| Term | Definition |
|---|
| Standard Rain Gauge | consists of a funnel attached to a graduated cylinder that fits into a larger container. If the water overflows from the graduated cylinder the outside container will catch it. |
| Tipping Bucket Rain Gauge | Consists of a large copper cylinder set into the ground. At top of the cylinder is a funnel that collects and channels the precipitation. The precipitation falls onto one of two small buckets or levers which are balanced in same manner as a scale (or child's seesaw). |
| Weighing Type Rain Gauge | Consists of a storage bin, which is weighed to record the mass. Certain models measure the mass using a pen on a rotating drum, or by using a vibrating wire attached to a data logger. The advantages of this type of gauge are that it does not underestimate intense rain, and it can measure other forms of precipitation, including rain, hail and snow. |
| Water Equivalent of Snowfall Coverage | 1" of liquid rainfall equals 10" of snowfall |
| Wet snow may yield... | 1" of liquid rainfall to 5" of snowfall |
| Dry powdery snow may yield... | 1" of liquid rainfall to 15" of snowfall |
| What is Air pressure? | it is the weight of air above a given surface |
| Air pressure ALWAYS... | decreases with height |
| As one climbs in elevation... | there are fewer air molecules |
| In a column with fixed width... if we move air INTO the column with NO temperature change... | Surface pressure would INCREASE |
| In a column with fixed width... if we move air OUT OF the column with NO temperature change | Surface pressure would DECREASE |
| In a WARM column with fixed width and same air pressure... | the molecules move faster and spread farther apart, the air becomes less dense and the column expands in height |
| In a COLD column with fixed width and same air pressure... | the molecules move more slowly and crowd closer together, the air becomes more dense and the column shrinks in height |
| ** It takes a shorter column of cold, dense air to... | exert the same surface pressure as a taller column of warm, less dense air |
| **Atmospheric pressure decreases more RAPIDLY with... | elevation in a COLD column in a cold column of air |
| elevation in a WARM column of air | elevation in a WARM column of air |
| Warmer air aloft is normally associated with... | HIGHER ATMOSPHERIC PRESSURE aloft (resulting in a more stable atmosphere) (in texas with no rain) |
| **COLDER AIR ALOFT is normally associated with... | LOWER ATMOSPHERIC PRESSURE aloft (resulting in a more unstable atmosphere) |
| Horizontal temperature differences results in a... | hoorizontal difference in pressure |
| *** Unequal heating of the earth's surface... | causes wind to blow |
| two types of Barometers are... | -Mercurial and -Aneroid (without fluid) |
| Barometer | An instrument that measures air pressure |
| When measuring air pressure with a barometer, corrections must be made for... | -Temperature ;-Instrument / -Gravity ;-Sea Level |
| Atmospheric pressure decreases on average... | 1" of mercury for each 1000 feet RISE in altitude |
| ***Standard Surface Atmospheric Pressure*** in Mercury: | 29.92"/mercury |
| ***Standard Surface Atmospheric Pressure*** in millibars: | 1013.2 millibars |
| ***Standard Surface Atmospheric Pressure*** in pounds: | 14.7 lbs/in 2 (squared) |
| An altimeter is... | an instrument used to measure the altitude of an object above a fixed level... it is mainly used in airplanes to measure air pressure |
| Always correct air pressure to... | sea level so as to compare pressure to other cities |
| Does cold air weigh more? | YES, because it is more dense |
| Example of place with high pressure | Siberia |
| Example of low pressure | tropical cyclones and tornados (10% less than 29.92"/mercury => around 26%) |
| Characteristics of High Pressure | Air blows around a high in a clockwise manner in the northern hemisphere and counterclockwise in the southern hemisphere. In a cross-section, there is surface divergence and upper air conversion |
| Characteristics of Low Pressure | Air blows around a low in a counterclockwise in the northern hemisphere and clockwise in the in the southern hemisphere.In a cross-section, there is surface convergence and upper air divergence |
| surface pressure | is the atmospheric pressure at a point of Earth's surface. It is directly proportional to the mass of air over that point. With corrections made to surface pressure readings, surface pressure charts use ISOBARS to depict lines of equal surface pressure |
| newton's first law of of motion | Done in millibars - 1013.2 millibars => standard atmospheric pressure **(not the same as upper air charts)** |
| Upper Air (Constant Height) Charts are constructed to show... | height variations along a constant pressure height surface |
| Higher heights equals... | higher pressure |
| Lower Heights equals... | lower pressure |
| On upper air charts, what kind of lines depict pressure? | Height contour lines |
| Where is the ideal location of the upper air chart? | 500 millibars because it's at the halfway point |
| at which level are high or low pressure driven at? | 500 millibar level |
