MAUSAM

Winter Season

Editor Mausam — Fri, 17 Jan 2025 00:00:00 +0000

Journey of India Meteorological Department during last 150 years

R. R. Kelkar — Thu, 16 Jan 2025 00:00:00 +0000

The article describes the developments that led to the establishment of the India Meteorological Department in 1875, the seminal and inspiring contributions of the pioneers and the visionaries, and IMD’s continuing progress through the last 150 years in the service of the nation.

Evolution of surface meteorological observations systems in India.

R. R. Mali — Thu, 16 Jan 2025 00:00:00 +0000

The article describes the developments that led to the establishment of the Surface meteorological Observation systems in India Meteorological Department (IMD). IMD is continuing upgrade & modernize the surface meteorological instrument network through the last 150 years in the service of the nation.

Evolution of satellite meteorology and its future scope- India’s perspective

R. C. Bhatia, A. K. Mitra — Thu, 16 Jan 2025 00:00:00 +0000

During last six decades satellite-based systems have evolved into a very powerful tool for observing earth and its atmosphere. Their prodigious areal coverage combined with capability of very frequent observations over a given area makes them ideal platform for a wide variety of vital observations of atmosphere and the processes that manifest into weather phenomenon on the earth. Developmental efforts initiated in the early stage at NASA, USA have culminated into availability of sophisticated instruments of various types which measure radiation in different spectral ranges of the electromagnetic spectrum. Using appropriate Electro-Optical systems with scanning capabilities on board satellites, large areas of the earth can be viewed. Such measurements can be converted to pictures of earth’s cloud cover as well as profiles of temperature and humidity on a global basis using a system of satellites in different orbits. Such unique capabilities of satellites have enabled weather forecasters to make a realistic assessment of the present state of the atmosphere with a three-dimensional perspective. When combined with more frequent observations, evolution of weather systems at various spatial and temporal scales can be seen with a high precision. Satellite systems have therefore revolutionized the science of weather forecasting. As a result of all these developments the weather forecasting services all over the world have improved considerably, particularly during the last two decades. Data and products generated from number of satellites are also assimilated in the NWP based models to generate forecast charts for operational use by weather forecasters. There is a positive impact of assimilating satellite products in the model based forecast charts. Particularly, data from two sensors AMSU-A and IR based Hyperspectral sounders on polar satellites, are found to have large impact as compared to all other types of sensors. INSAT series of Indian Geostationary satellites started from early 1980s, have made significant contributions to the weather forecasting services of India Meteorological Department. Like some of the currently operational Geostationary meteorological satellites of the other countries, future generations of INSAT satellites are also planned to be equipped with advanced payloads like multi-spectral imagers, lightning imagers and IR based Hyperspectral sounders.

Evolution of Radar Meteorology in India and the latest trends

G. S. BHAT , J. VIVEKANANDAN, D. PRADHAN — Thu, 16 Jan 2025 00:00:00 +0000

Weather radar is an indispensable tool in the continuous monitoring and warning of extreme events including tropical cyclones and thunderstorms. The India Meteorological Department (IMD) has been operating radars since 1949. The evolution of radar meteorology in India may be divided into three broad phases, namely, the 1950s (phase-I), then up to the year 2000 (phase-II), and thereafter (phase-III). During phase-I, radars were imported and installed in cities to aid aircraft operations. Photographs of radar scopes were analysed to provide a broad understanding of temporal evolution and spatial extent of precipitating clouds in different parts of the country and seasons. During phase-II, storm warning (X-band) and cyclone warning (S-band) radars with more power and range were installed, and some of them were indigenous. Phase-III ushered in the era of digital Doppler weather radars in India. Interfacing between numerical models and radars started in phase-III including assimilation of radar winds and model verification. Installation and operation of weather radars outside IMD also started in phase-III. Important areas where more work needs to be done include a well-trained workforce in radar meteorology, radar calibration and data standardization, radar area coverage and networking, algorithms for quantitative precipitation estimation using polarimetric products, assimilation of radar products in numerical models, research on cloud physics and dynamics, applications of AI/ML in storm and severe weather nowcasting.

