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Dr.Balakrishnan [email protected]
Indo-Norwegian winter school on operational oceanography: Indian oceancirculation and sea level variation ,16-21 October, 2016, INCOIS, India
Oceanogenic Hazards
Sea State/ Marine-met/Tectonic
Sea State/ Marine-met/Tectonic
General CirculationGeneral Circulation
Wave, Swell, Wind,Visibility, Cyclone, Storm
surge, Tsunami
Surface current, , SST, T&Sprofile, mixed layer depth,
thermocline, undercurrents,tides
Ocean Forecast- the parameters
General Circulation
Biogeochemical/Ecological
Biogeochemical/Ecological
Marine PollutionMarine Pollution
Nutrients, Chlorophyll,Oxygen, productivity,
Fishery, HAB
Oilspill, Pollutants etc.
Early Warning
Geospatial & Web
• Tsunami• Storm/swell surge• High Waves• Coral Bleach Alert
• Ocean State Forecast• Marine Fishery Advisories
• MHV Mapping Services• Web Based Services
Com
pute
r Inf
ra
Operational Ocean Services from INCOIS
Daily Forecast
Geospatial & Web • MHV Mapping Services• Web Based Services
Data Services
Regional Forecast Centres
• Insitu• Satellite
• East Coast• West Coast
Com
mun
icat
ion
Com
pute
r Inf
ra
SOP Early Warning• Observation• (satellite & Insitu)
• Modeling• (Numerical/statistical/
Soft computing
• Verification
Component of Ocean forecast Systems
• Verification
• ICT based
• Regular• Onsite• INCOIS
Argo Floats102/305
Moored Buoys20 NIOT + 13 RAMA
Drifting Buoys10
XBT3 lines
Current MeterArrays - 3
NIO/INCOISNIOT/INCOISINCOIS NIO/INCOIS NIO/INCOIS
Coastal ADCP6 + 4
NIO/INCOIS
In-situ Observation Systems by India
TideGauges - 21
NIOT/NCAOR/CMLREResearch Vessels
3 + 3
INCOIS/SOI
Tsunami Buoy
SATELLITE
NIOT/INCOIS
BPR
AcousticTransducers
Antenna
Tsunami Buoy
SATELLITE
NIOT/INCOIS
BPR
AcousticTransducers
Antenna
Deep OceanTsunami Buoys - 7
CoastalRadars - 10
Bhuj BhopalBokaro
Chennai
DehradunSamlaDharamshala
DELHI
HYDERABAD
Goa
Pune
Shillong
ThiruvananthapuramMinicoy
Vishakapattinam
Diglipur
Seismic Network17 + 100
NIOT/INCOIS NIOT IMD
Ship AWS6
INCOIS
Wave Rider Buoys10
INCOIS
Bio Optical Observations
15
12
35
07
31
806
35
In-situ Observation Systems by India
35
12
10
23
05
04
00
Model Name Model Products Setup Temporal resolution
ROMS General circulation parameters RegionalCoastal
Every 6 hour for 7 days
Spectral Wave model(Flexible mesh)
Wave/Swell paremetrs/High waveAlert
Regional,Coastal and Locationspecific
Every 3 hour for 7 days
WAVEWATCH-III(Single grid) Wave/Swell paremters Global Every 6 hour for 5 days
SWAN Wave/Swell parametrs/High waveAlert Coastal Every 3 hour for 7 days
WAVEWATCH III(Multi grid) Wave/Swell paremters Global and Regional Every 6 hour for 5 days
Numerical models for Early Forecast generation
WAVEWATCH III(Multi grid) Wave/Swell paremters Global and Regional Every 6 hour for 5 days
GNOME Oil spill trajecory Location specific 3 hours
WRF Wind RegionalCoastal Every 1 hour for 5 days
GODAS General circulation parameters Global Every 6 hour for 7 days
Search & Rescue Model Probable location of lost objects Location specific Event Based
