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  2. Pressure system - Wikipedia

    en.wikipedia.org/wiki/Pressure_system

    A low-pressure area is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. [1] The formation process of a low-pressure area is known as cyclogenesis. [2]

  3. Low-pressure area - Wikipedia

    en.wikipedia.org/wiki/Low-pressure_area

    In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area . Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible rain or storms), [ 1 ] while high-pressure areas are ...

  4. Polar low - Wikipedia

    en.wikipedia.org/wiki/Polar_low

    Polar lows have been referred to by many other terms, such as polar mesoscale vortex, Arctic hurricane, Arctic low, and cold air depression. Today the term is usually reserved for the more vigorous systems that have near-surface winds of at least 17 m/s (38 mph).

  5. Synoptic scale meteorology - Wikipedia

    en.wikipedia.org/wiki/Synoptic_scale_meteorology

    Most high-and low-pressure areas seen on weather maps (such as surface weather analyses) are synoptic-scale systems, driven by the location of Rossby waves in their respective hemisphere. Low-pressure areas and their related frontal zones occur on the leading edge of a trough within the Rossby wave pattern, while high-pressure areas form on the ...

  6. Atmospheric circulation - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_circulation

    Those cells exist in both the northern and southern hemispheres. The vast bulk of the atmospheric motion occurs in the Hadley cell. The high pressure systems acting on the Earth's surface are balanced by the low pressure systems elsewhere. As a result, there is a balance of forces acting on the Earth's surface.

  7. Convergence zone - Wikipedia

    en.wikipedia.org/wiki/Convergence_zone

    An example of a convergence zone is the Intertropical Convergence Zone (ITCZ), a low pressure area which girdles the Earth at the Equator. [3] Another example is the South Pacific convergence zone that extends from the western Pacific Ocean toward French Polynesia. The ITCZ shifts with the tilt of the earth, coinciding with the changing of seasons.

  8. Ultra-high vacuum - Wikipedia

    en.wikipedia.org/wiki/Ultra-high_vacuum

    In any vacuum system, some gas will continue to escape into the chamber over time and slowly increase the pressure if it is not pumped out. [5] This leak rate is usually measured in mbar L/s or torr L/s. While some gas release is inevitable, if the leak rate is too high, it can slow down or even prevent the system from reaching low pressure.

  9. Walker circulation - Wikipedia

    en.wikipedia.org/wiki/Walker_circulation

    The Walker circulation is associated with the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean, and a low pressure system over Indonesia. The Walker circulations of the tropical Indian, Pacific, and Atlantic basins result in westerly surface winds in northern summer in the first basin and easterly ...