feature oriented analysis for high-resolution observations in shallow waters of sneb
DESCRIPTION
Feature Oriented Analysis for high-resolution observations in shallow waters of SNEB. Avijit Gangopadhyay University of Massachusetts Dartmouth Email: [email protected] In collaboration with the NRL-Stennis group Funded by NASA and ONR. OUTLINE. Feature Oriented Regional Modeling - PowerPoint PPT PresentationTRANSCRIPT
Feature Oriented Analysis for high-resolution observations in
shallow waters of SNEB
Avijit Gangopadhyay
University of Massachusetts Dartmouth
Email: [email protected]
In collaboration with the NRL-Stennis group
Funded by NASA and ONR
OUTLINE
• Feature Oriented Regional Modeling
• Concept -- Initialization/Synthesis Methodology
• Vertical Structure of Features via EOFs
• Shallow water applications – MODIS
• Feature oriented data synthesis…..
Gulf Stream Front and Ring Analysis
Features in Western North Atlantic
• Gulf Stream
• Warm Core Rings
• Cold Core Rings
• Southern Recirculation Gyre
• Northern Recirculation Gyre
• Deep Western Boundary Current
• Gangopadhyay et al., 3-part series in 1997: Journal of Atmospheric and Oceanic Tech. (14) 1314:1365
• Maine Coastal Current• NEC Inflow• GSC Outflow• Jordan Basin Gyre• Wilkinson Basin Gyre• Georges Basin Gyre• Georges Bank Gyre• Tidal Mixing Front• Gangopadhyay et al. 2002
(Continental Shelf Res. In Press)• Gangopadhyay and Robinson,
2002: DAO 36(2002) 201-232
Deep Sea region (GSMR) Coastal region (GOMGB)
Table I. List of GOMGB features and selected studies
Features Selected Studies
Maine Coastal Current(including Great South Channel Outflow)
Beardsley et al. (1985), Bisagni et al. (1996), Brooks(1987, 1990, 1994), Brooks and Townsend (1989),Chapman and Beardsley (1989), Holboke and Lynch(1995), Mavor and Huq (1996), Mountain and Manning(1994), Lynch et al. (1992, 1996, 1997), Lynch (1999),Naimie et al. (1994), Naimi (1995,1996), Smith (1989).
Gorges Bank Anticyclonic circulation,Tidal Fronts
Loder et al. (1992), Butman and Beardsley (1987),Butman et al. (1987), Bisagni et al. (1996), Flagg(1987), Houghton et al. (1982).
Jordan Basin Gyre Brooks (1987), Pettigrew et al. (1998), Wright et al.(1986), Beardsley et al. (1997).
Wilkinson Basin Circulation Brown and Beardsley (1978), Brown and Irish (1992,1993), Brown (1998a), Mountain and Jessen (1987).
Georges Basin Gyre Brooks, (1985), Wright et al. (1986), Beardsley et al.(1997), Pettigrew et al. (1998), Xue et al. (2000).
North East Channel Inflow Brooks (1987), Ramp et al. (1985), Bisagni and Smith(1998)
Abbreviations:GOMGB : Gulf of Maine and Georges Bank
MCC : Maine Coastal CurrentGSC : Great South ChannelTMF : Tidal (Mixing) FrontJBG : Jordan Basin GyreWBG : Wilkinson Basin GyreGBG : Georges Basin GyreNEC : North East Channel
T(x,y,z)=Ta(x,z)+(x,z)(y)where,Ta(x,z)={[T0(x)-Tb(x)](x,z)
+Tb}
U(x,y,z)=(y){[UT(x)-UB(x)](x,z)+ UB(x)}
Tss(x,y,Z) = Tsh + (Tsl – Tsh) m(,Z)
m(,Z) = ½ + ½ tanh[(-.Z)/]
=tan
Where, m is the melding function:
In general, a coastal current (CC), a front (SSF) and an eddy/gyre (E/G) are represented by:
CC: TM(x, η, z) =TMa(x, z)+ αM(x, z) M(η)
SSF: Tss(x, y, z) = Tsh (x, z) + (Tsl (x, z) – Tsh(x, z)) (, z)
E/G T(r, z) = Tc (z) - [Tc (z) - Tk (z) ] {1-exp(-r/R)}
where, TM
a(x, z), Tsh (x, z) and Tc (z) are axis, shelf and core
(η) = (0 W)
(, z) = ½ + ½ tanh[(-.Z)/]
Strategy for GOMGB
MCC WBG JBG GBG GBAG TMF SSF Inflow/Outflow
FORMS Protocol
• Identify Circulation and Water mass features• Regional Synthesis -- Processes from a modeling
perspective• Synoptic Data sets -- in-situ and satellite• Regional Climatology (Background Circulation)• OA (Climatology + Feature Models)• Simulation -- Nowcasting/Forecasting
FORMS Applications in Different Oceans
• Western north Atlantic – Operational modeling in GOMGB – AFMIS-RFAC
• Strait of Sicily – Dynamical analysis• Monterey Bay real-time forecasting with ROMS –
AOSN-II in summer 2003 -- Upwelling• Brazil Current Meander-eddy-Upwelling System• Persian Gulf, Arabian Sea – Rapid response• Chilean Waters – Northern Humboldt Current –
Biophysical modeling
Feature oriented methodology is applicable to ALL different
Numerical Models • MOM (Modular Ocean Model)
• POP (Parallel Ocean Program)
• ROMS (Regional Ocean Model System)
• POM (Princeton Ocean Model)
• MIT GCM
• HOPS (Harvard Ocean Prediction System)
• Finite Element / Finite Volume modelsIt is an Initialization and Assimilation Methodology
Strait of Sicily Feature Oriented Regional Modeling Set Up
Persian Gulf: FM+Climatology
Southern CaliforniaCoastalregion
Humboldt Current System
Meander-eddy-Upwelling System
The Hardest Work of All!!
