Philippine Weather and Climate Patterns PDF

CLIMATE IN THE PHILS 1. Topography and location 2. Trade winds 3. Intertropical Convergence Zone (ITCZ) 4. Easterly waves 5. Monsoon winds 6. Fronts 7. Tropical cyclones CLIMATE IN THE PHILS 1. Philippine Geography and Topography has varied geographical and topographic features...

CLIMATE IN THE PHILS 1. Topography and location 2. Trade winds 3. Intertropical Convergence Zone (ITCZ) 4. Easterly waves 5. Monsoon winds 6. Fronts 7. Tropical cyclones CLIMATE IN THE PHILS 1. Philippine Geography and Topography has varied geographical and topographic features that bring a variety of climatic conditions and influence the orographic type of rainfall divided into two seasons (based on rainfall and temperature) 1. rainy season (June-Nov) 2. dry season (Dec-May) Cool dry season (Dec-Feb) Hot dry season (Mar-May) CLIMATE IN THE PHILS CLIMATE IN THE PHILS 2. Trade Winds Northeast (NE) trade winds Southeast (SE) trade winds 3. Intertropical Convergence Zone (ITCZ) region of convergence of the NE and SE trade winds that is characterized by a relatively low-pressure zone 4. Easterly Waves wave-like oscillations that move with the easterly currents of the tropics in an east to west direction have the tendency to propagate typhoon CLIMATE IN THE PHILS 5. Monsoon Winds seasonal winds arising from the temperature differences between the land and the ocean Two types of Monsoon winds 1. Northeast (NE) monsoon (amihan: cool, dry air) 2. Southwest (SW) monsoon (habagat: warm, moist air) 6. Fronts developed in the middle latitudes and considered as the interface between the NE monsoon and north Pacific trades Types of front: warm front and cold front CLIMATE IN THE PHILS 7. Tropical Cyclones a large vortex of air (usually 25 km) spiraling inwards towards the center where the pressure is at a minimum number of tropical cyclones that enter PAR (based from 1948-2000 data) average: 20 per year; minimum: 11 per year (1998); maximum: 32 per year (1993) affect the Philippines from June to December (although the rest of the year is not entirely free from cyclones) Names of destructive tropical cyclones are DECOMMISSIONED. Criteria for TC name Decommissioning: At least 300 deaths; or At least Php 1B damage to agriculture and infrastructure. https://thecolumn.ahacentre.org/posts/insight-posts/vol-56-typhoons-in-the-philippines/ 01 solar radiation 05 humidity 02 temperature 06 wind 03 rainfall 07 evaporation 04 pressure 08 cloud cover Climate of the Philippines tropical and maritime relatively high temperature, high humidity and abundant rainfall Temperature, humidity, and rainfall: most important elements of the country's weather and climate (PAGASA, n.d.)  Drives the atmospheric and oceanic circulation that powers the winds and storms Atmospheric circulation is responsible for weather and climate Solar energy from the sun: ultimate source of energy and is received on earth in the form of electromagnetic waves. Relationship between surface temperature, amount of radiation, and wavelengths At low temperatures, small amount of radiant energy is emitted and occurs mostly at long wavelengths At higher temperatures, large amount of energy is radiated and is at predominantly shorter wavelengths  powers the earth’s climate system 51 % of incoming SR is absorbed by Earth’s surface (land and water) 19 % of incoming SR is absorbed by atmosphere (clouds, gases, and aerosols) 30 % of incoming SR is reflected back to space (atmosphere, water, and land surface)  Heat emitted as a result of absorption of solar radiation Amount of energy emitted is based on Stefan-Boltzmann Law Atmospheric longwave (RLW↓) radiation emitted by atmosphere determined by air temperature Terrestrial longwave (RLW↑) radiation emitted by earth determined by earth surface temperature  energy available at the earth’s surface to drive processes of evapotranspiration, air and soil heating, as well as other, small energy-consuming processes such as photosynthesis Accounting of all incoming and outgoing components of radiation Incoming radiation includes incident direct and diffuse SW, and incident LW radiation emitted by sky and surrounding Outgoing radiation includes SW radiation reflected or transmitted by surface, and LW radiation emitted by surface 1. incoming shortwave radiation (direct and diffuse) RSW↓ 2. outgoing (reflected) shortwave radiation from earth’s surface RSW↑ 3. incoming (atmospheric) longwave radiation RLW ↓ 4. outgoing (terrestrial) longwave radiation from the earth’s surface RLW↑ 1. Pyrheliometer – direct solar radiation 2. Pyranometer – global solar radiation (direct and diffuse) 3. Pyrradiometer – total radiation (shortwave and longwave) 4. Pyrgeometer - longwave radiation 5. Quantum (PAR) sensor – visible light (PAR)  Sunshine duration is the length of time that the ground surface is irradiated by direct solar radiation (i.e., sunlight reaching the earth's surface directly from the sun) measured in the absence of solar radiation data/instrument Instruments: Campbell-Stokes sunshine recorders, Jordan sunshine recorders Jordan Sunshine Recorder Campbell-Stokes Sunshine Recorder  a measurement of the amount of kinetic energy present in the air, which