TAMU ATMO 201 EXAM 2

An adiabatic process is one where no heat is lost or gained by the air parcel. 

True

The dry adiabatic lapse rate is

9.8 °C/km

The moist adiabatic lapse rate is 

~6.0 °C/km

If I move a dry air parcel with a temperature of 20C up adiabatically 2.5km, what is its new temperature?

-5 °C

The dry and moist adiabatic lapse rates represent the only two options for temperature decrease (increase) a parcel can have as it rises (sinks). 

True

What is the environmental lapse rate?

The rate at which the temperature of the real atmosphere changes with height.

What is the difference between the environmental lapse rate and the dry/moist adiabatic lapse rate?

The environmental lapse rate will measure temperature change within the atmosphere, while the dry/moist adiabatic lapse rate measures the change of a sinking or rising air parcel due to either expansion or compression.

A parcel is absolutely unstable:

When the environmental lapse rate is greater than the dry-adiabatic lapse rate

A parcel is conditionally unstable:

When the environmental lapse rate is between the dry and moist adiabatic lapse rates

A  layer which is stable if a parcel is  lifted dry adiabatically, but unstable if lifted and condensation occurs, is:

Conditionally Unstable

Which of the following sets of conditions would produce a cumulus cloud with the lowest base?

air temperature 90F, dew point temperature 60F

Which of the following sets of conditions would produce a cumulus cloud with the highest base?

air temperature 90F, dew point temperature 20F

What two sets of conditions, working together, will make the atmosphere the most unstable?

Warm the surface and cool the air aloft

What two sets of conditions, working together, will make the atmosphere the most stable?

Cool the surface and warm the air aloft

Water cannot exist in liquid form below freezing. 

False

A parcel of air starts at the surface with a temperature of 20C and a dew point of 13C.  It is lifted up over one side of a 1000-meter tall mountain range.  When it reaches the other side, this parcel’s temperature will be________? Assume the elevations of the starting and ending positions are the same.

Higher than 20C

In the Bergeron Process:

Ice Crystals grow at the expense of liquid water.

Air pressure in the atmosphere:

Decreases with height

Above surface low pressure centers we expect rising motion. 

True

At upper levels, warm air is associated with:

high heights/pressure

Below is a 500mb upper-air chart, where the grey lines indicate the height in of the 500mb surface in decameters (add a zero to the end for meters). This is a constant pressure map. Where, geographically, is there an upper-level trough (i.e., low-pressure) located? 

Wisconsin

Below is a 500mb upper-air chart, where the grey lines indicate the height in of the 500mb surface in decameters (add a zero to the end for meters). This is a constant pressure map. Where, geographically, is there an upper-level ridge (i.e., high-pressure) located?

Utah

Which way does the Coriolis force turn parcels in the Northern Hemisphere? 

Right

Which way does the Coriolis force turn parcels in Australia? 

Left

For a parcel near the surface in the Northern Hemisphere, which of these arrows shows the Coriolis Force?

D

Review question. A parcel of air starts at the surface with a temperature of 20°C and a dew point of 8° C.  It is lifted up over one side of a 1000-meter tall mountain range.  When it reaches the other side, this parcel’s temperature will be (Assume the elevations of the starting and ending positions are the same.):

 

lower than 20C

Geostrophic balance is a balance between what forces? Select all that apply. 

Coriolis
Pressure Gradient Force

What forces are involved in determining horizontal wind speed at the surface?

Coriolis

Pressure Gradient Force
Friction
Gravity

Warm air at the surface leads to what sort of pressure change at the surface?

Low Pressure

Land cools/warms slower than water. 

False

Which of the following are thermal circulations?

Dust Devils

Mountain Valley Breezes

 Santa Anna Winds

 Sea Breezes

 Monsoons

Monsoon circulations are similar to land/sea breezes, but on a much larger scale. 

True

Air that is descending down terrain:

 

Cools at the dry adiabatic lapse rate

Warms at the dry adiabatic lapse rate

When rotation is added to the planet, how many vertical circulation cells do we get in each hemisphere?

3

A band of high pressure centers is located roughly:

30 Degrees both north and south of the equator

What direction is the wind coming from at point X? Note this is a 500mb chart and heights are given in decameters. 

South

What forces are in balance at point X (select all that apply). Note this is a 500mb chart.

Coriolis

What is the balance of forces called at point X? Note this is a 500mb chart. 

Geostrophic

At what point would you expect the winds to be the fastest? Note this is a 500mb chart. 

D

El Nino occurs when the Walker Circulation reverses and warm water is present in the eastern Pacific ocean. 

True

El Nino impact for Texas in winter generally means:

Cooler and Wetter