REVIEW THE FOLLOWING MET – O1 TOPICS (TOPICS 1 – 7)

I. Mulitple Choice:

Which of the following statement is TRUE about geostrophic wind?

a. flows perpendicular to the pressure gradient force
b. usually not affected by the Coriolis force
c. follows the pressure gradient force
d. flows horizontally on a straight line
In what latitude does the Coriolis effect is considered the strongest?
a. 15 degrees
b. 45 degrees
c. 60 degrees
d. 90 degrees
Where can the maximum concentrations of ozone are found?
a. ionosphere
b. mesosphere
c. stratosphere
d. troposphere
The blue color of the sky is caused by the scattering of sunlight off the molecules of the atmosphere.
This scattering is called _____.
a. absorption
b. mie scattering
c. rayleigh scattering
d. reflection
Volcanic out gassing was responsible for the formation of the Earth's _____.
a. asthenosphere
b. atmosphere
c. crust
d. core and mantle
What will you call a line on a map connecting points having the same atmospheric pressure at a given
time or on average over a given period?
a. isobar
b. isotones
c. isotopes
d. isotherm
Which among the choices describes a “sea breeze”?
a. It blows from the shore towards the water
b. It is driven by differences in temperature
c. It is driven by differences in air pressure
d. It forms on hot days because land warms more rapidly than the water
How does “front” occur?
a. It happens when two air masses from different regions, such as polar and tropical regions, are brought
together.
b. It happens when cold front moves faster than the warm front and gradually overtakes it, causing the
warm air to be lifted up from the surface
c. It happens when warm air at the bottom of the valley, being less dense, rises to the top by following
the warm sides of the valley
d. It happens when positively charged warm air meets with negatively charged cold air
Which of the following describes dew point temperature?
a. tells us how cold the air is
b. tells us how moist the air is
c. can be larger or smaller than the air temperature
d. neither A or C
What will happen when two unsaturated air masses mix together?
a. The air will become saturated
b. The air will become dense
c. The air will create thunder-like sounds
d. The air will stay unsaturated
Which of the following will you obtain if you take the wind speed and direction directly from the on
board wind sensor while your vessel is en route?
a. Relative wind speed and direction
b. True wind speed and direction
c. Calculated wind speed and direction
d. Estimated wind speed and direction
Which of the following types of fog normally occurs in patches at night and is due to the cooling of
land masses after sunset?
a. Radiation fog
b. Advection fog
c. Ice fog
d. Sea fog
Which of the following types of fog occurs when moist air passes over a cool surface?
a. Radiation fog
b. Advection fog
c. Ice fog
d. Sea fog
You observed that targets are visible between 5.5 to 10.8Nm, which “visibility” code number will you
use when recording it in the log book?
a. 6
b. 8
c. 10
d. 12
What does “Beaufort Scale Force 10” mean?
a. Gale
b. Hurricane
c. Strong Gale
d. Storm
Which of the choices is the BEST reason why we need to calculate for the true wind upon obtaining
wind direction and speed from the anemometer?
a. It is needed for the logs and is used to analyze weather forecast
b. It lets you know that anemometer sometimes gives erratic readings
c. It is required in master’s standing orders and external inspections
d. It will keep you busy throughout you watch
You observed a wind barb in the weather forecast having a fully blackened pennant and two long
lines, what does that mean?
a. The wind in the area is approximately 70knots
b. The wind in the area is approximately 30knots
c. The wind in the area is gusting occasionally at 20knots
d. The wind in the area is calm
What will be produced when warm air at the bottom of the valley, being less dense, rises to the top?
a. Anabatic winds
b. Katabatic winds
c. Monsoons
d. Occlusion
How does wind circulation behave around anticyclones?
a. Clockwise in the Northern hemisphere and Anti-clockwise in Southern hemisphere
b. Anti-clockwise in the Northern hemisphere and clockwise in Southern hemisphere
c. Clockwise in both hemispheres
d. Anti-clockwise in both hemispheres
Atmospheric pressure drops as altitude _____.
a. remains the same
b. increases
c. decreases
d. differ by 1 atm
What do you call the process wherein the water vapor changes to liquid?
a. Condensation
b. Evaporation
c. Sublimation
d. Vaporization
What do you call to the amount of water vapor that is present in air?
a. Dew Point
b. Humidity
c. Moist
d. Saturated Air
It blocks some of the Sun's dangerous rays from reaching Earth.
a. clouds
b. rain
c. atmosphere
d. ozone layer
Which air in the entire atmosphere contains a gas of 20.95%?