SEC
IWBC
OBJECTIVELY BASED FEATURE MODEL
• Wilkinson basin water masses
• Brooks June 1982 data
• Cluster model of water masses
• EOF vertical analysis
• Feature model of vertical temperature and salinity
Brooks 1982 June survey in Wilkinson Basin
T,S Diagram
CLUSTER MODEL
Distance function
222nnnD dSTF
dcnScnTcn ddSSTT /,/,/ where
Water mass Ellipsoids
Explained Percent Variance
No. of Modes Included
The 1997 PRIMER IV
Field experiment
To-be-analyzed via Cluster-EOF analysis with NRL-Stennis team
Shallow water feature models
• Use of ‘intelligent observations’ that are important to resolve the scales and represent the underlying dynamical processes
• Not only temperature-salinity structure, but include first-order dynamics
• Process-oriented feature models
Upwelling
• Wind speed and direction at highest available resolution from QuikScat
• Mixed-layer depth estimate from MODIS• Infer the Ekman Current in the Upper Mixed layer• Additional baroclinic currents may be added for
coastally trapped waves or alongshore currents• Monterey Bay in Summer 2003, Vietnamese shelf
in summer 2003, Brazil Current - Cape Frio upwelling region in austral summer 2003.
Transient feature models
• Coastal filaments, jets, squirts and eddies• Automated gradient-detection algorithm (Cayula
and Cornillon, 1995)• Small scales (1-100 km) and short-life (20-40
days)• Spatial and temporal dependence of FM
parameters• Low vs. high chlorophyll regions (Chan, 1999)
Feature tracking in shallow coastal regions
• MODIS instrument on Terra and Aqua
• Resolution ~ 250 meters (1-km globally)
• Temperature precision – 0.3-0.5K
• Navigational accuracy – 50 meters per pixel
• Moving mesh algorithm (Rowley and Ginis, 1999) ; Wavelet approach (Liu et al., 2002)
• Monterey Bay application – SNEB?
MODIS chlorophyll on July 23, 2002 for southern California from Terra (left) at 1815 GMT, and the same field from Aqua (right) at 2115 GMT. A feature-tracking algorithm that uses the chlorophyll field as tracer will deduce the surface currents, which can be assimilated in the Navy’s modeling system. [Courtesy:Ron Vogel, http://www.modis-ocean.gsfc.nasa.gov/whatsnew.html]
Application to CODAR
• Pair of HF radars for measuring surface currents in our coastal regions
• Virtually continuous surface currents at ~1km resolution over tens of kilometers
• Tides, Baroclinic components, barotopic component, wind-driven component
• Vertical Projection Method (Shen and Evans, 2001) obtains subsurface current structure within the Ekman Layer from CODAR and wind obs. – Extend this method to include baroclinic structure – with NRL-DC
• Assimilation in parts in a dynamical model – POM in GOMOOS and ROMS-3Dvar in Monterey Bay
CONCLUSIONS
• Synthesis of Multi-sensor observational system: Satellite (SST, SSH, SSC), in-situ, CODAR -- using feature-oriented approach
• Feature Tracking -- High resolution data fusion (X-Band) 0.25 km MODIS data assimilation
• EOF analysis for Vertical Structure determination
Thank You!!
MODAS
High-resolution scales in FM
Future Directions
Future Directions
Ti
k
iiim
iiiTmim
SLWMBWMIWMSWMHWm
SLWMBWMIWMSWMHW
jiji
vuA
uuAA
AAAAAA
AAAAAA
TTa
1
2
,,
,,,,
EOF Analysis
Reconstructed mean temperature
Number of Modes
Error of reconstructed mean temperature
Depth (m)
DMSP
NPOESS
NPOESS
METOP
POES
POES
EOS-Aqua
NPP
DMSP
Windsat/Coriolis
0530
1330
DMSP-II
DMSP-II
POES
EOS-Terra
Future Missions – NASA/NOAA/DoD sponsoredFuture Missions – NASA/NOAA/DoD sponsored
0730-1030
FY 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18
http://aqua.gsfc.nasa.gov/
EOS – AquaEOS – Aqua
Characteristics Channels: 36 (visible, near-, and thermal-infrared) Resolution: 2 @ 0.25km, 5 @ 0.5km, 29 @ 1.0km Data Rate: 13.125mbps Revisit: 2 Days Swath: 1780km
Compare to NOAA-AVHRR
Channels: 5 (VIS,IR,WV) Resolution: 1.1km Data Rate: 680kbps Revisit: 2 Days Swath: 3000km
MODIS - MODIS - Moderate-resolution Imaging Spectroradiometer
(Double-click the image to animate)
Feature Oriented Data Synthesis
• Satellite Oceanography is here and more coming!!
• Multiple Satellites -- multiple variables are being sensed for the same piece of ocean simultaneously!!
• SST, SSH, SSC -- SSS coming soon!
• High Resolution data in coastal regions -- MODIS, Aqua, Oceansat, FY-1