Introduction

Government of India, in its Cabinet meeting held on 9^th May 2006, have approved formation of the Earth Commission and re-organisation of the Ministry of Ocean Development as Ministry of Earth Sciences. Earth Commission has been patterned on the lines of Atomic Energy Commission/ Space Commission for delegation and authority.

The 21^st century is likely to be dominated by concerns of water, global climate change, environment, land use and ocean resources. The need for taking up an integrated view of Earth System Sciences, i.e. land-ocean atmosphere is being recognized across the world. The Indian efforts till recently, were being independently made by individual agencies like Ministry of Ocean Development (now Ministry of Earth Sciences), India Meteorological Department (IMD), research institutes like Indian Institute of Sciences, Indian Institute of Technology (IITs), a few laboratories of Council for Scientific and Industrial Research (CSIR), etc. There is a need to integrate these activities.

The Ministry of Earth Sciences aims to create a framework for understanding the complex interactions among key elements of the Earth System, namely ocean, atmosphere and solid earth, by encompassing the existing national programmes in meteorology, climate, environment and seismology. The Earth System Organisation (ESO) will act as an executive mechanism under the Ministry of Earth Science, consisting of two major entities – (i) Ocean Science and Technology Department, and (ii) India Meteorological Department. In addition, the Earth System Organisation would have, at its Headquarters, the Ministry of Earth Sciences office and the Programme Offices for coordination among the constituent organisations and units engaged in similar work in other departments, academic institutions and research bodies. The Ocean Science and Technology Department consists of the existing centres and attached offices of the erstwhile Ministry of Ocean Development. The Indian Institute of Tropical Meteorology (IITM) and National Centre for Medium Range Weather Forecasting (NCMRWF) would be active partners of the ESO.

The Ministry of Earth Sciences will provide the nation with best possible services in forecasting the monsoons and other weather/ climate parameters, ocean state, earthquakes, tsunamis and other phenomena related to earth systems through well integrated programmes and utilizing world class science and technology resources. In addition, the Ministry will work on science and technology for exploration and exploitation of ocean resources (living and non-living), and play nodal role for Antarctic/ Arctic and Southern Ocean research. The Ministry would closely work with other agencies both public and private to provide them scientific and technical support and assist in ensuring adequate preparedness for handling natural disasters.

The Right to Information Act, 2005

India Meteorological Department

MANUAL-(I)

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The particulars of its organization, functioning and duties.

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1. PARTICULARS OF ORGANIZATION

1.1 Historical Background:

The beginnings of meteorology in India can be traced to ancient times. The Upanishadas contain serious discussion about the processes of cloud formation and rain and the seasonal cycles caused by the movement of earth round the sun. Varahamihira’s classical work, the Brihatsamhita, written around 500 A.D., provides a clear evidence that a deep knowledge of atmospheric processes existed even in those times. It was understood that rains come from the sun (Adityat Jayate Vrishti) and that good rainfall in the rainy season was the key to bountiful agriculture and food for the people. Kautilya’s Arthashastra contains records of scientific measurements of rainfall and its application to the country’s revenue and relief work; Kalidasa in his epic, “Meghdoot” written around the seventh century, even mentions the date of onset of the monsoon over central India and traces the path of the monsoon clouds.

Meteorology, as we perceive it now, may be said to have had its firm scientific foundation in the 17^th century after the invention of the thermometer and the barometer and the formulation of laws governing the behaviour of atmospheric gases. It was in 1636 that Halley, a British scientist, published his treatise on the Indian summer monsoon, which he attributed to a seasonal reversal of winds due to the differential heating of the Asian land mass and the Indian Ocean.

India is fortunate to have some of the oldest meteorological observatories of the world. The British East India Company established several such stations, for example, those at Calcutta in 1785 and Madras (now Chennai) in 1796 for studying the weather and climate of India. The Asiatic Society of Bengal founded in 1784 at Calcutta, and in 1804 at Bombay (now Mumbai), promoted scientific studies in meteorology in India. Captain Harry Piddington at Calcutta published 40 papers during 1835-1855 in the Journal of the Asiatic Society dealing with tropical storms and coined the word “Cyclone”, meaning the coil of a snake. In 1842 he published his monumental work on the “Laws of the Storms”. In the first half of the 19^th Century, several observatories began functioning in India under the provincial governments.

