The HF Radar System in the Basque
Country
First validation and data analysis
results
Anna Rubio, Julien Mader, Manuel
González, Almudena Fontán, Vicente
Fernandez (QUALITAS REMOS), J.A.
Aranda (Euskalmet)
Surface currents in the SE of the Bay of
Biscay during 1978
15,000 plastic drift cards thrown into the sea from
different coastal points
REF: HYDROLOGICAL STUDIES AND SURFACE CURRENTS IN THE COASTAL AREA OF THE BAY OF
BISCA Y. Miguel Ibañez Artica.Instituto Geográfico Vasco. Lurralde :inv. espac. N. 2 (1979) p. 37-75 ISSN
1697-3070, extracted from: http://www.ingeba.org/lurralde/lurranet/lur02/iba02/iba02.htm
Outline
1. Introduction: Description of the Basque and
some observations over the slope
2. The HF Radar System
3. Data Availability and Quality Control
4. Validation and first results
5. Perspectives
Introduction: the OO System
MATXITAKO
DONOSTIA
Deep water buoy
Coastal station
HF radar antenna
BILBAO
MATXITXAKO
S. SEBASTIAN
DONOSTIA
Data available at:
http://www.euskalmet.euskadi.net
http://www.ibi-roos.eu/
Variability of currents over the SLOPE
Offshore buoys; over 450 and 550 m depth
2008
Matxitxako
Donostia
WELL-MIXED
STRATIFIED
Variability of currents over the SLOPE
Offshore buoys; over 450 and 550 m depth
2008
Lomb-Scargle peridogram 120 days, 60daysoverlapping segments. Vertically averaged
U component
V component
Processes governing the variability
SD
SD
f
f
D
Variability of currents over the SLOPE
Offshore buoys; over 450 and 550 m depth
2008
D2
f
D1
U+V COMPONENTS
Lomb-Scargle
peridogram 60 days,
30days-overlapping
segments.
Processes governing
the variability at high
frequencies, seasons
and depth
10-40 m
100-140 m
D2
f
D1
D2
f
Variability of currents over the SLOPE
Offshore buoys; over 450 and 550 m depth
2008
M2 f
VERTICAL SHEAR
U+V COMPONENTS
Lomb-Scargle power
spectra from the
vertical gradients of
the horizontal velocity
components.
Contribution to the
shear-induced mixing
at high frequencies,
seasons and depth
10-40 m
100-140 m
M2
f
Introduction: the HF RADAR System
Two radial site
stations: Higer
and Matxitxako
Central combine
site in Vitoria
WORKING
SINCE 2009
Matxitxako Antenna
(transmitter and receiver)
and electronics.
MAIN CARACTERISTICS of the BASQUE SYSTEM
Radar
Radar
Frequency Wavelength
(MHz)
(m)
4.86
60
Ocean
Wavelength
(m)
30
Typical
Typical Upper H1/3
Depth of Typical
3
Current1 Range2 Resolution Bandwidth Limit4
(km)
(kHz)
(m)
(km)
(m)
2-3
~150
~5
30
25
Introduction: the HF RADAR System
FROM CROSS SPECTRA TO RADIAL VELOCITIES
MUSIC (MUltiple SIgnal Classification) Algorithm
[Schmidt, R.O., (1986), IEEE Trans. Antennas Propagat., vol. AP-34, pp. 276-280]
•Linear solutions based on eigen-analysis of averaged spectral
covariances
•Capable of more than two solutions with little added numerical
burden
•Chooses number of bearings based on both eigenvalue & amplitude
ratios
•Capable of incorporating measured, distorted antenna patterns
OUTPUT: Vectors in polar coordinate system centered at receive
antenna:
1 radial map per averaged cross spectra file
Typically, seven radial maps “merged” into one hourly map
(3-hours running average)
Angular resolutions is 5˚
Introduction: the HF RADAR System
FROM RADIAL TO TOTAL RADIAL VELOCITIES