Tunami-N2 Amplitude and travel time of Tsunamiwaves Regional Event Based
ADCIRC+SWAN+WRF Inundation Height and extent of stormsurge Coastal Event Based
Standard Operating Procedure
General Forecast Products• Global Forecast
• Regional – 7 Regions
• Coastal – 9 Coastal states of India
• Island – A&N and Lakshadweep
• Location specific -100 locations
• Tidal forecast system for 178
locations
• High resolution Forecast for West
Coast of India
• Real time validation System
• Forecast dissemination in local
languages
• High Wave/swell/bulletins
• Joint INCOIS – IMD Bulletins
• Bulletins on Ocean State Forecast
along Standard shipping routes
• Tsunami bulletins
• Storm surge bulletins
• Forecast along ship-track
• Eddy Forecasts
• OSF for Neighbouring countries
through RIMES
• Navy specific forecast products
• OSF Web Map Services
• Sea State Forecast for ports and
Harbours
• Online Oil spill advisories (OOSA)
• Search and Rescue Aid Tool
(SARAT)
• High Wave/swell/bulletins
• Joint INCOIS – IMD Bulletins
• Bulletins on Ocean State Forecast
along Standard shipping routes
• Tsunami bulletins
• Storm surge bulletins
Customized productsCustomized products
Criteria for High Wave Warning
High Wave Warning
Sig. Wave Height > 3 m
Swell Wave Height > 2.5 m
Tidal Flooding / Wave Surge
Spring tide + High Swell +Wind direction
High Wave Warning VSCS Hudhud October 2014
High Wave Warning & Joint INCOIS-IMD Bulletins
HIGH SWELL ALERTS
High Swell warning to Andaman Coast and its validationwith buoy deployed at Port Blair
Tidal flooding/Wave surgesSuper Moons(2015 :
January 20
February 18
March 20
August 29
September 28 -Strongest tidal forcing
October 27
Super Moons(2015 :
January 20
February 18
March 20
August 29
September 28 -Strongest tidal forcing
October 27
When the moon is closest to the earth (perigee) and it happens to be the FullMoon or New Moon phase – Perigean Spring tides also known as King Tides /Supermoons form
Improvement in the tidal predictions for the 21 tide gauge stations operated by INCOIS
Swell surge during Unexpected seasurge at Alappuzha coast, 27 fishingboats washed away, Indian Express,Published: 02nd August 2016
Malayala Manorama
WAVEWATCHIIISeychelles,2016-07-31 08:00 UTC
INCOIS has issuedwave surge alert for lowlying coastal areas ofKerala from 30 Jul. 2016-03 Aug. 2016
A high wave, surge alertfor the West Bengal Coastvalid from 08:30 hours on02-08-2016 to 23:30 hoursof 03-08-2016 was issuedby INCOIS.
INCOIS high wave alert Feed back from users
Swell Surge (Kallakadal) during 30 JUL. - 03 AUG., 2016
The extra-tropical storm in the Southern IndianOcean(27 Jul. 2016 ). Here, geopotential heightat 500 hpa is in contours, sea level pressure isshaded and surface winds are shown as vectors.
High waves topping theembankment at old Digha,03 Aug 2016, West Bengal
INCOIS has issuedwave surge alert for lowlying coastal areas ofKerala from 30 Jul. 2016-03 Aug. 2016
A high wave, surge alertfor the West Bengal Coastvalid from 08:30 hours on02-08-2016 to 23:30 hoursof 03-08-2016 was issuedby INCOIS.
