#ACCESSION NUMBER: 0098789 #CONTRIBUTOR: Fernando Santiago-Mandujano Contact Information: Work: 808 956 7000 mandujan@soest.hawaii.edu #CONTRIBUTOR INSTITUTION: University of Hawaii Dept. of Oceanography 1000 Pope Road Honolulu, HI 96822 #ORIGINATOR: Dr. Roger Lukas Contact Information: Work: 808 956 4101 Fax: +1 808 956 9222 rlukas@hawaii.edu #ORIGINATOR INSTITUTION: University of Hawaii Dept. of Oceanography 1000 Pope Road Honolulu, HI 96822 #TITLE: Next generation vector averaging current meter data from the WHOI Hawaii Ocean Timeseries Site (WHOTS) program in the North Pacific from 2004 to 2011 #PROJECT: The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS) Data available free of charge. User assumes all risk for use of data. User must display CITATION in any publication or product using data. CITATION: "These data were collected and made freely available by Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS), supported by the National Oceanic and Atmospheric Administration (NOAA) through the Cooperative Institute for Climate and Ocean Research (CICOR) under Grant No. NA17RJ1223 to the Woods Hole Oceanographic Institution, and via a subcontract from the UH NSF project OCE03-27513." #ABSTRACT: The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS) is a coordinated part of HOT, and consists of a mooring that has been providing measurements of high-quality air-sea fluxes and the associated upper ocean response at Station ALOHA, about 100 km north of Oahu, Hawaii since August 2004. WHOTS is funded by NOAA and NSF and it is led by the WHOI Upper Ocean Processes Group. The WHOTS mooring is located at station ALOHA (a 6 nautical mile radius circle centered at 22 45'N, 158 W) in the central subtropical gyre of the North Pacific. The mooring has been in place for one-year periods since 2004 at a location that has been alternating between the eastern and southern edges of ALOHA. This NODC accession contains Next Generation Vector Averaging Current Meter (NGVM) measurements at 10 and 30 m depths for the first 7 WHOTS deployments (2004-2011). The northward and eastward current components are provided within NetCDF files (OceanSITES time-series Conventions 1.2). NODC accession 0090188 holds temperature and conductivity (salinity) data collected using SeaBird SBE-16 SeaCAT and SBE-37 MicroCAT instruments for the first 7 WHOTS deployments (2004-2011). Additional data for currents from ADCPs will be provided for WHOTS deployments 1-7. #PURPOSE: In 2003, Robert Weller (Woods Hole Oceanographic Institution [WHOI]), Albert Plueddemann (WHOI) and Roger Lukas (University of Hawaii [UH]) proposed to establish a long-term surface mooring at the Hawaii Ocean Time-series (HOT) Station ALOHA (22 45N, 158W) to provide sustained, high-quality air-sea fluxes and the associated upper ocean response as a coordinated part of the HOT program, and as an element in the National Oceanic and Atmospheric Administration’s (NOAA) array of global ocean reference stations. With support from the NOAA and the National Science Foundation (NSF), the WHOI HOT Site (WHOTS) surface mooring has been maintained at Station ALOHA since August 2004. The objective of this project is to provide long-term, high-quality air-sea fluxes as a coordinated part of the HOT program and contribute to the goals of observing heat, fresh water and chemical fluxes at a site representative of the oligotrophic North Pacific Ocean. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near Station ALOHA by successive mooring turnarounds. These observations will be used to investigate air sea interaction processes related to climate variability. #LOCATION EXTREMES: SOUTHERNMOST LATITUDE: 22.670167 SOUTHERNMOST LATITUDE HEMISPHERE: N NORTHERNMOST LATITUDE: 22.766667 NORTHERNMOST LATITUDE HEMISPHERE: N WESTERNMOST LONGITUDE: 157.95 WESTERNMOST LONGITUDE HEMISPHERE: W EASTERNMOST LONGITUDE: 157.89833 EASTERNMOST LONGITUDE HEMISPHERE: W #LOCATION KEYWORDS: North Pacific Ocean, Hawaii, Station ALOHA #SAMPLING STATIONS: The WHOTS mooring is located at station ALOHA (a 6 nautical mile radius circle centered at 22 45'N, 158 W) in the central subtropical gyre of the North Pacific. The mooring has been in place for one-year periods since 2004 at a location that has been alternating between the eastern and southern edges of ALOHA (22 46.00'N, 157 53.90'W (Station 50), and 22 40.21'N, 157 57.00'W (Station 52) respectively). #BEGIN AND END DATES: 13 August 2004 - 11 