Journey of Operational Weather Forecasting in India

P. N. Sen, Sunny Chug, Arti Bandgar — Thu, 16 Jan 2025 00:00:00 +0000

India Meteorological Department (IMD) was established in 1875. Its mandate was to study climate and weather of India as a whole and to issue storm and other warnings and daily weather forecast. IMD issues Cyclone Forecasts and Warnings; Day to day Forecasts, Medium Range and Extended Range and Long Range Forecasts; Forecast for Aviation activities; Nowcasting; Quantitative Precipitation Forecast for Flood warning etc. Initially, forecasting was done by Synoptic and Statistical methods. Nowadays, forecasts are issued using Numerical methods. Surface and upper air data along with Radar and Satellite data are used in forecasting work. How the forecasting work evolved in the last one hundred fifty years has been described in this paper.

A Journey Through Time The History of Mesoscale Severe Weather Monitoring and Forecasting in India

Thu, 16 Jan 2025 00:00:00 +0000

Improving the prediction of weather events is always an important research area and challenging task to the meteorologists since it poses a major impact on human life, properties and countries economy. The operational and research centers around the globe have been working to better understand the multiscale interactions involved to advance severe weather including Tropical Cyclones and thunderstorm predictions. The present review article focuses on research activities with a specific emphasis on Numerical Weather Prediction (NWP) methods that led to improvements in severe weather prediction over India during the last three decades. This work also highlights the continuous efforts of India Meteorological Department (IMD) in increasing the observational network and severe weather monitoring. The evolution of NWP models and associated advancements in genesis, movement and precipitation forecasts of extreme events by these models are discussed.

Evolution of Cyclone Monitoring and Forecasting System in India: A review

M. MOHAPATRA, M. SHARMA, D. R. PATTANAIK — Thu, 16 Jan 2025 00:00:00 +0000

Two severe cyclonic storms hit the east coast of India in quick succession causing enormous loss of human lives and property – the first one struck Kolkata in October and the second one struck Machilipatnam in November, 1864. Concerned with these disasters, the Government appointed a committee in 1865 to formulate a scheme to develop a cyclone warning system, especially for Kolkata part to begin with. Since then, the India Meteorological Department (IMD) moved ahead in a very systematic manner in different stages to address all components of early warning system (EWS) including enhancement of observational network, development of infrastructure & organizational set up, communication system, modeling, monitoring & prediction of tropical cyclones (TCs), introduction & implementation of new technology for monitoring, forecasting and warning services along with continuous upgradation of standard operating procedure. As an outcome, the IMD could achieve zero death in Gujarat state during TC Biparjoy (June 2023) and less than 100 deaths due to any TC not only in India but also in the 13 countries bordering the Bay of Bengal (BoB) and the Arabian Sea (AS) in last decade. All these have resulted in overall improvements in socio-economic conditions in the region and also earned name & fame not only to IMD but also to India. This manuscript provides an insight into various phases in the development of Cyclone Warning System in India.

Evolution of Monitoring and Forecasting of Southwest Monsoon

M. Rajeevan, D.R. Pattanaik — Thu, 16 Jan 2025 00:00:00 +0000

In this review article, we discuss how monsoon monitoring and forecasting has evolved over the last 150 years. Since there are several other articles in this issue on short-range and operational forecasts of the IMD, we focus only on the details of monsoon monitoring, extended range forecasts (10-30 days) and seasonal forecasts (up to one season). IMD now has a system to monitor the monsoon performance at the district level on a daily basis. Under the monsoon mission, IMD has been able to set up an extended range forecasting system which now has a capability of skilful prediction up to 2 weeks. In some special cases, the skill is extended to three weeks. IMD is the first country to begin systematic research into seasonal monsoon forecasting. Statistical models formed the backbone of the IMD’s seasonal forecasting system. Since 2017, the IMD has also been using dynamic models for seasonal forecasts. Opportunities to further improve monsoon monitoring and forecasting systems are also identified and discussed.

Understanding and prediction of Indian Northeast Monsoon over the years

Y. E. A . Raj, S. Balachandran, B. Amudha, B. Geetha — Thu, 16 Jan 2025 00:00:00 +0000

The five meteorological sub-divisions of India viz. Tamil Nadu, Coastal Andhra Pradesh, Rayalaseema, South Interior Karnataka and Kerala which together are referred here as the Southern Peninsular Region (SPR), are the major beneficiaries of Indian northeast monsoon which prevails over SPR during Oct-Dec. In this article how the knowledge base on Indian northeast monsoon evolved in the 19th, 20th and 21st centuries is presented. The article describes the transition from the southwest monsoon season to northeast monsoon season. The northeast monsoon rainfall (NMR) climatology of SPR based on 150 year data of 1871-2020 is presented and discussed. How the onset and withdrawal dates of northeast monsoon for 1871-2020 have been determined in various studies is set out. The inter-annual, intra-seasonal and diurnal variation features of NMR, components and weather systems of northeast monsoon are described. Short, medium range and seasonal forecasting of NMR, global teleconnections, relation between NMR and Indian southwest monsoon rainfall are elaborated. The climatic classification of SPR, research on northeast monsoon and a brief reference to the northeast monsoon of Sri Lanka are included.