The Kollam District administration(DMD) :Wave surge was reported incoastal regions of Alappad Village ofKarunagapally Taluk on on 1st and2nd of August, 2016
This information sent to all concerned disaster Management authorities anddirectly to fishermen via SMS. Total SMS sent ( Tamilnadu, Orissa, Kerala,West Bengal, Gujarat, Maharastra, Lakshadweep) – 6965 ; Number of SMSsent to Kerala Fishermen – 340; Lakshadweep – 25
Tidal flooding/ Wave Surge during January 2015Wave Surge (Kallakadal) during January –February 2105
High Wave Bulletin:
EVENT-TYPE: WarningISSSUE-DATE: 22-01-2015REGION: KeralaMESSAGE:High swell waves in the range of 2.0 - 2.3 meters areforecasted during 17:30 hours on 22-01-2015 to 2330 hours of24-01-2015 along the Kerala coast between Vizhinjam toKasargod.
MESSAGE:Because of the combined effect of Spring tide andhigh waves, waves may be surged in to low lying coastal areasintermittently.MESSAGE: Fishermen are advised to be cautious whileventuring into the sea. Tourists also adviced cautious whileventuring into sea.
Flooding along Kollam coast, Kerala
High Wave Bulletin:
EVENT-TYPE: WarningISSSUE-DATE: 22-01-2015REGION: KeralaMESSAGE:High swell waves in the range of 2.0 - 2.3 meters areforecasted during 17:30 hours on 22-01-2015 to 2330 hours of24-01-2015 along the Kerala coast between Vizhinjam toKasargod.
MESSAGE:Because of the combined effect of Spring tide andhigh waves, waves may be surged in to low lying coastal areasintermittently.MESSAGE: Fishermen are advised to be cautious whileventuring into the sea. Tourists also adviced cautious whileventuring into sea.
Kondalkattu forecasting (Location Specific Forecast) on high winds/waves in thePalk Bay
Kondal Kattu” is a Gusty wind which occurs near Rameswaram Coast during April and May (Premonsoon season). Near Rameswaram coast wind are below 10 m/s in pre-mosoon season. During thisevent wind suddenly increases to nearly 25 m/s. This gusty wind sustains for 2-3 hours or less. This gustywind along with sea-waves causing lot of damage to the boats which were moored at coast. The lowpressure forms over Salem or West coast of Srilanka region causing these gust winds. To forecast thesegusty winds, high resolution WRF model and wave model were setup for Rameswaram coast (southern tipof India)
10/31/13
Alert given in INCOIS websiteThe winds and waves may increase during 1530 hrs of
24-04-2015 to 0330 hrs of 25-04-2015 along theKanyakumari to Southern Nagapattinam stretch.
Operational Storm Surge Warning
Bathymetry/topography
Unstructured
mesh
Atmosphericforcing
DisseminationInput
Modeling
ADCIRC + SWAN(Tide + Surge + Wave)
ADCIRC(Spin-up with Tidealone simulation atHPC)Spin-up for 2 months.320 processors areusing.
u vη
Tide alonesolution
Bulletingeneration
WEB
Atmosphericforcing
H2010
Requirestrack &intensityinfo fromIMD
WRF
RequiresinitialconditionsfromNCMRWF
or
Forcing to the model
Output
ADCIRC + SWAN(Tide + Surge + Wave)
u vη
Inundation extent
Bulletingeneration
SMS
FAX
Real time storm surge forecasting for ‘Hudhud’ byINCOIS
Validation of Storm Surge - Hudhud
Finite element mesh of Chennai region
Validation of ADCIRC predicted water level at Chennai
Hydrodynamic model ADCIRC makes use of finite elementunstructured mesh. Tide can be predicted at any locationalong the coast.
Accuracy of the model is corroborated by years of successfultidal prediction well documented in the literature, makingthe ADCIRC model a logical component of any tidalprediction system
Ocean Monitoring Forecast System for RIMES member CountriesSeychelles, Sri Lanka and Maldives
Ocean Monitoring Forecast System for RIMES member CountriesSeychelles, Sri Lanka and Maldives
10/31/13
Deployment ofWave Rider BuoyOff Seychelles On16th March 2016
User Interaction
Awareness meeting and Ocean State Forecast -SMS has been inaugurated at Digha, West Bengalon Feb 2, 2016 by Mr. Sisir Adhikary, Chairpersonof the Digha Sankarpur Development Authority.