Several radials from each site contribute to each
total vector, being resolved into orthogonal
components (U, V)
Linear least squares performed on U, V
components separately
From radials with:
• An angle of incidence greater than α
α min = 20-30 º
•And total velocities < 100-120 cm/s
Defining a
•GRID SPACING: 5km
•AVERAGING RADIOUS: of 20 KM
Data Availability and Quality Control
MEAN COVERAGE AND STD OF TOTAL U, V COMPONENTS
Large
STD
values
DATA AVAILABILITY IN 2009
Data Availability and Quality Control
α min = 15º
radial velocities < 150 cm/s
α min = 30º
radial velocities < 100 cm/s
Data Availability and Quality Control
Comparison with Slope buoys
ADCP 12m
DONOSTIA
HF RADAR
ADCP sup
MATXITXAKO
HF RADAR
0.104
0.119
0.121
0.115
0.11
0.09
ADCP sup
0.117
0.134
Data Availability and Quality Control
Comparison with Slope buoys
ADCP DATA
SD
f
SD f
D
RADAR DATA
SD
D
SD
f
SD
f
D
f
D
Data Availability and Quality Control
Comparison with Slope buoys
M2 ELLIPES - HARMONIC ANALYSIS - SVD (Press et al., 1989)
Data Availability and Quality Control
Comparison with a drifter
COURTESY OF GILLES REVERDIN (LOCEAN)
Data Availability and Quality Control
QUALITATIVE Comparison with ADCP data
COURTESY OF MARIA SANTOS (AZTI)
Data Availability and Quality Control
QUALITATIVE Comparison with ADCP data
COURTESY OF MARIA SANTOS (AZTI)
Data Availability and Quality Control
Comparison withSST IMAGES and WIND forcing….
Data Availability and Quality Control
Comparison with SST IMAGES and WIND forcing….
Perspectives- Future work
• Use radial velocities for the comparison
• Validation of general patterns observed through the
comparison with other in-situ data (drifting buoys) and satellite
images
• Describe surface circulation:
– General patterns, seasonal and mesoscale variability (river
plumes, eddies)
– Harmonic analysis of the data (in progress) to compare with
in-situ data and existing models. Mapping current variability
associated to f
• Reconstruct velocity series (e.g. DINEOF on radial
components) to obtain a complete data set : use Lagrangian
model to describe surface transport
Perspectives- Future work
IMPROVING THE SYSTEM WITH A THIRD
ANTENNA IN COMTIS…
Perspectives- Future work
•
Abstract sent to EOF2010: ‘ COASTAL HF RADAR FOR OPERATIONAL
SURFACE CURRENT MONITORING AND MODEL VALIDATION IN THE
SE BAY OF BISCAY’. Mader J1.; Rubio, A1.; Fernández, V. 2; González, M1.;
Tarafa, N 2.; Fontán, A1.; Ferrer, L1.
1 AZTI-Tecnalia, Pasaia, Spain; 2 Qualitas Remos, Madrid, Spain
•
FCT GRANT – PHD Student for 2011 ¿?
•
Planning a workshop in OCTOBER at AZTI…
Thanks for your attention !
ADCP data – BIOMAN
46oN
ADCP DATA ECOANCHOA MAYO 2008 a 15 m
11May 23
ADCP DATA ECOANCHOA MAYO 2008 a 15 m
17May 14
12'
30'
44oN
45oN
48'
30'
36'
08May 04
09May 02
08May 12
08May 19
44oN
24'
06May 12
08May08May
04
12 09May 02
08May 19
30'
06May 12
30'
4 oW
30'
3 oW
4 – 25
May 2009
30'
2 oW
30'
12'
30'
4 oW
30'
3 oW
30'
2 oW
30'
6-23 May 2008
?
3 – 23
May 2010
MOORINGS “ECOSISTEMA” in 2010
•
•
•
•
4 x RCM9
1 x RCM7
2 x acoustic release
1 ADCP (workhorse ~300MHz ~100m rang)
upward looking
A
B
~100 m
~350 m
o
-500
44 N
-1000
48'
??
-1500
36'
A
Matxitxako
B
Donostia
-2000
??
-2500
??
24'
+ Pasaia
12'
3 oW
40'
20'
2 oW
40'
20'
-3000
??