Climatology is the scientific study of climate and a major branch of meteorology. There are three approaches to climatology: physical, descriptive, and dynamic. Physical climatology seeks to explain climate differences based on physical processes. Descriptive climatology orients itself geographically and describes climates regionally without causes. Dynamic climatology relates atmospheric circulation to climate. Climate is influenced by both physical processes like ocean currents and heat transport, and biological processes in the oceans like the biological pump. Changes in elements like temperature, precipitation, wind and others are driven by factors like latitude, land-sea distribution, and topography.

1. ANGELA LABRAD

2. *CLIMATE
*Climate is the average or collective state of
Earth’s atmosphere at any given location or
area over a long period of time. While
weather is the sum total of the atmosphere’s
variables for a relatively short period of time,
the climate of an area is determined over periods
of many years and represents the general
weather characteristics of an area or locality. The
term climate applies to specific regions and
is therefore highly geographical

3. CLIMATOLOGY
Climatology is the scientific study of climate and is a major branch of meteorology.
Climatology is the tool that is used to develop long-range forecasts. There are three
principal approaches to the study of climatology: physical, descriptive, and
dynamic.
Physical Climatology
The physical climatology approach seeks to explain the differences in
climate in light of the physical processes influencing climate and the processes
producing the various kinds of physical climates, such as marine,
desert, and mountain.
Physical climatology deals with explanations of climate rather than with
presentations.
Descriptive Climatology
Descriptive climatology typically orients itself in terms of geographic regions;
it is often referred to as regional climatology.

4. A description of the various types of climates is made on the
basis of analyzed statistics from a particular area.
A further attempt is made to describe the interaction of
weather and climatic elements upon the people and
the areas under consideration.
Descriptive climatology is presented by verbal and graphic
description without going into causes and theory.
Dynamic Climatology
Dynamic climatology attempts to relate characteristics of the
general circulation of the entire atmosphere to the climate.
Dynamic climatology is used by the theoretical meteorologist
and addresses dynamic and thermodynamic effects.

5. Energy from the sun
drives the earth’s
weather and climate,
and heats the earth’s
surface; in turn, the
earth radiates energy
back into space.
Atmospheric greenhouse
gases (water vapor,
carbon dioxide, and
other gases) trap some
of the outgoing energy,
retaining heat
somewhat like the glass
panels of a greenhouse.

6. Energy from the Sun reaching the Earth drives
almost every known physical and biological
cycle in the Earth system. The energy that
keeps the earth's surface warm originates
from the sun. The primary source of energy
to drive our global climate system (including
atmospheric and, to a lesser extent, oceanic
circulation) is the heat we receive from the
Sun, termed solar insolation. The amount of
insolation which reaches the Earth's surface
depends on site latitude and season. The
insolation into a surface is largest when the
surface directly faces the Sun. As the angle
increases between the direction normal to
the surface and the direction of the rays of
sunlight, the insolation is reduced in
proportion to the cosine of the angle. This is
known in optics as Lambert's cosine law.
This 'projection effect' is the main reason why
the polar regions are much colder than
equatorial regions on Earth. On an annual
average the poles receive less insolation than
does the equator, because at the poles the
Earth's surface is angled away from the Sun.

7. Although the energy
that is emitted from the
sun is almost constant,
even small changes can
have noticeable effects.
When the Sun's energy
reaches the Earth it is
partially absorbed in
different parts of the
climate system. The
absorbed energy is
converted back to heat,
which causes the Earth
to warm up

9. There are three main factors that directly influence the
energy balance of the earth and it's temperature:
The total energy influx, which depends on the earth's distance
from the sun and on solar activity
The chemical composition of the atmosphere
Albedo, the ability of the earth's surface to reflect light.
Solar Variability
The Earth's climate system is a compilation of the following
components and their interactions-
The atmosphere
The hydrosphere, including the oceans and all other
reservoirs of water in liquid form, which are the main source
of moisture for precipitation and which exchange gases, such
as CO2, and particles, such as salt, with the atmosphere.

10. The land masses, which affect the flow of atmosphere and oceans
through their morphology (i.e. topography, vegetation cover and
roughness), the hydrological cycle (i.e. their ability to store water) and
their radiative properties as matter (solids, liquids, and gases) blown by
the winds or ejected from earth's interior in volcanic eruptions.
The cryosphere, or the ice component of the climate system, whether
on land or at the ocean's surface, that plays a special role in the Earth
radiation balance and in determining the properties of the deep ocean.
The biota - all forms of life - that through respiration and other
chemical interactions affects the composition and physical properties air
and water. The biosphere is that part of Earth's atmosphere, land,
oceans that supports any living plant, animal, or organism. It is the
place where plants and animals, including humans, live. Large quantities
of carbon dioxide are exchanged between the land-based biosphere and
the atmosphere as plants take in carbon dioxide and give off oxygen,
and animals inhale oxygen and exhale carbon dioxide.