The buoy just before deployment off Digha,West Bengal on Jan 21, 2016
Multiple use of OSF/High Wave Alert Services :• Decision making – whether or not to venture into the sea• Selecting the type of nets for fishing• Changing the position of boat Anchoring• Anchoring and casting their nets• Life and livelihood asset saving• Reduce the boat and net damage• Determine number of crews in the boat for fishing
USAGE AMONG FISHERMAN
27-12-2016
Voice from the coast : Mr. Sukumar, Samathanpettai, Tamil Nadu
We were worst affected by the Tsunami. After this terrible incident, even the slightestchange in the sea would create anxiety and fear among the community. More than themen the women and children would discourage us from going into the sea for fishing.However this anxiety drastically come down ever since we started receivingINCOIS OSF information/High wave Alert through MSSRF. This information givesus confidence to venture into the sea without any hesitation or worry. Our familymembers are not very much worried about our safety in the sea and they have asecured feeling.
Multiple use of OSF/High Wave Alert Services :• Decision making – whether or not to venture into the sea• Selecting the type of nets for fishing• Changing the position of boat Anchoring• Anchoring and casting their nets• Life and livelihood asset saving• Reduce the boat and net damage• Determine number of crews in the boat for fishing
Impact based productsImpact based products--SARATSARAT
Search and Rescue Aid Tool (SARAT)
Triangular area boundaryAdvisory valid Period: 3 days
Probability Scale
Feedback regarding its usefulness
Triangular area boundaryAdvisory valid Period: 3 days
Search and Rescue activities (from 11-18June, 2015) for the missing Indian CoastGuard aircraft off Karaikal, southeastcoast of India, by assisting the IndianCoast Guard search and rescue team witha specialised in house developed SARAT(Search and Rescue Aid Tool)"module/system - which helps in locatinglost persons and objects in the sea, basedon the last known position details.
Probability Scale
Feedback from Commander Coast Guard forsupport and cooperation given by INCOIS duringSearch and Rescue operations for missed Coast
Guard Dornier CG 791.
Forecast Services for Shipping industry
Forecast Services for Shipping industry
Forecast for Port and Harbours
Forecast for Maritime Boards
1. The Experimental set up of GNOME based Online OilSpill Advisory system is launched for the Indian Coastguard, port authority, maritime boards and otheragencies involved in clean up measures
2. OOSA will generate the predicted trajectory aftersubmitting the details of the spilled oil. The trajectorywill be displayed in an open layers web map indicatingthe nearby locations with respect to time.
