Exam 2 Flashcards
T or F: Mid-Latitude Cyclones are often characterized by the presence of low pressure centers.
True
T or F: Clouds occurring at High Altitudes (at or above 30,000 feet) have no prefixes in their names.
False
T or F: In an unstable environment, air parcels continue to rise even after the forces lifting them are removed.
True
T or F: An unsaturated air parcels rise through the atmosphere they expand and cool and their dew point temperature remains constant.
True
T or F: In a mature mid latitude cyclone in the Northern Hemisphere, a cold front is typically found on the northern portion of the central low.
False
T or F: Warm Fronts are marked on weather maps as red lines with small closed triangles.
False
T or F: Wind spiral counterclockwise and inwards around low pressure in Northern Hemisphere
True
T or F: Lifting motions along cold fronts are often weak, gradual, and long lasting.
False
T or F: Assuming that it exists, the jet stream is found near the top of the troposphere near the tropopause.
True
T or F: When force is applied to neutrally- stable parcels, they do not return to their original position nor continue to move after the force is removed.
True
T or F: Environmental temperatures can vary widely with height, especially when compared to how temperatures of parcels change with height.
True
A temperature inversion describes _______ _____ in the temperature of the atmosphere with increasing height.
an increase
What vertical motions exist above centers of low pressure in the atmosphere?
Upward motions
Air in the Atmospheric Boundary Layer is acted upon by the frictional force. What effect does it have upon the air in this layer?
Slows the Air’s Velocity
What instrument is used to measure the “quasi-vertical” properties of the atmosphere, providing vertical measurements of temperature, humidity, pressure, wind speed, and wind direction?
Weather Balloon Rawindsonders
Which forces act upon the air in the free atmosphere?
Pressure Gradient Force and Coriolis Force
Divergence present aloft, associated with the Jet Stream is responsible for supporting _________ _____________ systems at the surface.
low pressure
In the Northern Hemisphere, low pressure systems spin_____ and high pressure systems spin ______
Counterclockwise, clockwise
In stable environments, the parcel’s air temperature is ___________ __________ the environment’s air temperature.
Colder than
Precipitation associated with warm fronts:
Falls on the cold side of the front, is typically light, and is widespread ahead of the front.
What is the value of the Dry Adiabatic Lapse Rate in C per Km)
9.8
What are the signs that a warm front had passed?
Rising temperatures, southerly/southeasterly winds, and increasing dew point
What are the signs that a cold front has passed
decrease in temperature, winds from the west/northwest, and decrease in dew point.
Why is the Moist Adiabatic Lapse Rate (MALR) less than the Dry Adiabatic Lapse Rate?
When a moist/saturated air parcel rises, its temperature decreases and eventually reaches its dew point where condensation occurs. Condensation is an exothermic process, and the heat released slows the rate at which the parcel’s temperature can decrease. The rising of a dry/unsaturated air parcel will not result in this exothermic process, and thus will be able to decrease in temperature at a faster rate.
Describe an environment that is unstable, discussing parcel temperatures and environmental temperatures in your answer. Why does this difference in temperature cause the parcel to behave in this manner?
An environment that is unstable has air parcels with a temperature that is higher than the environmental temperature. The higher the air parcels move up in the atmosphere, the warmer they become, causing them to be less dense (because they are now more spread apart) than the air in its surrounding environment. If the difference in temperature is great enough it creates a force that moves the parcels in a vertical motion. If they continue to behave in this manner, it can lead to storms and clouds developing.
How do low pressure systems (midlatitude cyclones) develop? What mechanisms drive their growth, and what mechanisms help to support the system?
The main mechanisms that drive their growth are the contrast in temperatures between the different air masses and when air converges at the air at the surface (which causes air to rise). These mechanisms are supported by the divergence of the upper level air which allows air to continuously rise over time.
What are Parcels? How can we think about them?
What does the behavior of parcels look like as they rise?
They expand as they move into a lower pressure environment, their molecules spread out and become less active, and their temperature decreases.
What is a force
An interaction that causes a substance to change speed or direction
What are the three types of forces?
Magnetic force, gravitational force, and electric force.
Example of Magnetic Force:
When the same charges of a magnet repel each other.
Example of Gravitational Force:
An apple falling to the ground.
Example of Electric Force:
Calcium changing the charge of the inside of the receptor.
Why are forces important to meteorology?
Winds are driven forces acting on air
What is a wind gradient?
The change in wind speed or direction over a vertical or horizontal distance.
What is the Pressure Gradient Force relationship to wind?
The force directed from high pressure towards low pressure, in the presence of a pressure gradient. PGF is the fundamental driver of wind, its what causes wind to blow.
Winds blow
What is the Coriolis Force?
Acts to deflect or turn the winds,
How does the Coriolis Force affect wind in the Northern Hemisphere?
Deflects objects to the right
How does the Coriolis Force affect wind in the Southern Hemisphere?
Deflects object to the left
What is the Atmospheric boundary layer, how does it affect wind flow?
Frictional Force?
Always acts opposite to an objects direction of motion, frictional forces always slow down the wind. primarily act upon winds in the boundary layer.
What is the Jet Stream?
Narrow band of strong winds that move from west to east in the upper atmosphere.
What is advection? How does the flow around lows cause advection of air masses?
The horizontal transport of atmospheric properties like temperature, humidity or moisture by the wind.
What are Fronts? What do they mark?
Are fronts associated with highs or lows? Why?
