Presentation Prep:

Greet

 Introduction:
 I did internship at RMC (Regional meteorological center, Nagpur) which is under IMD
(India Meteorological Department) which is an agency of Ministry of Earth Sciences of
the Government of India. It is the principal agency responsible for meteorological
observations, weather forecasting and seismology. Headquarters of IMD is located in
delhi.
 I started my internship by reading the basics and fundamentals which I thought would
help me during the training process which includes atmospheric phenomena, such as
clouds, winds, precipitation and the processes that produce the same. I was highly
fascinated by the fact that some people have the ability to predict rains and floods based
on annual cycles & the curiosity made me go for this internship.
 History:
 India is fortunate to have some of the oldest meteorological observatories of the world.
The British East India Company established several such stations.
 There was a disastrous tropical cyclone struck Calcutta in 1864 and this was followed by
failures of the monsoon rains in 1866 and 1871 So, In the year 1875, the Government of
India established the India Meteorological Department, bringing all meteorological work
in the country under a central authority. 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
grow
 Later IMD became the first organization in India to have a message switching computer
for supporting its global data exchange It has simultaneously nurtured the growth of
meteorology and atmospheric science in India.
 RADAR:
 Weather Radars are the basic and most important tool for a Meteorologist for Nowcasting
and Forecasting of various weather events. RMC is executing the network of 12 numbers
S Band Metstar WSR-98D with Vaisala signal processor and IRIS application in India. S
band radars operate on a wavelength of 8-15 cm and a frequency of 2-4 GHz and give
advantage of less attenuation. This makes them useful for near and far range weather
observation.
 The size of the Antenna is 8.5 meters and it requires a large motor to power it. To shelter
the antenna from adverse weather conditions with minimal attenuation of electromagnetic
signals a Radome is installed with it.
 Doppler Weather Radar Products can be used for the following applications-
 Weather surveillance
 Severe weather monitoring
 Hurricane, typhoon, and cyclone tracking
 Hail detection
 Hydrometeorological applications, such as flood forecasting
 Airport wind-shear detection
 Meteorological research
 Weather modification
 Agriculture
 Radiosonde Launch support systems
 AMSS and DATA Entry:
 Met telecommunication is very much required for exchange of Met data in real time for
proper utilization of met observations taken at different scheduled times Globally
throughout the day on a regular basis. To meet the requirement, IMD is having Regional
Telecom Hub (RTH) at New Delhi. It is connected with other International & seven
AMSS Installed in RMC’s. One AMSS is also installed at RMC Nagpur.
 Main purpose of AMSS is to receive, check and forward the metrorological data
according to WMO standards (automatically).
 AMSS uses 4 data formats CREX, BUFR, GRIB, ASCII.
 AMO:
 Job of AMO is to obtain and monitor Current Weather Data using airport instruments and
sensors, every one second for wind, Temperature, Humidity, pressure parameters, from
one Runway site to Multiple Runway sites and also obtains manual data entry of
observations for which sensors are not available viz. Present Weather, Clouds, Gen
Visibility, Runway Visual Range & Trend etc.
 All the data recorded goes to AMSS and OLBS and is made available to all
Meteorological Centers/stations. The data is further processed to find safe flight times,
altitude, route and given to ATC or Pilot.
 Field system is present at each runway site. It has
 Wind Direction sensor,
 Wind speed sensor,
 Air Temperature & Humidity Combined sensor,
 Atmospheric Pressure Sensor
 Data logger
 Wireless Modem for Data Transmission
 For Safety of Taking Off & Landing Meteorological Parameters Wind, Pressure,
Temperature & Dew Point, RVR, Clouds, Present Weather & Wind shear etc is to be
monitored, Processed & displayed in front of ATC for communicating to Air Borne Pilot.
 A New Aviation Weather Observing System is designed & developed by Surface
Instruments Division for Continuous monitoring of Aviation Met Parameters &
Generation of all Reports required for Aviation Industry.
 RSRW:
 IMD has a network of 39 upper air stations taking RS/RW observations twice daily. For
upper air observations balloons are released twice daily at 0000 UTC & 1200 UTC with a
radiosonde (RS) transmitter system, which transmits meteorological data i.e temperature,
humidity and pressure at different levels. The balloon is tracked for upper air wind data
(Wind direction and wind speed) with the help of theodolites. The Radiosonde consists of
sensors for atmospheric sensing. The parameter values indicated by the sensors are
suitably converted and communicated to the ground station with the help of the
transmitter and receiver link. The data is analyzed to get the atmospheric parameter
values. The accuracy of the radiosonde, receiver electronics and the software algorithm
all contribute to the correct atmospheric sensing. For measurement of upper air
 atmospheric pressure profile, the radiosonde uses a mechanical pressure sensor called
baroswitch. The baroswitch works on the principle of vacuumization. It consists of 37
different mechanical parts. All these parts are being manufactured and assembled
together in IMD workshop. The baroswitch works as a pressure sensor as well as a
switching device for selection of modulating entities like temperature, pressure and
humidity.
 PBO:
 Surface meteorological observatories
 These are observatories equipped with both eye-reading and self-recording instruments.
 Most of these observatories are equipped only with eye reading instruments. Regular
observations are taken at least twice daily.
 These observatories are the same as above, the only difference is here observations are
recorded only once in a day.
 These observatories have a lesser number of instrumental equipment or take non-
instrumental observation only.
 Double Stevenson Screen consists of a hygrograph for recording humidity and a
thermograph to record temperature.