Very early in the history of IMD, the importance of the puplication of scientific results had been recognized. Blandford introduced the publication of the “Memories of the IMD” and him self authored several of them. His work on the rainfall of India is unsurpassable in clarity of thought and content. In view of the importance of foreshadowing monsoon seasonal rainfall for the agricultural economy of the country, Blandford initiated the system of Long Range Forecasting (LRF). The system of LRF of monsoon rains went through several evolutionary phases and eminent pioneers like Sir J. Eliot and Sir Gilbert Walker (Both Directors–General of Observatories) and generations of Indian researchers have made their contributions to this scientific effort. To Sir Gilbert Walker also goes the credit of linking the monsoon with global meteorological situations and his discovery of the so-called Southern Oscillation phenomenon. Swings of the Southern Oscillation were later linked by J. Bjerknes with the EI nino in the equatorial Pacific Ocean and Bjerknes also coined the term “Walker circulation” for describing the east west vertical circulation in the equatorial plane in honour of walker.

Blanford had recognized the need for inducting young Indian in IMD and the first two Indians Lala Ruchin Ram Sahni (Father of Professor Birbal Sahni) and Lala Hemraj joined IMD in 1884 and 1886 respectively. The Indianisation of IMD was accelerated under Walker, soon after World War I, and further boosted by Sir C.W.B. Normand (Director-General during 1928 to 1944) Normand was succeeded by Dr. S.K. Banerji as the first Indian DGO in 1944. During these years, many Indian scientists joined IMD and they took IMD to greater heights themselves in the post – independence era.

1.2 Development of meteorology in India

From a modest beginning in 1875, IMD has progressively

expanded its infrastructure for meteorological observations, communications, forecasting and weather services and it has achieved a parallel scientific growth. IMD has always used contemporary technology. In the telegraph age, it made extensive use of weather telegrams for collecting observational data and sending warnings. Later IMD became the first organization in India to have a message switching computer for supporting its global data exchange. One of the first few electronic computers introduced in the country was provided to IMD for scientific applications in meteorology. India was the first developing country in the world to have its own geostationary satellite, INSAT, for continuous weather monitoring of this part of the globe and particularly for cyclone warning.

IMD has continuously ventured into new areas of application and service, and steadily built upon its infrastructure. It has simultaneously nurtured the growth of meteorology and atmospheric science in India. Today, meteorology in India is poised at the threshold of an exciting future.

2. FUNCTIONS OF IMD

IMD is the National Meteorological Service of the country and the Principal Government Agency in all matters relating to Meteorology, Seismology and allied subjects.

2.1 Major Objectives

- To take meteorological observations and to provide current and forecast meteorological information for optimum operation of weather-sensitive activities like agriculture, irrigation, shipping, aviation, off-shore oil exploration etc.

- To warn against severe weather phenomena like tropical cyclones, norwesters, dust storms, heavy rains and snow, cold & heat waves etc. which causes destruction of life and property.

- To provide meteorological statistics required for agriculture, water resource management, industries, oil exploration and other nation-building activities.

- To conduct and promote research in meteorology and allied disciplines.

- To detect and locate earthquakes and to evaluate seismicity in different parts of the country for development projects.

- To study and identify the potential consequences of an earthquake, both in relation to existing structures as well as in the planning and locating new facilities “in terms of cost effectiveness”.

2.2 Functions

- Install and maintain Departmental observatories, provide equipment and technical support for set up of observational networks of State Governments, other authorized agencies and ships of the voluntary observation fleet. Set up infrastructure for Satellite remote sensing of meteorological parameters.

- Record observations of meteorological parameters in India over land and adjoining sea areas on a routine basis. Receive and process satellite data from Indian and Foreign satellites.

- Maintain fast telecommunication links within the country and the world for dissemination of meteorological observations and exchange of meteorological products.

- Analyse and process meteorological data collected from observatories within the country and outside.

- Issue forecasts of weather events and meteorological parameters viz. temperatures, rainfall, humidity, winds and sky condition within the country for stipulated periods. Issue of forecasts and warnings of high impact weather events like Cyclonic Storms, Thunderstorms, Squalls, Tornados, Storm surge etc, and warnings of specific parameters viz. strong winds, heavy rainfall, heavy snowfall, hail storms, waves and tides, etc.