The History of Climate Services in IMD

B Mukhopadhyay, Rajib Chattopadhyay, O. P. Sreejith, Kripan Ghosh — Thu, 16 Jan 2025 00:00:00 +0000

IMD was created to act as the nodal agency in the country on weather and climate matters. This article broadly covers the journey of Climate Services becoming a separate branch with direct linkages to sectoral applications and is not an exhaustive documentation. Notionally, weather and climate differ in the former being a time specified information and the latter a statistical description valid for a certain duration of time. Both, however, refer to geophysical phenomena which impact life as individuals and collective societies. Climatic experiences have for ever lived through memories influencing human activities but in modern times physical observations have been recorded systematically and extensively subjected to mathematical and statistical treatment. This allowed societal applications to be done in objective manner. Of particular interest are the climate effects on agriculture, water resources, health, energy production and safety with respect to climate hazards. Climate services pertain to variability of climate over different periods of time including the changes due to anthropogenic effects. This had made applications of climate knowledge very critical. A framework within which these services need to function are also indicated here.

Technological Evolution of Communication and Dissemination of Meteorological Data and Information

Dulal Chakrabarti, SUNNY CHUG, SANKAR NATH, K. C. SAI KRISHNAN — Thu, 16 Jan 2025 00:00:00 +0000

150^th year of the foundation of India Meteorological Department ushers in a universal acclaim for the new World Meteorological Organization (WMO) Information System 2.0 (WIS 2.0), which is the framework for Earth Systems (meteorological, hydrological, climate and ocean) data sharing in the 21^st century. WIS 2.0 is a collective response by WMO member countries facing challenges to handle the 5 Vs (Volume, Variety, Velocity, Value and Veracity) of big data which, for example, for an advanced numerical weather prediction center such as ECMWF could be 1 peta (10**15) bytes daily for European Union’s Destine project which will simulate a Digital Twin (DT) of the earth to visualize high impact weather and climate changes at sub-kilometer resolution [ECMWF (2023)]. Similarly, NOAA is collaborating with Microsoft, Amazon, Google and IBM to host earth system data for any user including commercial users to generate products needed for the specific business needs [NOAA (2023)].

Advances in Environmental Meteorology and Air Quality Early Warning

K. J. Ramesh, Chinmay Jena, Anikender Kumar, Vivek Kumar, V. K. Soni — Thu, 16 Jan 2025 00:00:00 +0000

. India Meteorological Department (IMD) established in 1875 has a long legacy of monitoring climate and environmental parameters. IMD was the first institution in India to start systematic long-term observation of Solar Radiation, Ozone, Precipitation Chemistry and Aerosol Optical Depth (AOD) and Physical properties and Atmospheric Chemistry. The solar radiation measurement started for the first time at Kolkata as early as November,1879. However, a series of coordinated and systematic observations of various geophysical phenomena started all over the globe after International Geophysical Year (IGY) 1957-58. Post-independent IMD rose up to meet the demand for enhancing the density of observing systems through a self-reliant approach of total indigenization of the manufacture of meteorological instruments. IMD started manufacturing meteorological, radiation and ozone measurement instruments to the specified accuracy at par with the internationally established manufacturers. IMD has long history of measurement of all the three components of Ozone i.e. Total Columnar Ozone, Vertical Distribution and Surface Ozone measurement. Total Columnar Ozone measurements in India were first made during September 1928 to August 1929 at Kodaikanal observatory of IMD.
The air quality forecast is relatively recent initiative in IMD compared to digital weather and climate forecasts generation.
The Air Quality Early Warning System (AQEWS) provide real-time forecast products for early warning of changing profile of Air Quality Index (AQI) across the National Capital Region (NCR) of Delhi to designated air quality management/regulatory authorities in order to moderate anticipated high AQI levels through enforcing various sector targeted emission reduction actions specified under graded response action plans. This paper reviews emerging trends in environment meteorology and IMD’s pivotal role in monitoring and prediction of atmospheric environment.