11. The Earth has periods of time when the temperature
rises (warming cycles) and periods when the
temperature drops (cooling cycles) it is a series of
natural cycles of our planet. The Sun and it's level of
solar activity has an major influence on these cycles.
Today climate change and global warming are
receiving unprecedented attention due to the
possibility that human activity on Earth during the
past couple hundred years will lead to significantly
large and rapid changes in environmental conditions.

12. The first step in addressing the issue of global warming is to
recognize that the warming pattern, if it continues, will
probably not be uniform. The term "global warming" only
tells part of the story; our attention should be focuses on
"global climate change." The real threat may not be the
gradual rise in global temperature and sea level, but the
redistribution of heat over the Earth's surface. Some spots
will warm, while others will cool; these changes, and the
accompanying shifts in rainfall patterns, could relocate
agricultural regions across the planet.

13. Climate Variability
The first step in addressing the issue of global warming is to recognize that the
warming pattern, if it continues, will probably not be uniform. The term
"global warming" only tells part of the story; our attention should be focuses on
"global climate change." The real threat may not be the gradual rise in global
temperature and sea level, but the redistribution of heat over the Earth's
surface. Some spots will warm, while others will cool; these changes, and the
accompanying shifts in rainfall patterns, could relocate agricultural regions
across the planet.
The ocean is a significant influence on Earth's weather and climate. The ocean
covers 70% of the global surface. This great reservoir continuously exchanges
heat, moisture, and carbon with the atmosphere, driving our weather patterns
and influencing the slow, subtle changes in our climate. The oceans influence
climate by absorbing solar radiation and releasing heat needed to drive the
atmospheric circulation, by releasing aerosols that influence cloud cover, by
emitting most of the water that falls on land as rain, by absorbing carbon
dioxide from the atmosphere and storing it for years to millions of years. The
oceans absorb much of the solar energy that reaches earth, and thanks to the
high heat capacity of water, the oceans can slowly release heat over many
months or years. The oceans store more heat in the uppermost 3 meters (10
feet) that the entire atmosphere, the key to understanding global climate
change is inextricably linked to the ocean.

14. Climate is influenced by storage of heat and CARBON DIOXIDE in the
ocean, which depends on both physical and biological processes. Let's look
at some of these processes. At the end of the last ice age, about 15,000
years ago, and the ice sheets melted away and climate warmed at that
time. Ice sheets began to grow, and climate cool about 130,000 years ago
at the beginning of the last ice age. About 130,000 years ago, fed by
evaporation of ocean waters, the polar ice caps thickened and expanded
Earth cooled by almost 12° C and global sea level to drop 130m below its
current level.
About 15,000 years ago, this process was reversed as more sunlight reached
areas near the Arctic Circle, and Earth emerged from the ice age. Earth is
about 8° Celsius (14° Fahrenheit) warmer today than it was then. Still
recovering from the ice age, global sea level continues to rise. The past
century alone has seen global temperature increase by 0.6 degree Celsius
(1 degree Fahrenheit), and the average global sea level over the past
decade has risen steadily.

16. Climate is effected by both the biological and physical processes of the
oceans. In addition, physical and biological processes affect each other
creating a complex system.
Physical characteristics of heat transport and ocean circulation impact the
Earth's climate system. Like a massive 'flywheel' that stabilizes the speed of
an engine, the vast amounts of heat in the oceans stabilizes the
temperature of Earth.
The heat capacity of the ocean is much greater than that of the atmosphere
or the land. As a result, the ocean slowly warms in the summer, keeping air
cool, and it slowly cools in winter, keeping the air warm. A coastal city like
San Francisco has a small range of temperature throughout the year, but a
mid-continental city like Fargo, ND has a very wide range of temperatures.
The ocean carries substantial heat only to the sub-tropics. Pole ward of the
sub-tropics, the atmosphere carries most of the heat.

17. Both the ocean and the atmosphere transport roughly equal amounts of
heat from Earth's equatorial regions - which are intensely heated by the
Sun - toward the icy poles, which receive relatively little solar radiation.
The atmosphere transports heat through a complex, worldwide pattern
of winds; blowing across the sea surface, these winds drive
corresponding patterns of ocean currents. But the ocean currents move
more slowly than the winds, and have much higher heat storage
capacity.
The winds drive ocean circulation transporting warm water to the poles
along the sea surface. As the water flows pole ward, it releases heat into
the atmosphere. In the far North Atlantic, some water sinks to the ocean
floor. This water is eventually brought to the surface in many regions by
mixing in the ocean, completing the oceanic conveyor belt (see below).
Changes in the distribution of heat within the belt are measured on time
scales from tens to hundreds of years. While variations close to the
ocean surface may induce relatively short-term climate changes, long-
term changes in the deep ocean may not be detected for many
generations. The ocean is the thermal memory of the climate system.