- Disseminate weather information, advisories and warnings to the Public through media, to Government Departments and District authorities,

- Scrutinise and process meteorological observations for assimilation into climatological archives.

- Design, develop, manufacture and maintain meteorological and seismological instruments and procure sophisticated equipment for modernising observatories.

- Maintain a network of seismological observatories to record earthquakes and study of the earth’s crust.

- To provide a purposive turning point to guide national endeavour in mitigating the disastrous impacts of earthquake and to provide earthquake risk related knowledge products.

- Provide training facilities to all branches of meteorology, Seismology, telecommunication and instruments.

- Conduct research in theoretical and applied meteorology, Seismology and allied topics.

- International cooperation in meteorology and seismology.

- Provide hydrometeorological information and inputs for water resource management and flood forecasting.

- Maintain liaison with other scientific organisations in the country in the fields of agriculture, hydrology, oceanography, air pollution etc.

- To participate in special expeditions of meteorological interest like Antarctic Expeditions, Study of Himalayan glaciers, total Solar Eclipse, etc.

- To conduct study in Positional Astronomy, bring out related publication and issue Radio Times Signals.

3. ORGANISATION

The Director General of Meteorology is the Head of the India Meteorological Department, with headquarters at New Delhi. He is assisted by 5 Additional Directors General and 20 Deputy Directors General. 04 Additional Directors General and 10 Deputy Directors General are located in New Delhi, 01 Additional Director General and 05 Deputy Directors General are located at Pune.

For the convenience of administrative and technical control, there are 06 Regional Meteorological Centres, each under a Deputy Director General with headquarters at Mumbai, Chennai, New Delhi, Kolkata, Nagpur and Guwahati. In addition, there are separate divisions to deal with specialised subjects. They are:

(i) Agricultural Meteorology

(ii) Civil Aviation

(iii) Hydrometeorology

(iv) Instrumentation

(v) Climatology

(vi) Regional Specialised Meteorological Centre

(vii) Positional Astronomy

(viii) Seismology

(ix) Earthquake Risk Evaluation Centre

(x) Satellite Meteorology

(xi) Telecommunication

(xii) Training

Under the administrative control of Deputy Director General, there are different types of operational units such as Meteorological Centres, Forecasting Offices, Agrimet. Advisory Centres, Flood Meteorological Offices and Cyclone Detection Radar Stations.

3.1 MANAGEMENT STRUCTURE

The India Meteorological Department attached to Ministry of Earth Sciences w.e.f. 12.07.2006. The constitution of each commission was done by President of India w.e.f. 09.01.2007. The main features of this new set-up are as follows:-

Composition of the Earth Commission

Dr. P. S. Goel : Chairman

Secretary, Ministry of Earth Sciences.

Sh. T. K. A. Nair : Member

Principal Secretary to Prime Minister

Sh. V. K. Duggal : Member

Home Secretary

Sh. R.R. Saha : Member

Member Secretary, Planning Commission.

Dr. Sanjiv Mishra : Member

Secretary (Expenditure)

Member (Finance) : Member

(Common for Space Commission, Atomic

Energy Commission & Earth Commission.

Prof. R. Narasimha : Member

Jawaharlal Nehru Centre for Advanced

Scientific Research, Bangalore

Prof. S. K. Dubey : Member

Director, Indian Institute of Technology

Kharagpur.

Dr. B. N. Goswami : Member

Director, Indian Institute of Tropical

Meteorology, Pune.

Dr. Satish Shetye : Member

Director, National Institute of Oceanography,

Goa.

Dr. P. K. Mishra : Member

Secretary, Ministry of Agriculture

Sh. Ajay Prasad : Member

Secretary, Ministry of Civil Aviation.

3.2 OBSERVATIONAL ORGANISATION

A brief description of each types of observatory is given in the following paragraphs. Details regarding observations records, their frequency, the normal component of staff employed and the distribution of the observatories among the Regional Meteorological Canters are given in the Annexure –I.

