airborne magnetic measurements associated with sw06 experiment
DESCRIPTION
Airborne Magnetic Measurements Associated with SW06 Experiment. SW06 Post-Experiment Meeting. Will Avera Pat Gallacher, Wayne Kinney Naval Research Laboratory And Brad Nelson Defence Research and Development Canada. Objective / Purpose. Measure magnetic fields in the vicinity of NLIW’s - PowerPoint PPT PresentationTRANSCRIPT
Airborne Magnetic Measurements Associated with SW06 Experiment
Will AveraPat Gallacher, Wayne KinneyNaval Research Laboratory
And
Brad NelsonDefence Research and Development Canada
SW06 Post-Experiment Meeting
Objective / Purpose
• Measure magnetic fields in the vicinity of NLIW’s
• Test theoretical predictions – Internal waves can produce measurable magnetic
signatures
Plan / Measurements
• 12 flight lines were collected over NLIWs on August 2, 2006– 4 lines @ 300’ (Lines 1,2,3,4)– 4 lines @ 500’ (Lines 5,6,11,12)– 2 lines @ 1000’ (Lines 7,8)– 2 lines @ 2000’ (Lines 9,10)– each line was ~ 10 minutes in length (~ 60 km) + 3 minutes per
corner– All lines were along the same track
• 39.5317 N , 73.6478 W to 38.9560 N , 73.0213 W
• Start point and bearing for this line were given to us by Jim Moum who was on the OCEANUS
• OCEANUS was in the middle of one NLIW packet
SW06
NRC Convair flight line
Simulations and Analysis -Very high resolution -MITgcm nonhydrostatic simulation -Forced with nested NCOM -Focus on nonlinear internal wave -Based on previous work including -MITgcm simulations of Hudson Canyon generation area -Nested NCOM simulations of high amplitude internal waves on shelf and slope in SW06
SW_06_new Domain (0.5km)current simulations
LBSF Domain (0.5km)future simulations
SW06 Moorings
The NRC Convair
• Convair data acquisition system – 3 Cesium total-field magnetometers– 2 vector magnetometers for compensation– Attitude and noise sensors– Post-processed DGPS navigation @ 4 Hz
500’ Results: Track Reproducibility : Lines 5,6,11,12
• Excellent reproducibility => Good geologic noise removal
All 4 Lines OverlyLine 11
Unfiltered
So
uth
No
rth
Magnetic Results: 500’ Alt - Lines 5, 6, 11, 12
• OCEANUS located near the internal wave activity • OCEANUS location sufficiently distant not to be disturbing measurements
NLIW ?
OCEANUS
Lt. Blue = Line 11
Ships > 1 mile off line
Black = Line 5
Blue = Line 6
Green =Line 12
Magnetic DataModel : U Velocity
1700 UT
1600 UT
1500 UT
Magnetic Results: 500’ Alt - Lines 5, 6, 11, 12
• OCEANUS located near the internal wave activity • OCEANUS location sufficiently distant not to be disturbing measurements
NLIW ?
OCEANUS
Lt. Blue = Line 11
Ships > 1 mile off line
Black = Line 5
Blue = Line 6
Green =Line 12
Magnetic DataModel : W Velocity
1700 UT
1600 UT
1500 UT
Conclusions (So Far)
• Data processing techniques – Appear to work for external magnetic noise reduction
• Anomalous residual noise on east side of the line is good candidate for NLIW – Jim Moum claimed the ship was in the middle of the NLIW– Residual noise correlated with OCEANUS position