environmental science

• Wetlands play a crucial role in flood regulation by absorbing and storing excess water during heavy rainfall.
• Meteorology is the study of the atmosphere with special interest in weather and climate conditions.
• Weather refers to the existing conditions in a specific area at a specific time, while climate refers to the average prevailing conditions over a period of years.
• The hydrologic cycle is the global water budget, with 29% of the Earth's surface occupied by land and 71% covered by oceans.
• Condensation occurs when the air temperature falls below the dewpoint temperature, and the saturated air converts some of its water to a liquid or solid form.
• Condensation requires cooling below the dewpoint and the presence of nuclei of condensation.
• Common forms of condensed moisture include dew, frost, fog, and clouds.
• Precipitation is any condensed moisture that falls to the ground surface, and it occurs when droplets, ice pellets, or crystals become large enough to overcome buoyancy and updrafts in the atmosphere.
• Rain is precipitation in the form of liquid drops, and its size upon reaching the ground surface depends on the effect of friction and evaporation during descent.
• Tropical cyclones are classified based on their degree of intensity, with tropical disturbances being the most widespread, followed by tropical depressions, tropical storms, and typhoons or hurricanes.
• The climate conditions in the Philippines can be classified into different types based on the presence of wet and dry seasons, the distribution of rainfall throughout the year, and the influence of monsoon winds.
• Cyclic storms are caused by the rising or lifting of air as it converges on an area of low pressure, with the intensity of precipitation associated with a cold front usually being heavy and covering a relatively small area.
• Orographic storms are caused by warmer air rising over a high geographic feature and meeting cooler air, resulting in precipitation if the rising air mass has a condensation level of moisture.
• The SW Monsoon is the most powerful in August and gradually weakens towards the end of September, bringing rainfall to Luzon and the Visayas.
• Tornadoes are small in horizontal extent but are the most violent disturbance of the atmosphere, appearing as funnel-shaped clouds that can cause destruction once they touch the ground.
• A thunderstorm is characterized by the presence of sudden electrical discharges manifested as lightning and accompanied by thunder.
• Public Storm Signal No. 1 indicates that a tropical cyclone will affect the locality with winds of 30-60 kph expected in at least 36 hours, causing no to very light damage.
• Public Storm Signal No. 2 indicates that a moderate tropical cyclone will affect the locality with winds of greater than 60 kph to 120 kph expected in at least 24 hours, causing light to moderate damage.
• Public Storm Signal No. 3 indicates that a strong tropical cyclone will affect the locality with winds of 121 to 170 kph expected in at least 18 hours, causing moderate to heavy damage.
• PAGASA (Philippine Atmospheric, Geophysical, and Astronomical Services Administration) is responsible for issuing information about cyclones in the area.
• Public Storm Signal No. 4 indicates that a very intense typhoon will affect the locality with winds of 171-220 kph expected in at least 12 hours, causing heavy to very heavy damage.
• The NE Monsoon brings cool, dry air to the Asian continent and causes rains in Indonesia, Australia, and NE Philippines.
• Public Storm Signal No. 5 indicates that winds greater than 220 kph may be expected in at least 12 hours, causing very heavy to widespread damage.
• Air mass: Large air body whose physical properties are approx constant in a horizontal plane
• Glaze: A sheet or coating of ice formed when rain falls on objects or on grounds having sub-freezing temperature; referred to as freezing rain
• Sleet: Occurs when water drops falling from clouds encounter a layer of air with freezing temperature, and it solidifies into small, hard, clear ice pellets; referred to as frozen rain
• Mist: Droplets that completely evaporate before reaching the ground; suspension in the air of microscopic water droplets of wet hydroscopic particles, reducing the visibility at the earth's surface
• Hail: Precipitation of solid water in the form of balls or irregular lumps of ice of diameters ranging from 50 mm or more; either transparent or composed of clear layers of ice alternating with opaque layers of snow, the clear layers usually more than 1 m thick
• Drizzle: Uniform precipitation of very numerous minute drops (dia < 0.5 mm) which seem to float in the air and eventually follow slight air motion; rain of very slight intensity, composed of fine droplets barely reaching the ground
• Rime: Thick frosty deposit formed when objects of sub-freezing temperature encounter a fog; also called freezing fog
• Convectional precipitation: Results from warm, moisture-rich air rising over heated land; as the warm air rises, the temperature drops, and so does the air's ability to hold water; if the air mass has circulation, including draft that travels up and down, hail can be released
• Snow: Hexagonal ice crystals formed when condensation occurs in rising air that has cooled to sub-freezing temperatures; exists in isolated form or may coalesce to form snowflakes of varying size and shapes at temperatures above -10ºC