18. Climate is also influenced by the "biological pump," a biological process
in the ocean that impacts concentrations of carbon dioxide in the
atmosphere.
The oceanic biological productivity is both a source and sink of carbon
dioxide, one of the greenhouse gases that control climate.
The "biological pump" happens when phytoplankton convert carbon
dioxide and nutrients into carbohydrates (reduced carbon). A little of
this carbon sinks to the sea floor, where it is buried in the sediments. It
stays buried for perhaps millions of years.
Oil is just reduced carbon trapped in sediments from millions of years
ago. Through photosynthesis, microscopic plants (phytoplankton)
assimilate carbon dioxide and nutrients (e.g., nitrate, phosphate, and
silicate) into organic carbon (carbohydrates and protein) and release
oxygen.

19. Carbon dioxide is also transferred through the air-sea interface. Deep
water of the ocean can store carbon dioxide for centuries.
Carbon dioxide dissolves in cold water at high latitudes, and is subducted
with the water. It stays in the deeper ocean for years to centuries before
the water is mixed back to the surface and warmed by the sun. The
warm water releases carbon dioxide back to the atmosphere. Thus the
conveyor belt described below carries carbon dioxide into the deep
ocean. Some (but not all, or even a large part) of this water comes to the
surface in the tropical Pacific perhaps 1000 years later, releasing carbon
dioxide stored for that period. The physical temperature of the ocean
helps regulate the amount of carbon dioxide is released or absorbed into
the water. Cold water can dissolve more carbon dioxide than warm
water.
Temperature of ocean is also impacted the biological pump. Penetrative
solar radiation warms the ocean surface causing more carbon dioxide to
be released into the atmosphere. Oceanic processes of air-sea gas fluxes
effect biological production and consequentially impacting climate. But
as plant growth increases, the water gets cloudy and prevents the solar
radiation from penetrating beneath the ocean surface.

20. ELEMENTS OF CLIMATE
To study weather and climate the following elements has to be kept in record.
1. Rainfall and Precipitation
2. Temperature
3. Air Pressure / Atmospheric Pressure
4. Wind
5. Moisture content or Relative Humidity
6. Meteorological Phenomena
Changes in these elements are driven by several controls: the latitude,
atmospheric circulation, ocean circulation, distribution of land and water,
water elevation of landforms, topographic barriers.
1. RAINFALL and PRECIPITATION
- These include rain water and other form of precipitation such as dew, frost
and snow. They are measured using an instrument called RAIN GUAGE.
- Globally, it is expected that water vapor and precipitation will increase
along with the warming

21. However this increase in precipitation will not be evenly spread across
the globe. It is expected that precipitation will increase over northern
middle and high latitudes and Antarctica in winter.
It s also expected that more precipitation will fall in large single events
rather than spread over numerous events. At low latitudes both regional
increases and decreases of rainfall over land areas are expected. Larger
year to year variations are likely over those areas where the mean
precipitation is predicted to increase.
Precipitation is water in any form falling from the air onto the surface of
the earth. It occurs when water vapor in air condenses. And the upward
movement as being caused by the heating of the land or water surface,
but horizontal movement of air may be altered by the landscape to also
create this rising movement of air.
Thus, when the surface below is heated, moisture-laden air rises, clouds
form, and air cools; water vapor then condenses.

22. Precipitation is the term given to any water that fall to the
Earth from overload cloud formations. It is considered as an
element of weather when determining if rivers or creek levels
will rise or to decide if outdoor activities are suitable of not.
When considered as an element of climate, precipitation is a
long term factor of a region’s make up that is predictable.
e.g. A desert may experience a storm (weather) but still
remains a typically dry area (climate).

23. MAJOR INFLUENCE OF RAINFALL IN LIVESTOCK IN N-S 300 INDIRECT.
1. Feed supplies
2. Parasitism
RAINFALL INTENSITY IS CLASSIFIED ACCORDING TO THE RATE OF
PRECIPITATION
1. Light rain – precipitation rate <2.5 mm (0.098 in) per hour.
2. Moderate rain – precipitation rate between 2.5 mm (0.098 in) – 7.6 mm
(0.30 in) or 10 mm (0.39 in) per hour.
3. Heavy rain – 7.6 mm (0.30 in) per hour.
4. Violent – 50 mm (2.0 in) per hour.
SEASONAL RAINFALL PATTERN OF LIVESTOCK PRODUCERS:
1. Amount of feed that can be produced
2. Length of time forages maintain in high quality
3. Grazing practice that can be employed
4. Requirements for stored & supplementary feed supplies
5. Types of feed preservation system that will be most important.