India Meteorological Department: A journey of 40-Year of polar meteorology

Thu, 16 Jan 2025 00:00:00 +0000

The multi-disciplinary and multi-institutional scientific expedition to Antarctica of national and global relevance was initiated by India for the first time in 1981. India Meteorological Department (IMD) started meteorological observations since the very first expedition. The extensive meteorological observations collected from Dakshin Gangotri (70.75^oS 11.58^oE), Maitri (70.76^oS 11.73^oE) and Bharati (69.4^oS 75.18^oE) stations provide a comprehensive overview of the Antarctic climate over the past four decades.

The paper highlights the significance of polar meteorology within the broader context of climate science. It provides an overview of IMD's involvement in setting up and maintaining meteorological infrastructure at the aforementioned polar stations, emphasizing the challenges and achievements associated with continuous data collection in these extreme environments. The analysis includes a range of meteorological variables, including temperature, precipitation, wind patterns, solar radiation and atmospheric ozone.

Evolution of Agromet Advisory Services in India

L. S. Rathore, Kripan Ghosh, K. K. Singh — Thu, 16 Jan 2025 00:00:00 +0000

The need for a close collaboration between the Departments of Agriculture and Meteorology in India was felt by the Royal Commission on Agriculture during 1920s to better understand the relationship between weather and crops, so that disruption and damage caused to agriculture, economy and human life by weather hazards like drought etc. which could be reduced, marginalized or even controlled from turning into famine. This resulted in the establishment of Agricultural Meteorology Division at Pune in 1932. During the formative years, initiative was taken for implementation of the “Co-ordinated Crop Weather Scheme”, to establish observational set up and conduct research activities in collaboration with various organizations to understand crop stresses and related remedial measures. Journey of weather services to the farmers commenced in India Meteorological Department (IMD) with “Farmers’ Weather Bulletin” in 1945 to provide district wise weather forecast twice a day exclusively for them. In order to provide information on day-to-day weather based farm operations along with weather forecast, as per recommendations of the National Commission on Agriculture (1976), IMD started Agromet Advisory Services (AAS) at state level in July, 1977 from the then Madras (presently RMC, Chennai) and covered all the states. Numerical Weather Prediction (NWP) model forecast based services to the farmers were started by National Centre for Medium Range Weather Forecasting (NCMRWF) at agro-climatic zone (ACZ) level in 1991 in collaboration with Indian Council of Agriculture Research (ICAR) and State Agriculture Universities. AAS provided by two organizations were integrated into a single window system and started functioning as “Integrated Agromet Advisory Services (IAAS)” scheme in IMD, in XIth plan, at district level from 1 June 2008, which was further extended as “Gramin Krishi Mausam Sewa (GKMS)” in XIIth plan and IMD jointly with ICAR started catering services at block level from 2018 by establishing network of District Agro-Met Units at Krishi Vigyan Kendras. Agromet Advisories are being disseminated to the farmers through multichannel dissemination systems like print and electronic media, Door Darshan, radio, internet etc. including SMS under Public Private Partnership (PPP) mode supported by govt. and private organizations. State of art technologies are presently being used for development of Agromet Decision Support System, online system for receipt and transmission of Agromet data, generation of various land and satellite observation based Agromet products as well as for identification of appropriate remedial measures to save the crops from adverse weather situation. Various leading organizations of the country like, IMD, NCMRWF, IITM, ICAR, ISRO, IITs, NIC, SAUs, SDAs etc. joined hands for meaningful research activities and operational supports to extend the services to further finer spatial scales for longer duration.

Hydrometeorological Services, an application of weather and climate services to water sector

N. Y. Apte, Ashok Kumar Das — Thu, 16 Jan 2025 00:00:00 +0000

Evolution of Aviation Meteorological services in India

Ajit Tyagi, R. Suresh, R. K. Jenamani, Gajendra Kumar, Anoop Kumar Mishra — Thu, 16 Jan 2025 00:00:00 +0000