| Newton's First Law of Motion | An object at rest will remain at rest and an object in motion will remain in motion (and will travel at a contant velocity along a straight line) as long as no force is excerted on the object |
| Newton's Second Law of Motion | The force exerted on an object equals its mass times the acceleration produced (F=ma) |
| Newton's Third Law of Motion | For every action, there is an opposite and equal reaction |
| How much coriolis is there around the equator? | ZERO!! |
| How much coriolis is there around the poles? | A LOT?!! |
| Coriolis Force... | (Deflection caused by a rotating object) Coriolis Force ONLY effects wind direction!!!!! (not speed) |
| The amount of Coriolis deflection depends on... | -Rotation of the Earth -The latitude -The objects speed |
| What kind of coriolis deflection is there in the Northern hemisphere? | Rightward deflection! |
| What kind of coriolis deflection is there in the Southern hemisphere? | Leftward Deflection! |
| Fricton... | wiond blowing across the Earth's surface and against other air molecules |
| ***The stronger the winds are... | ...the greater the deflection will be |
| *** The Coriolis affects... | large scale circulation |
| Which direction do hurricanes rotate in? | counterclockwise |
| A theoretical horizontal wind blowing in a straight path, parallel to the the isobars/constant contour lines, at a constant speed | A theoretical horizontal wind blowing in a straight path, parallel to the the isobars/constant contour lines, at a constant speed |
| What are Geostropic Wind caused by? | an exact balance of pressure gradient force and the coriolis force |
| Where are Geostropic Winds found? | they are found in upper level wind flow (parallel) |
| Hydrostatic Balance | occurs in the vertical when an EXACT BALANCE between vertical pressure gradient force and gravity (the earth's atmosphere remain in place) |
| What causes the earth's atmosphere to be imbalanced? | Thunderstorms |
| WInd is characterized by... | -Direction -Speed -Gustiness -Wind Roses |
| Scales of Atmospheric Motion: Microscale... | example... around a building |
| Scales of Atmospheric Motion: Mesoscale*** | Example... in a county, state => This one is used for forcasting!! |
| Scales of Atmospheric Motion: Macroscale | example... synoptic (weather map) scale-surface map of USA (at 500 millibar level) and -Global scale |
| -wind vane -Anemometer -Aerovane -Wind Sock -Rawinsonde -Doppler Radar -Atmosperic profilers | -wind vane -Anemometer -Aerovane -Wind Sock -Rawinsonde -Doppler Radar -Atmosperic profilers |
| *****With (doppler) radar... | there is range and height!!!! |
| Intertropical Convergence Zone | An area of low pressure near or on the equator where the northeast trades and the southeast trades converge |
| Doldrums | Region of ocean near the equator, characterized by calm, light winds (constant low pressure) |
| Horse Latitude | Either of two belts or regions near 30 degrees north or 30 degrees south; characterized by calms and light-baffling winds |
| Single Cell Atmospheric Circulation | With higher air pressure at the poles, sinking cold air flowed southward from the polar regions, once it got to the equator, after warmer air was lifted... it's one big circulation cell with various cells of lows & highs at different latitudes |
| Hadley Cell | Three-dimensional atmospheric circulation cell located at roughly 0 to 30° North and South of the equator. The Hadley cell consists of rising air (intertropical convergence zone) at the equator and descending air (subtropical highs) at 30° North and South |
| The Intertropical Convergence Zone stays at north of the Equator because of... | Continentality |
| Average Global Surface Pressure | During winter, "highs" hoover over land, during warm seasons, "Highs" hoover over water |
| Jet Streams | narrow belts of high speed winds that blow in the (upper level) upper troposphere and lower stratosphere |
| Polar Jet Streams | Where cold air from the North pole moves southward and converges with warmer air... found best at 300 mb height/130,000 ASL |
| Subtropical Jet Streams | Where warm air and moisture move away from equator toward the north... found best at 200 mb height/38,500' ASL |
| Low Level Jet Streams | Found best at 850 mb to 700mb height/4000' to 9800' ASL... forms in plains states and *provides moisture for thunderstorms** |
| What sustains thunderstorms?? | Updrafts because air has to rise |
| Upwelling | an upward flow of cold water from the ocean depths (brings nutrient rich waters to the surface) |
| Surface water of oceans tend to move with ... | the surface winds |
| La nina | An ocean and weather pattern that causes the eastern Pacific Ocean to be colder than normal (air moves from High to Low)... -west of south America |
| El Nino | an event that occurs every two to seven years in the pacific ocean, during which winds shift and push warm surface water toward the coast of south America; it can cause dramatic climate change |
| A change in water temperature... | changes wind patterns |
| prevailing wind | a wind that consistently blows from one direction more than from any other |
| doppler Radar | a type of radar that calculates distance and shows direction of movement |
Combine with other sets
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