July 2011 #SAMPLING PERIODS: Deploy- Deployment-Recovery Station Coordinates ment Date Date Number Number ------- ---------------------------- --- ---------------------- WHOTS-1 12 August, 2004-25 July, 2005 50 22 46.00'N 157 53.90'W WHOTS-2 28 July, 2005-26 June, 2006 50 22 46.00'N 157 53.91'W WHOTS-3 26 June, 2006-28 June, 2007 50 22 45.99'N 157 53.99'W WHOTS-4 25 June, 2007-6 June, 2008 52 22 40.21'N 157 57.00'W WHOTS-5 5 June, 2008-16 July, 2009 50 22 46.01'N 157 53.83'W WHOTS-6 10 July, 2009-3 August, 2010 52 22 39.91'N 157 56.66'W WHOTS-7 27 July, 2010-11 July, 2011 50 22 39.91'N 157 56.66'W Specifics for NGVM time series Columns 1: WHn, where n is WHOTS deployment number 2: depth of current meter in meters 3: date of start 4: time of start (GMT) 5: date of end 6: time of end (GMT) 1 2 3 4 5 6 WH1_NGVM_10 2004-08-13 03:41:00Z 2005-04-18 05:15:00Z WH1_NGVM_30 2004-08-13 03:41:00Z 2005-07-25 17:14:00Z WH2_NGVM_10 2005-07-28 03:42:00Z 2006-06-24 18:29:60Z WH2_NGVM_30 2005-07-28 03:42:00Z 2006-06-24 18:29:60Z WH3_NGVM_10 2006-06-27 01:47:00Z 2007-06-28 15:18:60Z WH3_NGVM_30 2006-06-27 01:47:00Z 2007-06-28 15:18:60Z WH4_NGVM_10 2007-06-26 01:50:00Z 2008-04-07 01:52:60Z WH4_NGVM_30 2007-06-26 01:50:00Z 2008-06-06 17:17:60Z WH5_NGVM_10 2008-06-05 04:25:00Z 2009-03-06 18:35:00Z WH5_NGVM_30 2008-06-05 04:25:00Z 2009-04-16 18:20:00Z WH6_NGVM_10 2009-07-11 02:21:00Z 2010-04-07 21:09:00Z WH6_NGVM_30 2009-07-11 02:21:00Z 2010-08-02 17:08:60Z WH7_NGVM_10 2010-07-29 04:01:00Z 2011-07-11 16:28:00Z WH7_NGVM_30 2010-07-29 04:01:00Z 2011-07-11 16:28:00Z *note series length truncated for some instruments such as WH1 at 10m. #PARAMETERS: northward and eastward current components #METHODOLOGY: NGVM data from the WHOTS deployments were processed at the University of Hawaii. The records were truncated to 2 hours after deployment allowing time for mooring motions associated with the sinking anchor to die out. Velocity data from the NGVM at 30 m was compared with the ADCP data from the equivalent depth cell. Complete details of post-deployment processing is summarized (Mandujano et. al., 2008). Data were replaced by an interpolated value if a data point exceeded four times the standard deviation of the deployment mean. Velocity differences between the NGVM and the ADCP were compared with wave data from the Datawell directional buoy located approximately 5 miles offshore of Waimea Bay on the north of O’ahu. A burst sampling scheme was utilized for the WHOTS-1 deployment in order to resolve orbital motions due to large swell. However, the subsequent deployment, WHOTS-2, did not utilize a burst sampling scheme and any influence due to swell might be reflected in a larger disparity with the NGVM data. Velocity differences greater than 0.1 m s-1 were identified, but do not seem to correlate with episodes of large swell for either deployment. We conclude that orbital wave motions from large swell do not adversely affect the velocity data and that there appears to be no bias from the different sampling schemes used for the two deployments. #INSTRUMENT TYPES: Next Generation Vector Averaging Current Meter (NGVM) #REFERENCES Fernando Santiago-Mandujano, Paul Lethaby, Roger Lukas, Jefrey Snyder Robert Weller, Albert Plueddemann, Jeffrey Lord, Sean Whelan, Paul Bouchard, and Nan Galbraith, Hydrographic Observations at the Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS): 2004 - 2006, Data Report No. 1. School of Ocean and Earth Science and Technology, University of Hawaii, Honolulu, 2008. pp 229. http://www.soest.hawaii.edu/whots/docs/Whots_data_report_1.pdf #SUBMITTING MEDIUM: FTP #FILE FORMATS: Directories and files: /data root data directory /0-data Files as received by NODC from the originator File Naming Convention and Format filename: WHn_NGVM_dd.nc where n: WHOTS deployment number dd: depth (meters) of current meter .nc: denotes NetCDF file Conventions = OceanSITES 1.2 Netcdf_version = 4.0.1 naming_authority = OceanSITES /1-data Files created by NODC filename: WHn_NGVM_dd_metadata.txt where n and dd are defined above content: these text files contain metadata associated with each NetCDF file created using NetCDF function ncdump. #DATASET SIZE: 105,584 mbytes #NUMBER OF DATA UNITS: 7 unique mooring deployments #MISCELLANEOUS: NODC accession 0090188 holds temperature and conductivity (salinity) data collected using SeaBird SBE-16 SeaCAT and SBE-37 MicroCAT instruments for the first 7 WHOTS deployments (2004-2011).