Test 2 Flashcards
Fog forms when the air temperature is
Equal to, or below the dewpoint temperature
What does water tend to do when cooled?
Condense
When cold air displaces warm air you have a
Cold front
Fog most commonly encountered at sea is called
Advection fog
Radiation fog is formed by a
Temperature inversion
What color is an occluded front on the weather map?
Purple
What kind of fog is produced by warm moist air passing over a cold surface?
Advection fog
While on watch you notice that the air temperature is dropping and is approaching the dewpoint. Which type of weather should be forecasted?
Fog
Fog that occurs on clear nights with light breezes and forms because the earths surface is cooling rapidly is known as
Radiation fog
A weather front exists when
Air masses of different temperatures meet
What is a stationary front look like on a map?
Alternating circles and triangles, red and blue
Cold front symbols are
Blue triangles
Warm fronts symbols are
Red circles
An occluded front is caused by a
Cold front over taking a warm front
What is the approximate geographic visibility of an object with a height above the water 70 feet for an observer with the height of 65 feet?
19 miles
1.17 x sq rt he + sq rt ho
What factors determine safe speed?
State of the wind, sea, current, and the proximity of navigational hazards
In restricted visibility a vessel being towed, if manned is required to sound which signal?
One prolonged in three short blasts
The rules also require this factor to be taken into account when determining safe speed.
Location of vessels detected by radar
In fog, you hear forward of your beam fog signal to prolong blast in succession every two minutes. What does the signal indicate?
Power driven vessel underway but stopped and making no way
You’re underway and fog when you hear a whistle signal of one prolonged blast followed by Too $hort blast. The signal could indicate all the following except
A vessel being towed
A local wind occurs during the daytime and caused by the different rates of warming of land and water is a
Seabreeze
According to Buys ballots Law, when an observer in the northern hemisphere experience a northwest wind the center of low pressure is located to
Northeast
In most cases, the direction of the apparent wind lies between the bow and
Direction of the true wind
A warm air mass is characterized by
Stability
The height of a wave is the vertical distance
From the crest to the trough
When looking at the weather map, closely spaced pressure gradient lines would indicate
Highwinds
The time interval between successive wave crest is called the
Period
Fetch is the
Stretch of water over which a wave forming wind blows
The Beaufort scale is used to estimate the
Wind speed
And air mass that has moved down from Canada would most likely have the symbols
cPK
You were at 30° north and 95° west approximately, where are you?
North America
What two things decrease continuously with altitude in the atmosphere?
Pressure and temperature
Is the temperature in the tropopause related to the temperature at the base of the troposphere?
No
The gas that has the greatest variation from place to place in from time to time ….Lower atmosphere is
Carbon dioxide
The difference of temperature between 233K and -40°F is
0°C
The amount of radiation wavelength from an object is determined by its
Temperature
The albedo is a measure of
Reflectivity
The transport of heat and wind and ocean currents is what process?
Advective
The polar side of a hill would tend to have what characteristic opposite the equator side of the hill?
The cooler, more moist, have vegetation more characteristic of higher altitude and latitude
Heat energy released when water vapor changes to a liquid is called
Latent heat of condensation
Melting of ice is what process for the atmosphere?
Heating
Sinking air ______ by _________.
Cools
Compression
Irregular heating of the earth surface could result from
Curvature of the earth, thickness of the atmosphere, length of the day
The earth is tilted at an angle of 23.5° with respect to the place of its orbit around the sun. If the amount of tilt were increased to 40°, what could we expect in the middle latitudes?
Hotter summers and colder winters
The only substance near the surface that is found naturally in the atmosphere as a solid, liquid and gas is
Water
The primary source of oxygen for the earths atmosphere during the past half billion years or so appears to be
Photosynthesis
Tibetans are above roughly what percent of the air molecules in the atmosphere?
50%
Wind direction is
The direction from which the wind is blowing
In the middle latitudes of the northern hemisphere, surface winds tend to blow ________ and _______ around an area of low pressure.
Clockwise
Inward
Which of the following is most likely associated with Fairweather?
High-pressure area
Generally weather in the middle latitudes tend to move from
West to east
What provides a measure of the average speed of air molecules?
Pressure
What is released as sensible heat during the formation of clouds?
Latent heat
What are the processes of condensation and freezing?
Both released sensible heat into the environment
Heat transferred from the surface of the moon can take place by
Radiation
The sun emits its greatest intensity of radiation in what portion of the spectrum?
Infrared
If the earths average temperature were to increase, the amount of radiation emitted from the earth surface would ________ And the wavelength of maximum radiation which shift toward ______ wavelengths.
Increase
Shorter
The atmosphere greenhouse effect is produced mainly by the absorption in remission of
Infrared radiation by the atmosphere
Low clouds retard surface cooling at night better than clear skies because
The clouds absorb and radiate infrared energy back earth
The albedo of the moon is 7%, this means that
7% of the sunlight striking the moon is reflected
Clouds _________ infrared radiation and _________ visible radiation
Absorb, reflect
During the winter solstice in the northern hemisphere
All the above
Which of the following helps to explain why even though northern latitudes experience 24 hours of sunlight on June 22, they are not warmer than the latitude further south?
All the above
For maximum winter warmth, in the northern hemisphere large windows in the house should face
South
Seasons are caused by
Changing distance between the earth and the sun, angle at which sunlight reaches the earth, length of the daylight hours
Although the polar regions radiate away more heat energy then they receive by insulation in the course of the year, they are prevented from becoming progressively colder each year by the
Circulation of heat by the atmosphere and oceans
In clear weather the air next to the ground is usually ________ Then the air above during the night and ________ then the air above during the day.
Colder
Warmer
Assuming that the night will remain clear and calm and that predicted minimum temperature is 0°C, suddenly the wind speed increases and remains gusty throughout the night. The minimum temperature will most likely be
Higher than predicted due to mixing
Thermal belts are
Warmer hillsides that are less likely to experience freezing conditions
Which of the following is not a reason why water warms and cools much more slowly than land?
It takes more heat to raise the temperature of a given amount of land then it does to raise the temperature of water
