SAFDE - Analysis & Display Standards

Below are a few analysis & display issues that we have agreed should be standardized for SAFDE in order to promote consistency among our analyses and maximize communication at national and international meetings.

(1) The name of the experiment is: Sub-Antarctic Flux and Dynamics Experiment (SAFDE).

(2) When a temporal axis for plots is needed, use `digital day', i.e., days since 1/1/95 0000 GMT.

(3) Low-pass filtering is to be accomplished with one pass of the filter described by Watts in his 6/9/98 email to all of us (i.e., a 72-hr 4th-order Butterworth); OR, you can use a shorter-length filter to first knock down the high frequencies (as might be required, for instance, with current meter data that have strong tidal and inertial signals), followed by Watts' filter.

(4) After low-pass filtering, decimation is to daily data where the points from Noon GMT of each day are taken.

(5) In plan view map displays, if bathymetry is needed use the Smith-Sandwell bathymetry, smoothed as needed or not. This dataset is far superior to anything else available for the Southern Ocean. For example, in the SAFDE area GEBCO, ETOPO5 and DBDBV get the structure of the 140E fracture zone quite wrong.

(6) The following symbols will be used for displaying SAFDE array elements on plots:

(7) A common analysis time period is defined for the purpose of calculating means from the data, in order to avoid differences in our calculations that might arise from using different data segments. The comon time period recommended by Luther for the low-pass filtered and daily decimated data (per (3) & (4) above) is from digital day 95.5 through 795.5, where digital day is defined in (2) above. This corresponds to April 6, 1995, through March 6, 1997. The total number of days is 701.

Last Revised: 4 December 2001