24. INFECTIVE AGENT ARE AFFECTECTED BY RAINFALL IN VARIOUS WAY.
1. Free living organism flourish only with in fairly narrow range of humidity.
2. Adversely both by too little precipitation & by too much
EFFECT OF DIRECT RAINFALL TO LIVESTOCK.
1. Heat dissipation through evaporation, interfere with feeding & increase health
problems.
2. Animals increase to graze & stand or leave the grazing area for the protection of
trees.
3. Intake of animals will be lower than normal when forage is very wet.
4. In hot, environment, rain falling upon or retained by the hair coat will evaporate
thereby mitigating the thermal stress, depend upon the depth which water penetrates
the hair coat & depend the structure of pelage.
WOOL OF ANIMALS – Prevent water from reaching the skin unless the rain is extremely
heavy.
LONG HAIR – reduce the penetration & projecting beyond underlying longer ones that
shed water easily. Example : (Yak, Highland cattle)
SHEEP – most suitable species for hot, dry climate since wool give added protection
against the radiant heat load.

25. The OROGRAPHIC PRECIPITATION
It depicts that, as air moves horizontally over the land surface, it may
be forced to rise by hills or mountains and thus cool. And its moisture
content will condense.
When the windward side of the mountain “capture” most of the
moisture in a moving air mass, he drier and warmer air becomes even
warmer as it moves down the lee slopes of the mountain.
Precipitation is the transfer of water from the atmosphere back to earth.
Precipitation is the primary mechanism for
transporting water from the atmosphere to
the surface of the earth. There are several
forms of precipitation, the most common is
“rain”. Other forms include: hail, snow,
sleet and freezing rain. A well developed
extra-tropical cyclone could be responsible
for the generation of any or all of these
forms of precipitation.

26. Amounts of precipitation can vary by location.
For deserts like this in Nevada, average less
than an inch of total precipitation per year.
And the agricultural Midwest however,
receives approximately 15 inches per year,
while tropical rain forest like this one in
Hawaii, can receive more than 100 inches of
precipitation per year.
Amounts of precipitation also vary from year
to year.

27. Climate, Average Weather of Philippines
•Of the land area, 92.6% has a tropical monsoon climate (Am), 7.4% has a
tropical wet and dry/ savanna climate (Aw).
•Of the population, 96.5% live in a tropical monsoon climate (Am), 3.5% live in a
tropical wet and dry/ savanna climate (Aw).
Location Lat. Long.
Alt.
m(ft)
Climate Biome
Av.
Temp.
Precip.
Basco 20°27'N 121°58'E 11 (36) Af - 26 (79)
2848
(112)
Aparri, Luzon 18°22'N 121°38'E 3 (10) Am Tropical moist forest 27 (80) 2233 (88)
Daguaan City 16°5'N 120°21'E 2 (7) Am Tropical moist forest 28 (82) 2426 (96)
Manila, Luzon 14°35'N 120°59'E 18 (59) As Tropical moist forest 28 (82) 2061 (81)
Naia, Mai (Pasay City) 14°30'N 121°0'E 15 (49) As Tropical moist forest 27 (81) 1877 (74)
Legaspi 13°9'N 123°44'E 17 (56) Af
Subtropical wet
forest
27 (81)
3330
(131)
Tacloban City 11°14'N 125°1'E 3 (10) Af
Subtropical wet
forest
27 (81) 2293 (90)
Iloilo 10°43'N 122°33'E 8 (26) As Tropical moist forest 28 (82) 1954 (77)
Mactan 10°19'N 123°59'E 24 (79) As Tropical dry forest 28 (83) 1260 (50)
Surigao, Mindanao 9°47'N 125°29'E 55 (180) Af - 27 (81)
3086
(122)
Puerto Princesa,
Palawan
9°45'N 118°44'E 16 (52) As Tropical moist forest 27 (81) 1607 (63)
Zamboanga City 6°55'N 122°4'E 6 (20) As - 28 (82) 1067 (42)
Zamboanga, Mindanao 6°54'N 122°4'E 6 (20) As - 27 (80) 1226 (48)
Philippines Average 12°31'N 122°16'E 14 (46) As Tropical moist forest 27 (81) 2097 (83)

28. 2. TEMPERATURE
- Its is the degree of hotness or coldness of a place. Temperature is
measured with an instrument called “THERMOMETER”. Temperature
are measure in degree centigrade (C) or degree Fahrenheit (F).
- The global average surface air temperature is estimated to increase
between 1.4 degree Celsius and 5.8 degree Celsius by 2100. climate
models cannot yet provide a detailed picture of regional climate
change, but it is likely that nearly all land areas, particularly those at
high latitudes in the winter season.
- Most notable is the warming in the northern regions of North
America, and northern and central Asia. In contrast, the warming is
less than the expected global mean over south and southeast Asia in
summer and southern south America in winter. The surface
temperature is likely to rise least in the North Atlantic and the
circumpolar Southern Ocean.

