UCLA A&O3 Midterm

Equation for ELR

-Delta T/-Delta Z

Suppose an air parcel is at the surface with temperature Tp=25 degrees C. Suppose the environmental temperature decreases linearly from Tsfc=25 degrees C at z=0km to T= 15 degrees C at z=2km. The dew point temperature at the surface is DP=18 degrees C. Calculate the LCL for the air parcel.

0.875 km

If air starts out with a temperature of 18°C with a dew point of 10°C, an ascent of ________ is necessary for the air to become saturated.

1000 m

What will be the temperature of an unsaturated parcel of air at an altitude of 410 meters if it has a temperature of 10 degrees Celsius at the surface?

5.9 degrees Celsius

Which of the following is the relative humidity of an air parcel with a vapor pressure of 8 mb and a saturation vapor pressure of 16 mb?

50 percent

The pressure gradient force forms an angle of _____

90 Degrees

If the pressure gradient force exactly balances the Coriolis force above the boundary layer, which of the following is the result

A geostrophic wind occurs

Which direction do cyclones spin?

Counter-clockwise

How does temperature affect vapor pressure at saturation?

It increases with increasing temperature

What is the caveat of the Scientific Process?

It is not a rigid process

An airplane is flying forward at constant speed. At a given moment the forces acting on the airplane are such that Thrust is balanced by Air Friction, but Lift is smaller than the Weight. How is the airplane motion going to respond?

It will continue moving forward at the same speed, but will accelerate downward

Suppose we increase the temperature of an air parcel without changing its mass of water vapor. The air parcel is not saturated. We can say that

Its dew point temperature will not change

Isobars point in the direction of

Low Pressure

From which direction does the wind seem to blow from in northern Florida?

Northwest

What is Climate

an aggregation of many observations to describe the weather over time

According to the equation of state p = RT,

an increase in density requires an increase in pressure or a decrease in temperature or both

Where is wind in relation to isobars

between isobars

Which direction do anti-cyclones spin

clockwise

Lower pressure areas tend to be

colder

Your hand feels cold when you hold a cold can of soda. Energy is being transferred from your hand to the can by

conduction

Warm air rises. This is an example of energy transfer by

convection

What happens to relative humidity when air temperature increases

decreases

Frost forms on your windshield through which process?

deposition

Radiation, as an energy transfer mechanism, is especially important because

everything Radiates. radiation provides us with visible light. radiation energy can travel without an intervening medium.

Winds along the ridge axis are

faster than geostrophic

Which of the following is most likely why Hurricane Isabel's wind speed decreases after it makes landfall?

friction

The atmosphere is a mixture of

gas molecules, small particulates, and moisture

If a column of air is heated, it will

have a smaller vertical pressure gradient

Technological advances in computer hardware and software

have had a huge impact on our ability to understand and predict the weather

High heights of isobaric surfaces (e.g., 500-mb surface) correspond to ______ pressure on a nearby constant- height surface.

high

Which of the following are used to identify places of equal atmospheric pressure?

isobars

Why is water unique

it exists in all three states naturally at the same time

Why is Hurricane Isabel a low pressure system?

it rotates counterclockwise

Which of the following would most likely happen to Hurricane Isabel if it were to approach the equator?

it would weaken dramatically

Atmospheric motions are mostly horizontal because

its shallowness doesn't allow large vertical motions

Horizontal pressure changes are

less than vertical pressure changes

The three processes for saturating air with water vapor

lowering the temperature to the dew point, mixing cold air with warm, moist air, adding water vapor to the air

According to the scientific method, a hypothesis

must lead to predictions

Adiabatic processes,

often involve changes both in temperature and pressure

A network of surface and upper-air observations is crucial to meteorological understanding because

organized weather systems often cover large areas

This is the layer in the atmosphere where friction is important in determining wind speed

planetary boundary layer

What is Weather

the state of the atmosphere as it was measured by a single observation

The heights of the 500 mb surface in air column A is 5700 meters and 5640 meters in air column B. Choose the best answer from the following

the temperature in air column A is higher while the density is lower

Which layer of the atmosphere is thicker in summer

the troposphere

What causes an updraft to occur

the vertical pressure gradient force is larger than the gravitational force.

