#CONTRIBUTOR(S), INSTITUTE(S), CONTACT INFORMATION: Jessica Podoski U.S. Army Corp. of Engineers Building 230, Fort Shafter, HI 96858-5440 (808) 438-1069 email: jessica.h.podoski@poh01.usace.army.mil #ORIGINATOR(S), INSTITUTE(S), CONTACT INFORMATION: Kent K. Hathaway Research Oceanographer Coastal and Hydraulics Laboratory, Field Research Facility U.S. Army Engineer Research and Development Center 1261 Duck Road Kitty Hawk, NC 27949 (252) 261-6840 (x224) (252) 261-4432 (FAX) Kent.K.Hathaway@usace.army.mil Stan Boc Coastal and Hydraulics Laboratory U.S. Army Engineer Research and Development Center 3009 Halls Ferry Raod Vicksburg, MS 39180 #TITLE: Wave and Current Data from Southeast Oahu, Hawaii during August - September 2005 #ABSTRACT: Field data collection was conducted for the U.S. Army Engineer District, Pacific Ocean, Honolulu (POH), during August 9 - September 14, 2005, off Kailua, Lanikai, and Waimanalo, Oahu, Hawaii. Wave and current data were collected at five fixed locations using bottom-mounted RD Instruments Workhorse, 1.2 MHz, ADCPs (Acoustic Doppler Current Profilers) and Sontek Hydra ADVs (Acoustic Doppler Velocimeters). The ADCPs include wave measurements. Four inexpensive current drogues (drifters) were designed and built at the CHL Field Research Facility (FRF) that used GPS tracking and radio telemetry for positioning. Deployments were made on 10 August and 13 September. June. #PURPOSE: Learn of current and wave patterns in the bay for design considerations. #PROJECT: US Army Corp. of Engineers Regional Field Study-- Southeast Oahu 2005 #FUNDING: Funding for the study was provided by the POH District of the U.S. Army Corps of Engineers #ACKNOWLEDGEMENTS: The field data collection study of the Southeast Oahu, Hawaii was performed for the U.S. Army Engineer District, Pacific Ocean, Honolulu (CEPOH) with support from the U.S. Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory's (CHL) Field Research Facility (FRF). #LOCATION EXTREMES: SOUTHERNMOST LATITUDE: 21.329912 SOUTHERNMOST LATITUDE HEMISPHERE: N NORTHERNMOST LATITUDE: 21.398416 NORTHERNMOST LATITUDE HEMISPHERE: N WESTERNMOST LONGITUDE: 157.71798 WESTERNMOST LONGITUDE HEMISPHERE: W EASTERNMOST LONGITUDE: 157.67976 EASTERNMOST LONGITUDE HEMISPHERE: W #LOCATION KEYWORDS: North Pacific, Hawaii, Oahu, Southeast Oahu, Kailua, Lanikai, Waimanalo #SAMPLING STATIONS: Maps and specific locations given in ../data/0-data/SoutheastOahu_FieldData/HiRSM.analysis-2.0.doc ../data/1-data/SoutheastOahu_FieldData/HiRSM.analysis-2.0.txt #BEGIN AND END DATES: yyyymmdd 20050809 - 20050914 #SAMPLING PERIODS: See Reports noted above #PARAMETERS: u-component current velocity v-component current velocity w-component current velocity current speed current direction amplitude of acoustic backscatter temperature depth wave height wave direction wave dominant period wave spectrum wave directional spectrum #METHODOLOGY: The following was taken from the above mentioned report: ADCP Gauges: The ADCP gauges were RD Instruments 1200 kHz Workhorse, bottom mounted facing upward with the sensor head approximately 0.4 m off the bottom. Figure 2 (report) shows the custom built mount that was held to the bottom with about 80 lbs of lead weight. These gauges have four acoustic transducers for measuring currents and a pressure sensor, from which horizontal and vertical current profiles were computed at 0.2 m vertical spacing. These units sampled at 2 Hz for directional wave measurements. Each hourly wave burst was approximately 34 minute long, starting at the top of each hour, and consisted of 4096 points. There is a 0.44 m blanking distance from the transducer head, and with a 0.2 m bin width this makes the first sample 0.72 m past the transducer, or about 1.12 m off the bottom. Current profiles were collected every 10 minutes from a 200 point average. Deployments were on 9 Aug 2005 and retrieved on 14 Sep 2005. ADCP-2 was reprogrammed on 10 Aug so collection started a day later, and the batteries were depleted on 4 Sep, about 10 days before retrieval of the other gages. ADV Gauges: The three ADV gages were the Sontek's Hydra model that sample a single point current velocity (U, V, and W) and contained an external pressure sensor. The instrument frame and ADV transducer are shown in Figure 3 ( report, after gauge retrieval). The sample volume for the current measurement is approximately 1-2 cm in size and about 0.17 m from the center transducer. This unit uses three beams to determine the three current components. Current Drogues: Four inexpensive current drogues (drifters) were designed and built at the CHL Field Research Facility (FRF) that used GPS tracking and radio telemetry for positioning. They were constructed with off the shelf plumbing supplies (PVC pipe, vertical risers, rubber unions, hose clamps), a Garmin Geko GPS receivers, and MaxStream (model XStream-PKG-R) radio modems (Figure 4, report). The sails had about a one