a. nitrogen
b. oxygen
c. carbon dioxide
d. argon
Jet airliners fly in this layer, for it is far less turbulent than the underlying troposphere.
a. thermosphere
b. mesosphere
c. stratosphere
d. troposphere
It is a layer in the atmosphere where you can see the auroras. It is also where the space shuttle orbits.
a. mesosphere
b. stratosphere
c. troposphere
d. thermosphere
What in the various layers of Earth's atmosphere rises and falls as one moves upward from the
ground, in a haphazard fashion.
a. solar energy
b. gravity
c. temperature
d. pressure
Which of the following has the lowest temperature?
a. mesopause
b. stratopause
c. stratosphere
d. tropopause
30. Which of the following is the correct order of radiation from the longest wavelengths to the
shortest wavelengths?
a. gamma rays, radio, ultraviolet, infrared, visible, x-rays
b. radio, gamma rays, ultraviolet, visible, infrared, x-rays
c. radio, infrared, visible, ultraviolet, x-rays, gamma rays
d. x-rays, ultraviolet, infrared, gamma rays, visible, radio
Which of the following statements is TRUE about solar constant?
a. It depends on all kinds of atmosphere
b. It is higher for Earth than for Mars
c. It is the same throughout the solar system
d. Varies inversely with the fourth power of an object's distance from the Sun's surface
The four factors that are totally responsible for wind are _____.
a. friction, centripetal acceleration, pressure gradient force, moisture content
b. the centripetal acceleration, moisture content, friction, Coriolis force
c. the Coriolis force, friction, the centripetal acceleration, the pressure gradient force
d. the pressure gradient force, the Coriolis force, the centripetal acceleration, moisture content
What force acting on the atmosphere causes horizontal pressure differences and winds?
a. Centrifugal Force
b. Coriolis Force
c. Gravity
d. Pressure Gradient Force
It is the intensity of the amount of solar radiation reaching a given area.
a. water vapor
b. dew point
c. latent heat of vaporization
d. insolation
It is the temperature at which air becomes saturated if cooled at constant pressure.
a. absolute humidity
b. dew point
c. saturation
d. precipitation
It is the partial pressure of a given sample of moist air that is attributable to the water vapor.
a. vapour pressure
b. absolute humidity
c. saturation
d. relative humidity
It is a volume of air at a given temperature holds the maximum amount of water vapour, the air is
said to be saturated.
a. insolation
b. absolute humidity
c. saturation
d. absolute humidity
It is the heat necessary to change 1 kilogram of water to 1 kilogram of Vapour at saturation
temperature.  If a quantity of water changes to vapour an amount of latent heat will have been
required.
a. solar energy
b. insolation
c. absolute humidity
d. latent heat of vaporization
It is any product of the condensation of atmospheric water vapour that falls under gravity. The main
forms of precipitation include drizzle, rain, sleet, snow, graupel, etc.
a. vapour pressure
b. insolation
c. saturation
d. precipitation
Which of the following weather instruments will you use in order to measure the amount of humidity
in the atmosphere?
a. Hygrometer
b. Anemometer
c. Aneroid barometer
d. Thermometer
What will be produced when warm air at the bottom of the valley, being less dense, rises to the top?
a. Anabatic winds
b. Katabatic winds
c. Monsoons
d. Occlusion
As the air temperature increases, with no addition of water vapor to the air, the relative humidity will
_____.
a. remain the same
b. increase
c. decrease
d. differ by 1 degree
Each individual water molecule which transitions between a more associated liquid and a less
associated (vapor/gas) state does so through the absorption or release of kinetic energy.
a. evaporization
b. condesation
c. saturation
d. insolation
It is the change of water from its gaseous form (water vapor) into liquid water.
a. absolute humidity
b. dew point
c. saturation
d. condensation
It can be produced from the evaporation or boiling of liquid water or from the sublimation of ice.
Unlike other forms of water, It is invisible.
a. Water vapor
b. dew point
c. saturation
d. absolute humidity
A reaction that generally occurs in the atmosphere when warm air rises, cools and looses its capacity
to hold water vapor. As a result, excess water vapor condenses to form cloud droplets.
a. evaporization
b. condesation
c. saturation
d. insolation
Which air in the entire atmosphere contains a gas of 0.039%?
a. nitrogen
b. oxygen
c. carbon dioxide
d. argon
Argon contains a gas of how many percent in the atmosphere?
a. 0.93%
b. 20.95%
c. 78.09%
d. 0.039%
This layer contains the ozone layer. Ozone acts as a shield for in the earth's surface. It absorbs