Weather plays critical role in the safety and operational efficiency of aircraft operation.As early as 1913 India Meteorological Department started taking upper air observation to support aviation and first aviation forecast was issued in 1921 for the Royal Air Force (RAF). While evolution of Aviation Meteorological services in early years was primarily driven by military aviation, it was post second World war rapid growth of commercial aviation gave boost to Aviation Meteorological services in India. India Meteorological Department kept pace with growing demands of aviation sector by modernising its observing systems, communication and forecasting. The On Line Briefing System (OLBS) has been a boon to low cost carriers. IMD delegates have been atively contributing to ICAO proceedings for the efficient international aviation services. IMD is also working closely with Met Services of the Indian Air Force and Indian Navy to provide coordinated services at Joint User Airfields under UDAN scheme. To meet future requirements. IMD is in the process of developing Decision Support System and implementing MET-ATM to give reliable warning against severe aviation hazards. This will contribute to safety and enhance operational efficiency of airlines and airports.In view of climate change, Aviation community and policy makers also need to take in to account the impact on climate change on airport management and aircraft operations.

Time Evolution of Meteorological Training and Education in India

Thu, 16 Jan 2025 00:00:00 +0000

An attempt has been made to trace out the time evolution of training services of India Meteorological Department in the disciplines of General Meteorology, Agricultural Meteorology, and Meteorological instruments & telecommunication through its two World Meteorological Organization Regional Training Centre (WMO RTC) components. The success of the training courses which are organized by these RTCs in the framework of Guidelines for the Education and Training of Personnel in Meteorology and Operational Hydrology (WMO- No. 258) has been widely recognized by the national and international stakeholders as well as the WMO and other related international organizations. The design of the training syllabi fulfils the competency requirements, set by WMO & ICAO. Some new training courses which reflect the advances in meteorology and hydrology have also been offered to enhance the capabilities of trainees in the use of the up-to-date numerical products. In addition to face-to-face teaching, blended learning has been introduced for some training courses to enhance the training efficiency.

Evolution of Heat Wave Monitoring and Forecasting in India

M. Mohapatra, Akhil Srivastava, Raghu Nadimpalli , Naresh Kumar — Thu, 16 Jan 2025 00:00:00 +0000

The article describes the journey of India Meteorological Department as a nodal agency with respect to weather related aspects since its inception through the lens of Heat Wave forecasting and warning services. It deals with the evolution specific to India in terms of heat waves definitions, scientific understanding, researches and operational forecasting methodologies during the past 150 years. The article also touches upon the current situation of the monitoring and forecasting strategies, tools and techniques followed by IMD with respect to Heat Wave impact based early warning and forecasting services.

Evolution of thunderstorm monitoring & Forecasting in India

Soma Sen Roy, M. Mohapatra — Thu, 16 Jan 2025 00:00:00 +0000

Thunderstorms over India are associated lightning, rainfall, dust storms, gusty winds and hail. The short lead period for forecast, short lifetime, rapid temporal evolution, mesoscale region of occurrence and associated severe weather cause thunderstorms to be amongst the most devastating weather phenomena over India. The present study reviews the gradual evolution of thunderstorm monitoring and forecasting over India. The study highlights the fact that while monitoring and forecasting these weather phenomena has a long history in India, this field has gained impetus in recent years with the technological advancement in monitoring and forecasting of thunderstorms, awareness of the devastation potential as well as improvement of communication methods. Synoptic understanding of these weather systems which evolved during the last century has been complemented in recent years with in-depth understanding of their mesoscale nature due to improvement and densification of the network of surface observatories, Doppler Weather Radars, ground based lightning detection network and upper air soundings and space based Geostationary satellites. These datasets have also brought about a remarkable improvement in NWP models with mesoscale data assimilation. All these improvements are integrated into Standard Operating Procedures for thunderstorm forecasting in short range to nowcast scale, which has produced reliable forecasts of thunderstorms and associated phenomena for the general public in recent years. Additionally, the awareness of the high cost of human casualties has also brought about a requirement of location specific, actionable thunderstorm forecasts with impact information and colour coded location specific warnings as thrust areas in recent years.

A Need to Revisit Air Temperature Measurements in India in the 19th and Early 20th Centuries

R. R. Kelkar — Thu, 16 Jan 2025 00:00:00 +0000

ABSTRACT. The paper focuses on two major transitions that the meteorological observational system in India has undergone. The first was in the late 1870s when thermometer sheds were set up at Indian observatories, and the second in the 1920s when there was a changeover from thermometer sheds to Stevenson screens. The paper expresses the need to investigate possible biases in the data and apply corrections in order to construct a more credible and homogeneous 150-year temperature record over India.