“weather services to karnataka state delivered by imd”imdbangalore.gov.in/mchistory.pdf ·...

“Weather Services to Karnataka State delivered by IMD”

INTRODUCTION

A disastrous tropical cyclone struck Calcutta in 1864 and this was followed by failure of the monsoon rains in

1866 and 1871. In the year 1875, the Government of India established the India Meteorological Department

(IMD), bringing all meteorological work in the country under a central authority. Mr. H. F. Blanford was appointed

as Meteorological Reporter to the Government of India. The first Director General of Observatories was Sir John

Eliot who was appointed in May 1889 at Calcutta headquarters. The headquarters of IMD was later shifted to

Shimla, then to Poona (now Pune) and finally to New Delhi.

IMD is the National Meteorological Service provider of the country and the principal government agency in all

matters relating to meteorology, seismology and allied disciplines and provides weather and climate services to

different sectors. The IMD was established to fulfill the following mandates:

i) Take meteorological observations and to provide current and forecast meteorological information for optimum

operation of weather-sensitive activities like agriculture, irrigation, shipping, aviation, offshore oil explorations, etc.

ii) Warn against severe weather phenomena like tropical cyclones, norwesters, dust storms, heavy rains and snow,

cold and heat waves, etc., which cause destruction of life and property.

iii) Provide meteorological statistics required for agriculture, water resource management, industries, oil exploration

and other nation-building activities.

iv) Conduct and promote research in meteorology and allied disciplines.

v) Detect and locate earthquakes and evaluate seismicity in different parts of the country for development projects.

THE CENTRAL OBSERVATORY, BENGALURU

The Central observatory at Bengaluru was established on 01st November 1867 at Bowring Hospital, Bengaluru

as per the proposal of Col. Strachey of the Asiatic Society of Bengal. This Observatory was under the control of the

Government Astronomer of the old Madras Presidency and regular observations were taken at 10, 16 and 22 hours

daily since 14.07.1868. Fig.1 is an archived copy of the observation recorded at Bengaluru on 14 July 1868. This

observatory was shifted in 1892 to the Central College compound due to the keen interest and efforts of Prof. Cook

of the Central College, Bengaluru. Prof. Cook became the first Director of the Central Observatory and it was he

who persuaded the then Government of Mysore to have the observatory building constructed in 1893 on the model

of Alipore Observatory of Calcutta.

Fig.1 Observations recorded at Bengaluru on 14 July 1868

India Meterological Department, Meterological Centre, Bengaluru 1


The Mysore State Meteorological Department was formed on 1st January 1894 by amalgamating the four

Observatories located at Bengaluru, Mysore, Hassan and Chitradurga with Prof. Cook as the first Meteorologist to

the then Government of Mysore. The Central Observatory started functioning as a Class I observatory at the

existing old building on 1st January 1894. After Prof. Cook, the Mysore State Meteorological Department functioned

under the leadership of many eminent meteorologists like S/Shri N. Venkatesha Iyengar (1907 – 1922), C. Seshachar

(1922 – 1943) and T.V. Ramachandra Iyer (1943 – 1951). Following the integration of princely States with the

Indian Union, the Mysore State Meteorological Department was taken over by India Meteorological Department

on 1st January 1951 and the Central Observatory at Bengaluru became a part of the India Meteorological Department.

REGIONAL METEOROLOGICAL CENTRE, CHENNAI

Since 1945, the meteorological offices of IMD in the southern states of Andhra Pradesh, Tamil Nadu,

Karnataka, Kerala and Lakshadweep islands come under the administrative control of the Regional Meteorological

Centre (RMC), Chennai. RMC Chennai issues a regional daily weather report and weather forecast, farmer's

weather bulletins and warnings for adverse weather such as cyclones, heavy rainfall etc. for the entire southern

region including Karnataka state. At present, RMC Chennai is headed by an officer of the rank of Deputy Director

General of Meteorology.