ultraviolet radiation from the sun. This causes a temperature increase in the upper part of the layer.
a. mesosphere
b. stratosphere
c. troposphere
d. thermosphere
This is the coldest region of the atmosphere. This layer protects the earth from meteoroids. They burn
up in this area.
a. mesosphere
b. stratosphere
c. troposphere
d. thermosphere
A ship’s weather instrument that does not use liquid in measuring the pressure of the air. The
atmospheric pressure changes as the weather changes. It goes up and down. We say the pressure is
rising, is falling, or is steady.
a. anemometer
b. psychrometer
c. thermometer
d. barometer
It is an instrument for measuring and indicating the force or speed and sometimes direction of the
wind . It is one instrument used in a weather observation on board.
a. anemometer
b. psychrometer
c. thermometer
d. barometer
It is instrument used for measuring the moisture content (relative humidity and dew point) in the
environment. Humidity measurement instruments usually rely on measurements of some other
quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as
moisture is absorbed.
a. barometer
b. anemometer
c. hygrometer
d. psychrometer
It is an instrument for measuring pressure. It uses a small, flexible metal box called an aneroid cell
(capsule), which is made from an alloy of beryllium and copper.
a. anemometer
b. psychrometer
c. thermometer
d. barometer
It is a device that measures temperature. It is sealed in a glass tube that contains a column of liquid,
as mercury, that expands and contracts, or rises and falls, with temperature changes, the temperature
being read where the top of the column coincides with a calibrated scale marked on the tube or its
frame.
a. anemometer
b. psychrometer
c. thermometer
d. barometer
The most abundant gas in the atmosphere by volume is _________. This gas comprises 78% of the
Earth atmosphere by volume.
a. Oxygen
b. Argon
c. Carbon Dioxide
d. Nitrogen
The definition of a variable gas is a gas that varies significantly from time to time and place to place.
The most significant variable gas by volume in the planetary boundary layer in the atmosphere is:
a. Ozone
b. Water vapor
c. Oxygen
d. Carbon dioxide
An isobar is a line of constant ________________.
a. Pressure
b. Density
c. Temperature
d. Dewpoint
Which clouds are at the highest altitude?
a. Cirrus
b. Altocumulus
c. Altostratus
d. Stratocumulus
About 78 percent of the atmosphere is nitrogen and 21 percent is oxygen. Most of the remaining
one percent of the atmosphere is ... 
a. Neon
b. Hydrogen
c. Helium
d. Argon
The seasons of Spring, Summer, Winter, and Fall are a direct result of which phenomenon?
a. The sun's energy output and the Earth's proximity to the sun
b. Shifting of ocean currents
c. The 23.5 ° tilt of the Earth from vertical
d. The jet stream
________________ refers to the horizontal transport of air while _______________ is the vertical
transport of air. 
a. Advection, convection
b. Convection, advection
c.Heat transfer, Diffusion
d.Diffusion, Heat transfer
Which of the following has the highest albedo and thus more reflected solar radiation?  
a. Fresh snow
b. Grass
c. Water
d. Blacktop
Which of the following is NOT a primary "control" of climate? 
a. Altitude
b. Latitude
c. Daily weather
d. Ocean currents
Water has a ___________ heat capacity. This means a large amount of energy is needed to raise the
temperature of water relative to other substances. 
a. Low
b. High
c. Medium
d. Moderate
Which of the following processes ABSORBS the most latent heat? 
a. Melting
b. Freezing
c. Evaporation
d. Condensation
Which of the following statements is FALSE: 
a. Cloud droplets freeze once temperature drops below 0 ° C.
b. The vapor pressure is higher over water than over ice
c. The typical raindrop is about 2 millimeters in diameter
d. Salt particles make good condensation nuclei
What causes thunder?
a. Clouds cracking
b. Lightning impacting the ground
c. Air particles slamming together
d. Expanding gases along the path of the lightning
If the Earth's axis were straight up and down instead of tilted, ...
a. Earth would be uninhabitable
b. The seasons would not change
c. There would be no night or day
d. Earth would be covered with ice
What colorless gas is a major constituent of photochemical smog at the Earth's surface but is
beneficial in the stratosphere by absorbing most of the Sun's ultraviolet radiation?
a, Ozone
b. Nitrogen
c. Argon
d. Carbon Dioxide
What type of precipitation is formed when sulfur dioxide from coal-burning power plants combines
with water vapor in the atmosphere? 
a. Acid rain
b. Sleet
c. Squall
d. Hail
When warm air moves in over cold land, the layer of air in contact with the surface cools and
becomes denser, while the air above is still warm. This is called a temperature ... 
a. Convection
b. Radiation