If the wind is parallel to the isobars, we can say that

the wind could be geostrophic, supergeostrophic or subgeostrophic

Regarding isobars, it is true that

their spacing indicates the strength of the pressure gradient

Relative Humidity Equation

vapor pressure/saturation vapor pressure x 100%

Higher pressure areas tend to be

warmer

When air within a cloud begins to sink, it

warms at the saturated adiabatic lapse rate

What happens when the relative humidity in the air is 100 percent

water will condense out of the air

When does saturation occur

when the condensation rate equals the evaporation rate.

When does advection fog occur?

when warm air passes over a cool surface

Vapor pressure is

the part of atmospheric pressure due to water vapor

What are enclosed areas of high pressure marked by roughly circular isobars or height contours called?

Anticyclone

Suppose we do our "saturation" experiment. Assume the air, the container, and the liquid water are all at the same temperature. Where is the condensation going to occur?

At the liquid surface and at the walls of the container

Consider a closed container filled with air at a fixed temperature. Suppose we double the number of molecules inside the container and keep the temperature the same. What can we say about the changes in pressure and density in the container?

Density and pressure will both double

What can be used with air temperature to indicate the value of relative humidity

Dew Point Temperature

Which of the following best describes the process in which water droplets form onto hygroscopic particles?

Heterogeneous nucleation

Which direction does pressure go towards

High to Low

Two paper balls with mass m and 5m and the same shape and size are dropped from the same height. What happens?

Paper ball with mass 5m reaches the ground first

Suppose you are at a location where the sea-level pressure is lower than the surface pressure. Where are you?

Possibly in the Death Valley, because it is located below the sea level

Suppose that instead we keep the density constant and increase the temperature of the gas. What happens to the pressure of the gas?

Pressure increases as we increase temperature

Equation for LCL

T-DP/8

What is density inversely proportional to?

Temperature

Consider a closed container filled with air at a fixed pressure. Suppose we double the number of molecules inside the container and keep the pressure the same. What can we say about the changes in temperature in the container?

Temperature will be reduced by half.

In the video "A Year of Weather" from lecture 01, we observed a lot more swirling motion in the high latitudes than near the equator. What could be a reason for that?

The Coriolis force is larger in the high latitudes.

What is the lifting condensation level?

The altitude at which clouds begin to form in a rising parcel of air

The relationship between air pressure and elevation is nonlinear because

air is compressible

When an air parcel moves north in the Northern Hemisphere, it gets deflected to its right due to the Coriolis force. What is the reason for this deflection?

The parcel is moving toward the axis of rotation of the planet, so it must spin faster to conserve angular momentum

Suppose the wind is initially in geostrophic balance, and then frictional forces are added. As a consequence, we would observe that

all alternatives are correct

Equation for DALR

The proportion of 1/100=uA/Height=Delta T. T-Delta T=DALR

During Santa Ana winds, air blos from the high deserts towards Los Angels. Suppose the mass of water vapor in the air does not change between the desert and L.A.

The relative humidity in L.A. will be lower than in the desert

Diabatic processes,

add or remove energy from a system

Radiosondes

allow us to measure weather conditions in the upper atmosphere

Sea-level pressure is used instead of surface air pressure on weather maps for which of the following reasons?

To correct for the effect of altitude

If we hypothesize that pressure gradient forces are the only forces driving horizontal winds in the upper atmosphere, what would be an observation that proves our hypothesis to be wrong?

Winds are mostly parallel to isobars in the upper atmosphere

What is an updraft

a region of rising air where clouds are likely to form

When the pressure gradient force exceeds the Coriolis effect

subgeostrophic flow

This occurs around a high-pressure system when the Coriolis effect exceeds the pressure gradient force, causing air to turn

supergeostrophic flow

What happens when the atmosphere contains more moisture than theoretically possible

supersaturation

Saturation vapor pressure is dependent upon this variable

temperature

This prevents wind from following the direction of the horizontal pressure gradient force

the Coriolis effect

The Coriolis Effect is zero at

the Equator

According to the Ideal Gas Law, the pressure will increase if

the air density increases while the temperature is held constant

Wind direction is properly referred to as

the direction the wind is blowing from

Hydrostatic equilibrium occurs when

the force of gravity and the vertical pressure gradient have equal value and oppose each other

The invention of the telegraph in the mid-1800s improved weather forecasting because

the location and movement of weather conditions could be tracked