ESTABLISHMENT OF METEOROLOGICAL CENTRES AT STATE CAPITALS

After Independence, there has been rapid growth of industry and agriculture due to the various development

plans undertaken in practically all the States. The demand for meteorological advice increased rapidly and it was

decided to decentralise the meteorological activities by establishing Meteorological Centres at the capital cities of all

major States in India. Under RMC Chennai region, such centres have been established in Bengaluru,

Thiruvanathapuram, and Hyderabad to cater to the weather forecasting needs of Karnataka, Kerala and Andhra

Pradesh respectively. Thus, the Meteorological Centre with its forecasting centre at Bengaluru came into existence

on 08th January 1973.

METEOROLOGICAL CENTRE, BENGALURU

The Meteorological Centre (MC) with its forecasting office was functioning at H.A.L. Airport premises since

January 1973. With the increase in activities/responsibilities of Meteorological Centre, Bengaluru, the need to

relocate the MC to a centralized location of the city in a spacious premise to enable easy access and interaction with

various users including State/Central Government agencies was acutely felt. A new building was constructed in the

Central Observatory (CO) premises in 1995. The offices of the Director and other non-aviation forecasting activities

were shifted from HAL Airport to Central Observatory premises during November 1995. Most of the weather

services to the public and users are delivered from the premises of CO. The meteorological office at H.A.L Airport,

Bengaluru continued to provide aviation meteorological services. A new Airport Meteorological Office (AMO) was

established at Bengaluru International Airport, Devanahalli in May 2008, in order to provide the weather services to

Aviation with state-of-art Integrated Automatic Weather Station. An Agriculture Research Unit is functioning from

the premises of the University of Agricultural Sciences, GKVK campus, Bengaluru.

In the last 144 years of its existence, the CO at Bengaluru has come a long way. From its very humble beginning

of having only thermometers housed in thatched shed to record temperature, it has now transformed into a modern

Meteorological Centre equipped with sophisticated and state-of-art facilities such as

India Meterological Department, Meterological Centre, Bengaluru2


l Wind-finding Radar(EEC-make)

l Digital Meteorological Data Dissemination (DMDD) for reception of satellite cloud pictures

l High Speed Data Terminal (HSDT) 64 Kbps

l High Power Computing system (HPC) - a platform for high resolution Numerical Weather Forecast Modelling

l Interactive Voice Response System (IVRS)

l Virtual Private Network (VPN)

l Automatic Weather Station (AWS)

IMD OBSERVATORY NETWORK IN KARNATAKA

The Meteorological Centre (MC) provides a variety of services including hydro meteorological, agro

meteorological and Climatological services to different categories of users besides its core activity of providing

weather forecasts, both for aviation and non-aviation sectors. 30 surface meteorological observatories including 10

departmental, 17 Part Time Observatories, Two Co-operative aided observatories and one Experimental Model

Observatory at Agumbe are functioning under this centre. Observations are taken two to eight times a day at these

stations and are transmitted daily to MC, Bengaluru by telephone/e-mail. In addition, three Pilot Balloon observatories

(Bengaluru, Mangalore and Gadag) and two Radiosonde / Radio wind stations (Bengaluru and Mangalore) are also

maintained by this centre. The surface observatories at Bengaluru, Karwar, Belgaum, Bidar, Bijapur, Gulbarga,

Hassan, Madikeri, Mysore, Raichur and Bellary have been functioning for more than 100 years

(Table -2 at Page No. 12). In Karnataka state, Airport Meteorological Observatories are functioning at Bengaluru

International Airport, Devanahalli, HAL airport, Bengaluru, Hubli airport, Bajpe airport, Sambra airport and

Mysore Airport. In order to provide better services to the agriculture sector, IMD has established one Agriculture

Research Unit at University of Agricultural Sciences, GKVK, Bengaluru, one Auxiliary Evapo Transpiration observatory

at Dharwad, one Principal Evapo Transpiration observatory at Bellary and one Soil Moisture Observatory at Vittal

in Karnataka. MC Bengaluru receives rainfall data from 310 rain gauge stations on real time basis daily. In Phase I

of IMD modernisation plan, 26 Automatic Weather Stations (AWS) have been established in Karnataka. Fig.2

presents the AWS site at Bagalkot.