c. Inversion
d. Advection
A dense, towering vertical cloud,forming from water vapor carried by powerful upward air current.  
a. Cumulus
b. Cumulonumbus
c. Altostratus
d. Cirrostratus
Low-level clouds characterized by horizontal layering with a uniform base. It may produce a light
drizzle or a small amount of snow.
a. Stratus
b. Cumulus
c. Altostratus
d. Nimbostratus
They are thin, white clouds that cover the whole sky like a veil. These clouds are most commonly
seen in the winter, and can cause the appearance of halo around the sun or the moon.  
a. Cirrus
b. Altocumulus
c. Nimbostratus
d. Cirrostratus
These clouds are shaped like flying saucers. They may get their shape from hilly terrain or just the
way the air is rising over flat terrain. 
a. Mammatus clouds
b. Orographic clouds
c. Lenticular clouds
d. Contrail clouds
These clouds look like fluppy, white cotton balls in the sky. They are beautiful in sunset.
a. Stratus
b. Cumulonimbus
c. Cumulus
d. Stratocumulus
These are 6,500 ft. - 20,000 ft. high, dark and gray clouds that seem to fade into falling rain or
snow.They are so thick that they are often blot the sunlight.
a. Nimbostratus
b. Altocumulus
c. Stratus
d. Stratocumulus
Define parallax:
a. A thin line of convective clouds that forms along the leading edge of a weakening cold front
b. The apparent displacement of a cloud due to the viewing angle of the satellite sensor
c. The point where the sun's most direct rays strike the Earth
d. The maximum upward displacement of a wave
The word MONSOON as it applies to climatology refers to:
a. Very heavy rain
b. The intensification of the polar jet
c. A seasonal reversal in wind direction and pressure distribution
d. A cyclone or typhoon with winds over 100 miles per hour
In a volume of air near the earth's surface, ____ occupies 78 percent and ____ nearly 21 percent.
a. nitrogen, oxygen
b. hydrogen, oxygen
c. oxygen, hydrogen
d. nitrogen, water vapor
The amount of force exerted over an area of surface is called:
a. density.
b. weight.
c. temperature.
d. pressure.
When the air temperature is below freezing, the saturation vapor pressure over water is ____.
a. equal to zero
b. less than the saturation vapor pressure over ice
c. greater than the saturation vapor pressure over ice
d. equal to the saturation vapor pressure over ice
The percentage of water vapor present in the air compared to that required for saturation is the:
a. mixing ratio.
b. absolute humidity.
c. dew point.
d. relative humidity. e. specific humidity.
The time of day when the relative humidity reaches a maximum value is usually:
a. at the time when the air temperature is highest
b. in the middle of the afternoon
c. at the time when the air temperature is lowest
d. just before sunrise
e. about midnight
Which of the following statements is not correct?
a. The length of human hair changes as the relative humidity changes.
b. During the winter, low relative humidity can irritate the mucus membranes in the nose and throat.
c. The relative humidity is a measure of the air's actual water vapor content.
d. A change in the air temperature can change the relative humidity.
Suppose it is a winter night and at about 11 p.m., the air cools to the dew-point temperature and a
thick radiation fog develops. If the air continues to cool during the night, in 5 hours the dew point
temperature will probably:
a. decrease as the air becomes drier.
b. decrease as the air becomes moister.
c. increase as the air becomes drier.
d. increase as the air becomes moister.
Frost typically forms on the inside of a windowpane (rather than the outside) because:
a. the inside of the pane is colder than the outside.
b. there is more water vapor touching the inside of the pane.
c. there is less water vapor touching the inside of the pane.
Condensation nuclei may be:
a. particles of dust.
b. nitric acid particles.
c. smoke from forest fires.
d. salt from the ocean. e. all of these
Which of the following types of fog occurs when moist air passes over a cool surface?
a. Radiation fog
b. Advection fog
c. Ice fog
d. Sea fog
You observed that targets are visible between 5.5 to 10.8Nm, which “visibility” code number will you
use when recording it in the log book?
a. 6
b. 8
c. 10
d. 12
What does “Beaufort Scale Force 10” mean?
a. Gale
b. Hurricane
c. Strong Gale
d. Storm
Which of the choices is the BEST reason why we need to calculate for the true wind upon obtaining
wind direction and speed from the anemometer?
a. It is needed for the logs and is used to analyze weather forecast
b. It lets you know that anemometer sometimes gives erratic readings
c. It is required in master’s standing orders and external inspections
d. It will keep you busy throughout you watch
You observed a wind barb in the weather forecast having a fully blackened pennant and two long
