Figure 1
Map of the NE Pacific Ocean showing SeaWiFS summer chlorophyll distribution (blue is low, orange/red is high), temperature contours (unlabelled, decreasing to the north), the approximate position of the High Nutrient-Low Chlorophyll (HNLC) boundary in summer (dashed red line) and location of the stations sampled for water properties along Line P. Ocean Station Papa (OSP) is also designated as station P26, the terminal station of Line P.
| Figure 2
SeaWiFS chlorophyll image from July 2002, showing the formation of mesoscale eddies off the west coast of North America. These eddies create patchiness in the adjacent ocean by transporting coastal water, nutrients and organisms westward. Their influence has been observed at Station Papa.
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Site: NOAA/PMEL Ocean Station Papa
Project Name: NOAA PMEL Ocean Climate Stations
Position: 50N, 145W
Gulf of Alaska
Categories: Air-Sea Flux, Observatory; meteorological, physical, biogeochemical; ocean acidification
Safety distance for ship operations: 2 nm (4 km)
Short description:
1 surface buoy with taut-line mooring (and 1 nearby (10km away) subsurface mooring)
Variables measured (meteorological, physical, carbon):
Surface: wind speed and direction (from a sonic anemometer), air temperature, relative humidity, rain, shortwave and longwave radiation, 1m sea surface temperature and salinity, barometric pressure, air and sea surface water pCO2, and O2.
Subsurface temperature at nominal depths of 5m, 10m, 15m, 20m, 25m, 30m, 35m, 45m, 60m, 80m, 100m, 120m, 150m, 175m, 200m, 300m
Subsurface salinity at nominal depths 5m, 10m, 15m, 20m, 25m, 35m, 45m, 60m, 80m, 100m, 150m, 200m
Ocean currents at: 5m, 15m, 35m; upper ocean ADCP
Variables measured (ocean biogeochemical):
Ocean pH: 1m (UW)
Ocean fluorometer measurements: 4m, 26m (OSU)
Ocean gas tension device: 1m (UW)
Ocean O2: 1m (UW)
All physical measurements are recorded hourly or more frequently (most are 10 minutes or less). Surface biogeochemical measurements are recorded every 3 hours. Subsurface biogeochemical measurements are recorded hourly.
Start date of the time series: December 1949 – occupied by weatherships until 1981
DFO Line-P time series 1981 to present
Previous surface mooring (NOPP) was from 1997 to1999
Present mooring effort began in June 2007
Service interval: once per year, but is visited during DFO Line P Program three times per year (Feb, June, Aug)
Scientific rationale:
Station Papa at 50°N, 145°W is one of the longest oceanographic time series in the world. From December 1949 through December 1950, Station Papa was occupied by a U.S. Coast Guard weather ship organized through the U.S. Weather Bureau, and from December 1950 through August 1981, Station Papa was occupied by Canadian weather ships. Routine oceanographic measurements were made aboard these weather ships through much of this period. After the advent of the satellite era, the weather ship programs were discontinued, but shipboard measurements continued to be made along Line P by the Canadian Institute of Ocean Sciences (IOS) in Sidney, BC. Through the years there have been several process studies and mooring deployments located at Station Papa. The present mooring effort places the OceanSITES time series reference site within a historic context for monitoring rapid and episodic as well as slow changes to the climate system.
Groups / P.I.s /labs /countries involved / responsible:
Dr. Meghan Cronin (NOAA PMEL): mooring lead, meteorological and physical measurements
Dr. Chris Sabine (NOAA PMEL): air-sea pCO2 flux
Dr. Steve Emerson (University of Washington): Gas Tension Devices, CTD, O2 and pH sensor
Dr. Ricardo Letelier (OSU): fluorometers
Mr. Christian Meinig (NOAA PMEL): Lead Engineer
Status:
operating
time horizon / long-term plans: Long term (Ocean biogeochemical measurements funded through short term research grants)
The surface mooring is funded
The subsurface ADCP mooring is unfunded and its future is uncertain.
Technology:
Moored / autonomous sensors
real-time telemetry: The mooring is equipped with three independent measurement systems with separate telemetry pathways. Hourly surface meteorological and subsurface physical data are transmitted via Iridium from one system, and daily-averaged surface and spot surface data are transmitted via ARGOS from another. Of these two systems, at present, only ARGOS real time data are released. We expect the Iridium real time data to become the primary telemetry system sometime in 2009 or 2010. Carbon has daily transmissions of 3-hour measurements via a separate Iridium system.
SST measurement: self-contained sensor attached to bridle at 1m below surface
Profile measurements: Sensors are attached to taut-line mooring; Acoustic Doppler Current Profiler has been deployed on a nearby subsurface mooring (10km away).
