GEOG 1900: Geography of the Atmosphere Final Exam Study Guide

Vocabulary-style flashcards covering core atmospheric concepts, precipitation, circulation, fronts, storms, and climate change based on the GEOG 1900 study guide.

The Sun

The most important energy source for Earth's atmosphere, providing shortwave radiation that drives all atmospheric and oceanic processes.

Selective Absorption

The ability of atmospheric gases (GHGs) to be transparent to incoming shortwave solar radiation while absorbing outgoing longwave terrestrial radiation.

Greenhouse Effect

The trapping of heat in the lower atmosphere by gases like water vapor and $CO_2$, which raises Earth's mean temperature.

Albedo

The percentage of radiation reflected by a surface; high values (snow, clouds) cool the system, while low values (oceans, forests) warm it.

Adiabatic Cooling

The process where air parcels lift, expand due to lower pressure, and cool without the exchange of heat with the surrounding environment.

Rain Drop vs. Cloud Droplet

Rain drops are approximately $2,mm$ in size, making them roughly 100 times larger than cloud droplets, which are approximately $0.02,mm$.

Collision-Coalescence

A process in warm clouds (T > 0,^{\circ}C) where larger 'collector' drops fall through the cloud, colliding and merging with smaller droplets; primarily occurring in the tropics.

Bergeron Process

A process in cold clouds where ice crystals grow at the expense of supercooled water droplets because saturation vapor pressure is lower over ice; the cause of most mid-latitude precipitation.

Sleet

Precipitation formed when snow melts and then refreezes in a deep cold layer near the surface.

Freezing Rain

Precipitation formed when snow melts, becomes supercooled in a thin surface cold layer, and freezes on contact with surfaces.

Hail

Precipitation associated with Cumulonimbus clouds and intense updrafts.

Drizzle

Precipitation associated with Stratus clouds and stable lifting.

Cloud Seeding

The process of injecting ice nuclei, such as silver iodide, into clouds to induce the Bergeron process.

Hadley, Ferrel, and Polar Cells

The three atmospheric circulation cells created on a rotating Earth by the Coriolis force.

Trade Winds

Winds that blow from the Subtropical Highs toward the Intertropical Convergence Zone (ITCZ).

Westerlies

Winds that blow from the Subtropical Highs toward the poles.

ITCZ (Intertropical Convergence Zone)

A low-pressure zone at the equator where trade winds meet, resulting in high rainfall.

Jet Streams

High-speed winds aloft found at cell boundaries (Polar and Subtropical) formed by steep pressure gradients caused by temperature contrasts.

Asian Monsoon

A seasonal wind reversal resulting in wet onshore flow in the summer due to low pressure over land and dry offshore flow in the winter due to high pressure over land.

Katabatic Breezes

Local winds caused by the gravity drainage of cold air from ice sheets.

Chinook Winds

Dry, warm winds found on the leeward side of mountains.

Thermocline

The depth interval in the ocean where water temperature drops rapidly.

Upwelling

The upward movement of cold, nutrient-rich water caused by divergence at the ocean surface.

El Nino

A phase of ENSO characterized by weak trade winds and warm water moving East, stopping upwelling and leading to wet winters in the Southern US and drought in Australia.

Dryline

A boundary between moist mT (maritime Tropical) air and dry cT (continental Tropical) air that favors the development of severe weather.

Cyclogenesis

The initial stage of a mid-latitude cyclone's life cycle where a wave forms.

Return Stroke

The visible flash of lightning that occurs when the stepped leader (negative) and positive streamer meet.

Supercells

Large, rotating thunderstorms characterized by a mesocyclone.

Haboob

A dust storm formed by a thunderstorm downdraft.

Hurricane Formation Conditions

Requirements including warm water above $26.5,^{\circ}C$, Coriolis force between $5-20$ degrees latitude, and low wind shear.

Milankovitch Cycles

Cyclical variations in Earth's orbit including Eccentricity ($100,000,yrs$), Obliquity ($41,000,yrs$), and Precession ($23,000,yrs$) that trigger glacial cycles.

Holocene

The current interglacial period of Earth's climate.

Ocean Acidification

The formation of carbonic acid when the ocean absorbs excess atmospheric $CO_2$ from burning fossil fuels, affecting marine calcifiers.

Ice-Albedo Feedback

An internal feedback mechanism that amplifies warming, especially in the Arctic, because melting ice lowers albedo and increases energy absorption.