 The basic surface instruments at any meteorological observatories are
 1. Mercury Barometer
 2. Four Thermometers i.e., Dry Bulb, Wet Bulb, Maximum and Minimum fixed
inside the
 Thermometer screen known as Stevenson screen.
 3. Rain Gauge and Measure glass.
 4. Wind instruments – Wind vane and Anemometer
 RWFC:
 RWFC uses Numerical weather prediction (NWP) is a method of weather forecasting that
employs a set of Hydro-dynamical equations that describe the motion in the atmosphere
and oceans to predict the future weather condition based on current weather conditions
Current weather observations serve as input (initial condition) to the NWP models
through a process known as data assimilation to produce weather forecast of temperature,
wind, precipitation, and other meteorological parameters.
 Pre-processing initial condition
 In the pre-processing, observed data available at unevenly spaced observing station points
are subjected to different quality control checks, followed by interpolation techniques to
prepare initial conditions through a process known as data assimilation. Data assimilation
is the science of combining different sources of information to estimate possible states of
a system.

 NWP model processing

 With the above initial conditions, the dynamical equations are numerically integrated
forward with time in the model. After integration, future values of model variables are
different grid points are generated known as direct raw model output
 Post processing
 These above raw modes output may be of very little use for the weather forecasters rather
forecasters may like to have specific weather information, rainfall variability divergence
vorticity precipitable water content different convective indices etc.
 Radiation:
 At the radiation observatory, Shortwave Solar radiation and long wave Atmospheric
(Terrestrial) radiation are measured.

 Solar Radiation - is the distribution of radiant energy from the Sun, Solar radiation
sensors are also known as pyranometers. A type of actinometer, these devices are used
for measuring broadband solar irradiance as well as solar radiation flux density, which
means that they measure the power of the light and heat from the sun. When placed on a
flat surface, pyranometers can be used for identifying solar radiation. Solar radiation
sensors are commonly used in climatology, meteorology, building physics, and solar
energy studies. They are also used in weather stations and are usually installed in a
horizontal manner near solar panels. The level of possible measurement of a solar
radiation sensor will vary based on the position of the sun.

 Diffuse pyranometer - Simply said a pyranometer is a device that measures solar

irradiance from a hemispherical field of view incident on a flat surface. The SI units of
irradiance are watts per square meter (W/m²). * Traditionally pyranometers were mainly
used for climatological research and weather monitoring purposes Pyranometers measure
global irradiance: the amount of solar energy per unit area per unit time incident on a
surface of specific orientation emanating from a hemispherical field of view (2π sr),
denoted E.g., ↓. The global irradiance includes direct sunlight and diffuse sunlight

 Terrestrial Radiation - Electromagnetic radiation emitted by the Earth’s surface and

atmosphere is called terrestrial or longwave radiation (the latter being the preference of
the World Meteorological Organization). Since these bodies exhibit temperatures in the
range 200–300 K, terrestrial radiation lies in the infrared portion of the electromagnetic
spectrum.

 Campbell strokes recorder (Sunshine Recorder) - The unit is designed to record the hours
of bright sunshine which will burn a hole through the card
 The crystal ball is typically 10 cm (4 inches) in diameter, and is designed to focus the
rays from the sun onto a card mounted at the back and is set on a stand. The card is held
in place by grooves of which there are three overlapping sets, to allow for the altitude of
the sun during different seasons of the year.
 Sunshine duration monitoring - Sunshine duration is determined by CSD3. Sunshine
duration is defined by WMO as the time during which the direct solar radiation exceeds
the level of 120W/m². It does not have any moving components and makes use of three
photo-diodes with specially designed diffusers to make an analogue calculation of sun
exposure. The switching of the output is done too high or low in order to indicate sunny
or not sunny conditions. The calculated direct irradiance value is also available. CSD 3
operates from 12VDC power and has built-in heaters to dissipate rain, snow and frost.
These are normally switched externally but an optional internal thermostat control is
 available. It can be observed from the humidity indicator when a change of drying
cartridge is required.
 Conclusion:
I can honestly say that our time spent interning with RMC Nagpur resulted in one of the
best times of our academics. Not only did i gain practical skills but i also had the
opportunity to meet many fantastic people. The atmosphere at the RMC office was
always welcoming which made me feel right at home.
While I was able to learn a lot from normal college life, every day was a memorable one
at RMC. I was able to make connections with the staff and also friendly connections with
newly recruited members there. It was a great experience to interact with everyone during
the internship.
Overall, my internship at RMC Nagpur has been a success. I was able to gain practical
skills, learn in a fantastic environment, and make connections that will last a lifetime. I
could not be more thankful.