Weather, Climate, Ocean Circulation, and Tides

Flashcards of key terms and concepts from the provided lecture notes on Weather, Climate, Ocean Circulation, and Tides.

Northeast Trade Winds

Winds that blow steadily from the northeast to the southwest, influencing Columbus's first voyage route.

High-Pressure Region

An area where air moves away, the Coriolis effect causes air to curve to the right in the Northern Hemisphere, resulting in clockwise winds (anticyclonic flow).

Low-Pressure Region

An area where air moves towards; the Coriolis effect causes air to curve to the right in the Northern Hemisphere, resulting in counterclockwise winds (cyclonic flow).

Sea Breeze

A breeze created during the afternoon when warm, low-density air over the land rises, creating a low-pressure region, pulling cooler air over the ocean toward the land.

Land Breeze

A breeze created in the late evening and early morning hours when the land surface cools, causing cool, high-density air to sink and the wind to blow from the land.

Storms

Atmospheric disturbances characterized by strong winds, precipitation, and often thunder and lightning that occur in the middle latitudes (30 to 60 degrees north or south).

Air Masses

Large volumes of air that have a definite area of origin and distinctive characteristics; classified as continental (c) or maritime (m) for moisture content, and polar (P), Arctic (A), or tropical (T) for temperature.

Warm Front

The contact between a warm air mass moving into an area occupied by cold air.

Cold Front

The contact between a cold air mass moving into an area occupied by warm air.

Jet Stream

A narrow, fast-moving, easterly flowing air mass that exists above the middle latitudes just below the top of the troposphere, centered at an altitude of about 10 kilometers (6 miles).

Tropical Cyclones

Huge rotating masses of low pressure characterized by strong winds and torrential rain, called hurricanes in North and South America, typhoons in the western North Pacific Ocean, and cyclones in the Indian Ocean.

Latent Heat of Condensation

The heat released when water vapor condenses into a liquid (clouds and rain), powering tropical cyclones.

Tropical Depression

A tropical storm classified with winds are less than 61 kilometers (38 miles) per hour

Tropical Storm

A tropical storm classified with winds between 61 and 120 kilometers (38 and 74 miles) per hour.

Tropical Cyclone

A tropical storm classified with winds exceed 120 kilometers (74 miles) per hour.

Saffir-Simpson Scale

A scale that divides tropical cyclones into categories based on wind speed and damage.

Storm Surge

The mass of elevated, wind-driven water produced by a hurricane's low-pressure center, causing a dramatic increase in sea level at the shore, large storm waves, and tremendous destruction to low-lying coastal areas.

Trade Winds

Winds that generally move hurricanes from east to west across ocean basins in the low latitudes.

Eye of the Hurricane

he calm center of a hurricane, where horizontal wind speeds may be less than 15 kilometers (25 miles) per hour.

Atlantic Hurricane Season

The official period from June 1 to November 30 each year when most tropical cyclones form in the Atlantic basin.

Katrina

The sixth-strongest Atlantic hurricane ever recorded being the costliest and one of the deadliest hurricanes in U.S. history (2005).

Wilma

A category 5 that developed during the month of October, and its pressure of 88,200 Pascal (882 mil- libars, or 0.871 atmosphere) ranked it as the most intense hurricane ever recorded in the Atlantic basin.

Doldrums

Equatorial region with weak and variable surface winds.

Sea Ice

Ice that forms directly from seawater.

Pancake Ice

Disk-shaped pieces of ice formed when frozen slush is broken by wind stress and wave action.

Ice Floes

Layers of ice when pancakes coalesce

Icebergs

Bodies of floating ice broken away from a glacier.

Shelf Ice

Thick floating sheets of ice formed by the edges of glaciers near Antarctica.

Albedo

The fraction of total radiation reflected from any surface.

Antarctic Circle

66.5 Degrees South. During winter solstice, sun is not visible and the summer solstice the sun never sets.

Anticyclonic Flow

The movement of air around a high-pressure cell is clockwise.

Arctic Circle

66.5 Degrees North. During winter solstice, sun is not visible and the summer solstice the sun never sets.

Autumnal Equinox

The sun is directly overhead at the equator and all locations on Earth experience 12 hours of daylight and 12 hours of darkness (September 22).

Climate

The long-term average of weather

Cyclone

A swift and often destructive circular windstorm, usually with a diameter of 200 to 500 miles.

Cyclonic Flow

The movement of air around a low-pressure cell is counterclockwise

Declination

The angular distance of the Sun or Moon above or below the Earth's equatorial plane.

Ecliptic

The invisible plane that contains Earth's orbit around the Sun.

Equatorial

Areas near the Earth's equator.

Equatorial Low

The area of rising air at the equator.

Ferrel Cell

The circulation cell that lies between 30 and 60 degrees latitude

Hadley Cell

The circulation cell that lies between 0 and 30 degrees latitude

Horse Latitudes

Boundary between trade winds and prevailing westerlies.

Intertropical Convergence Zone (ITCZ)

The boundary between two trade wind belts is which coincides with the doldrums.

Land Breeze

At night, the land surface cools about five times more rapidly than the ocean and cools the air around it. This cool, high-density air sinks, creating a high-pressure region that causes the wind to blow from the land.

Northeast Trade Winds

Winds that blow from northeast in the Northern Hemisphere

Polar

Regions near the North and South Poles.

