Flux data from RV Ron Brown

Introduction The flux data are products from the NOAA/ETL Air-Sea Interaction Group's deployment on the NOAA Ship Ronald H. Brown during the 1999 KWAJEX campaign. Sponsor The distribution of these data sets is funded by NASA's Earth Science Enterprise. The data are not copyrighted; however, we request that when you publish data or results using these data, please acknowledge as follows: The authors wish to thank Dr. Jeffrey Hare of the NOAA Environmental Technology Laboratory's Air Sea Interaction Group, Boulder, CO, for the production of these data and the Data and Information Services Center(Code 610.2) at the Goddard Space Flight Center, Greenbelt, MD, 20771, which archives and distributes them under sponsorship of NASA's Earth Science Enterprise. The Data The data files kwaj_hr.txt and kwaj_10.txt contain measurements of turbulent and radiative fluxes plus bulk meteorological variables from the Research Vessel Ronald H. Brown in the KWAJEX leg of her 'around the world cruise' of 1999. The files also contain bulk estimates of the turbulent fluxes computed using a recently updated version (2.6) of the COARE flux algorithm (see ftp://ftp.etl.noaa.gov/et7/users/cfairall/bulkalg/ for documentation). Both direct (covariance) and inertial-dissipation (ID) turbulent flux calculations are included in this present data. Data Description Processing Level Release 1 Temporal Coverage July 28-September 12, 1999 Temporal Resolution 10 minutes* Spatial Coverage 8 N, 167.5 E Spatial Resolution In Situ Filename Description Format Size kwa_10.txt 10 minute Data File ASCII ~1.5MB kwa_hr.txt hourly means Data File ASCII .2MB flux_readme.txt documentation ASCII ~13KB *60 minute files averaged from 10 minute data Instrumentation The data in this file comes from three sources: The ETL motion-correct flux package sonic anemometer acquired at 20.83 Hz fast hygrometer acquired at 20 Hz 6-component motion measurements acquired at 10 Hz the ships SCS system acquired at 2 sec intervals the ETL mean measurement systems sampled at 10 sec and averaged to 1 min The sonic is 5 channels of data; the SCS file is 13 channels, and the ETL mean system is 16 channels. Data Processing A series of programs are run that read these data files, decode them, compute covariance, variances, spectra, etc. at 10-min time resolution. A set of 10-min process files are written for each cruise. One particular file, crus_da.dat consists of 164 columns of 10-min data including the turbulent and mean variables used here. A final program reads the crus_da.dat files, applies various corrections, computes the ID and bulk fluxes and the data quality indices, and writes the crus_10.txt files. This program also contains routines that average the data to fixed one-hr time intervals, computes the ID and bulk fluxes from one-hr means, and writes the crus_hr.txt files. Note, that in the case of the turbulent variables (covariances, variances, structure function parameters) only 10-min values that pass the data indicator criteria are used in the one-hr average. Quality Assurance Most quantities have been subjected to one round of intercomparison/calibration scrutiny; however, there may be future modifications based on accounting for other sources of data and revised calibrations. For Additional Experiment Information, click here The Files Formats The data files contain 47 columns; the length in rows of each file is determined by the number of hours of observation, 875 plus 2 header lines in the case of file kwaj_hr.txt. Column Parameter 1 julian date 2-11 mean variables from the ETL system 12-21 turbulent fluxes (covariance, ID, and bulk) 22-23 radiative fluxes 24 rain rate 25-28 turbulence data quality indicators 29-32 turbulent structure function parameters (indices of small-scale turbulence in the inertial subrange) 33-34 minor (rain and Webb) heat flux components 35-36 latitude and longitude 37-39 heights of the ETL wind, temperature, and humidity mean sensors 40-47 mean variables from the ships sensors Note: Click here for the complete parameter list Loading in MATLAB The data columns are presently labeled and numbered at the top (first two rows). Delete the first two rows and restore as a .txt file so they can be directly acquired with a MATLAB 'load' statement: x=load('your_local_directory\crus_hr.txt');%read file with hr-average data; set your local directory Data Access and Contacts FTP Site The flux data resides on DISC anonymous FTP. You may access the files from this document, Ron Brown Flux Data or directly via FTP at ftp disc2.nascom.nasa.gov login: anonymous password: < your internet address > cd data/KWAJ/surface_data/rv_rhbrown/flux Points of Contact The principal investigator for the flux data is: Dr. Jeffrey Hare CIRES Research Scientist University of Colorado NOAA Environmental Technology Laboratory 325 Broadway Boulder CO 80303 (303) 497-5864 jhare@etl.noaa.gov For additional information, please contact the GES DISC User Services: GES DISC User Services Code 610.2 NASA Goddard Space Flight Center Greenbelt, MD 20771 301-614-5224 Email: help-disc@listserv.gsfc.nasa.gov

Last update:Thu Dec 4 14:57:59 EST 2003 Page Author: Hydrology Data Support Team -- hydrology-disc@listserv.gsfc.nasa.gov Web Curator: -- Website Curator: Anthony Drake NASA official: Steve Kempler, DISC Manager -- kempler@disc.gsfc.nasa.gov