Fig.2 Automatic Weather Station at Bagalkot commissioned during Jan 2011



NON-AVIATION SERVICES PROVIDED BY MC BENGALURU

WEATHER SECTION

This section collects the surface and upper air data from observatories in the Karnataka state, transmits the data

to other IMD offices and continuously monitors the changes in weather in Karnataka State. Rainfall data is collected

at 0830 hrs IST daily from more than 310 stations in Karnataka. Different weather charts like surface, upper air and

constant pressure charts are plotted at 0530, 0830, 1130, 1730 and 2330hrs IST. Being an operational unit,

identification of weather systems that affect the State and issue of forecasts are done regularly besides issuing state

daily weather forecast for Karnataka twice a day. The local forecast for Bengaluru city is issued four times a day and

twice a day for Mangalore, Mysore, Gulbarga, Chitradurga, Belgaum Airport and Gadag. It may be noted that the

precision of forecast is 80% to 100%. Sample copy of the Daily Weather Report is presented in Fig.3.

Fig.3 Sample of a Daily Weather Report of 18th June 2011

Warnings for Heavy rainfall, Cold wave, Heat wave, Strong winds, fisherman extreme weather events and

cyclones are issued to concerned Deputy Commissioners and album page warnees. Port warnings are also issued

whenever needed. The State Daily Weather Report (DWR) and Weekly Weather Report (WWR) for Karnataka

state are issued regularly to state government departments, All India radio, electronic / print media and general

public. During the visit of VVIP/VIP in the Karnataka state, VVIP/VIP forecast are issued. Weather briefing is

done to print and electronic media. DWR/WWR/weather related data are supplied to all user agencies on payment

basis. Graphical representation of actual and normal rainfall time series, season wise and district wise rainfall

statistics are updated in IMD Bengaluru www.imdbangalore.gov.in. on daily basis.

HIGH PERFORMANCE COMPUTING UNIT

This facility was installed at MC, Bengaluru in 17th Dec 2009. Weather Research and Forecast (WRF) model

is being run at MC Bengaluru on two platforms, i.e., on the IBM P570 server and on the LINUX machine. IBM



server has 8 cores, each having clock speed of 4.2 GHz. The Peak Speed of the system is 134.4GFlops. The

present memory capacity is 32 GB. On IBM P 570 server, it is run for the domain 9–22 °N / 74°E – 87°E at 9km

resolution with 164 and 127 grid points in the X and Y direction and with 37 levels in the vertical. On the LINUX

Machine, it is, run for the domain 0- 24°N /60–90°E at 25km resolution. The model is run for 48hrs forecast in both

cases.

Fig.4 WRF model product

The model is run everyday based on initial conditions of 00 UTC till 51hrs and it takes approx 2 ½ hrs on the

IBM system to generate the forecast. Fig.4 is one of the WRF model products. The WRF model forecast products

are utilized for issuing the short range forecasts i.e. State level and city forecast. They are also used in preparing the

State agro-advisory bulletin. WRF products at 25, 9 and 3 km are being uploaded on the website of MC Bengaluru

(www.imdbangalore.gov.in).

COMMUNICATION UNIT

MC, Bengaluru is equipped with Telephone / Telefax / Internet / High Speed Data Terminal (HSDT) for

transmission and reception of weather data and for effective link with the IMD operational weather communication

set up depicted in Fig.5. Interactive Voice Responsive System (IVRS) to answer weather enquires from general

public over telephone. Digital Meteorological Data Dissemination (DMDD), a ground based satellite system used

for reception and dissemination of meteorological information. Two plotters are available since 15th September

2010, to plot all the surface and upper air charts automatically. Weather information in the web site of MC Bengaluru

is updated daily.

