Either of two times of the year when the sun's rays shine directly overhead at noon at the furthest points north or south, and that mark the beginning of summer and winter; in the northern Hemisphere, the summer solstice is the longest day and the winter solstice is the shortest.
each of the two days in a year on which the day and night are equal in length; marks the beginning of spring and autumn.
The condition of the atmosphere at a particular location and time.
The typical weather conditions at a particular location as observed over time.
Falling water droplets in the form of rain, sleet, snow or hail.
Storms that fall over warm, tropical ocean waters.
A tropical storm, like a hurricane, that occurs in the western Pacific.
A powerful funnel-shaped column of spiraling air.
A heavy snowstorm with winds of more than 35 miles per hour and reduced visibility of less than one quarter mile.
A long period without rain or with minimal rainfall.
The transfer of heat in the atmosphere by upward motion of the air.
A weather pattern created by the warming of the waters off the west coast of South America, which pushes warm water and heavey rains toward the Americas and produces drought conditions in Australia and Asia.
Layers of gases released by the burning of coal and petroleum that traps solar energy, causing global temperature to increase.
The flat treeless lands forming a ring around the Arctic Ocean; the climate region of the Arctic Ocean.
A permanently frozen ground.
An interdependent community of plants and animals.
Ecosystem of a region
a characteristic of a broad-leaf trees, such as a maple, oak, birch and cottonwood
a forest region located in the Tropical Zone with a heavy concentration of different species of broad-leaf trees.
flat, grassy, mostly treeless plains in the tropical grassland region.
temperate grassland region in the Northern Hemisphere
the study of the distribution and interaction of the physical and human features on the earth
the exact place on the earth where a geographic feature is found.
each half of the globe
the imaginary line at zero meridian used to measure longitude east and west, and dividing the earth's east and west halves
a set of imaginary lines that go around the earth over the poles, dividing its east and west.
a three-dimensional representation of the earth
a general reference map; representation of natural and man-made features on the earth
consists of the sun and nine known planets.as well as other celestial bodies that orbit the sun.
a rock layer about 1,800 miles thick that is between the earth's crust and the earth's core.
the thin rock layer making up the earths surface
the solid rock portion of the earth's surface
all the parts of the earth where plants and animals live, including the atmosphere, the lithosphere, and the hydrosphere
the continuous circulation of water among the atmosphere, the oceans, and the earth
water held under the earths surface. often in and around the pores of rocks.
the difference in elevation of a land form from the lowest point to the highest point
an enormous moving shelf that forms the earth's crust
a sometimes violent movement of the earth, produced when tectonic plates grind or slip past each other at a fault
the point on the earth's surface that corresponds to the location in the earth where an earthquake begins
a fracture in the earth's crust