3.2.1 Surface Observatories

Surface Observatories as far as possible are located one in each district so as to meet the requirements of agricultural, transport and other operations. Of the 556 observatories, about 66.7% are manned by staff of State Governments/Schools etc. on payment of an allowance by the Department. The instruments and stores are provided by the Department.

3.2.2 Upper Air Observatories (Radiosonde, Radio wind and Pilot Balloon Observatories)

There are at present 62 Pilot Balloon Observatories, 39 Radiosonde/ Radiowind and 01 Radiosonde Observatory. The upper air meteorological data thus collected all over the country are used on real time basis for operational forecasting. These data are also processed on computer and short period averages of Radiosonde data and normal of Radio wind data have been brought out.

3.2.3 Aeronautical Meteorological Instruments

For safety of Aircraft operations, particularly at the time of landing and take off, Modern meteorological instruments “Current Weather Instruments System” (CWIS) have been installed at Mumbai, Kolkata, Chennai, New Delhi, Thiruvananthapuram, Lucknow, Hyderabad, Bangalore, Ahmedabad, Guwahati and at Nagpur for continuous monitoring of runway visibility, height of cloud base and other weather elements, such as surface wind, air temperature and dew point temperature. Two Nos. dual-baseline transmission meters are also installed at Kolkata, Airport for ILS CAT III Operations.

3.2.4 Cyclone Detection Radars

There are 11 Nos. of S-band Cyclone Detection Radar Stations viz. Kolkata,

Para deep, Visakhapatnam, Machilipatnam, Chennai, Karaikal, Kochi, Goa, Mumbai and Bhuj. Out of these 11 stations, 6 stations (except Chennai & Kolkata) are using conventional radars. Two number of S-Band Doppler Weather Radars (Metero 1500S) imported from M/s Gematronik Germany has been installed,/ commissioned and made operational at Chennai and Kolkata respectively with effect from 22.02.2002 and 29.1.2003, 8.12.2004 and 27.7.2006. One indigenous Doppler Weather Radar developed by ISRO under IMD-ISRD collaboration has been installed and made operational at SHAR Centre, SriHari Kota (Andhra Pradesh) with effect from 9.4.2004. The EFC proposal for procurement & installation of two imported Doppler Weather Radar on each at Paradeep and Mumbais is in advance stage of processing supply order has been placed on M/s Bharat Electronic Limited, Bangalore in March, 2006 for two indigenous Doppler Weather Radars to be installed at Bhuj and Kochi. The first radar is scheduled for commissioning by December, 2008. Delivery period is 24 months and 30 months respectively.

It is also planned to replace the remaining existing old conventional CDRs by the state of art S-Band Doppler Weather Radar in a phased manner. Doppler Weather Radars provide vital information on radial velocity within tropical cyclone which is not available in conventional radar. A conventional radar provides information on reflectivity and range only whereas a DWR provides velocity and spectral width data alongwith various Meteorological, Hydrological and Aviation products which are very useful for forecasters in estimating the storm’s centre, its intensity, fixing its position and predicting its future path. The Doppler Weather Radar generates these products through a variety of software algorithms.

3.2.5 Storm Detection Radars

There are at present 9 X-Band, working on 3 cm. Wavelength for the purpose of storm detection, these are installed at Kolkata, Chennai, Guwahati, Ranchi, Delhi, Lucknow, Mumbai, Nagpur and Agartala airports. Also, there are two S-Band radars working on 10 cm Wavelength at Sriganganagar and Jaisalmer for warning against convective clouds and thunder storm formation and one S-Band Radar at Mausam Bhawan, Delhi for testing/training purpose.

Wind Finding Radars

There are 9 X-Band Wind Finding Radars working on 3 cm wavelength at Bhubneshwar A.P, Goa, Mangalore, Visakhapatnam, Bhopal A.P, Karaikal, Machillipatnam, Patna A.P., and Thiruvananthapuram.

Weather cum Wind Finding Radars

There are 8 X-Band radars working on 3 cm wavelength which are used for Weather Cum Wind finding purpose. These radars are installed at Ahmedabad, Bangalore, Mohanbari, Chennai & Hyderabad Airports, Delhi (HQ), Patiala and Srinagar.