Fig 5 IMD’s operational weather forecasting system and communication set up



RADIO SONDE AND RADIO WIND OBSERVATORY

Radio sonde and Radio wind observations of upper air temperature, humidity, wind direction and speed at

different upper levels up to a maximum of 34 km are taken by releasing meteorological balloons with radio sonde

instruments daily at 0530 and 1730 hrs IST (Fig.6). These observations are coded and sent to all the forecasting

centres of IMD and worldwide through dedicated global telecommunication network. These data are very much

useful for daily weather forecasting and for aviation.

Fig.6 Radiosonde observatory, balloon

RADIATION UNIT

Fig 7 Diffuse Radiation at MC Bengaluru

This unit is equipped with Pyreheliometer for measuring the amount of radiation. This unit has the instruments

like Direct, Global, Diffuse and Precission Infrared Radiation equipments. One sensor for measuring the UV-B

radiation is attached with Automatic Radiation System, which transmits the data directly through Insat 3A to the

earth station at Pune. This data is uploaded on a near real time basis in www.imdaws.com.



SURFACE AND PILOT BALLOON OBSERVATORY

The surface observations are taken at 0230 hrs, 0530 hrs, 0830hrs, 1130hrs, 1430hrs, 1730hrs, 2030hrs and

2330hrs IST daily. These observations are transmitted to the Regional Telecommunication Hub at IMD headquarters,

New Delhi in a coded form for further dissemination to various forecasting offices in India and also other countries.

The upper air observations i.e., the Pilot Balloon observations (Fig.8) are taken at 1130 hrs IST and 2330 hrs IST

and transmitted for the use of the forecasters through the telecommunication network of IMD. Evaporation observations

are recorded daily at 0830 hrs and 1730 hrs IST.

INSPECTORATE SECTION

This section inspects all departmental and part-time observatories, Experimental Model observatories and

cooperative aided observatories every year and undertakes maintenance and upkeep of surface instruments to

Fig.8 Balloon ready for release and a theodolite used for tracking the balloon

ensure that they are in good, and working condition to give accurate observations. Inspection of 310 rain gauge

stations under Districtwise Rainfall Monitoring Scheme is undertaken once in a year, 231 stations under the hydrology

project once in three years and 740 non-departmental rain gauge stations once in every five years. In addition to this

regular annual/biannual maintenance, whenever any station reports fault in surface instruments, they are attended

immediately. Fig.9 is the departmental surface meteorological observatory enclosure at Bengaluru.



CLIMATOLOGY SECTION

This section collects all meteorological records from the observatories in Karnataka state, scrutinises and tabulates

the records. The scrutinised surface weather data are computerised. The digitised data are verified and sent to

NDC Pune for archival. Climatological and weather enquiries from general public and research institutions are

entertained and meteorological data supplied as per the user’s requirement. The section also maintains all the old

weather records/charts.

AGROMET ADVISORY SECTION

The Agromet Advisory Services (AAS) unit started functioning at CO, Bengaluru from 1.12.1989. District

wise quantitative five days weather forecast is generated for various meteorological parameters and disseminated to

ten Agro Meteorological Field Units(AMFU) of Karnataka for the preparation of District wise Agromet Advisory

by the AMFUs for the allotted districts. The State Composite Agromet Bulletin for Karnataka (as in Fig.10) is

prepared in coordination with State Agricultural Department and State Agricultural Universities on every Tuesday

and Friday. These bulletins are prepared in both English and Kannada and the bulletins are further disseminated to

AIR / Doordarshan, State Govt. Agencies and to Agrimet Division Pune. These bulletins are uploaded in IMD

websites of Bengaluru and Pune agrimet division.

