect of Earth’s rotation on winds, causing them to curve rather than move in a straight line.
Global Pressure Belts
Location and characteristics of main pressure belts:
Equatorial Low: Low pressure at the equator, leading to moist and unstable weather.
Subtropical High: High pressure zones around 30°N and 30°S, characterized by arid conditions.
Subpolar Low: Low pressure zones around 60°N and 60°S.
Polar High: High pressure at the poles, cold and dry.
Surface Wind Belts
Trade Winds: Winds that blow from east to west in tropical regions.
Prevailing Westerlies: Winds that blow from west to east in temperate zones.
Polar Easterlies: Cold winds blowing from the polar regions toward the equator.
Intertropical Convergence Zone (ITCZ)
A region near the equator where trade winds converge, resulting in calm winds and often associated with heavy rainfall.
Monsoon
Characteristics: Seasonal shift of wind direction bringing wet and dry periods.
Cultural Impacts: Significant implications for agriculture, water supply, and local economies based on rainfall patterns.
Winds – Continental-Scale
Friction: Influence of surface roughness on wind speed and direction.
Pressure Cells: Regions of high (anti-cyclone) or low (cyclone) pressure that affect local wind patterns.
Vertical Movement of Air
Convergence: When air masses meet and rise.
Orographic Lifting: Occurs when air is forced over a mountain range, causing precipitation on windward slopes and dryness on leeward slopes.
Frontal Wedging: Occurs when warm air is lifted over cooler air at weather fronts.
Convective Lifting: Rising of warm air due to heating from the Earth's surface.
Local Winds
Land/Sea Breezes: Differentials in heating and cooling between land and water causing local winds.
Mountain/Valley Breezes: Wind patterns resulting from temperature differences between mountainous regions and valleys.
Katabatic Winds: Cold winds flowing down slopes.
Chinook Winds: Warm, dry winds descending the eastern slopes of the Rocky Mountains.
Orographic Lifting and Adiabatic Rates
Wet Adiabatic Rate: Rate of cooling of saturated air (typically around 6°C per 1000m).
Dry Adiabatic Rate: Rate of cooling of unsaturated air (approximately 10°C per 1000m).
Sample problem related to calculating temperature changes due to these rates.
Upper-Level Winds Characteristics
Geostrophic Winds: Winds that flow parallel to the isobars, influenced by the Coriolis effect and pressure gradients.
Tropical Easterlies and Upper-Level Westerlies: Patterns of winds found at higher altitudes.
Polar Jet Stream: Fast-flowing winds in the upper atmosphere affecting weather patterns.
Subtropical Jet Stream: Another significant jet stream influencing weather.
Airflow Types
Latitudinal: Flow of air from east to west across different latitudes.
Meridional: North-south airflow across the longitude.
Ridges and Troughs
Ridges: High-pressure areas creating fair weather.
Troughs: Low-pressure areas often associated with stormy weather.
Rossby Waves: Large-scale undulations in the jet stream influencing weather patterns.
Gradient Winds
Cyclonic vs. Anti-cyclonic: Differences in wind flow around low pressure (counterclockwise) versus high pressure (clockwise).
El Niño
Characteristics: Periodic warming of ocean surface temperatures in the central and eastern Pacific.
Impacts: Significant effects on global weather patterns, precipitation, and temperatures across different regions.
Atmospheric Moisture
Hydrology and Hydrologic Cycle: The continuous movement of water within the Earth and atmosphere.
Distribution of Earth's Water
Oceans, glaciers, groundwater, rivers, and lakes account for different volumes of Earth's water resources.
Types of Heat
Latent Heat: Energy absorbed or released during a phase change without temperature change.
Sensible Heat: Energy that causes a change in temperature.
Phase Changes of H2O
Processes include evaporation, condensation, freezing, melting, and sublimation.
Humidity and Relation to Temperature
Relationship between moisture content in the air and temperature, affecting comfort and weather.
Dew Point
The temperature at which air becomes saturated with moisture, leading to condensation.
Weather Map Symbols
Familiarity with symbols representing weather variables on maps (e.g., high and low-pressure systems, fronts).
Clouds: Formation and Classification
Formation: How clouds form from rising air and cooling.
Criteria for Formation: Includes temperature changes and humidity levels.
Types of Clouds
Cirrus: Wispy, high-altitude clouds.
Stratus: Layered clouds that cover the sky.
Cumulus: Fluffy, white clouds often seen in fair weather.
Cumulonimbus: Towering clouds associated with thunderstorms.
Lenticular: Cloud formations resembling lenses, often near mountains.
Mammatus: Pouch-like structures on the bottom of clouds.