any help would be great :)
-
Pretty simple. A denser material will always "fall" through a less-dense material, or alternatively look at it as the less dense material being more buoyant and thus rising through the denser material. Actually... look at it as both!
High pressure areas are normally caused by a phenomenon called subsidence, meaning that as the air in the high cools it becomes denser and moves toward the ground. Pressure increases here because more air fills the space left from the low. Subsidence also evaporates most of the atmosphere's water vapor so high pressure systems are usually associated with clear skies and calm weather.
Since everything in nature flows form high to low, you'll have winds blowing out of a high pressure area and toward a low pressure zone. The high pressure zone will generally be colder, but drier.
Alternatively... low pressure zones are where air rises. As the rising air cools, clouds will begin to form. The instability of the air will produce quite large vertical development of cumuliform clouds with associated rain showers (such as cumulonimbus cloud).
Now, hook this together and you get circulating currents with hot/less dense air rising in one place, cool/more dense air falling in another place, and thus creating surface winds from high to low, and upper atmosphere the other direction as it cools.
In the ocean, density-driven currents act the same way. The Global Ocean Conveyor Belt is created when very cold, dense ocean water in the North Atlantic descends through the water column. It starts the cycle of pushing the whole thing around the globe. In the warm waters of the equatorial Pacific, waters rise to the surface.
Just a version of high pressure to low pressure; the water behaves in essentially the same manner as the atmosphere (not surprising, because technically they're both fluids).
High pressure areas are normally caused by a phenomenon called subsidence, meaning that as the air in the high cools it becomes denser and moves toward the ground. Pressure increases here because more air fills the space left from the low. Subsidence also evaporates most of the atmosphere's water vapor so high pressure systems are usually associated with clear skies and calm weather.
Since everything in nature flows form high to low, you'll have winds blowing out of a high pressure area and toward a low pressure zone. The high pressure zone will generally be colder, but drier.
Alternatively... low pressure zones are where air rises. As the rising air cools, clouds will begin to form. The instability of the air will produce quite large vertical development of cumuliform clouds with associated rain showers (such as cumulonimbus cloud).
Now, hook this together and you get circulating currents with hot/less dense air rising in one place, cool/more dense air falling in another place, and thus creating surface winds from high to low, and upper atmosphere the other direction as it cools.
In the ocean, density-driven currents act the same way. The Global Ocean Conveyor Belt is created when very cold, dense ocean water in the North Atlantic descends through the water column. It starts the cycle of pushing the whole thing around the globe. In the warm waters of the equatorial Pacific, waters rise to the surface.
Just a version of high pressure to low pressure; the water behaves in essentially the same manner as the atmosphere (not surprising, because technically they're both fluids).