3. Future upgradation includes the integration ofHydrodynamic outputs from flow model 21 flexiblemesh (mike 21)
4. Various officials from ICG, RIL, ONGC, PORTS haveregistered this product .
LAUNCH - EXPERIMENTAL SET UP OF OOSA,12.05.2014 OOSA – BETA VERSIONONLINE OIL SPILL ADVISORY SYSTEM
Ocean State Forecast system for neighboring countries
Ocean State Forecast system for Sri Lanka and Seychelles in collaboration withRIMES, inaugurated on 10th July 2015
VSCS HUDHUD VSCS PHAILIN
Balakrishnan Nair, T.M., Remya, P.G., Harikumar, R., Sandhya, K.G., Sirisha, P., Srinivas, K., Nagaraju, C.,Nherakkol, A., Krishna Prasad, B., Jeyakumar, C., Kaviyazhahu, K., Hithin, N.K., Kumari, R., Sanil Kumar, V.,Ramesh Kumar, M., Shenoi, S.S.C., Nayak, S. Wave forecasting and monitoring during very severe cyclonePhailin in the Bay of Bengal (2014) Current Science, 106 (8), pp. 1121-1125
Sirisha P, Remya PG, Balakrishnan Nair TM, Venkateswara Rao B . Numerical simulation and observations ofvery severe cyclone generated surface wave fields in the north Indian Ocean. 2015.J earth system sciences. Vol 124. pp 1639-1651
Balakrishnan Nair, T.M., P. Sirisha, K. G. Sandhya, K. Srinivas, L. Sabique, Arun Nherakkol, B. Krishna Prasad,Rakhi Kumari, C. Jeyakumar,K. Kaviyazhahu, M. Ramesh Kumar, R. Harikumar, S. S. C. Shenoi and ShaileshNayak (2013) Performance of the Ocean State Forecast system at Indian National Centre for Ocean InformationServices Current Science, 105 (2), pp. 175-181
Sandhya, K.G., Balakrishnan Nair, T.M., Bhaskaran, P.K., Sabique, L., Arun, N., Jeykumar, K. Wave forecastingsystem for operational use and its validation at coastal Puducherry, east coast of India (2014) OceanEngineering, 80, pp. 64-72
Murty,P.L.N., Sandhya,K.G., Bhaskaran, P.K., Josec,F., Gayathri,R., Balakrishnan Nair, T.M., Srinivas KumarT., Shenoi S.S.C (2014) A coupled hydrodynamic modeling system for PHAILIN cyclone in the Bay of Bengal,Coastal Engineering, 93, pp.71–81.
Reliability of Forecast products- VerificationsReliability of Forecast products- Verifications
34
With nesting Without nesting
Balakrishnan Nair, T.M., Remya, P.G., Harikumar, R., Sandhya, K.G., Sirisha, P., Srinivas, K., Nagaraju, C.,Nherakkol, A., Krishna Prasad, B., Jeyakumar, C., Kaviyazhahu, K., Hithin, N.K., Kumari, R., Sanil Kumar, V.,Ramesh Kumar, M., Shenoi, S.S.C., Nayak, S. Wave forecasting and monitoring during very severe cyclonePhailin in the Bay of Bengal (2014) Current Science, 106 (8), pp. 1121-1125
Sirisha P, Remya PG, Balakrishnan Nair TM, Venkateswara Rao B . Numerical simulation and observations ofvery severe cyclone generated surface wave fields in the north Indian Ocean. 2015.J earth system sciences. Vol 124. pp 1639-1651
Balakrishnan Nair, T.M., P. Sirisha, K. G. Sandhya, K. Srinivas, L. Sabique, Arun Nherakkol, B. Krishna Prasad,Rakhi Kumari, C. Jeyakumar,K. Kaviyazhahu, M. Ramesh Kumar, R. Harikumar, S. S. C. Shenoi and ShaileshNayak (2013) Performance of the Ocean State Forecast system at Indian National Centre for Ocean InformationServices Current Science, 105 (2), pp. 175-181
Sandhya, K.G., Balakrishnan Nair, T.M., Bhaskaran, P.K., Sabique, L., Arun, N., Jeykumar, K. Wave forecastingsystem for operational use and its validation at coastal Puducherry, east coast of India (2014) OceanEngineering, 80, pp. 64-72
Murty,P.L.N., Sandhya,K.G., Bhaskaran, P.K., Josec,F., Gayathri,R., Balakrishnan Nair, T.M., Srinivas KumarT., Shenoi S.S.C (2014) A coupled hydrodynamic modeling system for PHAILIN cyclone in the Bay of Bengal,Coastal Engineering, 93, pp.71–81.
INCOIS
IISc
Inter-comparison - IISC & INCOIS AWSs
Validation and Refinement of Model Forcing FieldsValidation and Refinement of Model Forcing Fields
Though the performance of ECMWF and NCMRWF are almost equal, ECMWF airtemperature at ETIO and wind speed (especially in SO) is marginally more close toreality compared to that of NCMRWF.
