Title: CPIES: Current and Pressure recording Inverted Echo Sounder
1CPIES Current and Pressure recording Inverted
Echo Sounder
Measures Round trip travel times of acoustic
pulses to sea surface and back. Bottom
Pressure Bottom Temperature Currents 50m above
bottom Acoustic release and relocation aids Data
Telemetry available Deployments of up to 5 years
2Results from PIES CPIES measurements
- One PIES profiles of specific volume anomaly,
- steric height mass-loading component SSH
- __________________________________________________
______ - Two PIES / profiles of baroclinic velocity /
- CPIES plus barotropic referenced
velocity - absolute velocity profile
- 1-D line velocity transect, absolute
transports - __________________________________________________
______ - Three PIES / profiles of baroclinic velocity
vector / - CPIES plus barotropic velocity vector
- absolute velocity vector profile
- 2-D array 4-D maps of velocity and
density structure
3Tight empirical relationships exist between
acoustic travel time and Fofonoff Potential and
Geopotential Anomaly
Mass Transport Streamfunction
Baroclinic Velocity Streamfunction
WOCE SR3 examples, in SAF south of Australia
4View the vertical structure of Specific Volume
Anomaly, d, in streamfunction coordinates
When indexed by F3000 the d lookup table looks
like this
d
10-5 kg/m3
F3000 (m2 s-1)
WOCE SR3 examples, in SAF south of Australia
5View the vertical structure of Specific Volume
Anomaly, d, in streamfunction coordinates
When indexed by t3000 the d lookup table looks
like this
When indexed by F3000 the d lookup table looks
like this
d
10-5 kg/m3
F3000 (m2 s-1)
t3000 (s)
6Two IESs Profiles of baroclinic velocity
7Eastward baroclinic transports crossing WOCE SR3
Solid CTDs (S. Rintoul) Dashed IES method
Transports relative to 3000 dbar
8Three IESs, 2-D array profiles of BC
velocity vector
SYNOP moored Current Meter measurements and IESs
stack of velocities from Current Meters gt
stack of velocities from lt IESs (65 km
spacing)
differences can be entirely attributed to
point sampling vs. lateral-average sampling
differences
9A CPIES mapping array determines the velocity
field as the sum of a baroclinic profile plus
barotropic reference velocity
The BC velocities are aligned in a single
direction (called equivalent barotropic)
adding a BT component can cause turning.
10Mesoscale array of PIESs and deep CMs Abyssal
cyclones develop under steep upper-jet troughs
- Maps show three fields
- Pressure field anomaly at 3500 m In color
- Depth of the 12C isotherm contoured at 200
m intervals - Velocity vectors at 3500 m
Tick marks 50 km intervals
11Mesoscale array of PIESs and deep CMs Abyssal
cyclones develop under steep upper-jet troughs
12Summary
- PIES with deep current reference, e.g., CPIES
capabilities - 1-D transects provide absolute velocity and
transport estimates - Cost-effective for high horizontal spatial
resolution - Geostrophic velocities are laterally integrated
(intrinsically) - High temporal sampling for extended time periods
(up to 5 years) - 2-D arrays of CPIESs can provide velocity
structure - With mesoscale spatial and temporal resolution
- Well-resolved maps allow for dynamical diagnoses
case-studies
13- End of planned presentation
- Some extra slides follow
14IES-estimated temperatures agree with measured
temperatures In the Sub-Antarctic Front south of
Australia
Measured temperatures
IES-estimated temperatures
15Assemble regional hydrographic data set
T (oC)
Hydrographic data sorted by tau
Choose reference ?_index
Sort hydrographic data by ?_index
examples from Gulf of Mexico
t
16Fit cubic splines to data
T (oC)
t
17Final GEM field a lookup table
T (oC)
t
18Final GEM field a lookup table
T (oC)
t
19Three PIES and a deep CM yield profiles of
absolute velocity vectors
.
MMS / SAIC - Gulf of Mexico moorings
20IES-estimated currents agree with measured
currents In the Sub-Antarctic Front south of
Australia
Dotted Measured currents Solid
IES-estimated currents
21A CPIES mapping array determines the velocity
field as the sum of a baroclinic profile plus
barotropic reference velocity
The BC velocities are aligned in a single
direction (called equivalent barotropic)
adding a BT component can cause turning.
22Mapping and case studies, contdsteep meander
loop, deep eddy field, and RAFOS tracks
Tick marks 50 km apart