manifests itself physically through the experience of heat or cold. the response of an object to heat Instrument: thermometers mercury thermometer: because mercury is temperature sensitive, it expands when temperatures are high and contracts when they are low  mean annual temperature: 26.6 °C (excluding Baguio) coolest month: January (mean temperature: 25.5 ° C) warmest month: May (mean temperature: 28.3 ° C). altitude shows greater contrast in temperature the mean annual temperature of Baguio with an elevation of 1,500 meters is 18.3 °C no difference in the mean annual temperature of places in Luzon, Visayas or Mindanao measured at or near sea level. Annual Average Global Temperature Average Min and Max Temperature (Manila, Philippines) Weather-and-climate.com https://apollo.nvu.vsc.edu/classes/met130/notes/chapter3/daily_trend5.html NASA Climate Change NASA Climate Change  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. mean annual rainfall varies from 965 to 4,064 millimeters Baguio City, eastern Samar, and eastern Surigao receive the greatest amount of rainfall the southern portion of Cotabato receives the least amount of rain (PAGASA, n.d.)  dwd.de Global Precipitation (January 2010, in mm/month) Average Monthly Precipitation (Manila, Philippines) Weather-and-climate.com  Tipping Bucket Rain Gauge Tipping Bucket Rain Gauge Recorder 8-inch Standard Rain Gauge Rainfall Measuring Instruments  The air around you has weight, and it presses against everything it touches. That pressure is called atmospheric pressure or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is an indicator of weather. When a low-pressure system moves into an area, it usually leads to cloudiness, wind, and precipitation. High-pressure systems usually lead to fair, calm weather. Atmospheric pressure drops as altitude increases. As the pressure decreases, the amount of oxygen available to breathe also decreases. At very high altitudes, atmospheric pressure and available oxygen get so low that people can become sick and even die. Illustration by: Dr. BA Racoma  refers to the amount of moisture (water vapor) in the air water vapor exerts weight and pressure in air parcel air can hold up certain amount of water vapor depending on the temperature Philippines: has a high relative humidity (due to high temperature and the surrounding bodies of water) average monthly relative humidity varies between 71 percent in March and 85 percent in September. March to May: temperature and humidity attain their maximum levels. Role of Humidity in Plants and Animals influences the drying capacity of air influences rate of transpiration in plants affects phyto-pathogen growth and development influences thermal comfort (evaporative cooling) primary source of water (dew formation) Atmospheric moisture content can be expressed in several ways: 1. Absolute humidity 2. Mixing Ratio 3. Specific Humidity 4. Vapor Pressure 5. Relative Humidity 6. Dew-Point Temperature 7. Wet-bulb Temperature  Highly variable (time and space) and in direction and velocity Wind speed decreases rapidly as it approaches the surface Shape of wind speed profile (WS vs height) is logarithmic  direction where the wind is coming from (N means wind is blowing from north towards south) expressed as degrees (360° north wind, 90° east wind, 0 ° calm) or compass points (N, NE, NW, etc)  wind direction most often observed during a given time period represented by a wind rose (percentage of time the wind blows from different directions as indicated by length of line)  Evaporation is the process of changing liquid water into water vapor (a gas). It transports water from the Earth's surface to the atmosphere. Evaporation is called a "cooling process" because it removes heat from the surrounding air. The rate of evaporation depends on air temperature, wind speed, cloudiness. Evaporation is responsible for several weather phenomena, including humidity and clouds.  form throughout all the levels of the atmosphere affect both weather and climate. type and number of clouds impact the precipitation conditions Cloud cover may also influence temperatures at the surface of the planet. also act as an “atmospheric blanket” that helps to regulate the temperature at Earth’s surface. Cloud cover can also limit the cooling that occurs in a region at night.  cool Earth's surface by reflecting incoming sunlight. warm Earth's surface by absorbing heat emitted from the surface and re-radiating it back down toward the surface. warm or cool Earth's atmosphere by absorbing heat emitted from the surface and radiating it to space. warm and dry Earth's atmosphere and supply water to the surface by forming precipitation. Clouds are themselves created by the motions of the atmosphere that are caused by the warming or cooling of radiation and precipitation. climate change climate variability can be defined as a trend in one or defined as how the climatic variables more climatic variables characterized (such as temperature and precipitation) by a fairly smooth continuous increase depart from some average state, either or decrease of the average value above or below the average value during the period of record CLIMATE VARIABILITY & CLIMATE CHANGE