The weather is a set of all the phenomena in a given at
mosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the acti vity of these phenomena over short periods (hours or da ys), as opposed to the term climate. which refers to the
average atmospheric conditions over longer periods of t me. When used without qualification, "weather" is under stood to be the weather of Earth.<br/><br/>Weather mo st often results from temperature differences from one place to another. On large scales, temperature differenci es occur because areas closer to the equator receive m
ore energy per unit area from the Sun than do regions cl oser to the poles. On local scales, temperature differenc es can occur because different surfaces (such as ocean s, forests, ice sheets, or man-made objects) have differi ng physical characteristics such as reflectivity, roughne ss, or moisture content.cbr/s<br/>Surface temperature differences in turn cause pressure differences. A hot su
rface heats the air above it and the air expands, lowerin g the air pressure. The resulting horizontal pressure gra
dient accelerates the air from high to low pressure, crea
ting wind, and Earth"s rotation then causes curvature of the flow via the Coriolis effect. The simple systems thus formed can then display emergent behaviour to produce
more complex systems and thus other weather phenom ena. Large scale examples include the Hadley cell ue a smaller scale example would be coastal breezes.cbr/s
<br/>The strong temperature contrast between polar an d tropical air gives rise to the jet stream. Most weather systems in the mid-latitudes are caused by instabilities
of the jet stream flow (see baroclinity). Weather system s in the tropics are caused by different processes, such as monsoons or organized thunderstorm systerms.cbr/s
<br/>Because the Earth"s axis is tilted relative to its orbit al plane, sunlight is incident at different angles at differe nt times of the year. In June the Northern Hemisphere is tilted towards the sun, so at any given Northern Hemisp
here latitude sunlight falls more directly on that spot tha n in December (see Effect of sun angle on climate). This etfect causes seasons. Over thousands to hundreds oft
housands of years, changes in Earth"s orbital parameter s affect the amount and distribution of solar energy rec eived by the Earth and influence lonq-term climate (see Milankovitch cycles).br/xbr/>On Earth, common weat i her phenomena include such things as wind, cloud, rain, sTlow. T0d ahid dust Stofmis. Less cofhinonn evens
e natural disasters such as tornadoes, hurricanes and ic e storms. Almost all farmiliar weather phenomena occur In the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and can affect weather lower down in the troposphere, but the exact m echanisms are poorly understood.lebr/><br/>The atm osphere is a chaotic system, so small changes to one p
art of the system can grow to have large effects on the system as a whole. This makes it difficult to accurately
predict weather more than a few days in advance, thoug h weather forecasters are continually working to extend this limit through the scientific study of weather, meteor ology. It is theoretically impossible to make useful day-t
o-day predictions more than about two weeks ahead, im posing an upper limit to potential for improved predictio n skill.[1] Chaos theory says that the slightest variation I
n the motion of the ground can grow with time. This ide a is sometimes called the butterfly effect, from the idea that the motions caused by the flapping wings of a butt ertly eventually could produce marked changes in mt
ate of the atmosphere. Because of this sensitivity to sm all changes it will never be possible to make perfect for
ecasts, although there still is much potential for improv ement.-br/br/>The sun and oceans can also affect th e weather of land. If the sun heats up ocean waters for
Into the air, the moisture can spread throughout nearby and. thus making it coolerThe weather is a set of all the phenomena in a given atmosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the activity of these phenomena over sho...
The weather is a set of all the phenomena in a given atmosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the activity of these phenomena over sho...
The weather is a set of all the phenomena in a given at
mosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the acti vity of these phenomena over short periods (hours or da ys), as opposed to the term climate. which refers to the
average atmospheric conditions over longer periods of t me. When used without qualification, "weather" is under stood to be the weather of Earth.<br/><br/>Weather mo st often results from temperature differences from one place to another. On large scales, temperature differenci es occur because areas closer to the equator receive m
ore energy per unit area from the Sun than do regions cl oser to the poles. On local scales, temperature differenc es can occur because different surfaces (such as ocean s, forests, ice sheets, or man-made objects) have differi ng physical characteristics such as reflectivity, roughne ss, or moisture content.cbr/s<br/>Surface temperature differences in turn cause pressure differences. A hot su
rface heats the air above it and the air expands, lowerin g the air pressure. The resulting horizontal pressure gra
dient accelerates the air from high to low pressure, crea
ting wind, and Earth"s rotation then causes curvature of the flow via the Coriolis effect. The simple systems thus formed can then display emergent behaviour to produce
more complex systems and thus other weather phenom ena. Large scale examples include the Hadley cell ue a smaller scale example would be coastal breezes.cbr/s
<br/>The strong temperature contrast between polar an d tropical air gives rise to the jet stream. Most weather systems in the mid-latitudes are caused by instabilities
of the jet stream flow (see baroclinity). Weather system s in the tropics are caused by different processes, such as monsoons or organized thunderstorm systerms.cbr/s
<br/>Because the Earth"s axis is tilted relative to its orbit al plane, sunlight is incident at different angles at differe nt times of the year. In June the Northern Hemisphere is tilted towards the sun, so at any given Northern Hemisp
here latitude sunlight falls more directly on that spot tha n in December (see Effect of sun angle on climate). This etfect causes seasons. Over thousands to hundreds oft
housands of years, changes in Earth"s orbital parameter s affect the amount and distribution of solar energy rec eived by the Earth and influence lonq-term climate (see Milankovitch cycles).br/xbr/>On Earth, common weat i her phenomena include such things as wind, cloud, rain, sTlow. T0d ahid dust Stofmis. Less cofhinonn evens
e natural disasters such as tornadoes, hurricanes and ic e storms. Almost all farmiliar weather phenomena occur In the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and can affect weather lower down in the troposphere, but the exact m echanisms are poorly understood.lebr/><br/>The atm osphere is a chaotic system, so small changes to one p
art of the system can grow to have large effects on the system as a whole. This makes it difficult to accurately
predict weather more than a few days in advance, thoug h weather forecasters are continually working to extend this limit through the scientific study of weather, meteor ology. It is theoretically impossible to make useful day-t
o-day predictions more than about two weeks ahead, im posing an upper limit to potential for improved predictio n skill.[1] Chaos theory says that the slightest variation I
n the motion of the ground can grow with time. This ide a is sometimes called the butterfly effect, from the idea that the motions caused by the flapping wings of a butt ertly eventually could produce marked changes in mt
ate of the atmosphere. Because of this sensitivity to sm all changes it will never be possible to make perfect for
ecasts, although there still is much potential for improv ement.-br/br/>The sun and oceans can also affect th e weather of land. If the sun heats up ocean waters for
Into the air, the moisture can spread throughout nearby and. thus making it coolerThe weather is a set of all the phenomena in a given atmosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the activity of these phenomena over sho...
The weather is a set of all the phenomena in a given atmosphere at a given time. It also includes interactions with the hydrosphere. The term usually refers to the activity of these phenomena over sho...