29. IMPURITIES IN THE AIR:
1. Dust
2. Smoke
3. High water vapor content
High water vapor content – reduces the heat energy reaching the earth’s
surface.
Clouds – absorbs solar energy, making air temperature of the warm humid
tropics lower than that of dry regions.
Heat normally passé by conduction from the warm skin about (330C) of most
species of livestock. Winds coming from oceans are more equitable & moist
than those blowing across large land masses.
250C – temperature of Still air
The prevailing temperature pattern is also influence by latitude.
Air temperature tends to diminish at a rate of 0.650C / 100 m increase in
elevation.

30. THE FACTORS THAT AFFECT AIR TEMPERATURE ARE:
1. Isolation
2. Radiation from land or water below
3. Water vapor, carbon dioxide, dust & particles in the air.
“The greater the amounts of the above, the higher the temperature”
LATITUDE
- Differential heating of the earths’ surface means some places
receive greater amounts of energy than others. The difference is
found in both the angle at which the sun’s rays hit the earth and the
duration of the period of daylight. Thus, temperatures will generally
decreases as you move away from the equator.
ALTITUDE
- Environmental lapse rate of 1 degree C. / 150 meters.

31. DISTANCE FROM THE SEA
- Land surfaces reach higher and cooler temperature more quickly than water
surfaces.
- RESULT: Places near the sea have their temperatures moderated (maritime
climate)
- INLAND – extreme temperatures (continental).
This factor increased or decreased by 2 things:
1. Prevailing Winds – direction will decide oceans’ moderating effect. If wind
onshore – increased effect.
2. Ocean Currents – a warm current off a coastline will increase the moderating
effect on a northern location.
CLOUD COVER
- More clouds = less sunlight
- Less clouds = more sunlight
- But at night more heat is lost to upper atmosphere.

32. What would be the effect on the diurnal range?
- Slope of the land – local influence , south facing slopes in the northern
hemisphere are warmer (sun’s rays hit at steeper angle) than North
facing (also , sheltered from the cold north winds).
ALBEDO
- An important factor to consider in all of this type of surface than sun’s
rays are reaching. Albedo is the fraction of light that is reflected by a
body or surface. It is the % of the radiation that is reflected back into
space.
- Examples:
Water – 5%
Coniferous forest – 5 – 15%
Meadow – 10 – 20%
Dry desert soil – 25 – 35%
Snow – 75 – 95%

33. Factors affecting albedo:
1. Nature of Material – light in color means more is reflected and vice versa.
2. Wetness of material- usually this darkens material and increases its moisture
content.
3. Roughness of material or surface- flat surface will increase reflection but in a
rough surface (forest) multiple reflections can occur, thus increasing the
amount absorbed.
How can man alter the albedo of a land surface?
- Ability of atmosphere to absorb the Long Wave Radiation emitted from the
Earth’s surface depends on its composition.
- CO2 content
- Water vapor
- Dust
- Clouds

34. The element of temperature is the measurement of how hot or cold a
region is. As an element of weather and climate, temperature can change
throughout the day but typically falls within predictable highs and lows.
Within, climate temperature is affecting by phenomena such as heat
waves and cold snaps.
In a quantitative manner, we can describe the temperature of an object as
that which determines the sensation of warmth or coldness felt from
contact with it.
And we can then define the temperature of the system by saying that the
temperature is that quantity which is the same for both systems when
they are in thermal equilibrium.
And, if two systems are separately in thermal equilibrium with a third,
then they must also be in thermal equilibrium with each other.
And they all have the same temperature regardless of the kind of system
they are.

35. 3. AIR PRESSURE / ATMOSPHERIC PRESSURE
- This is the forces of gases exerted on the surface of the earth. Air has
gases in it which has weight. Air pressure is measured by an instrument
called “Barometer” . It is measured in Millibar (mb).
- Air pressure is the weight of the atmosphere pressing down on the
earth. It is measured by a barometer in units called millibars. Most
barometers use a mercury in a glass column, like a thermometer, to
measure the change in air pressure. And is the most considered as an
aspect of the weather but in some cases it can be said that changing
atmospheric pressures from part of a predictable climate.
- When the weather is calm the mercury in the barometer seldom moves
more than half – an-inch below the 30-inch mark.
- If a high pressure system is on its way, often you can expect cooler
temperatures and clear skies. If a low pressure system is coming, then
look for warmer weather, storms and rain.

36. The weight pressing down on a one square-inch sample of air at sea level is 14.7
pounds which is equivalent to a column of mercury 29.92 inches in height (1000
millibars). Air pressure changes with altitude. When you move to a higher place,
say a tall mountain, air pressure decreases because there are fewer air molecules
as you move higher in the sky.
As well as , Atmospheric Pressure is the force exerted by the weight of the air and
further defined as the force per unit area exerted against a surface by the weight
of the air above that surface. In the diagram below, the pressure at point "X"
increases as the weight of the air above it increases. The same can be said about
decreasing pressure, where the pressure at point "X" decreases if the weight of the
air above it also decreases.

