Suggested Guide for Discussion, grade 7 (like and share)

1. Grade 7 Science
Suggested Guide for Discussion (Remedial Lesson)
MA. RACHEL B. ESPINO
Buhatan National High School
Purok Marcos, Buhatan, Sorsogon City

2.  Land breeze and sea breeze are two breezes
occurring along coastal areas or areas with
adjacent large water bodies.

3.  Water and land have different heating
abilities.Water takes a bit more time to warm
up and is able to retain the heat longer than
land does.This phenomena can be explained
as follows:

4. 1. It takes much more heat to raise the
temperature of water than is needed to raise
the temperature of an equal amount of soil.
That is to say, water has higher specific heat.

5. 2.The land is opaque and the sun’s rays reach only the
surface layers which can be heated in a shorter time.
The sun’s rays can penetrate water deeper and it takes
a longer time to heat its surface.

6. 3.The water surface has movement in the form
of waves, currents and tides and these help
distribute the heat energy received.

7.  During the day, when the sun is up, the land
heats up very quickly and the air above it
warms up a out more than air over the water.
The warm air over the land is less dense and
begins to rise. Low pressure is created.
 The air pressure over the water is higher with
cold dense air which moves to occupy the
space created over the land.The cool air that
comes along is called a sea breeze.

9.  During the night, the reverse happens.The
land quickly loses its heat while the water
retains its warmth.This means the air over
the water is warmer, less dense and begins to
rise. Low pressure is created over the water.
Cold and dense air over the land begins to
move to the water surface to replace the
warmer rising air.The cool breeze from the
land is called a land breeze.

12.  Many people think that monsoons are rains.
They are not. Monsoons are wind systems,
but these winds usually brings abundant
rainfall to the country.The prevailing wind
systems in our country are affected by our
proximity to large bodies of land and water.

13.  Earlier, we learned that the land and water
surfaces differ in their rate of heating and
cooling. Land heats and cools faster than
water, this is particularly evident in extensive
surfaces. Continents heat and cool faster than
oceans. As a result a center of low pressure
develops over the continent while high
pressure develops over the adjacent ocean.

14.  These differences in temperature and
pressure between continents and oceans
brought about by changes in the seasons
develop wind systems known as seasonal
winds or monsoons.

17.  During the colder months in the Northern
Hemisphere, a high pressure area develops
over India and Southern Siberia in winter
because of the colder air over them.The mass
of cold air then moves toward the Philippines
from a north-easterly direction and the air
mass is called the Northeast Monsoon or
Amihan.This prevails the cold morning
experienced in the country from December to
February.

18. NORTHEAST
MONSOON
(AMIHAN)
December
to February

20.  During the summer in the Northern
Hemisphere, the Asian continent becomes
warmer than the oceans surrounding it. A
cold air mass develops over the Pacific ocean
and begins to move toward the Asian
continent.This forms the Southwest
Monsoon or habagat which prevails over the
Philippines in the months of July, August and
September.

21. SOUTHEAST
MONSOON
(HABAGAT)
July to
September

23.  The trade winds which are the prevailing
winds in the tropics likewise affect the
Philippines during the rest of the year and
whenever the Northeast monsoon and the
Southwest monsoon weaken.

25.  The northeast
trades meet the
southwest trades
somewhere near
the equator.This
results in a land
of convergence
that gives rise to
massive cloud
formation.

26.  The Intertropical Convergence Zone or ITCZ
is the place where winds in the tropics meet
or converge, this happens when the air from
the north of the equator and air from south of
the equator moves toward the place where
warm air is rising.Where ITCZ forms, there is
an increased probability of rainfall and bad
weather. Most tropical cyclones in the
Philippines originate as weather disturbances
embedded within the ITCZ.

28.  Example, during the summer months in the
Northern hemisphere, the ITCZ forms just
north of the Philippines.This also coincides
with the time of the southwest monsoon.
Thus it is not surprising that we experience a
lot of rain and bad weather during this time
up to around November.