BACKGROUND

Countries in the World Meteorological Organization (WMO) network are encouraged

to establish Global Atmospheric Watch (GAW) stations to carry out systematic monitoring of

background atmospheric constituents for the purpose of acquiring reliable, high quality data to

study and understand regional and global environmental issues such as transboundary haze,

acid deposition, climate change and stratospheric ozone depletion.

In 1883, Meteorological Stations were began in Penang and Malacca to observe air

pressure, temperature and rain fall in Malaysia, which formally known as Federal Malay

States. The development continuous throughout the years till 1965, Malaysian Meteorological

Service was established and placed under the Ministry of Transport with the separation of

meteorological services in Malaysia and Singapore. Research and Training,

Hydrometeorology and Agrometeorology was established and in 1984 Malaysian

Meteorological Service was transferred to the Ministry of Science, Technology and the

Environment

Formally established in 1989, GAW integrated a number of existing WMO monitoring

activities in the field of atmospheric environment. The GAW consists of a worldwide network

of strategically-located global, regional and national monitoring stations coordinated by the

WMO. The Malaysian Meteorological Department (MMD) is operating two GAW regional

stations, one at Tanah Rata, Cameron Highlands and the other at Petaling Jaya. The GAW

station at Petaling Jaya monitors urban air quality and meteorology towards developing a

better understanding of urban environment issues

. MMD has established a GAW global station in the Danum Valley, Sabah since

November 2003. The Danum Valley is globally, one of the best-known research sites in

tropical rainforests in the world. The GAW station, located within a Class 1 forest

conservation area, offer an ideal location for investigating atmospheric-biosphere interactions

in a tropical rainforest environment, study of long-range transport of pollutants and ability of

forests to act as sinks for atmospheric pollutants. 

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FUNCTIONS

Maintain a technically-advanced observation station network to support monitoring of

weather conditions and seismic activities in the country.

Issue timely meteorological information and forecasts for civil and military aviation,

marine activities and general public.

Provide early warnings on the occurrences of adverse weather phenomena and

dangerous sea conditions in the Malaysian region to the public and relevant agencies

involved in disaster mitigation.

Provide immediate information on earthquake events that affect the country to the

public, media and relevant government agencies involved in disaster mitigation.

Provide seismological information to civil engineering and construction industries.

Compile quality climatological, atmospheric composition and seismological data and

prepare climatological statistics.  

Monitor atmospheric composition in Malaysia and provide information and technical

advice on the meteorological aspects of air pollution.

Conduct cloud seeding operations to increase water resources for agriculture and other

purposes.

Participation in international programmes on research, data collection and exchange,

and other related activities in meteorology.

Publish meteorological reports and bulletins.

Publish meteorological reports and bulletins

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SERVICES PROVIDED BY MALAYSIAN METEOROLOGICAL DEPARTMENT

1. Weather forecast

- General Weather forecast

- State Weather Forecast

- Weather Forecast for Major Towns/ Tourist Destinations

2. Seasonal and Long-Range Weather Outlook

- Current El-Nino condition

- Long-Range Weather Outlook

3. Weather Warning

- Strong winds and Rough Seas Warning

- Severe Weather Warning

- Tropical Cyclone and storm Warnings

4. Marine Meteorological Forecast

- Forecast for fishermen

- Seven-day weather, wind, wave

- Seven-day tide forecast

- Wave Model (WAM) products

5. Aviation Meteorology

- Weather forecast kiosk

- Aviation briefing terminal

6. Meteorological Observations

- Satellite picture

- Radar image

- Surface observation

7. Earthquake and tsunami

- Earthquake information/ tsunami warning

- Map of latest earthquake

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- List of recent earthquakes

8. Weather modification

- Cloud seeding operations

9. Environmental studies

- Solar UV index

- Particulate Matter (PM-10)

- Multigas

- Oxidant and particle photochemical processes (OP3) project

10. Climate

- Malaysian fire danger rating system

- Southeast Asia fire danger rating system

- Monthly rainfall review

11. Agromet

- 10-day Agromet bulletin

- Rainfall

- Evaporation

- Solar radiation

- Temperature

- Soil moisture distribution

- Mean evapotranspiration

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METEOROLOGICAL OBSERVATION

a)Weather Instruments

1. Automatic Weather Stations (AWS)

In recent years, weather monitoring has become increasingly automated. An unmanned

weather observation station is normally equipped with an automated weather system

consisting of the following major components:

- A suite of meteorological sensors housed in instrument shields and connected to a

field processing unit *data-logger) by means of shielded cables

- A field-processing unit (data-logger) of data acquisition, processing, storage and

data transmission

- Peripheral equipment such as stabilized power supply, modem, built-in-diagnostics

and local terminals for manual entry, data editing and display

The AWS measures precipitation (amount of rainfall), atmospheric pressure, temperature,

humidity, wind speed and direction and global solar radiation, updating the data every

minutes, 24 hours a day without human intervention

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2. Wind Speed and Direction Sensor

Wind direction is the direction from which the wind is blowing. It is expressed in degrees

measured clockwise from geographical north. Wind vanes do not respond to changes in wind

direction when the wind speed is less than one metre per second or two knots. Wind speed is

measured in metres per second or knots. Calm is reported when the wind speed is less than 0.5

metres per second or less than one knot. Instruments used for measuring the surface wind

speed are called anemometers, the most common of which is the cups mounted symmetrically

at right angle to a vertical shaft. The difference in wind pressure from one side of the cup to

the other causes the cup to spin about the shaft. The rate at which they rotate is directly

proportional to the speed of wind.