lines, what does that mean?
a. The wind in the area is approximately 70knots
b. The wind in the area is approximately 30knots
c. The wind in the area is gusting occasionally at 20knots
d. The wind in the area is calm
What will be produced when warm air at the bottom of the valley, being less dense, rises to the top?
a. Anabatic winds
b. Katabatic winds
c. Monsoons
d. Occlusion
How does wind circulation behave around anticyclones?
a. Clockwise in the Northern hemisphere and Anti-clockwise in Southern hemisphere
b. Anti-clockwise in the Northern hemisphere and clockwise in Southern hemisphere
c. Clockwise in both hemispheres
d. Anti-clockwise in both hemispheres
Atmospheric pressure drops as altitude _____.
a. remains the same
b. increases
c. decreases
d. differ by 1 atm
What do you call the process wherein the water vapor changes to liquid?
a. Condensation
b. Evaporation
c. Sublimation
d. Vaporization
What do you call to the amount of water vapor that is present in air?
a. Dew Point
b. Humidity
c. Moist
d. Saturated Air
Fog that forms off the coast of Newfoundland is mainly a form of:
a. advection fog.
b. frontal fog.
c. steam fog.
d. radiation fog.
e. upslope fog.
Fog that most often forms as warm rain falls into a cold layer of surface air is called:
a. radiation fog.
b. evaporation (mixing) fog.
c. advection fog.
d. upslope fog.
Fog is a major hazard to aviation.
a. true
b. false
A dim, "watery" sun visible through a gray sheet-like cloud layer is often a good indication of ____
clouds.
a. stratocumulus
b. cirrostratus
c. cumulonimbus
d. altostratus
e. nimbostratus
Which among the choices describes a “sea breeze”?
a. It blows from the shore towards the water
b. It is driven by differences in temperature
c. It is driven by differences in air pressure
d. It forms on hot days because land warms more rapidly than the water
How does “front” occur?
a. It happens when two air masses from different regions, such as polar and tropical regions, are brought
together.
b. It happens when cold front moves faster than the warm front and gradually overtakes it, causing the
warm air to be lifted up from the surface
c. It happens when warm air at the bottom of the valley, being less dense, rises to the top by following
the warm sides of the valley
d. It happens when positively charged warm air meets with negatively charged cold air
Which of the following describes dew point temperature?
a. tells us how cold the air is
b. tells us how moist the air is
c. can be larger or smaller than the air temperature
d. neither A or C
What will happen when two unsaturated air masses mix together?
a. The air will become saturated
b. The air will become dense
c. The air will create thunder-like sounds
d. The air will stay unsaturated
Which of the following will you obtain if you take the wind speed and direction directly from the on
board wind sensor while your vessel is en route?
a. Relative wind speed and direction
b. True wind speed and direction
c. Calculated wind speed and direction
d. Estimated wind speed and direction
Which of the following types of fog normally occurs in patches at night and is due to the cooling of
land masses after sunset?
a. Radiation fog
b. Advection fog
c. Ice fog
d. Sea fog
Suppose two unsaturated air masses mix horizontally. The resulting mixture cannot possibly be
saturated.
a. true
b. false
Typically, water vapor occupies about what percentage of the air's volume near the earth's surface?
a. about 78 percent
b. about 21 percent
c. close to 10 percent
d. less than 4 percent
e. none of these
The unit of pressure most commonly found on a surface weather map is:
a. inches of mercury (Hg).
b. millibars or hectopascals.
c. pounds per square inch.
d. millimeters of mercury (Hg).0
The gas responsible for the greenhouse effect on Venus is:
a. carbon dioxide (CO2).
b. oxygen (O2).
c. ozone (O3).
d. nitrogen (N2).
e. water vapor (H2O).
Carbon dioxide is a naturally-occurring component of the atmosphere.
a. true
b. false
The atmospheric layer in which we live is called the:
a. troposphere.
b. stratosphere.
c. thermosphere.
d. ionosphere.
e. exosphere.
In the middle latitudes of the Northern Hemisphere, surface winds tend to blow ____ and ____
around an area of surface low pressure.
a. clockwise; inward
b. clockwise; outward
c. counterclockwise; inward
d. counterclockwise; outward
A change of one degree on the Celsius scale is ____ a change of one degree on the Fahrenheit scale.
a. equal to
b. larger than
c. smaller than
d. is in the opposite direction of
The temperature scale where 0° represents freezing and 100° boiling is called:
a. Fahrenheit.
b. Celsius.
c. Kelvin.
d. absolute.
The transfer of heat by molecule-to-molecule contact is:
a. conduction.
b. convection.
c. radiation.
d. ultrasonic.