meter cross-section. The lower vertical PCV pipe (submerged) contained the modem and batteries, the upper horizontal pipe contained the GPS receiver and radio antennas. A NEMA GPS data string was transmitted once per second and the Garmin GCP unit internally recorded positions every 30 seconds. These GPS units are WAAS enabled and should have a horizontal accuracy of about 3 m. The radio tracking was partially successful- it required line of sight which was not possible to simultaneously receive drifters in the Kailua and Waimanalo Bays. Also the antennas and connectors should be more robust, two broke during deployment. #INSTRUMENT TYPES: RD Instruments Workhorse ADCPs (Acoustic Doppler Current Profilers) Sontek Hydra ADVs (Acoustic Doppler Velocimeters) current drogues (drifters) #REFERENCES: Similar instruments and procedures are described in: Hathaway, K. K and S. Boc, 2008. Field Data Collection Study Final Report: Natatorium Current Study, Waikiki, HI. U.S. Army Engineering POH District, Honolulu, HI., ERDC/CHL TR-08. 55p. #SUBMITTING MEDIUM: DVD #DIRECTORY ORGANIZATION, FILE NAMES AND FORMATS: Note: all times are in UTC within ../data/ 0-data/ : This directory contains the original set of directories and files 1-data/ : Directories and files prepared by NODC (such files are prepared if original formats are non-proprietary) Contents of 0-data/: Directory SoutheastOahu_FieldData/adcp1/ Files: HI010adc.20050809_20050914.meta HI010adc.sum.20050809_20050916.txt Comment: Deployment summaries from instrument configuration files. File: HI010adc_vac_2005_mm.txt (mm=month, ie, 08, 09) Comment: Vertically averaged current (VAC) by month. Uave = positive going eastward (mm/s), Vave = positive going north (mm/s). file: readAdcpDSpec.m comment: Matlab code snippet to read directional wave spectra files (DSpec/). subdirectory: adcp1/Dspec comment: Wave directional spectra files (reformatted) from RDI WavesMon program. One file for each hour. See the Matlab code snippet readAdcpDSpec.m. Units are m^2/Hz/Deg. subdirectory adcp1/Fspec comment: Non-directional ADCP spectra, one file each hour Filename example: VSPspec.HIAD1.200508092100.UTC.asc This example is for 09 Aug 2005 at 2100 UTC. Format: Columnar ASCII spectra from ADCP Velocity, Surface, and Pressure (VSP). Energy units are m^2/Hz/Deg, And frequency is in Hz. subdirectory adcp1/Stats comment: wave and current statistics files by month (08=Aug, 09=Sep) file: HI010adc_cur_2005_mm_pfl.mat comment: (by month, mm) Matlab format current profile data Variables: Uave1 = vertically averaged east current (mm/s) Vave1 = vertically averaged north current (mm/s) Ux1 = east current profile (cm/s) Vx1= north current profile (cm/s) depth = nominal depth of center of each bin stime = Matlab time format ASCII text files of all parameters in ../data/1-data/SoutheastOahu_FieldData/adcp1/Stats file: HI010adc_wmo_2005_mm_UTC.txt comment: (by month, mm) Wave and current profiles, file by month, mm, columnar ASCII, one line per wave collection, space delimited. Format follows: Burst# YY MM DD HH mm ss cc Hs(m) Tp(s) Dp(deg) Depth(mm) Hmax(m) Tmean(s) bins depthlevel1Magnitude(m/s) depthlevel1Direction(deg) depthlevelNMagnitude(m/s) depthlevelNDirection(deg) Symbols: YY Year MM Month DD Day HH Hour mm Minute ss Second cc 1/100ths seconds Hs Significant Wave Height = 4*sqrt(area under the power spectrum) Tp Peak period = Wave period associated with the largest peak in the power spectrum Dp Peak Direction = peak direction at the peak period. subdirectory adcp2/ See explanation for filenames, directory names, and formats in adcp1/ subdirectory advData/ Processed ADV files. Files listed below are for ADV-1, there are similar files for ADV-2 and 3. The ADV wave data from ViewHydra was suspect and has been removed from the dataset use adv_??.curWave.txt files (?? = y1, g2, and r3). file: README.advFormat comment: summary of formats for files on this directory file: adv_??config.txt comment: configuration files file: adv_??.curWave.txt comment: Wave and curent stats with some QC data (where ?? = Gauge ID: y1, g2, or r3) See README.advFormat for details subdirectory advData/spec comment: Columnar ASCII spectra files, one per collection per gauge (see README.advFormat). subdirectory drogue/ comment: GPS drogue (drifter) data, 10 Aug and 13 Sep. file: gpsNmmm.dat comment: N: track number of the drogue mmm: month (Aug or Sep); for example, gps1Aug.dat is for track-1 on 10 Aug. columnar ASCII, with UTC time, (ignore data in column 6) latitude and longitude minutes (from Lat 21 degrees N and Lon 157 degrees W), drogue speed (m/s) and direction going towards (degrees positive clockwise from north). #DATASET SIZE: 231756 kbytes #NUMBER OF DATA UNITS: 5 stations; 2 drogue deployments #MISCELLANEOUS: Similar sets at NODC NODC Accession Comment 0044080 Wave and current data Natatorium, Waikiki August 2007 0051060 Wave and current data Hilo, Hawaii March-June 2007