Operational Programs > Ocean Observation Systems > Activities
Quality Control & Data Dissemination
The most important aspect of  NDBP is the real time dissemination of data especially during extreme weather conditions. The data is utilized by a wide spectrum of end users like Meteorologists, Oceanographers, Environmentalists, Offshore Engineers, etc. for their reference, research and developmental activities in the marine related studies. Therefore utmost care has been given for data quality control and dissemination to various end users. Depending on the end application, NDBP has established two modes of data dissemination, real-time and delayed mode to supply data / data products. The data from the buoys are transmitted through the ’INMARSAT-C’ satellite system to the shore station located at NIOT Chennai at synoptic hours. The data received from the buoys are sent on real-time to INCOIS for further dissemination to the operational users such as India Meterological Dept (IMD), Coast Guard (CG), INCOIS, Navy etc.,
Real-time retrieval & dissemination
Quality control of buoy data
The systematic long-term information from data buoys has greatly improved our understanding of the monsoon system especially during the Bay of Bengal and Arabian Sea Monsoon experiments (BOBMEX & ARMEX) organized under the Indian Climate Research Programme (ICRP). The buoy data is extensively used as ground truth for the calibration of observations made by the satellite sensors. Long-term time series observations of buoy data are also used for various applications like, fisheries, coastal zone management, oil exploration, etc. Another significant application of buoy data is in the field of calibration and validation of sea-state forecasting model.
Maintenance of data buoys
Buoy maintenance are undertaken at regular intervals to up-keep the buoy network and to ensure continuous data return. Sensor calibrations are carried out before deployment and after retrieval of buoys to guarantee the quality of the data. Since inception more than 340 maintenance operations have been carried out.
OMNI (Ocean Moored buoy Network for Indian monsoon) Buoys:
The OMNI buoys are Moored Buoy Network in Northern Indian Ocean and are more similar to data buoys but have the capability to measure Ocean Current, Conductivity and Temperature up to 500m depth and transmit hourly data through satellite. In addition, these buoys are also equipped with Radiation sensors and Rain Gauges too. This prestigious project with suite of sensors and special induction mooring was installed on a trial basis in the Bay of Bengal. These buoys which were established before the onset of North-East Monsoon could capture JAL cyclone during November 2010 with the onset of low pressure and its effects of atmosphere and ocean, which gave a new insight into this phenomenon. Six OMNI buoys were ordered and were deployed by May-June 2011 and functional in Bay of Bengal.
Tsunami Buoys:
As challenges arise in the form of natural disasters, OOS is now entrusted to deploy buoys capable of identifying Tsunami?s as part of Tsunami Early Warning System in India. Under the Ministry of Earth Sciences, the Ocean Observation Systems group of National Institute of Ocean Technology (NIOT) has been maintaining Tsunami buoy system since 2006. Under this program, the National Technical committee has identified ideal locations for deployment of Tsunami buoys in Indian Seas. These buoys have been deployed and maintained at these locations and data from these buoys is obtained real time and is disseminated to INCOIS, Hyderabad for further processing as part of tsunami early warning system.
Other Activities:
CAL-VAL Phase II
Vicarious calibration of ocean color sensors and validation of Geo-physical products are very important activities for remote sensing applications. In-situ measurements play a very important role in quantifying the errors associated with various data products hence, establishing sites for in-situ measurements are very essential for meaningful applications. Kavaratti CAL-VAL site is primarily responsible for vicarious calibration of OCM-2 sensor launched by ISRO and has been used successfully in OCEANSAT-UP project. This site was made operational jointly by SAC and NIOT in April, 2008. All the systems have been working well since then and a large volume of data has been generated by this site for CAL/VAL activity. Kavaratti CAL-VAL site, presently operational in the open ocean, has been extremely useful for monitoring OCM-II system performance in the orbit and providing valuable feedback to Oceansat-II UP project. The in-situ data is being provided to INCOIS and MOSDAC via INSAT-3C on operational basis for utilization by various users. The Phase-I activities related to development and operationalization of Kavaratti CAL-VAL site have been completed in January 2011.
Further to collect un-interrupted in-situ data in Open Ocean for Oceansat-II project from Kavaratti CAL-VAL site & to achieve this periodic maintenance and up gradation of existing CAL-VAL site at Kavaratti the CALVAL Phase ?II project is in progress.
Inter Calibration Project: Pilot  Project  Wave  Measurement  and  Evaluation Test (PP-WET) - UNESCO-IOC
As advised by MoES, a joint project is undertaken with INCOIS which is an Inter Calibration exercise on the request of UNESCO-IOC global Pilot Project on Wave Measurement and Evaluation Test (PP-WET) is initiated. In this regard, one wave rider buoy and data buoy were successfully deployed in April 2011 Off Agatti Both Data buoy and wave rider buoy are working satisfactorily and inter comparison exercise is in progress. Preliminary report was submitted to the Ministry. In order to carry out wave spectrum analysis data will be downloaded after retrieval of the buoy in fair weather and will be sent to INCOIS.