II ENUMERATION

1. LAYERS OF ATMOSPHERE
exosphere
Thermosphere
Mesosphere
Stratosphere
Troposphere

2. TYPES OF PRECIPITATION
Rain - is liquid water in the form of droplets that have condensed from atmospheric water
vapor and then precipitated that is, become heavy enough to fall under gravity.
Drizzle - is a light liquid precipitation consisting of liquid water drops smaller than those of
rain – generally smaller than 0.5 mm (0.02 in) in diameter.
 Snow - is composed of small ice particles in the form of flakes of crystalline water ice that falls
from clouds.
Sleet - is a regionally variant term that refers to two distinct forms of precipitation: Rain and
snow mixed, snow that partially melts as it falls 
3. TYPES OF FOG
Evaporation fog
Mixing fog
Orographic fog
Radiation fog
Advection fog
4. TYPES OF LOCAL WINDS
Land and Sea Breeze Thunderstorm downdrafts
Slope and Valley Winds Whirlwinds
Katabatic wind
Anabatic wind

III IDENTIFICATION/ DEFINITION

1. METEOROLOGY- is the study of the atmosphere, atmospheric phenomena, and atmospheric

effects on our weather.
2. ATMOSPHERE - The Earth’s atmosphere is the layer of gases surrounding the planet Earth that is
retained by Earth's gravity. It is an important part of what makes Earth livable. It blocks some of
the Sun's dangerous rays from reaching Earth. Air in the atmosphere contains 78.09% nitrogen,
20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. It has 5
layers namely: troposphere, stratosphere, mesosphere, thermosphere, exosphere
3. ITCZ – INTERTROPICAL CONVERGENCE ZONE
4. CUMULUS- Dense clouds with vertical development (Clouds forms by rising air which is cooled
as it reaches greater heights) Fair and Good Weather. (Atoll Clouds
5. INSOLATON - Insolation is the intensity of incoming solar radiation on an object. Incoming Solar
Radiation varies depending on: Time of year, Time of Day, Solar Declination, Atmospheric
Condition, Earth – Sun Distance and Latitude.

