Weather observation system

A weather observation system, according to, John R. Holton in

“An Introduction to Dynamic Meteorology”, refers to, “a
network or technology designed to collect and monitor
meteorological data such as temperature, humidity, wind
speed, and atmospheric pressure. These systems help in
forecasting, climate studies, and understanding atmospheric
processes”. World Meteorological Organization (WMO):

The WMO describes weather observation systems as "a

coordinated system for observing atmospheric, hydrological,
and related environmental conditions, which integrates various
types of instruments and techniques to measure and monitor
weather and climate variables."

Mark D. Miller (2010), Atmospheric Scientist: "A weather

observation system is a network of instruments and platforms
designed to capture real-time data from the Earth's
atmosphere, including temperature, humidity, wind speed, and
pressure, enabling precise short-term and long-term weather
forecasting."

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Paul N. Edwards (2011), Historian of Climate Science, defines
it as, "a complex infrastructure that integrates a variety of
tools—such as satellites, ground stations, and weather
balloons—to continuously monitor atmospheric conditions,
facilitating both the scientific understanding of weather
patterns and the management of climate risk.”

So, in an easy word, A weather observation system is a

network of instruments and platforms that collect and analyze
atmospheric data, such as temperature, humidity, wind, and
pressure, to monitor and forecast weather conditions.

Types of weather observation system

Weather observation systems can be classified into several
types based on the platforms and methods used for data
collection. Here are the main types:

1.Surface-based Observation Systems:

Weather Stations: These are located on the ground and
measure variables like temperature, humidity, wind speed,
pressure, and precipitation.

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This Photo by Unknown Author is licensed under CC BY-SA

●Radar Systems: Used to detect precipitation, thunderstorms,

and other weather phenomena by bouncing radio waves off
rain droplets or snowflakes.
● Wind Profilers: Ground-based systems that use radar or
sound waves to measure wind speed and direction at various
altitudes.

2. Upper-air Observation Systems:

●Weather Balloons (Radiosondes): Released into the
atmosphere to collect data on temperature, humidity, pressure,
and wind speed at different altitudes.
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 ●Doppler Lidar: Uses laser pulses to measure wind speed and
direction at various heights above the ground.

3.Satellite-based Observation Systems:

●Geostationary Satellites: Orbit the Earth at a fixed position
above the equator, providing continuous weather monitoring
for large regions.
●Polar-Orbiting Satellites: Orbit the Earth from pole to pole,
capturing detailed weather data and imagery as they pass over
different parts of the planet.

4.Marine Observation Systems:

●Buoys: Floating devices anchored in the ocean that measure
atmospheric and oceanic conditions, such as air and sea
temperature, wave height, and wind.
●Ships and Voluntary Observing Ships (VOS): Equipped with
instruments to collect weather data over the ocean.

5.Airborne Observation Systems:

●Aircraft-based Observations: Instruments mounted on
aircraft to measure atmospheric conditions, often used to track
storm development and gather data in hard-to-reach areas.

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 ●Drones (UAVs): Increasingly used for weather monitoring,
especially in remote or dangerous areas, to gather data on
temperature, wind, and other variables.

6.Citizen-based Observation Systems:

●Personal Weather Stations: Individuals install personal
weather stations at home, contributing data to global networks
like the Citizen Weather Observer Program (CWOP).
●Crowdsourcing Weather Apps: Mobile applications that
gather real-time weather observations from users, such as
reports on rainfall or snow conditions.

These systems work together to provide comprehensive and

accurate weather monitoring and forecasting.

There are two main type of weather observation system:

1. Conventional (un-automated) weather observation
system.
2. Modern (automated) weather observation system.

Conventional or manual observation system:

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 A conventional or manual weather observation system,
refers to traditional methods of observing and recording
meteorological parameters manually by human observers,
typically at specific intervals. These systems rely on
instruments that require human intervention for reading,
recording, and transmitting data. The observations are
usually conducted at weather stations, where meteorological
staff physically monitor and note weather conditions.

Types of Conventional/Manual Weather Observation

Systems

1. Thermometer (Temperature Observation):

Definition: A thermometer is an instrument used to measure
air temperature.

CC BY

Types:

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 Mercury Thermometer: Uses mercury to indicate the
temperature on a scale.
Alcohol Thermometer: Uses alcohol, often in colder regions as
it can measure lower temperatures.

2.Barometer (Pressure Observation):

Definition: A barometer measures atmospheric pressure, which
helps predict weather changes.
Types:
Mercury Barometer: Uses a column of mercury to measure air
pressure.

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Aneroid Barometer: Does not use liquid but a sealed, flexible

metal chamber that expands/contracts with pressure changes.
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3.Hygrometer (Humidity Observation):
Definition: A hygrometer measures the moisture content or
humidity in the air.

This Photo by Unknown Author is licensed under CC BY

Types:
Dry and Wet Bulb Thermometer: Measures humidity based
on the difference in readings between a dry bulb (regular
thermometer) and a wet bulb.
Hair Hygrometer: Uses human or animal hair that stretches
or contracts based on humidity.
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4. Rain Gauge (Precipitation Measurement):
Definition: A rain gauge collects and measures the amount
of liquid precipitation over a period.
Types:
Standard Rain Gauge: Uses a graduated cylinder to measure
rainfall.

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Tipping Bucket Rain Gauge: Consists of a funnel that

directs rain into a seesaw-like bucket that tips and records
the amount.

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This Photo by Unknown Author is licensed under CC BY

5. Wind Vane and Anemometer (Wind Observation):

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Wind Vane: Measures wind direction.

Anemometer: Measures wind speed.