Harikumar, R., Balakrishnan Nair, T.M., Bhat, G.S., Nayak, Shailesh.,Reddem, V.S., Shenoi, S.S.C.(2013) Ship-mounted real-time surfaceobservational system on board Indian vessels for validation andrefinement of model forcing fields, Journal of Atmospheric andOceanic Technology, 30 (3), pp. 626-637
AltiKa Significant Wave Height Validation for Coastal OceansAltiKa Significant Wave Height Validation for Coastal Oceans
Differences between the Hsmeasurements from AltiKa and the buoysfor different Hs bins from the buoys.
Assessed the Altika derivedsignificant wave height along thecoastal areas all over the world forutilization for forecast verification.The paper is published in IEEEJournal JSTAR.
Hithin, N.K.; Remya, P.G.; Balakrishnan Nair, T.M.; Harikumar, R.; Kumar, R.;Nayak, S., "Validation and Intercomparison of SARAL/AltiKa and PISTACH-DerivedCoastal Wave Heights Using In-Situ Measurements," IEEE Journal of SelectedTopics in Applied Earth Observations and Remote Sensing (2015), vol.PP, no.99,pp.1,10
Bias correction is done for global products using entireI-RAWS datasets
Ground zero ocean met observations at the landfall point of Very SevereCyclonic Storm Hudhud from the Ship-mounted AWS
Ground zero ocean met observations at the landfall point of Very SevereCyclonic Storm Hudhud from the Ship-mounted AWS
10/31/13
•Bias-corrected winds – more close to reality.•Huge energy is getting attenuated<<< exponentially as cyclone enters inland.
Harikumar, R., T.M. Balakrishnan Nair, B.M. Rao, P. Rajendra Prasad, P.Ramakrishna Phani, C. Nagaraju, M. Ramesh Kumar, C. Jeyakumar, S.S.C.Shenoi and Shailesh Nayak, 'Ground zero ocean met observations at the landfallpoint of Very Severe Cyclonic Storm Hudhud from the Ship-mounted AWSs, Curr.Sci., 2016).
Ocean State Forecast along Ship Routes: Evaluation Using ESSO-INCOIS Real-Time Ship-Mounted Wave Height Meter (SWHM) and Satellite Observations
Evaluate the Forecast along shipping RoutesEvaluate the Forecast along shipping Routes
•Wave Height Meter (WHM) is a good option for wavemeasurements (with r ~ 0.8 in buoy comparison) in movingships/platforms.•Validation of Altimeter data using WHM shows a good match.Hence,• Further evaluation of OSF using altimeter shows a good matchwith average r > 0.85 with a SI < 20%.
Harikumar, R., N.K. Hithin, T.M. Balakrishnan Nair, P. Sirisha, B. Krishna Parasad,C. Jeyakumar, Shailesh Nayak and S.S.C. Shenoi, ' Ocean State Forecast AlongShip-routes: Evaluation Using ESSO-INCOIS Real-time Ship-Mounted Wave HeightMeter and Satellite Observations', J. Atmos. Oceanic Technol., 2015, DOI:10.1175/JTECH-D-15-0047.1.
Location Specific Forecast Error estimation
Error reduction in Early Warning systemsError reduction in Early Warning systems
39
Location Specific Forecast Error estimation
Soft Computing techniques in error correction of numerical models
• Deshmukh A. N, Deo M C., Bhaskaran P. K, Balakrishnan Nair. T. M, Sandhya K. G: Neural Networkbased data assimilation to Improve Numerical Ocean wave forecast IEEE Journal of OceanEngineering (2016)-In press
• Sirisha P, Sandhya KG, Balakrishnan Nair TM, Venkateswara Rao B Evaluation of wave forecast in thenorth Indian ocean during extreme conditions and winter monsoon. (2016). J OperationalOceanography (Under Review).
• Swarnali majumder, Balakrishnan Nair TM, Sandhya KG, Remya PG, Sirisha P Multi-model Ensembleforecasting of wave height during extreme weather conditions. (2016) J Operational Oceanography(Under Review).
Multi-model Ensemble forecasting of wave height
• Multimode and multilingual disseminationsystem include Web, SMS (voice & text), EDB,MDB, VIC, Radio (FM, AIR, Community), TVchannels, VHF and INSAT).