Data policy:
real-time data: All real-time data are public from primary telemetry system.
delayed mode data: High-resolution data will be made public within 6 months of recovery.
Data management:
Data Assembly Center (DAC): All data accessible through www.pmel.noaa.gov/stnP/data.html. Carbon data available from the Carbon Dioxide Information Analysis Center (CDIAC).
Satellite data collection system: Argos and Iridium (physical data), Iridium (carbon data)
Real-time data processing and distribution system: PMEL real-time processing, QA and web distribution. GTS data limited to data telemetered via Argos. WMO number 48400 reflects status as a time series reference site.
Metadata scheme: see website (http://www.pmel.noaa.gov/stnP/)
Possibilities of evolution to comply with a more general JCOMM GTS scheme: in compliance
Societal value / Users / customers:
Ocean Station Papa users include the research community, weather and climate forecasting communities, fisheries research, and satellite and numerical weather prediction products assessments communities.
Role in the integrated global observing system:
The Ocean Climate Station Papa mooring serves as an air-sea heat and carbon flux reference site and as an observatory for the northeast subpolar gyre (Gulf of Alaska) region of the north Pacific. The surface mooring was initiated through a National Science Foundation Carbon and Water in the Earth System project "North Pacific Carbon Cycle" to Dr. Emerson (UW). Its continuation as an element of the Global Climate Observing System (GCOS) is supported through funding from the NOAA Office of Climate Observations. The Ocean Climate Station mooring program works cooperatively with the Fisheries and Oceans Canada, Pacific Region, Line-P Program. The Ocean Climate Station Papa surface mooring will also act as the central mooring of the NSF Ocean Observatory Initiative global node at station Papa. Its carbon observations make KEO a key element of the U.S. Ocean Carbon and Biogeochemistry (OCB) program, and international Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) and Surface Ocean Lower Atmosphere (SOLAS) programs. Since this is the first mooring, to our knowledge, that has long-term, high-frequency measurements of two carbon parameters (pCO2 and pH), it is the first mooring capable of properly documenting changes in Ocean Acidification.
Contact Person:
for enquiry about the OCS Papa data and possible enhancements to the mooring:
Meghan Cronin (Meghan.F.Cronin@noaa.gov )
for enquiry about possible ancillary measurements during cruises to the site:
Marie Robert (Marie.Robert@dfo-mpo.gc.ca)
for information about the carbon component: Chris Sabine (Chris.Sabine@noaa.gov)
Links / Web-sites:
for Project information : http://www.pmel.noaa.gov/stnP/
for data access : http://www.pmel.noaa.gov/stnP/data.html
for information on carbon system : http://www.pmel.noaa.gov/co2/moorings/
for information on the Canadian DFO Line P program:
http://www.pac.dfo-mpo.gc.ca/sci/osap/projects/linepdata/default_e.htm
Compiled by: Meghan Cronin (Feb 2009)
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Site: HOT (Hawaii Ocean Time-series Station ALOHA)
Position: 22.75 º N, 158 º W
Categories: Observatory, Air-Sea Flux reference site; physical, meteorological, biogeochemical
Safety distance for ship operations: Several (surface and subsurface) moorings are installed. Coordination with Principal Investigators is strongly requested prior to any sampling in the area.
Short description:
Station ALOHA: 22°45’N, 158°W, depth = 4780 m. Several moorings installed
Variables measured :
Full suite of physical and biogeochemical measurements including temperature, salinity, inventories and fluxes of gases, dissolved nutrients, plankton stocks and rate processes. Samples are collected throughout the water column, with intensive sampling efforts in the upper 1000 m.
Shipboard Measurements conducted during near-monthly cruises
I. Continuous Measurements: Depth (Pressure), Temperature, Conductivity, Dissolved Oxygen, Fluorescence (Chloropigment), Nitrate (0-1000 m); 0-4750 m transducers on Sea-Bird CTD package
II. Water Column Discrete Chemical Samples:
Full ocean depth: Salinity, Oxygen, Dissolved Inorganic Carbon, Total Alkalinity, Nitrate Plus Nitrite, Soluble Reactive Phosphorus (SRP), Silicate, Dissolved Organic Carbon.
