Adding Decibels

Speed of Sound in Water Depth Salinity Pressure Temperature Medium Effects: Elasticity and Density Salinity Pressure Temperature Variable Effects of:

Speed of Sound Factors Temperature Pressure or Depth Salinity

Temperature, Pressure, and Salinity

Class Sound Speed Data

More Curve Fitting Chen and Millero Leroy

Expendable Bathythermograph LAUNCHER RECORDER Wire Spool Thermistor PROBE (XBT) Canister Loading Breech Terminal Board Stantion Launcher Recorder Cable (4-wire shielded) Alternating Current PowerCable (3-wire) Optional Equipment Depth/Temperature Chart Canister Loading Breech

Typical Deep Ocean Sound Velocity Profile (SVP) Typical Deep Ocean Sound Velocity Profile (SVP) Sonic Layer Depth (LD) Deep Sound Channel Axis T P C

Refraction A B D E High c 1 Low c 2

Multiple Boundary Layers 11 22 33 44 where c 1  2 >  3 >  c 1 c 2 c 3 c 4 depthdepth

Simple Ray Theory z c (c,z) (c 1,z 1 ) Snell’s Law

Ray Theory Geometry Positive gradient, g z1z1 z2z2 x1x1 x2x2 c1c1 c2c2 11 22 R

The z (Depth) and x (Range) Directions  I =20  c surface =1500 m/s z x

The z (Depth) and x (Range) Directions  I =20  c surface =1500 m/s z x

Why is R = Radius? Positive gradient, g z1z1 z2z2 x1x1 x2x2 c1c1 c2c2 11 22 R 11

Summary Positive gradient, g z1z1 z2z2 x1x1 x2x2 c1c1 c2c2 11 22 R

Negative Gradient Negative gradient, g z1z1 z2z2 x1x1 x2x2 c1c1 c2c2 11 22 R

Example 1 Given: c 1 = 964 m/s, c 2 = 1299 m/s,  2 = 30 o  z(between 1 and 0) = 3000m Find:  1, c o, g (between pt 1 and 0), R c0c0 11 22 00 c1c1 c2c2

Example 2 Find gradient, g Find Radius of Curvature, R, for each ray. Skip distance – i.e. the distance until the ray hits the surface again Max depth reached by each ray  I =20   II =30  c surface =1500 m/s c 100 m =1510 m/s

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Slope = tan  x1x1 z1z1 z2z2 x2x2