• Number of dissemination modes hassignificantly increased.
• Secondary dissemination system is also wellestablished collaborating with NGOs(MSSRF, Reliance foundation, IKSL, AlertIndia etc).
• Initiated and made operational a jointdissemination of Ocean forecast informationwith IMD.
• Guided the team developing software andhardware for dissemination of ocean stateforecasts through different modes.
Improvement in the dissemination chain
Expanded the multi user, multi-lingual and multimode dissemination chain.
• Multimode and multilingual disseminationsystem include Web, SMS (voice & text), EDB,MDB, VIC, Radio (FM, AIR, Community), TVchannels, VHF and INSAT).
• Number of dissemination modes hassignificantly increased.
• Secondary dissemination system is also wellestablished collaborating with NGOs(MSSRF, Reliance foundation, IKSL, AlertIndia etc).
• Initiated and made operational a jointdissemination of Ocean forecast informationwith IMD.
• Guided the team developing software andhardware for dissemination of ocean stateforecasts through different modes.
40
0
10
20
30
40
50
60
2009 2010 2011 2012 2013 2014 2015 2016 Total
No of new products
0
10
20
30
40
50
60
70
80
2012 2013 2014 2015 2016 Total
No of Publications
Forecast along Ship Routes Webmap services Forecast for PortsNo of Users
Products, Users and PublicationsProducts, Users and Publications
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
1
10
100
1000
10000
2013 2014 2015
Forecast along Ship Routes Webmap services Forecast for Ports
Value added services Ship_route_registered Users Maldives
Seychells Srilanka Total number of users
Tota
l no
of u
sers
/Rea
ch
Use
rs fo
r cus
tom
ized
pro
duct
s
Ocean Forecast Lab
AWARDS
10/31/13ISO Certification for our services National Geoscience Award 2014
What is Leeway ?Leeway is the movement of an object through the water caused by the wind acting onthe exposed surface of the object.
How do you calculate the trajectory ?
budt
rd
r
bu
Position vector of the lost object.
Velocity vector of the lost object.
How to get the velocity ?
Search and Rescue modelSearch and Rescue model –– TheoryTheory
From the leeway and the surface currents
)()()( tutLtu cb
Wave effects ignored. ( Possible for small objects* )
Stokes drift included in Leeway coefficients.
The leeway of the object is related to the wind velocity.
* Komen G. et al, On the existence of fully developed wind-sea spectrum, J. Phys Oceanogrphy 14(8), 1271-1281.
* Richardson,P.L, Drifting in the wind: leeway error in ship-drift data, Deep Sea Res I 44, 1807-1903 ( 1997).
t
t
c
t
t
b dttutLdttutrtr00
'''''0Solve using 2nd order Runge-Kutta.
•Monte Carlo ensemble approach:–S&R object represented by O(1000) particles, each with thecharacteristics of the object spread around the lost location within someradius determined by the confidence in the last known position information.–Uncertainties in the model, initial conditions and forcing are accounted forby seeding strategy and perturbations to the forcing.–The changing cloud of particles represents a probability density for the objectlocation.
•Stokes drift is assumed included in the empirical leeway data from USCG.– US Coast Guard has compiled data for 63 classes of S&R objects through
extensive field campaigns, made available for operational services.
Search and Rescue modelSearch and Rescue model ––AssumptionsAssumptions•Monte Carlo ensemble approach:
–S&R object represented by O(1000) particles, each with thecharacteristics of the object spread around the lost location within someradius determined by the confidence in the last known position information.–Uncertainties in the model, initial conditions and forcing are accounted forby seeding strategy and perturbations to the forcing.–The changing cloud of particles represents a probability density for the objectlocation.
•Stokes drift is assumed included in the empirical leeway data from USCG.– US Coast Guard has compiled data for 63 classes of S&R objects through
extensive field campaigns, made available for operational services.
