weather Refers to the conditions of the atmosphere,temperature, pressure and humidity of a place for ashort period of time. generally refers to day-to-day temperature andprecipitation activity, whereas climate is the term for theaverage atmospheric conditions over longer periods oftimee.g. Too rainfall Wind direction and strength Cloud cover and; sunshine
climate Is the average state of the atmosphereover a long period of time. the weather averaged over a long period. The standard averaging period is30 years.
season A season is a subdivision of the year,marked by changes in weather, ecology, andhours of daylight. Seasons result from theyearly revolution of the Earth aroundthe Sun and the tilt of the Earth’saxis relative to the plane of revolution.
"Climate is what youexpect, weather is what you get."
The main elements of the atmosphere thatdetermine weather and climate at a givenplace are: Temperature Precipitation (including humidity andclouds) Air pressure Winds storms and; visibility
visibilityDoppler radar - in Virac,Catanduanes. The equipment,developed by the Japan RadioCo. (JRC), is the first facility in theworld to use the Solid-StateMeteorological Radar Systemtechnology, which has 95 percentaccuracy.
Factors interacting to cause weather are: Heat energy Air pressure Winds and; Moisture
How are typhoons formed? Typhoons start off as tropical thunderstorms. Thestrong winds pull in moisture from the oceans. Thethunderstorms convert the moisture into heat. The heatcauses more air to flow to the center of the storm whichcauses more evaporation. All the heat and air flowtoward the eye creating the typhoon.
Weather differs from climate due to: Latitude – determines the angle at whichthe sun’s rays strike the earth’s surface andtheir effectiveness; Distribution of lands and water; Winds; Altitude; Mountain barriers; Big semi-permanent high and lowpressure centers; ocean currents; and Different kinds of storms.
Combinations of these factors in different intensities changetemperature that makes weather different from climate.
temperatureThe degree of hotness and coldness of asubstance.
Thermometer Shows that the amount ofchange is different for differentmaterials.
Temperature is the most importantelement of weather because weatherchanges are brought about by the change intemperature of the different parts of theatmosphere. Temperatures in the continental climatesdiffer according to where air masses thatblow come from. Large & dry continents = deserts Mountains = cooler climateso Climates in the cities are warmer thanopen countries.
Water vapor in the air is humidity. Comes from the evaporation of: Oceans; Rivers; Lakes; Soil; Plants; and Animals. Warm air can hold more moisture than anequal volume of cold air. Why?
Relative humidity The amount of moisture in the air or the percentage of the moisture the air can holds a definite temperature
Relative humidityThe relative humidity of an air-watermixture is defined as the ratio of the partialpressure of water vapor (H2O) in themixture to the saturated vapor pressure ofwater at a prescribed temperature.Relative humidity is normally expressed asa percentage and is calculated by using thefollowing equation: ew 100% ew
Relative Humidity Dry-bulb Wet-bulb % a. 27°C 25°C % b. 20°C 16°C % c. 15°C 12°C % d. 17°C 12°C % e. 30°C 29°CBased on the percentage relative humidity obtained tells when (a-b-c-d-e)1. It is driest2. It is warmest3. It is coldest4. Rain will soon fall
Air moves either horizontally as wind orvertically as currents. Winds and currents transfer heat from theequator to the poles. Heat comes directly from the earth andindirectly from the sun. Air has weight.
More molecules?Cold Air 1cm3 Warm air 1cm3 Denser?
Temperature and amount of water vapordetermine the density of air. The weight ofthe air at any given place is It is measured by an instrument calledbarometer.
Mercurial barometer The first mercurial barometer was made by Torricelli, a student of Galileo.
Aneroid barometer If the pressure increases, the sides of the container bend inward. If air pressure decreases the sides bulge out again. Can be used both for measuring air pressure and altitude above sea level. – Altimeter The higher the altitude, the thinner the air, the lighter it becomes.
Which zone has thelowest and highestair pressure? Why?
Cool pole air flows toward theequator and forces warm air upin the upper atmosphere, warm air flows toward the poles.
Air pressure is determined by: Altitude - the higher you go, the lower the air pressure, as the amount of air molecules decreases. Temperature - cold air has more air molecules than hot air Water vapor Temperature and amount of water vapordetermine the density of the air.
Local winds At daytime, air over land areas is warmerthan air over bodies of water. - Flow of air from the sea to land is calledsea breeze
At night, land cools faster than waterbodies. Sea air is warmer than land air. Seaair rises, land air takes its place. This is theLand Breeze. The name of the wind tells where itoriginates.
Huge land and sea breezes are called monsoons.–seasonal winds. Northeast monsoon October – February Winds blows from cooler continent to warmer ocean. It comes from northern Asia and blows toward the Pacific Ocean. Cold season – Philippines – cool, dry season to the northern. Winter season – north temperate and polar areas. “Hanging Amihan”
Southwest monsoon Winds blows from cooler ocean to warmer continent. It comes from the Pacific Ocean and brings rainy and typhoon season to the Philippines. Oceans winds bring in warm, moist air, therefore heavy rains and warm temperatures over the land “Hanging Habagat”
Factors affecting the winds in the earthare:The earth’s rotation, Pressure belts,Differences in topography and In the heatingof air masses over land and water. Ferrells law The law that wind is deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere . The force that deflects it is the Coriolis Force.
Doldrums A region of hot air, low air pressure and calm. Air currents move upward or downward. Trade winds Slanting winds Blow in form north and south toward the doldrums
Horse latitudes A regions of high pressure between the trade wind belts and westerlies. Air that rises in the doldrums sinks to the earth. From the HPA of the horse latitudes, air moves toward the equator and toward the poles.If the equator has a LPA due to heat, thepoles have high pressure areas due totheir coldness. The cold polar windsmove toward the sub-polar low pressurebelts, turn to the east, according toferrel’s law, and become the polareasterlies.
Prevailing westerlies Moves away from the horse latitudes toward the sub-polar low belts, but they are turned to the east by the earth’s rotation. As they come from the west, they are called the westerlies