37. Air movement – Aids in heat loss from the skin by conduction as long as air
temperature is lower than skin temperature but when the air temperature is
higher than skin temperature the skin will gain heat from the surrounding air.
Increased air flow will help heat help heat loss by evaporation when
moisture is present on the skin but when the moisture supply is low, the
object on the animal is higher.
The pressure changes that accompany storms may affect birds, insect, &
other animals. It has been suggested that animals sense storm conditions from
the pressure changes & make modifications in behavior. It has been
postulated that declining atmospheric pressure may stimulate feed intake.
When the pressure was high, part of the regularly offer at feed was withheld.
This was added to the scheduled feedings when the pressure decline.

38. Thinking in terms of air molecules, if the number of air molecules above a
surface increases, there are more molecules to exert a force on that
surface and consequently, the pressure increases. The opposite is also
true, where a reduction in the number of air molecules above a surface
will result in a decrease in pressure. Atmospheric pressure is measured
with an instrument called a "barometer", which is why atmospheric
pressure is also referred to as barometric pressure.
In aviation and television weather reports,
pressure is given in inches of mercury ("Hg), while
meteorologists use millibars (mb), the unit of
pressure found on weather maps.
As an example, consider a "unit area" of 1 square
inch. At sea level, the weight of the air above this
unit area would (on average) weigh 14.7 pounds!
That means pressure applied by this air on the
unit area would be 14.7 pounds per square inch.
Meteorologists use a metric unit for pressure
called a millibar and the average pressure at sea
level is 1013.25 millibars.

39. 4. WIND
- Wind is described geographically as air in motion which has direction
and speed. The instrument used in measuring the direction of wind is
“Wind Vane”.
- Wind is air in motion. It always moves from an area of high pressure to
low pressure. If there is a high pressure system over an area, this would
imply a downward movement of air. Low pressure systems imply an
upward movement of air.
- When warmed by the sun, land will radiate heat much more quickly than
a water. The operation reverses itself as the water has “held” its
warmth and continues to radiate heat for longer. Warm air rises up the
valley sides as it is heated during the day, and subsequently reverses
this operation in the night.
- Air that becomes drier as it crosses a mountain range often becomes
warmer as it sinks.

40. Air in a HIGH pressure area is heated by compression as it sink toward the
ground.
The major types of winds are:
1. Planetary winds
2. Monsoon winds
3. Sea breeze
4. Land breeze
5. Valley wind
6. Outflow wind
7. Hurricanes Mid-Latitude Cyclones Tornadoes Prow winds
Wind directions are usually indicated by devices called “weather vanes”.
When describing the direction of a wind it is customary to refer to the
direction of origin. (i.e. a westerly wind is one which is blowing from the
west to the east. ) wind speed are measured by instruments called
“anemometers”.

41. 5. MOISTURE CONTENT / RELATIVE HUMIDITY
- This is the amount of moisture in the air. Relative humidity is described
as the ration between the actual amount of vapor and the total amount
of vapor air can hold. The instruments used in measuring relative
humidity are “Hygrometer and Wet-bulb thermometers”.
- it is also the amount of moisture the air can hold before it rains. The
most it can holds is 100% it can also be measured y “Psychrometer”,
which indicates the amount of water in the air at any one temperature.
- It is considered as the measurable amount of moisture that is in the air
of the lower atmosphere. Within weather , it makes the days feel hotter
and can be used to predict storms. As an element of climate humidity is
the prolonged moisture level of a whole area that can affect entire
ecosystems. Warmer air can hold more moisture than cooler air, which
means that for a given amount of atmospheric moisture, Relative
humidity will be lower if air is warm than it would be if the air is cool.
This can be seen by comparing the daily 9AM maps (higher RH values)
with the daily 3 PM maps (lower RH values) for any month of the year.

42. The average monthly relative humidity of the Philippines varies between 71
percent in March and 85 percent in September.*

43. 6. METEOROLOGICAL PHENOMENA
- meteorological phenomena are hard to predict events such as
tornadoes, hail, storms, and fog. Within weather, meteorological
phenomena appear random and as a result of a set of unique
circumstances. However, some regions consider meteorological
phenomena as part of their climate. These regions experience these
phenomena so regularly that they are a predictable part of their
climate.
* Thus The Climate of the Philippines is tropical and maritime. It is
characterized by relatively high temperature, high humidity and abundant
rainfall. It is similar in many respects to the climate of the countries of
Central America. Temperature, humidity, and rainfall, which are discussed
hereunder, are the most important elements of the country's weather and
climate.