Ten X Band radars (at Ahmedabad, Goa, Mangalore, Chennai, Visakhapatnam, Bhubneshwar, Kolkata, Guwahati, Ranchi & Bangalore) out of 26 X-Band radars mentioned above have been replaced by latest digital technology EEC radars. These radars have the facility of computer controlled operation with presentation of wind profile data and display of colors picture of clouds on monitor and hard copy print outs of these images. One Doppler Weather Radar imported from M/s Gematronik, Germany, Commissioned w.e.f. 0900 UTC of 27.7.2006.

3.2.6 Hydro meteorological Observatories

These observatories recording mainly precipitation data, were set up in connection with flood forecasting, river basin studies (like the Damodar Valley, Ganga, Brahamputra etc.) compilation of rainfall statistics for use in construction of dams, railways and road bridges, evaluation of snow-melt in Himalayan rivers and water balance and glaciological studies. These observatories are manned by part-time staff. The number of observatories depends upon the need of the specific project. The expenditure involved in the observatories set up for projects undertaken on behalf of other organization, is recovered from the sponsoring agency.

3.2.7 Non-departmental Rain gauge Stations

In addition to the raingauges maintained by the Department, State Governments are maintaining over 7610 raingauge stations whose data are made available to the India Meteorological Department in manuscript form.

3.2.8 Agrometeorological Observatories

These observatories supply meteorological data to the India Meteorological Department. They are maintained by the State Agricultural and Irrigation Department, Agricultural Research Institutes and research farms, The India Meteorological Department renders technical assistance to these organisations in selection of site, procurement, testing and standardization of instruments, setting up of observatories, their inspection and training the personnel.

3.2.9 Evaporation Observatories

Standard USA open pan-evaporimeters are installed at 238 observatories to measure evaporation. Most of these are at departmental observatories and few are part-time observatories and Agromet. Observatories. The staff employed for taking other observations also record evaporation.

3.2.10 Evapotranspiration Stations

Evapotranspiration in plants is measured by means of lysimeters at 40 stations to determine the water requirement of important crops. The network of 40 stations is the representative of different agro-climatic regions in the country. Three of these evapotranspiration stations will be provided with additional instruments to undertake more intensive studies on crop weather relationship. At present three stations are functioning at Gandhi Krishi Vigyan Kendra Farm, Bangalore; Gujarat Agricultural University, Anand and Mahatma Phule Krishi Vidyapeeth, Rahuri with additional meteorological instruments.

3.2.11 Soil Moisture Observational Network

43 soil moisture stations are at present functioning. Most of these stations are manned by departmental personnel.

3.2.12 Dew Fall Measuring Stations

Besides rainfall, dew fall is one of the secondary source of moisture available to the crops. It plays a significant role in plant growth, particularly in arid and semi-arid regions. It is measured from September to April by 76 observatories.

3.2.13 Seismological Observatories

India Meteorological Department is maintaining the National Seismological Network (NSN) consisting of 47 Seismological Observatories. Four more Seismological Observatories are also being maintained for river valley studies under the Bhakra Beas Management Board (BBMB). Twenty four of the NSN stations are equipped with state-of-the-art digital seismograph systems and matching V-SAT based communication facilities for real time downloading of earthquake waveform data. The NSN stations are also equipped with Strong Motion Accelerograph systems for recording strong ground motions expected during major earthquakes. The functioning of the Central Seismological Observatory, Shillong and Ridge Seismological Observatory, Delhi also comes under the ambit of Seismology Division at HQ.

India Meteorological Department is also maintaining a local network consisting of 16 field stations under Delhi Telemetry Network to monitor the earthquake activities in the region. These 16 field stations are connected with Central Receiving Stations (CRS) at New Delhi through V-Sat communication Systems. The ground motion data generated at these field stations is received at CRS New Delhi on real time mode. In addition IMD maintains a set of digital portable seismograph systems for specific earthquake related studies all over the country.

3.2.14 Earthquake Risk Evaluation Centre (EREC)

There are at present 16 field stations under Delhi. Telemetry Network to monitor the earthquake activities in the region. These 10 field stations are connected with Central Receiving Stations (CRS) at New Delhi through V-Sat communications Systems. The ground motion data generated at these field stations is received at CRS New Delhi on real time mode. In addition EREC maintains a set of digital portable seismograph for specific earthquake related studies all over the country.