6. PRECIPITATION- is any product of the condensation of atmospheric water vapour that falls
under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail.
7. WATER VAPOR - is the gaseous phase of water. It is one state of water within the hydrosphere.
Water vapor can be produced from the evaporation or boiling of liquid water or from the
sublimation of ice. Unlike other forms of water, water vapor is invisible.

8. VALLEY BREEZE
9. CONDENSATION- is the change of water from its gaseous form (water vapor) into liquid water.
Condensation generally occurs in the atmosphere when warm air rises, cools and looses its
capacity to hold water vapor. As a result, excess water vapor condenses to form cloud droplets
10. LAND BREEZE
11. EVAPORIZATION
12. LATENT HEAT OF VAPORIZATION- Latent heat is the heat necessary to change 1 kilogram of
water to 1 kilogram of Vapour at saturation temperature.  If a quantity of water changes to
vapour an amount of latent heat will have been required.
 13. SATURATED AIR - When a volume of air at a given temperature holds the maximum amount of
water vapour, the air is said to be saturated.
14. MOONSON- is the seasonal changes in atmospheric circulation and precipitation associated with
the asymmetric heating of land and sea. Usually, the term monsoon is used to refer to the rainy
phase of a seasonally changing pattern, although technically there is also a dry phase. are large-
scale sea breezes which occur when the temperature on land is significantly warmer or cooler
than the temperature of the ocean. These temperature imbalances happen because oceans and
land absorb heat in different ways.
15. BAROMETRIC PRESSURE
16. SMOG
17. DEW POINT- is the temperature at which air becomes saturated if cooled at constant pressure.
18. VAPOR PRESSURE
19. WIND- Wind is air in motion. It is produced by the uneven heating of the earth’s surface by the
sun. Since the earth’s surface is made of various land and water formations, it absorbs the sun’s
radiation unevenly. Two factors are necessary to specify wind: speed and direction.

20. KATABATIC WIND- is a wind that carries high density air from a higher elevation down a slope
under the force of gravity. Such winds are sometimes also called fall winds. Katabatic winds can
rush down elevated slopes at hurricane speeds.

IV ESSAY

1. Describe the principle of the aneroid barometer and explain how to read atmospheric
pressure on the aneroid barometer?
An aneroid barometer is an instrument for measuring pressure. It uses a small, flexible metal
box called an aneroid cell (capsule), which is made from an alloy of beryllium and copper. An
aneroid barometer measures the distortion of an evacuated, sealed elastic capsule inside with
change in atmospheric pressure. Small changes in external air pressure cause the cell (capsule)
to expand or contract. The reading of the aneroid barometer should be corrected with the
correction value against the obtained observation with the mercury barometer. When reading
the barometer, pat the glass surface slightly and read the value in the unit of 0.1 hPa, with close
attention to the parallax error.
2. What is the significance of monitoring the atmospheric pressure on board the vessel?
3. Define Buys-Ballots Law and explain how it will help you in practical navigation.
Northern Hemisphere Face the wind. The Low Pressure area is towards to the right and slightly
behind. The High Pressure area is towards to the left and slightly in front.
Southern Hemisphere Face the wind. The Low Pressure area is towards to the left and slightly
behind. The High Pressure area is towards to the right and slightly in front.
4. Define Coriolis Effect and explain its significance in practical navigation?
The Coriolis effect is the observed deflection of a moving object, caused by the moving frame of
reference on the spinning Earth. As air warms, expands, and rises at the equator, it moves
toward the pole, but instead of traveling in a straight path, the air is deflected eastward. In the
Northern Hemisphere air turns to the right. In the Southern Hemisphere air turns to the left.
5. Differentiate fog, mist and haze.
Mist is a phenomenon caused by small droplets of water suspended in air.
 Haze – is an atmospheric phenomenon where dust, smoke and other dry particles obscure the
clarity of the sky. Fog is caused by the cooling of air in contact with the surface to a temperature
at which it can no longer maintain, in an invisible state, the water vapour, which is present in it.  
6. As an officer on watch, how can you tell if a potentially dangerous storm is coming?

SUMMARY

TEST I 30 POINTS
TEST II 15 POINTS
TEST III 10 POINTS
TEST IV 45 POINTS
TOTAL 100 POINTS