44. - It is either tropical rainforest, tropical savanna tropical monsoon, or
humid subtropical (in higher-altitude areas) characterized by relatively
high temperature, oppressive humidity and plenty of rainfall. There
are two seasons in the country, the wet season and the dry season,
based upon the amount of rainfall. Based on temperature, the seven
warmest months of the year are from March to October; the winter
monsoon brings cooler air from November to February. May is the
warmest month, and January, the coolest.
- Temperature
Based on the average of all weather stations in the Philippines, excluding
Baguio, the mean annual temperature is 26.6o C. The coolest months fall
in January with a mean temperature of 25.5o C while the warmest month
occurs in May with a mean temperature of 28.3o C. Latitude is an
insignificant factor in the variation of temperature while altitude shows
greater contrast in temperature. Thus, the mean annual temperature of
Baguio with an elevation of 1,500 meters is 18.3o C. This makes the
temperature of Baguio comparable with those in the temperate climate
and because of this, it is known as the summer capital of the Philippines.

45. The difference between the mean annual temperature of the
southernmost station in Zamboanga and that of the northermost station in
Laoag is insignificant. In other words, there is essentially no difference in
the mean annual temperature of places in Luzon, Visayas or Mindanao
measured at or near sea level.
- The average year-round temperature measured from all the weather
stations in the Philippines, except Baguio City, is 26.6 °C (79.9 °F). Cooler
days are usually felt in the month of January with temperature averaging
at 25.5 °C (77.9 °F) and the warmest days, in the month of May with a
mean of 28.3 °C (82.9 °F).[1] Elevation factors significantly in the
variation of temperature in the Philippines. In Baguio City, with an
elevation of 1,500 m (5,000 ft) above sea level, the mean average is 18.3
°C (64.9 °F) or cooler by about 4.3 °C (15 °F).

46. [hide]Climate data for Manila
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Average
high °C (°F)
30.1
(86.2)
31.1
(88)
32.8
(91)
34.3
(93.7)
34.2
(93.6)
32.4
(90.3)
31.3
(88.3)
30.8
(87.4)
31.1
(88)
31.2
(88.2)
31.0
(87.8
)
30.3
(86.5)
31.72
(89.08)
Daily mean
°C (°F)
25.6
(78.1)
26.1
(79)
27.6
(81.7
)
29.1
(84.4)
29.5
(85.1)
28.4
(83.1)
27.7
(81.9)
27.4
(81.3)
27.6
(81.7)
27.3
(81.1)
26.9
(80.4
)
26.0
(78.8)
27.43
(81.38)
Average low
°C (°F)
20.9
(69.6)
21.1
(70)
22.5
(72.5
)
24.0
(75.2)
24.8
(76.6)
24.4
(75.9)
24.1
(75.4)
24.0
(75.2)
24.0
(75.2)
23.5
(74.3)
22.8
(73)
21.6
(70.9)
23.14
(73.65)
Precipitatio
n mm
(inches)
6.3
(0.248
)
3.3
(0.13
)
7.1
(0.28
)
9.3
(0.366
)
100.4
(3.953
)
272.7
(10.736
)
341.2
(13.433
)
398.3
(15.681
)
326.0
(12.835
)
230.0
(9.055
)
120.4
(4.74
)
48.8
(1.921
)
1,863.8
(73.378
)
Avg. rainy
days
1.0 1.0 1.0 1.0 7.0 14.0 16.0 19.0 17.0 13.0 9.0 5.0 104
Source: Hong Kong Observatory[8]

47. Climatedatafor CebuCity
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Averagehigh°C
(°F)
29.8
(85.6)
30.2
(86.4)
31.2
(88.2)
32.3
(90.1)
33.0
(91.4)
32.1
(89.8)
31.7
(89.1)
31.9
(89.4)
31.7
(89.1)
31.6
(88.9)
31.2
(88.2)
30.3
(86.5)
31.42
(88.56)
Dailymean°C
(°F)
26.8
(80.2)
27.0
(80.6)
27.8
(82)
28.8
(83.8)
29.4
(84.9)
28.7
(83.7)
28.3
(82.9)
28.4
(83.1)
28.3
(82.9)
28.1
(82.6)
27.9
(82.2)
27.3
(81.1)
28.07
(82.5)
Averagelow °C
(°F)
23.8
(74.8)
23.7
(74.7)
24.4
(75.9)
25.4
(77.7)
25.9
(78.6)
25.3
(77.5)
24.9
(76.8)
25.0
(77)
25.8
(78.4)
24.7
(76.5)
24.7
(76.5)
24.2
(75.6)
24.82
(76.67)
Rainfallmm
(inches)
110
(4.33)
70
(2.76)
20
(0.79)
30
(1.18)
70
(2.76)
170
(6.69)
180
(7.09)
110
(4.33)
160
(6.3)
200
(7.87)
110
(4.33)
110
(4.33)
1,540
(60.63)
Source:Weatherbase [8]