3. Temperature sensor

The temperature sensing system uses integrated circuit technology in combination with an

accurate resistance thermometer element to allow reliable measurements

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The dry and wet bulb thermometers are placed vertically on a support inside the Stevenson

screen. The bulb of the wet bulb thermometer is wrapped with muslin and is tied up with a

wick. The wick is then dipped inside a container which contains distilled water.

4. Solarimeter / Pyranometer

The solarimeter measures routine global solar radiation on a plane or level surface. It has a

thermocouple junction-sensing element. The sensing element is coated with a highly stable

carbon based non organic coating, which delivers excellent spectral absorption and long term

stability characteristics, The sensing element is housed under two concentric fitting glass

domes.

5. Tipping Bucket Rain Gauge

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A tipping bucket rain gauge has a receiving funnel leading to two small metal collectors

(buckets). When a bucket accumulates 0.2 mm of rain water, the weight of the water causes it

to tip and empty itself. Each time a bucket tips, an electrical contact is made, thereby enabling

recording or rainfall amount and intensity with time. The maximum detectable rainfall rate is

200 mm/hr

6. Atmospheric Pressure Sensor

The pressure sensor is a pressure capsule or a solid state capacitive device which outputs

voltage which is converted into digitally encoded values of atmospheric pressure

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b) Weather Observations

Surface observations

made at least every three hours over land and sea.  Land-based weather stations around the

world and automatic stations observe the atmospheric pressure, wind direction and speed,

temperature of the air, humidity, clouds, precipitation and visibility using standard weather

instruments such as the barometer, wind vane, anemometer, thermometer, psychrometer or

hygrometer and raingauge.  In addition to these, coastal weather stations, weather ships and

ocean data buoy observe the state of the sea by observing the height and period of wave.

Upper air stations

also make observations at least every twelve hours.  The pressure, temperature, dew point

temperature, wind direction and speed are observed at selected levels in the atmosphere using

radiosondes which record these data by tracking helium-filled balloons attached to

transmitters.  Another apparatus, the theodolite, is used in observing wind direction and speed

also at selected levels.  In addition to these, commercial air planes observe the weather along

their routes at specified times.

Meteorological satellites

geostationary and polar orbiting, take pictures of the cloud imagery of the atmosphere.  These

satellites take picture of the earth's cloud formations every hour and continuously,

respectively.

Weather radars

used to observe the cloud coverage within the range of the radar.

A vast array of weather data are fed to the computer which analyzes them as programmed and

makes a time integration of physical equations.  This is called numerical weather

prediction.

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METEOROLOGY SATELLITE

How Malaysian Meteorology Department observe the global weather and climate

Global Observing System

- Stations are not evenly distributed over the land surface

- Fewer stations over mountains, deserts, unpopulated regions

- Ship routes and aircraft routes are concentrated in certain regions

- Ocean data buoys and floats are very recent additions to the observing system

To get a complete global picture of the earth’s weather and climate, remote sensing is used.

Remote sensing is a technology involving the use of sensors placed on platform moving at a

far distance from earth's surface and it can be used for collecting data of the earth for the

purposes of inventorying and monitoring.

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Global Meteorological Satellite Network

1. Operated by different countries

2. Different types

3. Different orbits

Meteorology application

1. Weather and climate

2. Rainfall amount

3. Wind speed and direction

4. Cloud detection and movement

5. Typhoon track

6. El-Nino and La-Nina

7. Agriculture

8. Fisheries

9. Environment

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Component of satellite meteorology

1. Source of energy for satellite meteorology

2. Satellite

-Orbit : Geosyhnchronous Orbit and Low Earth Orbit

- Inclination :0°

- Sensor : visible sensor, opyical sensor

3. Ground station and processing system

- Receive

- Process

4. Analysis and interpretation

Division of satellite meteorology

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Established in 1968 as one of the supporting divisions to the department.

Provide satellite imageries for

- Weather monitoring and forecast

- Cloud seeding operation

- Monitoring hotspot

- Private and government agencies

- Research work in MMD, institutes of higher learning and also other research

agencies

MMD’s satellite ground receiving station

1. Geostationary meteorological satellite

-FY-2E

- MTSAT-1R/ MTSAR-2R

2. Polar orbiting meteorological satellite

-NOAA/ FY-1D

- TERRA and AQUA

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METEOROLOGY RADAR

Radar is coined for acronym of “Radio Detection Ranging”. Radar is a detection system that

uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving

and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain.

The objects that are targetted (such as raindrops, ice, snow, birds, insects, terrain, and

buildings) reflect that energy of elctromegnatic pulses. Part of the reflected energy is received

back at the radar. Once the radar receives the reflected signal, computer programs and

meteorologists interpret the signal to determine where it is precipitating.

Purpose using radar in weather observation is to give bigger range of wheater infomation in

real wheater phenomena. From the infomation given, the meteorology department can easily

forecast for short term period and the data obtain may also be used for others reasearch fields.

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Figure : weather radar by MMD

The product obtain from radar such as :

a. Radar Echo Map for single radar

b. Composite Map for all type of radar

c. Time Series

d. Vertical Cross-section

e. Radial Wind

Example of Radar Products:

a) 3D-TOP

b) RHI

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c) PPI

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