WHOTS Mixed Layer and 1-D 1 D Model. Station ALOHA: Time-series Science and Status

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1 Station ALOHA: Time-series Science and Status 25 years of HOT Fernando Santiago-Mandujano and Roger Lukas University of Hawaii Station ALOHA (~4750m deep) 9 years of WHOI Hawaii Ocean Time-series (WHOTS) Hawaii Ocean Time-series (HOT) October present (252 cruises; ~10/yr) 3-hourly CTD profiles to 1000 m for 36 hours Shipboard ADCP 5-minute profiles Deep casts many other measurements ~2 years of ALOHA Cabled Observatory (ACO) Local and Remotely-Forced Salinity Trends and Variations Gunter Seckel Bureau of Commercial Fisheries Honolulu Laboratory sea surface Koko Head WHOTS 34.5 ALOHA potential density (kg m -3 ) z HOT fully-resolved temporal sampling & forcing 27 long-term trend (disrupted historical hydrographic ) profiles within 200 km of ALOHA (note gaps) 34 National University 05/27/2013 Seoul OceanSITES Steering Committee 35.4 decadal variations WHOTS Mixed Layer and 1-D 1 D Model ML T Photo Credit: Sean Whelan (WHOI) ML S Need to bring in 3-D advective contributions WHOTS mooring mixed layer depth

2 Ocean Reference Station: WHOTS Observing and helping to model the hydrological cycle WHOTS net freshwater flux Growing populations require better management of water resources, including effects of climate variation and change E-P present E-P Hawaii Rainfall Index Sea Surface Salinity S Sustained open ocean measurements (L) provide the foundations for testing S models. Two IPCC class WHOTS mixed layer salinity models (R) show different E-P and salinity projections. Capotondi et al. (2012) Mauna Loa SIO & NOAA/ESRL ALOHA/HOT UH & SIO & OSU & UW & UM & WHOI & NSF & NOAA Observing the Carbon Cycle pco 2 ph trends, ENSO and annual cycle resolved by HOT effects of eddies and storms are not resolved by HOT but are resolved by WHOTS (NOAA&NSF) pco 2 water NOAA/PMEL MAPCO 2 pco 2 air December 2011 from PMEL ocean carbon website Real-time and accumulated data at Daily mean 4726 m compared to HOT shipboard CTD profiles Note range and time scales cold overflow events and oscillations at Station ALOHA o C/year Johnson et al. (2007) Δ T s 0.05/15 years Lukas et al. (2001, DSR), Alford et al. (2011, GRL)

3 Data Management Principal Investigators Roger Lukas (UH) Robert Weller (WHOI) Albert Plueddemann (WHOI) Matthew Church (UH) David Karl (UH) Bruce Howe (UH) Christopher Sabine (NOAA/PMEL) Robert Bidigare (UH) John Dore (MSU) Michael Landry (SIO) Ricardo Letelier (OSU) Data are available via: Any opinions, findings, and conclusions or recommendations ftp://ftp.ifremer.fr/ifremer/oceansites/ expressed in this material are those of the author(s) and do not ftp://data.ndbc.noaa.gov/data/oceansites/ National Science Foundation. necessarily reflect the views of the Station ALOHA Sustained, consistent, collaborative, interdisciplinary science Creating a long, accurate, and high-resolution surface and upper ocean climatology including atmospheric forcing and carbon variables Air-sea fluxes, ocean-truthing atmospheric reanalyses, and benchmarking ocean models Providing essential information on climate change, eddy fluxes, and ecosystem dynamics Impacts as part of a global observational network Assessing ocean changes (incl. C) and enabling climate predictions Atmosphere and ocean modeling Ocean Reference Stations Institutions & agencies needed to sustain infrastructure Sustained multi-institutional collaboration (WHOI, UH/SOEST, PMEL) Collaborative funding, NOAA, NSF and SOEST OceanSITES data management (setting metadata standards) JCOMM OPS Confidence in changes Connections among processes Strong tests of models

4 Upper ocean stratification variations in NPSG are important for nutrient fluxes, primary productivity and community structure (Corno et al., 2007; Bidigare et al., 2009; Church et al., 2009). SURFACE FORCING Wind gases; aerosols Rain Clouds stress 3-D dynamics Isopycnal flow, Ekman pumping, Rossby waves, & mesoscale eddies Nutricline Depth TKE production mech. & evap. Stratification TKE buoyancy sink Mixed Layer Depth Shortwave & longwave radiation buoyancy sources & sinks turbidity Shortwave radiation Euphotic Zone Depth PRIMARY PRODUCTION Seoul National University OceanSITES Steering Committee R. Lukas (1998) 05/27/2013 Price Weller Pinkel (1986) 1 dimensional mixed layer model diagnostic ML model Ri# based vertical diffusive mixing Model code improved with 4 th order Runge Kutta integration. Errors in previous public Matlab version corrected. dt = 900 s, dz = 1 m forced with WHOTS 1 minute heat, moisture and momentum fluxes T and S initialized with a 36 hr mean of HOT cruise 3 hr interval CTD profiles removes internal tides influence u and v initialized with a 36 hr mean of 5 min HOT ADCP profiles reduces initial influence of inertial motion Potential temperature and currents from the ALOHA Cabled Observatory reveal cold overflow event dynamics Thermistor string plus ACO Microcat Symbols indicate heights of sensors above bottom ACO currents m above bottom The support of the U.S. National Science Foundation and the State of Hawaii is gratefully acknowledged R. Lukas, F. Santiago-Mandujano, E. Firing, and B. Howe Seoul National University OceanSITES Steering Committee (SOEST/University of Hawaii) 05/27/2013

5 ALOHA Updated and adapted from Dore et al. (2009, Proc Natl Acad Sci USA 106:12235 ) ph of surface ocean Annual, interannual, decadal and longer term changes in surface forcing, mixing, and advection ph DIC Maximum not in surface layer ph trend vs depth Local and remote physics are crucial, not just pco 2, temperature and biology This point was made in the paper