As we grow accustomed to the area we live in, we know what weather to expect as seasons change. Being prepared for the best or worst weather is not usually a challenge, however the atmosphere is capable of some surprises. With climate change becoming a more prevalent issue in today's world, the wonders of the weather can be even more unpredictable. Understanding how weather works may help us prepare for the changes.
Atmospheric conditions vary widely. Characteristics of these conditions include humidity, wind speed, cloud cover, precipitation and air temperature. "Weather" is the blanket term used to describe these conditions over a short time period.
The "climate" of an area or country is the term used to describe the average weather conditions over a long period of time. For example, in Russia the weather is predominantly cold throughout the year, therefore it would be said that it has a cold climate.
As moist warm air rises into the sky, it cools down to form miniscule droplets of water, which form clouds when millions of these droplets come together. Very cold clouds are made up of ice crystals.
Rainbows are multi-colored arcs of light that form in the sky when the sun shines through the rain. Although we normally see light as white, it is actually in seven colors–red, orange, yellow, green, blue, indigo and violet. These all become visible as the light is refracted through the raindrops.
Snowflakes form in clouds during subzero temperatures. Water droplets freeze and fall through clouds, bumping off other frozen crystals. This bumping process, combined with a little melting and re-freezing, contribute to the complex design of snowflakes.
Ultimately, the sun plays a pivotal role in weather conditions. Rays from the sun are absorbed differently by land and water. As a result, the overlying air masses will have variations in temperature and pressure. Warmer air masses rise, as they are lighter, while air masses will get heavier as they cool and then they sink. A weather front is the boundary between two air masses. The atmosphere can be unstable in these boundaries due to abrupt changes in temperature, wind and humidity. Storms develop whenever things become unbalanced, which can result in rain or snow and sometimes thunder and lightning.
Weather extremes such as hurricanes and tsunamis endanger lives and destroy property and livelihoods. According to the World Health Organization, approximately 600,000 deaths occurred worldwide as a result of weather-related natural disasters during the 1990s.
The temperature on Earth is regulated by a natural system known as the "greenhouse effect.” Our atmosphere traps the heat from the sun near the surface of the Earth, primarily through the properties of certain “greenhouse gases.” Without these gases, the average temperature on Earth would be over 30°C colder.
As we burn fossil fuels to heat our homes, run our cars and manufacture various products, we’re adding more greenhouse gases to the atmosphere. The warming capability of the natural greenhouse effect is being enhanced as a result, which in turn is leading to increases in the average temperature on Earth and changes in climate. This is commonly known as "global warming."
As the global climate changes, the Earth is becoming warmer. These changes have the potential to affect human health in various ways. Ecosystems will be affected, which could harm food-producing capabilities of certain areas. Diseases could become more geographically widespread and extreme weather events, such as Hurricane Katrina, which devastated New Orleans in 2005, could become more frequent.
