‘Drifting’ buoy data- their effect on‘Weather’ Analysis and ForecastingIan Hunter S A Weather Service 29/7/2002 Louis Vermaak – DBCP XVIII – Martinique 14-18 October 2002
South African Weather Service (SAWS)METAREA VII • Our marine environment • ‘Fixed platform’ in situ observation sites • Remotely-sensed marine data • SAWS marine products/ activities • Drifters and some case studies • Comments
SAWS – our Marine Environment
Tropical cyclone ‘Eline’ 22 February 2000
‘Magdalena Oldendorff’ – icebound in METAREA VII
Explosive cyclogenesis south-west of Cape Town
Cut-off low generating heavy SE’ly swell
Heavy SW’ly swell arrives at ‘The Dungeon’ south of Cape Town
Warm Agulhas Current water penetrating the South Atlantic Courtesy OSIS Cape Town
10% + of world’s seaborne oil trafficrounds the Cape…. Courtesy : MRG Munich
SAWS – our “Fixed Platforms”
cf FA Platform central Agulhas Bank Courtesy MRG Munich
A visitor to Marion Is (48° S) – March 2002
Bouvet Is. Norwegian AWS v. important for wave forecast models
SAWS AWS on South Thule, South Sandwich Islands - see ‘ship wave’ clouds, top left.
Remotely-sensed Marine Data
NOAA AVHRR data – Agulhas Current – 5 knots +
MODUS – Terra – Gulf Stream even higher resolution ...
Scatterometer winds ex QUICKSCAT – not always available
QUICKSCAT sees the pack ice – June 2002
SAWS – our Marine Products/ Activities
SAWS Global Spectral Model (GSM)
SAWS regional Eta model
A few Marine Case Studies in METAREA VII
Heavy, very long-period SW’ly swell to Agulhas Bank - semi-submersibles unprepared, go into resonance. Damage several $m.
Tropical Cyclone Domoina visits the KwaZulu Natal Coast
Meteosat 7 – 4 September 2001HmO 10m + off Cape Townwidespread coastal damage
Explosive cyclogenesis 24 May 2002. Heavy swell -> coastal damage/ flooding
Drifting buoy 17513, south-west of Cape Town
Antarctic Mesoscale Prediction System model - AMPS
Drifting buoy 71566 – important input for AMPS – wakes up !
NOAA WAVEWATCH model – buoy data please !
Concluding Comments :Marine DATALife blood – Bread & butter !
Bouvet AWS data – received 8 hours later ...
International cooperation versus NMS commercialisation
SA Agulhas returning from Marion Is – August 1999 Photo : Brent Appel - SAWB