Context: Union Minister of State Science & Technology; Minister of State Earth Sciences; MoS PMO, Personnel, Public Grievances, Pensions, Atomic Energy and Space said, Entire Country will be covered by Doppler Weather Radar Network by 2025.

• According to the Annual Statement on Climate of India 2022 issued by the India Meteorological Department (IMD), 2,227 extreme weather-related deaths in India.

Doppler Weather Radar Network

• Aim- to predict extreme weather events more accurately.

• Doppler radar is a specialized tracking system that uses the Doppler effect to track weather conditions and calculate information about the location and velocity of a storm or other forms of extreme weather events.

• Forecasting with the help of doppler radar is more timely and accurate which can be critical during safe evacuations in the likelihood of extreme weather events.

• IMD has augmented Doppler Weather Radar network in HP, Uttarakhand, Ladakh and J&K which will help further to predict extreme weather events more accurately.

• Accuracy has increased by about 20-40% for different severe weather events forecast during last five years by making best use of Space based observation of INSAT-3D and 3DR, OceanSat satellites for prediction

Benefits

• Warning and advisory services are helping farmers and fishermen to improve their economy as found from a latest survey by National Centre for Applied Economic Research. For example, the investment in monsoon mission programme has resulted in return of 50 rupees for investment of each one rupee.

• 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.

• Climate Services are very important for short and long term planning and strategy development

• Soon a National Framework will be created on priority to provide climate products and information for Sectoral applications.

Other initiatives

• Flash Flood Guidance in 2021 has been augmented further by increasing the number of watersheds from 30,000 to 1,00,000 of the country in 2022.

• It is being provided every 6 hours to Nepal, Bhutan, Bangladesh and Sri Lanka apart from our national use.

• The web GIS services launched by IMD in 2021 have been augmented further with addition of hazard and vulnerability element in collaboration with other state and central agencies is helping the public, disaster managers and stakeholders to initiate timely response action to mitigate the disasters further

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.

• For instance, when a sound object moves towards you, the frequency of the sound waves increases, leading to a higher pitch.

• Conversely, if it moves away from you, the frequency of the sound waves decreases and the pitch comes down.

• The drop in pitch of ambulance sirens as they pass by and the shift in red light are common examples of the Doppler Effect.

• Edwin Hubble made the discovery that the universe expands as a consequence of the Doppler Effect. It has important applications in the fields of astronomy and space technology.

• The use of Doppler Effect in astronomy in relation to light waves depends on the fact that the spectra of stars are not constant.

• Different stars exhibit different absorption lines at defined frequencies, but Doppler Effect is identifiable only when these absorption lines are away from these defined frequencies.

• There are various applications of Doppler Effect. It is used in: Sirens; Astronomy; Radar; Medical imaging and blood flow managemen; Flow management; Velocity profile management; Satellite communication; Audio and Vibration measurement.