3.2.15 Ozone Observatories

Ozone in the atmosphere is monitored through a network of observatories (Figure 3). The Observational programme consists of:

(a) Total ozone and Umkehr observations by Dobson Ozone spectrophotometer are taken daily from 4 stations viz. Delhi, Varanasi, Pune and Srinagar. At New Delhi, Kodaikanal, Maitri (Antarctica) stations, ozone is monitored with Brewer Spectrophotometer which has an additional facility to measure NO₂, SO₂ and UV-B radiation also.

(b) Vertical ozone profile by IMD-made balloon-borne ozonesonde (fortnightly) at 4 stations viz. New Delhi, Pune, Thiruvananthapuram and Maitri (Antarctica).

(c) Surface ozone measurement with electrochemical instruments at 7 stations viz. New Delhi, Nagpur, Pune, Kodaikanal, Srinagar, Thiruvananthapuram and Maitri (Antarctica).

Research facilities:- A high quality data on ozone is available at the “National Data Centre” Pune and also the National Ozone Centre established at IMD, New Delhi. This centre has been also designated as the Regional Centre for the Regional Association II (Asia) of the world meteorological organisation (WMO).

3.2.16 Radiation Observatories

(i) Surface Observatories

There are at present 45 radiation observatories (20 Principal and 19 ordinary and 6 other types) recording limited radiation parameters.

(ii) Upper Air Observatories

Besides the measurements on the surface, fortnightly airborne sounding with radiometersonde to measure directly the vertical distribution of the infra-red radiative fluxes and radiation cooling from surface upto a height of 20 Km or more in the free atmosphere, are made at New Delhi, Srinagar, Thiruvananthapuram, Pune, Nagpur, Jodhpur, Kolkata and Bhubaneswar. Radiometersonde ascents are being conducted regularly at Maitri, the Indian Antarctic station also.

3.2.17 Atmospheric Electricity Measurement

Continuous and automatic recording of surface electrical potential gradient and electrical conductivity are being done at Pune. The study of surface potential gradient is now being done at three more stations viz. Nagpur, Thiruvananthapura and Srinagar.

3.2.18 Automatic Weather Stations.

A data receiving earth station has also been installed at Pune for receiving data from Automatic Weather Stations. ISRO has also planned installation of 25 AWS to operate in TDMA mode and for trial a TDMA receiving station has also been installed at Pune for ISRO.

3.2.19 Global Atmosphere Watch (GAW) [formerly BAPMoN]

With a view to document the long term changes in chemical composition of the atmosphere and related parameters IMD established a network of 10 GAW stations under WMO’s GAW monitoring program. The Indian GAW network includes Allahabad, Jodhpur, Kodaikanal, Minicoy, Mohanbari, Nagpur, Port Blair, Pune, Srinagar and Vishakhapatnam covering different geographic regions. At these stations chemical composition of precipitation and atmospheric turbidity is determined. Total suspended particulate matter is also measured for varying period at Jodhpur using High Volume Air Sampler.

Precipitation Chemistry Program: Wet precipitation samples collected at GAW stations are sent to Chemical laboratory at Pune where these are analysed for PH, conductivity, major cations (Ca, Mg, Na, K) and major anions (SO₄, NO₃, Cl). Measurements of organic acids in precipitation will be undertaken in near future.

Atmospheric Turbidity Program:

Atmospheric Turbidity which indicates the columnar aerosol load of the atmosphere; is also measured at these GAW stations using Volz’s Sunphotometers. This single channel Sunphotometer is being replaced in phased manner by the multichannel Sunphotometer purchased recently under Plan Scheme. In the first phase these are installed at Pune, Nagpur & Kodaikanal, Atmospheric Turbidity is also measured at Antarctica and one multichannel Sunphotometer has been handed over to the team of 23^rd Antarctica Expedition.

These data from GAW stations provide reliable long-term observations of the chemical composition of the atmosphere and related parameters in order to improve our understanding of atmospheric chemistry and to organize assessment in support of formulating environment policy. Chemical composition of precipitation is useful in quantifying the level of pollution due to increasing anthropogenic acitiv