Introduction ###################################################################### This is a readme file for a data set collected by the OSU Ocean Mixing Group during the River Influences on Shelf Ecosystems (RISE) cruises. prfx : Approximate Time Period ------:------------------------ cr04 : July 2004 cr05 : August 2005 cr06 : May 2006 The data has been processed and compiled into this form by Levi Kilcher. License ###################################################################### This data is intended for use by members of the RISE project only. All others must recieve prior consent from the OSU Ocean Mixing Group before obtaining or using this data in any way. Data Format ###################################################################### -The data is provided in a single Matlab 7 format file: Summ.mat -This file provides a compact way of looking at a large fraction of the data from a given cruise. -This file contains a single structured variable summ (short for summary) with avg, vel and head data. -Data below 100 meters has been dropped out of this data set. -IMPORTANT NOTE: The last bin in each Chameleon drop is actually the average over the meter above the bottom of the drop. This means that the last non-NaN point in EACH column of EACH chameleon variable (this issue does not apply to velocity data, which does not even contain data near the bottom) is actually taken as the average over the 1-meter above the end of the profile. This means that these points do not fall exactly on the depth grid summ.depth. In order to find the exact depth of each bin use pressure (summ.P). When simply looking at the data as provided, this should not be too much of an issue, i.e. summ.depth should work fine as a depth axis. Variables/Units ####################### This is a list of all variables that may or may not be present in the data. The existance of a particular variable depends primarily on the level of confidence that we have in the accuracy of each variable. As we trust the our estimates of various variables, we will make them available here. IMPORTANT NOTE: Historically, we've made variables available which were not quality controlled. Therefore, if you downloaded data prior to Feb-20-2006, be aware that many variables (particularly turbulence variables: EPSILON, Krho) are inaccurate and unfit for publishing or other interpretation. _Variable_ _Units_ _Definition_ P dbar Pressure T C Temperature S psu (ppt) Salinity C S/m Conductivity SIGMA kg/m^3 Density-1000 DRHODZ kg/m^2 Vertical Density Gradient N2 1/s^2 Square of Bouyancy frequency EPSILON W/kg (m^2/s^3) Energy Dissipation Rate KRHO m^2/s Turbulent Eddy Diffusivity OBS Volts** Optical Backscatter FLR ???Volts??? Fluorescence ustar m/s Friction Velocity (Crawford & Dewey 1988) h_csl m Constant stress layer height (Crawford & Dewey 1988) tau_b N/m^2 Bottom Stress = ustar^2*rho_0 castnumber Chameleon Castnumber time Matlab Time Time of Chameleon drop u m/s Eastward velocity v m/s Northward velocity w m/s Vertical Velocity (positive upward) lat Decimal Degrees Latitude of Chameleon drop lon Decimal Degrees Longitude of Chameleon drop depth dbar (approx=m) Depth of a given bin p_max dbar Max pressure of chameleon drop echo3 ??? Acoustic Backscatter from 300 khz ADCP (beam 3) echo12 ??? Acoustic Backscatter from 1200 khz ADCP (beam 3) Cruise Specific Notes ###################################################################### cr05 ################# **: For data set cr05, between cast numbers 7213 and 7212, the gain was turned down on the OBS sensor in order for the OBS signal to no longer go off scale. The data here has been adjusted so that all OBS signals are on the same scale as prior to cast number 7213. Note: there are many places when the OBS signal goes off scale prior to cast number 7213, and I believe it still does so occasionally after this drop. ###################################################################### This readme was written by Levi Kilcher Updated: 2/20/2007