48. Climate data for Baguio
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high
°C (°F)
26
(79)
27
(81)
27
(81)
28
(82)
27
(81)
26
(79)
26
(79)
26
(79)
26
(79)
27
(81)
26
(79)
26
(79)
28
(82)
Average
high °C (°F)
22
(72)
22
(72)
24
(75)
25
(77)
24
(75)
23
(73)
21
(70)
21
(70)
21
(70)
22
(72)
23
(73)
23
(73)
22.6
(72.7)
Average low
°C (°F)
11
(52)
13
(55)
14
(57)
15
(59)
16
(61)
16
(61)
16
(61)
15
(59)
15
(59)
15
(59)
15
(59)
13
(55)
14.5
(58.1)
Recordlow
°C (°F)
6
(43)
8
(46)
11
(52)
10
(50)
13
(55)
11
(52)
12
(54)
12
(54)
13
(55)
11
(52)
9
(48)
7
(45)
6
(43)
Precipitation
mm (inches)
20
(0.79)
20
(0.79)
40
(1.57)
100
(3.94)
400
(15.75)
430
(16.93)
1,070
(42.13)
1,160
(45.67)
710
(27.95)
380
(14.96)
120
(4.72)
50
(1.97)
4,500
(177.17)
Source: Weatherbase[9]

49. - Humidity
Humidity refers to the moisture content of the atmosphere. Due to high
temperature and the surrounding bodies of water, the Philippines has a
high relative humidity. The average monthly relative humidty varies
between 71 percent in March and 85 percent in September. The
combination of warm temperature and high relative and absolute
humidities give rise to high sensible temperature throughout the
archipelago. It is especially uncomfortable during March to May, when
temperature and humidity attain their maximum levels.
Relative humidity is high in the Philippines. A high amount of moisture or
vapor in the air makes hot temperatures feel hotter. This quantity of
moisture is due to different factors - the extraordinary evaporation from
the seas that surrounds the country on all sides, to the different prevailing
winds in the different seasons of the year, and finally, to the abundant
rains so common in a tropical country. The first may be considered as
general causes of the great humidity, which is generally observed in all the
islands throughout the year. The last two may influence the different
degree of humidity for the different months of the year and for the
different regions of the archipelago

50. In the cooler months, even though the rains are more abundant in the
eastern part of the Philippines, owing to the prevailing northeasterly
winds, the humidity is lesser than in the western part where a dry season
prevails. From June to October, although the rains are quite general
throughout the Archipelago, the rains are more abundant in the western
part of the Philippines, which is more exposed to the prevailing westerly
and southwesterly winds; hence the humidity of the air is greater there
than in the eastern part of the Archipelago.
The least comfortable months are from March to May where temperature
and humidity attain their maximum levels.
- Rainfall
Rainfall is the most important climatic element in the Philippines. Rainfall
distribution throughout the country varies from one region to another,
depending upon the direction of the moisture-bearing winds and the
location of the mountain systems.
The mean annual rainfall of the Philippines varies from 965 to 4,064
millimeters annually. Baguio City, eastern Samar, and eastern Surigao
receive the greatest amount of rainfall while the southern portion of
Cotabato receives the least amount of rain. At General Santos City in
Cotabato, the average annual rainfall is only 978 millimeters.

51. The summer monsoon brings heavy rains to most of the archipelago from
May to October. Annual average rainfall ranges from as much as 5,000
millimetres (196.9 in) in the mountainous east coast section of the
country, to less than 1,000 millimetres (39.4 in) in some of the sheltered
valleys. Monsoon rains, although hard and drenching, are not normally
associated with high winds and waves. Rainfall usually happen mostly from
the month of March to October. At least 30 percent of the annual rainfall
in the northern Philippines can be traced to tropical cyclones, while the
southern islands receiving less than 10 percent of their annual rainfall
from tropical cyclones. The wettest known tropical cyclone to impact the
archipelago was the July 1911 cyclone, which dropped over 1,168
millimetres (46.0 in) of rainfall within a 24-hour period in Baguio City.
- The Seasons
Using temperature and rainfall as bases, the climate of the country can be
divided into two major seasons: (1) the rainy season, from June to
November; and (2) the dry season, from December to May. The dry season
may be subdivided further into (a) the cool dry season, from December to
February; and (b) the hot dry season, from March to May.

52. Typhoons have a great influence on the climate and weather conditions
of the Philippines. A great portion of the rainfall, humidity and cloudiness
are due to the influence of typhoons. They generally originate in the
region of the Marianas and Caroline Islands of the Pacific Ocean which
have the same latitudinal location as Mindanao. Their movements follow
a northwesterly direction, sparing Mindanao from being directly hit by
majorty of the typhoons that cross the country. This makes the southern
Philippines very desirable for agriculture and industrial development.
Graphically the seasons can be represented this way:
Month
December-
February
March-
May
June-
August
September-
November
Rainfall DRY RAINY
Temperature COOL HOT
Season Cool Dry
Hot
Dry
Rainy