Record-setting weather and climate events may seem endlessly repetitive at times, yet occasionally there will be moments like an abruptly sounding cymbal that draw our attention back into focus.
Temperature, or the measure of atmospheric heat or cold, is one key indicator of weather. Additionally, precipitation consists of rain, hail, sleet and snowfall – two other key aspects.
1. Temperature
Temperature on Earth is determined primarily by solar heat energy reflected off its surface and human activities such as emitting greenhouse gases into the atmosphere, as well as using thermometers to record it in degrees Celsius, Fahrenheit or Kelvin (one of seven base units of International System of Units).
Heat transference between air and ground or ocean controls the weather in any given area. Since warmer air is lighter than cooler air, warmer air rises higher into the atmosphere via convection currents. Furthermore, this movement of heated air may create clouds or precipitation as a result.
Example of Hurricane: Hurricanes are large storms that form over water, producing humid and hot conditions with strong winds and rain that can bring flooding as well as damage to property. Hurricanes have the capacity to bring strong winds with it as well as powerful rainfall which may result in significant flood damage to property.
As humans have altered our climate, the United States is witnessing more hot days than cold ones. If this trend continues, more hot days could emerge in future.
Humidity, or water vapor content of the air, plays an integral part in weather patterns. Even small changes to humidity levels can have dramatic repercussions; warmer air holds more water vapor than cool air does and moist air acts as an excellent conductor of heat.
2. Wind
Wind is the movement of air. It can dry your clothes during summer days while chilling you to the bone during winter nights. Wind can even uproot trees from their roots and carry sailboats across oceans – serving as an equalizer of climate, transporting heat, moisture, and pollutants long distances across our globe.
Wind can be strong enough to take down houses, or so mild you hardly feel it. People have developed tools to measure this phenomenon such as wind vane mounted on top of buildings to measure breezespeed or barometers that measure air pressure; some computers even attempt to forecast weather based on air pressure, temperature and humidity readings; these scientists who make these forecasts are known as meteorologists.
Wind is caused by uneven heating of Earth’s surface by the sun. Land and water heat up at different rates, leading to air above it to expand as a warmer area heats up more, before being filled in by another mass of air rushing in to take its place and create wind. This process repeats day and night.
Friction between air molecules as it passes over surfaces affects wind strength, as does their change of direction depending on where they originate. Prevailing winds – those which remain steady year after year in their direction of travel – are known as prevailing winds, often classified into trade winds, westerlies or polar easterlies depending on where they come from.
Prevailing winds transport heat and moisture from other regions around the world to localized regions, creating diverse weather patterns in a region. For instance, northerly winds bring cold polar air from Antarctica while southerly ones bring warm, moist air from India’s Indian Ocean region.
3. Clouds
Clouds are clouds made up of mass accumulations of water droplets or ice crystals floating in the atmosphere, serving an essential function in weather patterns by reflecting some of the Sun’s radiation back into space and trapping some within our atmosphere – without which there would be no rain, sleet, or snow to form precipitation events.
Cloud water droplets can transform when they grow too large for their surrounding air to hold. This process, known as condensation, causes droplets to change shape when their size exceeds that of their surrounding atmosphere and eventually fall to Earth as rain, sleet or snow. Clouds play an integral role in Earth’s water cycle by moving it from place to place while also controlling how much of the Sun’s energy reaches our planet’s surface and is absorbed and released back out again as energy.
Clouds reside in the troposphere, the lowest region of atmosphere closest to earth, and are divided into 10 basic genera or types according to their physical forms and altitude.
Clouds can be challenging to understand due to temperature variations within their surrounding air. Warm air holds more water vapour, leading it to rise higher before becoming clouds – giving rise to different shapes and colours of clouds in the sky, as well as eliminating them on sunny days entirely! Scientists are currently conducting studies that aim to predict how climate change might influence clouds globally – they have found evidence suggesting global warming might increase certain kinds of clouds while decreasing others.
4. Rain
Rain is water that falls from the sky and forms part of nature’s water cycle, providing freshwater for people, plants and animals as well as hydroelectric power plants and crop irrigation projects.
Rain occurs when air cools and water vapour condenses into droplets of liquid. As these water droplets gather into clouds, as they grow larger and heavier the clouds become unstable and begin to release their contents as raindrops onto the earth’s surface.
Rain falls in many forms: drizzle is light rain; moderate rain falls as showers; heavier downpours are known as thunderstorms when wind speeds exceed 90 km/h; this type of event can bring with it flooding, hail, and lightning strikes that lead to destruction and can even bring with them hailstorms that cause flood damage, hailstorms or lightning bolts.
If you live in the southern United States, chances are high that you’ll see lots of rain. Seattle, Washington is known as one of the wettest cities with an annual precipitation average of 40 inches or so; while Cherrapunji in India receives 11 meters annually!
Chances of rain increase when airborne dust particles, whether organic or inorganic, act as cloud condensation nuclei and help water vapor condense into drops of raindrops. Artificial sources include automobile exhaust fumes and industrial factories.
Sometimes rain forms from frozen water; this phenomenon is known as “virga,” and is one of the main sources of precipitation in the Arctic. Rain and virga may also form when snowflakes melt when passing through warmer air; although such forms of precipitation tend to only occur occasionally; too frequently and it could have adverse impacts on the environment and make things dry and brown.
5. Snow
Snow falls most often in areas experiencing cold temperatures and covers 23% of Earth’s land surface. A thick cover of snow helps regulate global air temperature by reflecting much of the Sun’s energy back onto itself; if, however, too early melting occurs or too much heat accumulates beneath its layers then air temperature will become warmer and less likely to freeze over.
Snow is more than a beautiful winter sight; it plays an essential role in life on Earth. Not only can it provide water for humans and animals alike, it also protects plants from extreme temperatures by slowing air movement so wind speeds don’t become excessively high.
Snow forms high in clouds from water vapor, or liquid water molecules suspended in gas form. When these water vapor molecules freeze into solid form they produce ice crystals and snowflakes which either fall to earth or remain suspended above them for later collection by clouds.
There is always some amount of water vapor present in the atmosphere even when it isn’t raining, and this vapor may take form as snow or rain when certain air masses with differing temperatures collide; such as when meeting with warm or cold fronts.
Snowflakes’ shapes and sizes vary with weather conditions at any given time, with scientists having identified more than 30 unique snowflake shapes. Wilson Bentley was famous for photographing over 3,000 snowflakes up close in order to study their patterns.
Snowfall levels vary with each season and location. A blizzard is an intense snowfall lasting several hours or days while flurry snowstorms occur more frequently and last only briefly. On average, scientists have found that North American snow cover has decreased due to rising temperatures.