Clouds

Clouds

Clouds are made of very small drops of water of water, ice crystals, and other small particles in the atmosphere (mass of air surrounding Earth). The water comes from condensation, a process that allows small drops of water to form as the air cools. Cloud shapes and the way clouds form give scientists important clues about local weather and conditions in the atmosphere around the world.

Clouds are divided into several types or families of clouds. These families of clouds are named according to where or how they form, and include high-level clouds, middle-level clouds, and low-level clouds.

In addition to belonging to a family, clouds are also named for their shape. Puffy clouds are known as cumuliform clouds, and flat sheet-like clouds are known as stratoform clouds.

Climate

Climate

Global climate is the long-term pattern of temperature and precipitation on Earth’s surface. Heat and water are unevenly distributed around the globe, and Earth has many climate zones (areas with a characteristic climate) and subclimates (areas with unique climate features within a climate zone) with unique patterns of temperature, rainfall, winds, and ocean currents (the circulation of ocean waters that produce a steady flow of water in a prevailing direction).

Climate zones support communities of plants and animals (ecosystems) that have adapted to thrive there. The term climate refers to temperature and moisture patterns that characterize a large region over tens, hundreds, or even thousands of years. Local changes that last days, weeks, or seasons, like storms and droughts, are called weather.

Regulating sunlight: the ozone and greenhouse layers

Energy from the Sun drives Earth’s climate and biology. Sunlight heats the surface and nourishes plants that, in turn, feed animals. Heat drives ocean currents, winds, and the hydrologic cycle (the circulation of water between the land, oceans, and the layer of air surrounding Earth, called the atmosphere).

Monsoon

Monsoon

A monsoon is a regional wind that reverses directions seasonally. In southern Asia, wet, hot monsoon winds blow from the southwest during the summer months and bring heavy rains to a large area that includes India, Bangladesh, Sri Lanka, Pakistan, and Nepal. Northeasterly winds (winds are named by the direction from which they blow) that blow down from the Himalaya Mountains in the winter are cool and dry.

Monsoon winds occur in many regions around the world, in Africa, Australia, and in North America, where the Mexican monsoon brings over half of the year’s total rain to Northern Mexico, Arizona, and New Mexico each June through August. The Mexican monsoon is a smaller version of the classic and well-known southern Asian monsoon.

The word monsoon comes from the Arabic word mausim which means “season.” In southern Asia, the monsoon controls the seasons: hot and wet in the summer, cool and dry in the winter.

Storms

Storm

Storms are disturbances in the atmosphere (air surrounding Earth) that bring severe weather: heavy rain and snow, high winds, lightning and thunder, tornadoes, and hail.

There are storms that are mild, such as rainstorms, which are beneficial, bringing needed rainfall for plants, animals, and waterways. Yet storms also have the potential to cause great harm. Hurricanes batter coastlines and islands with high winds, drenching rain, and waves.

Thunderstorms and blizzards can cause floods and dangerous traveling conditions. During thunderstorms, lightning can ignite brush fires, and hail can destroy crops. Tornadoes can cut swaths of destruction across anything in its path.

Weather

Weather

Weather is the state of the atmosphere (mass of air surrounding Earth) at a particular place and point in time. Rain showers, gusty winds, thunderstorms, cloudy skies, droughts (prolonged period of dry weather), snowstorms, and sunshine are all examples of weather conditions.

Weather scientists, called meteorologists, use measurable factors like atmospheric pressure (pressure caused by weight of the air), temperature, moisture, clouds, and wind speed to describe the weather. Meteorologists make predictions of future weather based on observations of present regional weather patterns and past trends.

Weather prediction, or forecasting, is an important part of meteorology (weather science). Advance warning of such weather phenomena as extreme hot and cold temperatures, heavy rainfall, drought, and severe storms can protect people’s property and save lives.