1. A Comparison of Six Expendable Bathythermograph Data Acquisition Systems Derrick Snowden Molly Baringer Gustavo Goni

3. Instruments List System NameLauncher Type Recorder TypeController Software (PC) aomlautoAOML Autolauncher MK-12AOML (DOS 386 PC) devilhandSippican LM- 3A DevilDevil Software (Win XP PC) seasautoAOML Autolauncher MK-21SEAS2000 (WinXP PC) seashandSippican LM- 3A MK-21SEAS2000 (Win XP PC) sioautoSIO Autolauncher MK-21SEAS2000 (Win XP PC) siok98SIO Autolauncher MK-12 366 total profiles

4. XBT Errors XBT differs from the CTD due to : A: inaccurate depth measurements B: inaccurate temperature measurements AB 0 800 Depth (m) 0.250

5. MSE Bias Variance 0 80 0 Depth (m) 0.2 5 0

8. Fall Rate Error: Initial Conditions Hallock and Teague 1992

9. Fall Rate Equation a: Change of mass of the probe due to spooling wire. b: Probe geometry and initial terminal velocity c: Describes startup transients i.e. initial conditions Currently used FRE (WMO 1770:52) for Deep Blue probes contains no constant term ( c ). e.g. Hallock and Teague (1992)

10. Determining Depth Offset Focus on the temperature gradient: derivative of temperature with respect to depth Minimize temperature error effect Hanawa et al (1995)

11. Depth Offset Prior to Correction

12. Depth Correction Algorithm Assemble the depth offsets (dZ) Recalculate XBT depths Znew = Zxbt+dZ Back calculate time (t) Fit new fall rate equation to (t) z = at^2 + bt + c

13. Depth Offset: Post-Correction

14. Summary of Fall Rate Coefficients ABC Wmocode 52-0.002256.6910 this study-0.001916.4870 this study-0.002996.639-4.5117 other studies (1) -0.00131 – -0.00329 6.440 – 6.798 0 - 0 1: Taken from Hanawa et al 1995

15. 1.aomlauto 2.devilhand 3.seasauto 4.seashand 5.sioauto 6.siok98