test 5

• Climatology


  The study of climate and its effects
• Kaji Iklim AIB 1012
• DR. SHEEBA NETTUKANDY CHENOLI

  Senior Lecturer, Department of Geography, [e-mail]
• DR. FADZIL MOHD NOR


  Lecturer, Institute of Ocean and Earth Sciences, [e-mail]
• Factors Controlling Temperature Distribution

  • Latitude of the place
  • Altitude of the place
  • Distance from the sea
  • Airmass circulation
  • Presence of warm and cold ocean currents
  • Other local aspects (e.g. topography)
• Solstice


  The time when the sun reaches its northernmost or southernmost point in the sky
• Equinox


  The time when the sun crosses the plane of the earth's equator, making night and day of approximately equal length all over the earth
• The interaction of insolation with the atmosphere and the earth's surface creates Heat
• ASR differences between JJA and DJF show in excess of 200 Wm-2 highlighting the dominance of the solar input
• In tropics the differences between DJF and JJA are related to changing convection patterns in mid latitudes, this is more a function of temperature
• Isotherms


  Lines on a map connecting points of equal temperature
• Radiation and Temperature variation


  The daily variation in air temperature is controlled by incoming energy (primarily from the sun) and outgoing energy from the earth's surface
• Where incoming energy exceeds outgoing energy (orange shade), the air temperature rises. Where outgoing energy exceeds incoming energy (blue shade), the air temperature falls
• Malaysia (diurnal air temperature)


  • Minimum temperature usually before sunrise, Maximum temperature usually in late afternoon
• Mean daily temperature


  The average temperature of a place on any one day
• Daily temperature range


  The difference between the maximum and minimum temperatures recorded in a day
• Mean monthly temperature


  The average temperature of a place in a month
• Mean annual temperature


  The average temperature in a place within a year
• Being in the equatorial tropics, the temperature in Kuala Lumpur does not vary much from month to month
• Annual range of temperature


  The difference between the average temperature of the warmest and coldest months
• Interannual variability


  The variation in temperature from year to year
• Temperature anomaly


  The departure from the average temperature, positive or negative, over a certain period (day, week, month or year)
• Temperatures are obtained from surface and offshore weather stations, or inferred from meteorological satellite data
• Anomalies can be calculated for surface and upper-air atmospheric temperatures or sea surface temperatures
• Meteorological requirements for temperature measurements

  • The air near the Earth's surface (air temperature)
  • The surface of the ground
  • The soil at various depths
  • The surface levels of the sea (SST) and lakes
  • The upper air
• Instruments for measuring air temperature

  • Liquid-in-glass
  • Bimetallic
  • Electrical
  • Radiometer
  • Radiometer
  • Electrical
  • Bimetallic
  • Stevenson screen
• Radiation shield


  An enclosure designed to provide a uniform internal temperature that is the same as the outside air, excluding radiant heat, precipitation and other phenomena that might influence the measurement
• Maximum temperature thermometer


  A mercury-in-glass thermometer with a constriction in the neck that prevents the mercury from returning to the bulb as the temperature falls, allowing the maximum temperature to be recorded
• Resistance Temperature Detector (RTD)


  A sensor whose resistance changes as its temperature changes, used in automated weather stations to record temperature every second
• Minimum temperature thermometer


  An alcohol-in-glass thermometer with a moveable index that indicates the lowest temperature reached since the last reset
• Automatic Weather Station (AWS)


  A station that can operate independently with its own power supply and communication, automatically sending measurement data
• Radiosonde


  A battery-powered telemetry instrument carried by a weather balloon that measures atmospheric parameters and transmits them by radio
• Soil temperature sensors


  Sensors using thermistors, thermocouples, or averaging thermocouples to measure soil temperature
• Pyrheliometer


  An instrument that measures direct solar radiation, with the receiving surface arranged normal to the solar direction
• Sunshine recorder


  An instrument that uses a glass ball to focus sunlight onto a card, burning a mark that indicates the duration of sunshine