Reference Platform
Andaman Coastal Region Buoy: On the request of Department of Environment and Forest (DOEF), Andaman & Nicobar, successfully deployed Coastal Region Buoy in Mahatma Gandhi Marine National Park, Wandoor, Andaman & Nicobar Island during February 2011. Buoy is functional from 23rd February 2011. Daily report on the Coastal Region buoy deployed in Mahatma Gandhi Marine National Park, Wandoor, Andaman & Nicobar Island is sent by INCOIS to different departments in Andaman as requested by Department of Environment and Forest(DoEF), Andaman & Nicobar.
Data buoy as a reference platform was deployed Off Agatti, Lakshadweep and is functional from March 2011 with dual mast and redundant wind & humidity sensors.
Strom Surge Project
A meeting was held between representatives of IMD, DOD & NIOT on 31st October 2003 to scrutinise the proposal for Storm Surge project. The project aims in the establishment of infrastructure such as data buoys, tide gauges and surge measurement by chemical ribbons, necessary for providing effective and timely forecasts on storm surges and inundation.
Proposed Moored buoy and Tide gauge locations for Storm Surge Prediction
Prediction of Regional Weather using Observational Meso-Network and Atmospheric Modelling  (PROWNAM)
PRWONAM (Prediction of Regional Weather using Observational Meso-Network and Atmospheric Modelling) is an ongoing project at ISRO to facilitate short-term weather prediction over SHAR-KALPAKKAM-BANGALORE region through multi-institutional participation. NIOT through NDBP is participating in this endeavor. Primary focus of the project is to improve weather prediction on short time scales of 1~3 days over Southern peninsular region by making comprehensive measurements with high density network of surface stations to best capture the regional surface heterogeneity and Mesoscale phenomena.  NDBP has provided buoy data during May, July 2006 initial experiments.  NIOT agreed to deploy 4 buoys in May 2007 (Main Phase) between SHAR and Kalpakkam.
Highlights of the project:
Flux studies Low period intra seasonal oscillation/variability of SST and Salinity Thermohaline variability of mixed layer Seasonal land-sea breeze variability Seasonal variability of surface currents
Data Buoy locations:
Four data buoys PW1, PW2, PW3 and PW4 within 100km from coast between SHAR-Kalpakkam.
Projects Completed
BOBMEX
Atmospheric and oceanographic observations were carried out over the Bay of Bengal under BOBMEX (Bay of Bengal Monsoon Experiment) during 16 July to 30 August 1999 from multiple platforms. A large number of sensors and instruments were used, some already existing and others specially procured for BOBMEX. Several organizations were involved in BOBMEX measurements, and it was not possible to have uniformity in the type and make of the sensors measuring the same parameter, or the method of data collection. A Committee for Atmospheric and Oceanographic Instrumentation was set up by the Department of Science and Technology, Govt. of India, for the field experiments under the Indian Climate Research Program (ICRP), of which BOBMEX was the first. In order that inherent differences between instruments measuring the same quantity are clearly understood and do not lead to wrong inferences being drawn, two inter-comparison experiments, one each at the start and end of the field campaign were carried out as per the recommendations of this committee. The major observational platforms for the BOBMEX field programme comprised ORV Sagar Kanya (henceforth SK) belonging to Department of Ocean Development (DOD), INS Sagardhwani (hereafter SD) belonging to Defence Research & Development Organization (DRDO), and the met-ocean buoys deployed and maintained by National Institute of Ocean Technology (NIOT). The research vessels were located at 17.5_ & 89°E and 13_ & 87°E respectively for time series observations for a large fraction of the six weeks of BOBMEX. The met-ocean buoys, DS3 and DS4, are located at 13_ & 87°E and 18_ & 88°E respectively. The Inter- comparison experiments were carried out at the DS3 location for about 9 hours on 18-19 July 1999, and for 12 hours on 27 August 1999, henceforth referred to as ICE1 and ICE2 respectively. The buoy locations, the cruise tracks during BOBMEX as well as the locations at which time-series measurements were carried out for inter-comparison are shown in Figure 1.
Comparison of surface data during the BOBMEX period
During the time series observations, SK and DS4 were within 120 km from each other, and SD and DS3 were in the same location (Figure 1). Here, we briefly consider how the surface parameters from nearby platforms compare with each other. Figure 11 shows pressure, SST, air temperature and wind speed measured on SK and DS4. There is a good agreement between DS4 and SK data sets. Figure 12 shows the data at the DS3 location. In addition to the SD metkit data, air temperature and wind speed measured by the sensors fixed to the boom on SD are also shown. Here also, we find broad agreement between the data measured on two platforms. This suggests that two sets of the measurements on platforms (ship and buoy) in the central Bay and northern Bay have recorded similar variability in the surface meteorological variables.
