IMD Doppler Weather Radar Network

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    In News

    • The Keynote Address was delivered on the occasion of 148th Foundation Day of India Meteorological Department (IMD) in New Delhi.

    Minute of Address

    • Key Point: 
      • The Doppler Weather Radar Network will cover the entire country by 2025 to predict extreme weather events more accurately.
      • Recently, IMD has taken proactive steps to increase the Radar Network from mere 15 in 2013 to 37 in 2023 and will add 25 more in the next 2-3 years.
    • States: 
      • Four Doppler Weather Radar Systems in Jammu and Kashmir, Uttarakhand and Himachal Pradesh. 
    • Climate Services:
      • They are very important for short and long term planning and strategy development
      • IMD has already initiated these services in five major thrust areas of:
        • Agriculture, 
        • Health, 
        • Water, 
        • Energy and 
        • Disaster Risk Reduction
      • It has lined up plans to expand them through customization of products. 

    Doppler Weather Radar Network

    • It is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance.
    • It is designed to improve precision in long-range weather forecasting and surveillance using a parabolic dish antenna and a foam sandwich spherical radome.
    • It has the equipment to measure rainfall intensity, wind shear and velocity and locate a storm centre and the direction of a tornado or gust front.
    • It provides advanced information, enhancing the lead-time so essential for saving lives and property, in the event of natural disaster associated with severe weather. 
    • Division of  Doppler Radars and their applications: Doppler radar can be divided into several different categories according to the wavelength which are L, S, C, X, K.

    Image Courtesy: Engg 

    • L Band Radars: Operate on a wavelength of 15-30 cm and a frequency of 1-2 GHz.
      • Mostly used for clear air turbulence studies.
    • S-band radars: They operate on a wavelength of 8-15 cm and a frequency of 2-4 GHz. Because of the wavelength and frequency, S-band radars are not easily attenuated. This makes them useful for near and far range weather observation. 
      • The drawback to this band of radar is that it requires a large antenna dish and a large motor to power it.
    • C band radars: They operate on a wavelength of 4-8 cm and a frequency of 4-8 GHz. Because of the wavelength and frequency, the dish size does not need to be very large. 
      • This makes C band radars affordable for TV stations. The signal is more easily attenuated, so this type of radar is best used for short-range weather observation.
    • X-band radars: They operate on a wavelength of 2.5-4 cm and a frequency of 8-12 GHz. Because of the smaller wavelength, the X band radar is more sensitive and can detect smaller particles.
      • It is used to detect thunderstorms and lightning.
    • K band radars: They operate on a wavelength of .75-1.2 cm or 1.7-2.5 cm and a corresponding frequency of 27-40 GHz and 12-18 GHz. This band is split down the middle due to a strong absorption line in water vapour. This band is similar to the X band but is just more sensitive.

     

    About Doppler effect

    • Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer. 
    • It was discovered by Christian Johann Doppler who described it as the process of increase or decrease of starlight that depends on the relative movement of the star.
    • Doppler Effect works on both light and sound objects

    Radars (Radio Detection and Ranging)

    • It is a device that uses electromagnetic waves in the microwaves region to detect location (range & direction), altitude, intensity and movement of moving and non-moving objects.
    • It has its own source of illumination (a transmitter) for locating targets. 

    Image Courtesy: Brittanica 

    Significance

    • The Weather prediction accuracy has increased by about 20-40% for different severe weather events forecast..
    • The warning and advisory services are helping farmers and fishermen to improve their economy.
      • For example, the investment in the monsoon mission programme has resulted in return of 50 rupees for investment of each one rupee.
    • The farmers below the poverty line specially have benefited immensely as Agromet Advisories at District and Block Levels are used effectively by crores of farmers during various stages of farming and the service is being expanded. 
    • Its helps the public, disaster managers and stakeholders to initiate timely response action to mitigate the disasters further.
    • The forecasting of monsoons that are a lifeline to our food security has resulted not only in the improvement of the economy but also reducing the loss of lives due to monsoonal floods and droughts in the south Asian region.
    • Such developments have helped in  minimizing loss of lives from various extreme events like cyclone, heavy rain, thunderstorm, heat wave and cold wave etc. in recent years with its precise forecasting and timely warnings. 

    Way Ahead

    • A National Framework should be created on priority to provide climate products and information for Sectoral applications.
    • The disaster managers, general public and stakeholders under the umbrella of National Disaster Management Plans, guidelines, SOPs introduced by the present Government need to be vehemently followed so as to continue the rewards being reaped.

    India Meteorological Department (IMD)

    • It was established in 1875.
    • It is an agency of the Ministry of Earth Sciences of the Government of India.
    • It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
    • IMD has been continuously redefining its focus for accurate Prediction of Monsoon and cyclones as our GDP is mainly based on agriculture.

    Initiatives of weather predictions

    • Mausam App: It is a new mobile application called “Mausam” for the Indian Meteorological Department (IMD) which will help users track weather updates and also bring in the enhanced forecast as well as warning services from the government.
    • Meghdoot App: The Ministries of Earth Sciences and Agriculture have launched a mobile application that will provide location, and crop and livestock-specific weather-based agro advisories to farmers in local languages
    • Damini App: The Indian Institute of Tropical Meteorology (IITM)  launched ‘Damini’, a free mobile-based application that can warn people about lightning at least 30-45 minutes before it strikes.

    Source: PIB