Types:

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Cup Anemometer: Measures wind speed by the rotation of
cups attached to a vertical spindle.
Wind Vane: A free-moving arrow that points in the
direction of the wind.

6. Sunshine Recorder (Solar Observation):

Definition: A sunshine recorder measures the amount of
sunlight over a period.
Types:
Campbell-Stokes Recorder: Uses a glass sphere to focus
sunlight onto a calibrated card, which burns as the sun
shines.

7. Evaporimeter (Evaporation Observation):

This Photo by Unknown Author is licensed under CC BY-SA-NC

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Definition: Measures the rate of evaporation from a water
surface.
Types:
Class A Pan Evaporimeter: A circular pan filled with water,
where evaporation is measured by the drop in water level.

8. Ceilometer (Cloud Observation):

This Photo by Unknown Author is licensed under CC BY-SA-NC

Definition: Measures the height of cloud bases above

ground level.
Types:
Optical Ceilometer: Uses a beam of light directed at clouds,
and the reflection is used to calculate height.

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Key Features of Conventional Weather Observation
Systems:
- Require manual operation and observation.
- Data collection happens at set intervals (usually every 6
hours or more frequently).
- Highly reliant on the skill and accuracy of the observer.
- Simple and cost-effective, particularly in remote areas
where automated systems may not be available.

Automated weather observation system:

An Automated Weather Observation System (AWOS) refers
to an advanced system that automatically collects,
processes, and transmits meteorological data without the
need for human intervention. These systems are designed to
operate continuously, providing real-time weather
observations at regular intervals. AWOS typically includes a
suite of sensors that measure various meteorological
parameters, which are then transmitted to meteorological
centers or displayed for users such as pilots, weather
stations, and airports.

Types of Automated Weather Observation Systems

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1. Automatic Weather Station (AWS):
Definition: AWS is a station equipped with various sensors
to automatically record and transmit weather data such as
temperature, humidity, wind speed, pressure, and rainfall.

This Photo by Unknown Author is licensed under CC BY-NC-ND

Features:
- Often used in meteorological networks for climate and
weather monitoring.

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 - Can function in remote areas without human
intervention.

2. Automated Surface Observing System (ASOS):

Definition: ASOS is a highly sophisticated network used
primarily in aviation to provide real-time, reliable weather
observations.
Features:
- Operates continuously, providing essential data on
temperature, pressure, wind speed, visibility, and cloud
cover.
- Helps in the development of accurate weather forecasts,
especially for flight safety.

3. Ceilometer (Cloud and Visibility Observation):

Definition: A laser-based instrument that measures the
height of cloud bases and can also estimate visibility.
Features:
- Used at airports and weather stations to provide crucial
cloud ceiling information for aviation.
- Automated systems can measure cloud layers and
provide cloud cover assessments.
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4. Disdrometer (Precipitation Observation):
Definition: Measures the drop size distribution and velocity
of precipitation.
Features:
- Useful in assessing the type of precipitation (rain, hail,
snow) and its intensity.
- Commonly used in research and for flood warnings.

5. LIDAR (Light Detection and Ranging) System:

Definition: A remote sensing technology used to measure
atmospheric particles, pollutants, and wind profiles.

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Features:
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 - Used for high-resolution atmospheric measurements
like aerosol concentration and air quality.
- Often applied in research and advanced meteorological
studies.

6. SODAR (Sonic Detection and Ranging) System:

This Photo by Unknown Author is licensed under CC BY

Definition: Measures wind speed and direction by emitting

sound waves into the atmosphere and detecting the returned
signals.
Features:
- Provides vertical profiles of wind at different heights.
- Often used in wind energy studies and meteorological
research.

7. Pyranometer (Solar Radiation Observation):

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This Photo by Unknown Author is licensed under CC BY

Definition: Measures solar radiation intensity.

Features:
- Automatically records solar energy reaching the Earth's
surface.
- Useful for climate studies and solar energy research.

8. Snow Gauge:
Definition: An automated sensor used to measure snowfall
and snow depth.
Features:
- Provides continuous, accurate measurements of snow
accumulation without manual observation.
- Critical for winter weather forecasting and hydrological
studies.

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9. Lightning Detection Systems:

This Photo by Unknown Author is licensed under CC BY-SA-NC

Definition: Sensors that detect and locate lightning strikes in

real-time.
Features:
- Used for storm tracking and early warning systems.
- Automatically calculates the distance and intensity of
lightning strikes.

10.Automatic Rain Gauge:

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 This Photo by Unknown Author is licensed under CC BY-SA-NC

Definition: Automatically measures the amount of rainfall

and can transmit this data in real-time.
Features:
- Similar to manual rain gauges, but with automated
recording and data transmission capabilities.
- Frequently used in meteorological networks and
hydrological forecasting.

Key Features of Automated Weather Observation System

Real-time Monitoring: Continuous and real-time weather data
collection and transmission.
Remote Operations: Can operate in remote locations without
human presence.

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Low Maintenance: Requires less human intervention and can
function for long periods with minimal upkeep.
High Accuracy and Precision: Automated systems reduce
human error, improving data accuracy.
Wide Applications: Used in meteorology, aviation, agriculture,
hydrology, and research.

Differences Between AWOS Types:

AWS vs. ASOS: While both AWS and ASOS are automated,
ASOS is more specialized for aviation and includes
additional sensors for cloud cover and visibility, making it
essential for flight safety.
Pyranometer vs. Snow Gauge: Pyranometers focus on solar
radiation, whereas snow gauges measure snow depth,
showcasing the variety of automated sensors for different
meteorological needs.

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