Polar Cell

The circulation cell that lies between 60 and 90 degrees latitude

Polar Easterly Wind Belt

This winds move along Earth's surface from the polar high to the subpolar low

Polar Front

The boundary between the prevailing westerlies and the polar easterlies.

Polar High

The pole of high pressure region, where dense air descends, are located at the poles.

Prevailing Westerly Wind Belt

This winds moving away from the subtropical highs move toward higher latitudes.

Sea Breeze

The land heats the air around it and, during the afternoon, the warm, low-density air over the land rises. Rising air creates a low-pressure region over the land, pulling the cooler air over the ocean toward land

Southeast Trade Winds

Winds that blow from southeast in the Southern Hemisphere

Storm

An atmospheric disturbance characterized by strong winds, precipitation, and often thunder and lightning.

Storm Surge

Is responsible for 90% of the deaths associated with hurricanes. mass of elevated, wind-driven water.

Subpolar

Region bordering the polar regions.

Subpolar Low

The pressure system within the subpolar region, extensive precipitation occurs.

Subtropical

Region bordering the tropical regions.

Subtropical High

A belt of high pressure is centered there, so the dry, descending air produces little precipitation and a high rate of evaporation, resulting in the highest surface salinities in the open ocean

Summer Solstice

Sun reaches its most northerly point in the sky.

Temperate

The region lies between the tropics, the area near the Equator.

Trade Winds

Winds found in the tropical regions. Trade winds blow from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere

Tropic of Cancer

23.5 Degrees North Latitude

Tropic of Capricorn

23.5 Degrees South Latitude

Tropical

That extends north or south of the of the equatorial region, up to the Tropic of Cancer and the Tropic of Capricorn, respectively.

Troposphere

he lower portion of the atmosphere (up to about 12 kilometers or 7 miles), within which there is relatively strong circulation.

Typhoon

is a mature tropical cyclone that develops in the northwestern part of the Pacific Ocean between 180° and 100°E.

Vernal Equinox

The sun is directly overhead at the equator and all locations on Earth experience 12 hours of daylight and 12 hours of darkness (March 21).

Warm Front

The contact between a warm air mass moving into an area occupied by cold air.

Weather

Describes the conditions of the atmosphere at a given place and time.

Wind

That results from movement of air

Winter Solstice

Sun reaches its most southerly point in the sky.

Ocean Current

Masses of water that flow from one place to another.

Surface Currents

Wind-driven currents that move water horizontally and occur primarily in the ocean's surface waters.

Deep Currents

Density-driven currents that move water vertically and account for the thorough mixing of the deep masses of ocean water.

Gyres

Large, circular-moving loops of water driven by the major wind belts of the world; also called subtropical gyres when centered at 30 degrees north or south latitude.

Columbus Gyre

North Atlantic Subtropical Gyre.

Navigator Gyre

South Atlantic Subtropical Gyre.

Turtle Gyre

North Pacific Subtropical Gyre.

Heyerdahl Gyre

South Pacific Subtropical Gyre.

Majid Gyre

Indian Ocean Subtropical Gyre.

Equatorial Currents

Currents that travel westward along the equator, driven by the trade winds.

Western Boundary Currents

Currents that are deflected away from the equator by the Coriolis effect as they reach the western portion of an ocean basin.

Northern or Southern Boundary Currents

Currents in the Northern or Southern Hemisphere, between 30 and 60 degrees latitude, directed in an easterly direction across an ocean basin by the prevailing westerlies.

Eastern Boundary Currents

Currents that flow toward the equator along the eastern boundary of the ocean basins.

Equatorial Countercurrents

Narrow currents that flow to the east, counter to and between the adjoining equatorial currents, under the influence of gravity due to water piling up on the western margin of an ocean basin.

Subpolar Gyres

Gyres that rotate opposite adjacent subtropical gyres, driven in a westerly direction by the polar easterlies.

Ekman Spiral

A circulation model developed by V. Walfrid Ekman in 1905 that explains how surface waters move in a direction different than the wind due to the Coriolis effect.

Ekman Transport

The average movement of surface water (90 degrees to the right in the Northern Hemisphere and 90 degrees to the left in the Southern Hemisphere) as a result of Ekman spiral.

Geostrophic Current

A current that moves in a circular path around the hill of water formed in a subtropical gyre, resulting from a balance between gravity and the Coriolis effect.

Western Intensification

The phenomenon where western boundary currents of subtropical gyres are faster, narrower, and deeper than their eastern boundary counterparts.

Upwelling

The vertical movement of cold, deep, nutrient-rich water to the surface.

Downwelling

The vertical movement of surface water to deeper parts of the ocean.

Antarctic Circumpolar Current

The main current in Antarctic waters that encircles Antarctica and flows from west to east.

East Wind Drift

A surface current propelled by the polar easterlies that moves from an easterly direction around the margin of the Antarctic continent.

Antarctic Divergence

A divergence of currents along a boundary where East Wind Drift and Antarctic Circumpolar Current flow around Antarctica in opposite directions.

Gulf Stream

Moves northward along the East Coast of the United States, warming coastal states and moderating winters in these and northern European regions.

Sargasso Sea

The water that circulates around the rotation center of the North Atlantic gyre, known for its floating Sargassum algae.

Monsoon

Winds of the northern Indian Ocean have a pattern called monsoon (mausim = season) that changes direction by the season.