MIMO 1.1

• Uses of Meteorological Observations:

  • Real-time preparation of weather analyses, forecasts, and severe weather warnings
  • Study of climate
  • Local weather-dependent operations (e.g., aerodrome flying operations, construction work on land and at sea)
  • Hydrology and agricultural meteorology
  • Research in meteorology and climatology
• Factors affecting the quality of raw meteorological data:

  1. Sensor’s siting or exposure

  2. Intrinsic specifications and accuracy of the sensor

  3. Maintenance, verification, and calibration of sensor
• Metadata:

  • "Data about data"
  • Answers who, what, when, where, why, and how about every data being documented
  • Important for elements sensitive to exposure, such as precipitation, wind, and temperature
• Meteorological Measurements:

  • Direct measurements: measure mass, length, and time directly
  • Indirect measurement: employs a device to make a measurement which is then interpreted (e.g., anemometer and liquid-in-glass thermometer)
• Meteorological Observing Systems:

  • In-situ Sensing: obtained through direct contact between the sensing device and the medium, material, or object
  • Remote Sensing: obtained without direct contact between the sensing device and the substance
• Active Remote Sensing:

  • Uses electromagnetic and acoustic devices that rely on a transmitted pulse and a backscattered return signal
  • Examples: radar, lidar, and sodar
• Passive Remote Sensing:

  • Does not transmit a signal, relies on the emission or reflection of electromagnetic radiation from a source
  • Detected by a sensor, processed, and displayed
• WIGOS (WMO Integrated Global Observing System) components:

  • Surface observations
  • Upper-air observations
  • Marine observations
  • Aircraft-based observations
  • Satellite observations
  • Weather Radar observations
  • Other observation platforms
• General Requirements of a Meteorological Station:

  • Temperature, soil temperature, atmospheric pressure, relative humidity, wind direction and speed, precipitation, snow cover, solar radiation and/or sunshine, visibility, evaporation
• Elements observed at a station making surface observations:

  • Present weather, past weather, cloud amount, cloud type, cloud-base height, upper-air, soil moisture, ozone/trace gases
• Meteorological observers are required for:

  • Making synoptic and/or climatological observations
  • Maintaining instruments, metadata documentation, and observing sites
  • Coding and dispatching observations
  • Providing supplementary or back-up observations
  • Responding to public and professional inquiries
• Siting and exposure:

  • The purpose of a station dictates the precise location of an observing site and its associated sensing instruments
• Criteria for representativeness:

  • Spatial representativeness
  • Temporal stability
  • Microscale, toposcale, mesoscale, large/synoptic scale, planetary scale
• Other secondary criteria for representativeness:

  • Orographically induced severe winds
  • Locations with persistent periods of extreme snow depths
  • Nearby availability of personnel with an understanding of climate observing systems
• General requirements of a meteorological station:

  • Outdoor instruments should be installed on a level piece of ground, covered with short grass or a representative surface, and surrounded by fencing to exclude unauthorized persons
  • The site should have no steeply sloping ground, no hollows, and be away from trees, buildings, or obstructions
  • Instruments like the sunshine recorder, raingauge, and anemometer must be exposed according to their requirements, preferably on the same site as other instruments
• Coordinates of the station should include latitude, longitude, and height above mean sea level
• Changes of instrumentation and homogeneity are important to minimize the effects of instrument changes or changes in instrument siting, which can introduce apparent changes in site climatology
• All synoptic land stations and principal climatological stations should be inspected at least once every two years to ensure proper siting and exposure of instruments, instrument quality, observer competence, and up-to-date metadata information
• Routine quality control checks should be designed to detect equipment faults early, with corrective maintenance conducted according to agreed priorities and timescales
• Desirable characteristics of instruments include uncertainty according to the stated requirement, reliability, stability, convenience of operation, durability, and safety for staff and the environment
• The Minamata Convention on Mercury aims to protect human health and the environment from the adverse effects of mercury, with measures to phase out specific mercury-containing products by 2020