270 likes | 396 Views
QA/QC of Ocean Currents. Bill Burnett NOAA/NWS National Data Buoy Center Stennis Space Center, MS 27 February 2008. Currents Working Group.
E N D
QA/QC of Ocean Currents Bill Burnett NOAA/NWS National Data Buoy Center Stennis Space Center, MS 27 February 2008
Currents Working Group • The first workshop (QARTOD I) was held at the NOAA National Data Buoy Center (NDBC) office at the Stennis Space Center, MS in the winter of 2003. Over 80 participants attended with the primary task to develop minimum standards for calibration, QA/QC methods and metadata http://nautilus.baruch.sc.edu/twiki/pub/Main/WebHome/QARTOD_final_09.pdf • QARTOD II was held February 28-March 2, 2005 in Norfolk, VA. This workshop focused on wave and current measurements and thier unique calibration, metadata and QA/QC needs. http://nautilus.baruch.sc.edu/twiki/pub/Main/WebHome/QartodIIFinal.doc • QARTOD III was held at Scripps Institution of Oceanography, La Jolla, CA on November 2-4, 2005. It addressed QC for CTDs, in-situ currents, remote currents and waves. http://nautilus.baruch.sc.edu/twiki/bin/view/Main/Qartod3Presentations • QARTOD IV was held at Woods Hole Oceanographic Institution on June 21-23, 2006. The meeting was held to approve Quality Control standards developed in QARTOD I – III, and begin focusing on Quality Assurance standards.
Currents Strategy • Current Profiler • Bridle-mount • Cage-mount • Buoy-mount • Additional Current Profilers • Attached to C-MAN or ATON stations • Bottom-mounted • Single Point Current Meters
External Hull Mounts 37SM CTD Sensor External ADCP Battery Canisters (2) with Retainer Bracket
NDBC MMS Page Apply quality control to real- time ADCP data from deep- water oil platforms and rigs
Surface Current Plots East of Virginia Beach Onslow Bay Inside Buoy
Surface Current Plots Lake Huron
Celtic Sea and Transocean Marianas Inertial Currents and Current
Data Quality • Purpose: • Remove gross errors • Data rejected: • Virtually certain to degrade products • Typical causes: • Transmission errors, power degradations, broken cables • Limitations: • Won’t detect minor errors, biases
Data Quality • Limit check – Are the currents within standard data limits? • Time continuity check • Vertical velocity relational check • The limit and time continuity checks are applied to each velocity measurement • The vertical-velocity-relational check deletes horizontal current measurements when the corresponding absolute value of the vertical velocity is too high to be physically reasonable.
Real-Time Quality Descriptor Flags • Categories … agree with QARTOD I recommendations: • -9 = missing value • 0 = quality not evaluated • 1= bad • 2=questionable/suspect • 3=good
Questions? See the data sheets at: http://ioosdmac.fedworx.org Contact Info: Bill Burnett DMAC Branch Chief National Data Buoy Center Stennis Space Center, MS 39529 Bill.Burnett@noaa.gov 228-688-4766