Health

Four tips on how to layer up to keep cold weather at bay

Whether you're waiting at the bus stop or going for a run, dressing for the conditions and level of outdoor activity is key to staying safe and warm in bitter temperatures, say University of Alberta experts.

Diseases, Conditions, Syndromes

Computer model shows how to better control MRSA outbreaks

A research team led by scientists at the Columbia University Mailman School of Public Health report on a new method to help health officials control outbreaks of methicillin-resistant Staphylococcus aureus, or MRSA, a life-threatening ...

Health

Winter's many challenges to eye health

(HealthDay)—Dry, itchy eyes are a common problem in the winter and low humidity is a major reason, one ophthalmologist says.

Cardiology

Can sudden weather change cause strokes?

A collaborative study led by a neurologist at Rush University Medical Center and an environmental scientist at the University of Illinois at Chicago suggests that weather patterns that cause dramatic changes in barometric ...

Diseases, Conditions, Syndromes

Will the arrival of El Niño mean fewer mosquitoes this summer?

Once the warm weather arrives, you know mosquitoes won't be far behind. Spring heatwaves associated with the impending arrival of El Niño to the east coast of Australia may mean we'll get an early taste of summer, but what ...

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Weather

Weather is a set of all the phenomena occurring in a given atmosphere at a given time. Weather phenomena lie in the troposphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate is the term for the average atmospheric conditions over longer periods of time. When used without qualification, "weather" is understood to be the weather of Earth.

Weather occurs due to density (temperature and moisture) differences between one place and another. These differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics. The strong temperature contrast between polar and tropical air gives rise to the jet stream. Weather systems in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream flow. Because the Earth's axis is tilted relative to its orbital plane, sunlight is incident at different angles at different times of the year. On Earth's surface, temperatures usually range ±40 °C (100 °F to −40 °F) annually. Over thousands to hundreds of thousands of years, changes in Earth's orbit affect the amount and distribution of solar energy received by the Earth and influence long-term climate

Surface temperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes due to differences in compressional heating. Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. The atmosphere is a chaotic system, so small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts to control the weather have occurred throughout human history, and there is evidence that human activity such as agriculture and industry has inadvertently modified weather patterns.

Studying how the weather works on other planets has been helpful in understanding how weather works on Earth. A famous landmark in the Solar System, Jupiter's Great Red Spot, is an anticyclonic storm known to have existed for at least 300 years. However, weather is not limited to planetary bodies. A star's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar wind.

This text uses material from Wikipedia, licensed under CC BY-SA