Fig.9 Surface meteorological observatory at CO Bengaluru

Inspectorate Section has the responsibility of installation of meteorological instruments and opening of new

observatories, whenever required. Training is being imparted periodically to observers of part-time observatories

to ensure that the meteorological observations taken by them are reliable. The additional responsibilities of Inspectorate

Section are (i) Selecting sites for AWS and Automatic Rain Gauge (ARG) stations in Karnataka and (ii) Imparting

guidance to other agencies for installing rain gauges in Karnataka. It is also the nodal section for dealing with State

Government offices in hydrology matters.



Fig.10 Screenshot of the State Composite Bulletin

Fig. 11 GKVK campus, Bengaluru

AGRICULTURE RESEARCH UNIT AT GKVK, BENGALURU

Weekly phenological crop observations, daily Evapo Transpiration (ET) observations and weekly soil moisture

observations are taken at GKVK campus, Bengaluru(Fig.11) and ET observations are tabulated. Sunshine

observations are also recorded here. This observatory is also equipped with radiation instruments like Sunshine

recorder, Pyranometer and Pyrheliometer for measuring Global and Net radiation. Net and Global radiation are

tabulated and sent to National Data Centre, Pune for archival.

AUTOMATIC WEATHER STATION (AWS)

AWS records the hourly air temperature, relative humidity, wind direction, wind speed, station level pressure

and rainfall and transmits the data through satellite to the receiving earth station at Pune. AWS data are uploaded in

IMD web site http://www.imdaws.com in near real time basis and these data can be accessed by the public.

There are 18 AWS and 8 Agricultural AWS installed in Karnataka state. These AWS are maintained by the

State Instruments Maintenance Centre (SIMC) at Meteorological Centre, Bengaluru. The AWS installed at Bengaluru

is presented pictorially in Fig.12.



Fig.12 AWS site at Bengaluru

AVIATION WEATHER SERVICES

AIRPORT METEOROLOGICAL OFFICE AT BENGALURU INTERATIONAL

AIRPORT

Current weather observations are taken round the clock at every half hour interval and are provided through Air

Traffic Control to all aircrafts landing and taking off and flying over Bengaluru. These observations are uploaded to

the telecommunication network of Airports Authority of India (AAI) for international exchange and IMD network.

A state-of-art Integrated Automatic Weather station is installed at AMO, Bengaluru International Airport, Devanahalli.

Fig.13 Airport Services at Bengaluru International Airport, Devanahalli

Terminal Aerodrome Forecasts (TAFOR) for Bengaluru and for all the airports in Karnataka state and Route

Forecasts (ROFOR) are issued for all the aircrafts departing from AMO, Devanahalli (Fig.13). Route/Flight forecast

for helicopters and light aircraft are also issued whenever required. The local forecast and Aerodrome warnings for

Bengaluru and Mangalore Airports are also issued. VIP/VVIP flights are also provided special services at this

airport.

AIRPORT METEOROLOGICAL STATION, HAL, BENGALURU

Current weather observations are taken at half hourly interval from dawn to dusk and at full hours during

remaining part of the day. Synoptic observations are also recorded and transmitted to all forecasting offices in India



and other countries. Briefing and documentation are provided for all flights originating from HAL Airport including

VIP/VVIP flights.

FUTURE PROGRAMMES OF IMD IN KARNATAKA

1. Doppler Weather Radar will be installed at Heseraghatta, Bengaluru and Sakthi Nagar, Mangalore in Karnataka

state shortly for weather monitoring and nowcasting of adverse weather as a part of IMD mordernisation

programme.

2. About 87 ARG stations will be installed in Karnataka state level by the end of year 2011 for rainfall

monitoring.

3. Field Instruments Maintenance Centres (FIMC) for instruments in the state are planned at Gadag and

Gulburga.

4. New observatory building at Honavar proposed.

CLIMATE OF KARNATAKA

The tropical monsoon climate covers the entire coastal belt and adjoining areas. The climate in Karnataka

region is hot with excessive rainfall during monsoon season (June to September). Outside the coastal belt, the

southern half of the state experiences hot, seasonally dry tropical savanna climate while most of the northern half

experiences hot, semi-arid, tropical steppe type of climate.