Conclusions
Two inter-comparison experiments carried out during BOBMEX are found to be very valuable in assessing the confidence of measurements. In general, there is good agreement between data measured onboard two ships SK and SD and met-ocean buoy DS3. Important observations are:
There is good agreement between the radiation data from two ships and the differences are within the instrument accuracy levels. Wind speeds from SK, SD and DS3 are consistent with each other. The differences in values are about 1 m/s in general and occasionally larger when compared at 10m level. Perhaps the turbulent nature of the flow mainly contributed to the differences. Wind directions are generally within 10°-20° of each other. The SSTs values agree within the instrument errors. Air temperature data, particularly those measured manually, shows larger differences between platforms. SK and DS3 surface pressures agree well with each other and SD pressure typically differs by 0.5 to 1mb. The differences in air temperature from metkit (dry bulb) affected the relative humidity based on psychrometer data. Differences up to 7% are observed. Buoys and ships have recorded similar trends in the surface met parameters during BOBMEX. Water column temperature is accurately measured on SK and SD, especially in the mixed layer and below the upper thermocline. Salinity values from SK and SD differ by about 0.4 psu, during ICEI and by about 0.2psu during ICE2 in the mixed layer.
Arabian Sea Monsoon Experiment (ARMEX)
The Arabian Sea Monsoon Experiment (ARMEX) is a dedicated observational campaign carried out in the Arabian Sea in two phases under the Indian Climate Research Programme (ICRP).  The ARMEX Phase-I (during 2002) was dedicated for the ‘Monsoon Trough Experiment’ and the Phase-II (during 2003) for the ‘Evolution and collapse of the Arabian Sea Warm Pool’.  National Institute of Ocean Technology (NIOT) has actively involved in both observational phases of ARMEX by providing the time series measurements of near surface atmospheric and oceanic parameters, and upper ocean profiles of temperature from the moored data buoy network in Arabian Sea. During the Phase-I experiments, NIOT has provided data from the two deep-water buoys DS1& DS2 and four shallow water buoys SW1, SW2, SW3 & SW4.  For the Phase II experiment, NIOT has deployed additional data buoys DS6, DS6A, DS7 & DS7A off Minicoy other than the NIOT regular data buoy locations to measure anomalous warming and the associated features of the warm pool
	Buoy-Id Lat (oN) Long (oE) Depth (m) DS6 8.30 72.76 1900 DS6A 8.350 72.720 2120 DS7 8.315 72.664 2000 DS7A 8.310 72.650 2000
A close network of four data buoys are deployed off Minicoy Island at an average depth of 2000m. The data buoys DS7 & DS7A were deployed very close to each other (1nm apart). DS6 is deployed 4 nm east and DS6A at a distance of 4.5 nm north of DS7 (Fig.1). The observations made by these buoys during ARMEX–II are compared with each other and shows good correlation. The surface wind observations were made at a height of 3m above the sea surface and are extrapolated to 10m height using the power law (Panofsky and Dutton, 1984). Water temperature and salinity observations are made at a depth of 3m below the sea surface. One major cruise and two special cruises were conducted to deploy/re-establish the data buoys in the Arabian Sea warm pool. The major cruise started on 1st March 2003 from Tuticorin and deployed three buoys (DS6, DS7 & DS7A) in the warm pool region. The buoy DS6 was deployed on 05th March ’03 at a depth of 1900m and worked till 08th Dec. ’03.  The data buoys DS7 and DS7A were deployed at a depth of 2000m on 3rd and 4th March ’03 respectively. The DS7 buoy worked for a period of one month from 3rd March to 4th April ’03. The buoy DS7A was deployed with current meter mooring and worked till 16th May ’03.  The buoy was lost suspect due to vandalism and could not retrieve the current meter data.
The DS7 buoy was redeployed on 21st April ‘03, which worked till 04th Nov. ‘03.  To provide vertical profile of temperature in warm pool region one more buoy DS6A was deployed at a depth of 2120m on 27th May ’03 and was retrieved on 17th September ’03.
pronounced pre-monsoon warming of SST over a period of two months is observed in the warm pool, with a maximum value of 31.71oC on 18th April 2003. SST observations show that warm pool attains the mature stage much before the monsoon onset. The SST observations exhibit high amplitude diurnal oscillations (0.5oC) during the warming phase. Biweekly oscillation in SST is observed in the warm pool region during the pre-monsoon warming phase. The similar oscillations are reported in air temperature, which supports the role of net surface heat flux in warming up the warm pool region. The salinity observations in the beginning of March 2003 show the existence of low saline water (~34.2 psu) in the warm pool region.   The salinity has increased slowly as summer progressed till the end of observation
Services:
The data buoys have observed many cyclonic events since its inception.  Bangladesh Severe Cyclone during Sept. 1997, Arabian Sea Cyclone during June 1998, May 1999, May 2001, May 2003, May 2004 are a few to name and the increased buoy network shall continue to make better contributions.  In addition NDBP has also provided round the clock services to IMD and CG by supplying buoy data during cyclone and rough weather period.