Coastal Karnataka is the region of heavy rainfall and receives an average rainfall of 364cm per annum. North

Interior Karnataka is an arid zone and receives only 71cm average rainfall per annum. South Interior Karnataka

receives 107cm average rainfall per annum. The South West monsoon accounts for almost 80% of annual rainfall

that the state receives. The annual rainfall across the state ranges from low 50cm to copious 350cm. Agumbe, a

village in the Thirthahalli taluk of Shimoga district in Karnataka receives the second highest annual rainfall in India,

next only to Cherrapunji, earning it the sobriquet,”Cherrapunji of the South”. Agumbe receives an average of 754cm

of rainfall annually.

The temperature in May exceeds 40°C in the northern parts of the state like in Raichur, Bellary and Gulbarga,

while the ghat areas are comfortably cool with temperatures in the range 28°C to 32°C .The highest temperature

recorded was 46°C at Gulbarga on May 14, 2010. Lowest recorded minimum temperature was 2.8°C at Bidar on

December 16, 1918. Winter is comfortably mild over the State. The mean temperature for January ranges between

14°C to 18°C over most parts of the state. However there have been occasions when very low temperatures were

recorded in severe cold spells. Table 1 provides the mean maximum, mean minimum temperature and average

monthly total rainfall of Bengaluru, Mysore and Mangalore.



January 27.1 15.2 2.4 28.3 16.1 3.9 32.6 20.8 1.3

February 29.9 16.8 6.2 30.9 17.9 4.6 32.9 21.8 0.2

March 32.6 19.5 12.1 33.4 20.0 10.0 33.4 23.6 3.1

April 34.0 21.6 29.2 34.4 21.4 52.9 33.9 25.0 19.9

May 33.1 21.4 107.1 32.7 21.0 139.7 33.3 25.2 173.7

June 29.3 20.0 79.1 28.9 20.0 70.3 29.6 23.3 998.8

July 28.0 19.6 108.7 27.6 19.7 72.9 28.3 22.9 1158.9

August 27.5 19.5 127.8 27.7 19.6 67.2 28.3 23.0 853.0

September 28.1 19.4 226.4 28.9 19.6 131.4 29.4 23.0 297.5

October 28.0 19.1 142.3 28.7 19.5 132.2 30.9 23.1 182.8

November 26.9 17.3 63.6 27.9 18.1 49.3 32.3 22.2 66.4

December 26.1 15.9 23.8 27.5 16.8 15.8 32.8 21.3 16.8

Annual 29.2 18.8 938.7 29.7 19.1 750.2 31.5 22.9 3772.4

Month

Bengaluru

Temperature

(deg C)

Mean

Maximum

Mean

Minimum

Average

rainfall

(mm)

Mysore

Temperature

(deg C)

Mean

Maximum

Mean

Minimum

Average

rainfall

(mm)

Mangalore

Temperature

(deg C)

Mean

Maximum

Mean

Minimum

Average

rainfall

(mm)

Sl.No.

Name ofObservatory

No. of yearsold

1. Belgaum 1856 155

2. Bellary 01.12.1857 154

3. Bengaluru 01.11.1867 144

4. Karwar 24.10.1877 134

5. Bidar 20.11.1891 120

6. Gulbarga 04.10.1891 120

7. Raichur 05.12.1891 120

8. Hassan 20.11.1892 119

9. Mysore 10.05.1893 118

Year ofEstablishment

Table 2 - Establishment of Century old observatories in Karnataka

Table 1 - Mean Maximum and mean temperature and average monthly total rainfall of Bengaluru,

Mysore and Mangalore (based on normals for the period 1961-1990)


“weather services to karnataka state delivered by imd”imdbangalore.gov.in/mchistory.pdf ·...

Documents