Upper ocean (≤1000 m)Low Level Nitrate Plus Nitrite (0-200 m), Low Level SRP (0-200 m)
Dissolved Organic Nitrogen (0-200 m), Dissolved Organic Phosphorus (0-200 m),
Particulate Carbon (0-1000 m), Particulate Nitrogen (0-1000 m), Particulate Phosphorus (0-200 m)
Particulate Silica (0-200 m)
III. Plankton Biomass Measurements:
Chlorophyll a, b and c and Pheopigments 0-175 m
HPLC-derived pigments 0-175 m
Phycoerythrin 0-175 m
Adenosine 5′-triphosphate 0-350 m
Picoplankton abundances 0-175 m
Mesozooplankton 0-175 m Net tows
Particulate carbon, nitrogen, and phosphorus 0-1000 m
IV. Carbon Production and Particle Fluxes:
In situ 14C-bicarbonate assimilation primary production incubations (0-125 m)
Particulate Carbon, Nitrogen, Phosphorus, Silica fluxes 150 m Free-floating particle traps
V. Currents: Acoustic Doppler Current Profiler 20-300 (800) m hull mounted, RDI #VM-150; OS-75 (depending on vessel)
VI. Bow Intake System:
Remote temperature sensor at hull intake 8 m (for Kilo Moana; other R/Vs typically 3-5 m)
Temperature and conductivity sensors inside the thermosalinograph package
Fluorometry (Chloropigment) from intake at 8 m (for Kilo Moana; other R/Vs typically 3-5 m)
pCO2 from intake at 8 m on Kilo Moana
VII. Optical Measurements:
Incident Irradiance Surface LI-COR LI-1000 and Biospherical collector
Upwelling radiance and downwelling irradiance 0-175 m (Biospherical Profiling Reflectance Radiometer PRR-600)
Downwelling irradiance 0-3 m Tethered Spectral Radiometer Buoy
Absorption and Beam Attenuation AC-9,
Fast Repetition Rate Fluorometry 0-250 m
VIII. Moored Instruments (documented elsewhere)
Sequencing Sediment Traps 2800, 4000 m
Surface mooring (see WHOTS)
Deep thermistor array mooring (bottom to 200m above bottom)
Start date of the timeseries, service interval: Near-monthly shipboard observations since October 1988
Scientific rationale:
The objectives and scientific rationale for HOT are truly interdisciplinary. We seek to understand the interacting physics, chemistry and biology of the North Pacific subtropical gyre through detailed, long-term, co-located multivariate observations at Station ALOHA, within the context of the variability of the North Pacific climate system and the subtropical gyre ecosystem.
The physical oceanographic objectives of HOT have been to: 1) document seasonal, interannual and decadal variability and longer term trends of water masses; 2) relate water mass variations to subtropical gyre fluctuations; 3) determine the need and methods for monitoring currents at the HOT site; 4) develop a climatology of short term variability.
Chemistry and biology are inextricably linked in the objectives of HOT, framed within the Joint Global Ocean Fluxes Study. Central objectives of the HOT program have been to quantify fluxes and inventories of oceanic carbon pools, estimate the annual air-to-sea flux of carbon dioxide, and develop an understanding of the climatology of biogeochemical rates and processes, including microbial community structure, primary and export production, and nutrient inventories. Understand how the seasonal and interannual variability of water masses relates to biogeochemical fluxes. Understand the time-varying processes that control carbon, nitrogen, and phosphorus cycling in the ocean. Relate biogeochemical fluxes to subtropical gyre fluctuations and local and remote climate forcing of the subtropical gyre. Develop a climatology of short-term variability in chemical, and biological processes in subtropical ocean ecosystems.
After 20 years, we have made significant progress on all of these objectives; however we now know that decadal changes in the physical, biological, and chemical habitat are important in structuring ecosystem variability. The major impediments have been limited spatial and high frequency temporal coverage to help define the frequency and spatial variability of the physical and biogeochemical signals that we’ve observed.
Groups / P.I.s /labs /countries involved / responsible:
Most of the funding for HOT is provided by the US National Science Foundation, with significant contributions from the State of Hawaii. The PIs of the “core” Hawaii Ocean Time-series are David Karl and Roger Lukas of the University of Hawaii. Other PIs include Michael Landry (SIO), Robert Bidigare (UH), R. Letelier (OSU), and J. Dore (U. Montana). In 2009, the project is seeking renewed support to sustain the next 4 years of observations. If successful, the project will be lead by Matthew Church (UH), with R. Lukas, D. Karl and R. Bidigare continuing their respective leadership roles as co-P.I.s. Numerous ancillary projects and investigators take advantage of the core logistics, many of which contribute to the overall objectives of HOT. Ship support is provided by the US NSF through UNOLS.
Status:
operating;An observatory framework has been established at Station ALOHA, including two surface moorings that were deployed at the edges of the 6 nm radius circle that defines the station. These moorings, MOSEAN and WHOTS, are documented separately.
time horizon / long-term plans: Indefinite
funding status, source of funding: A renewal proposal for funding from mid-2009 through 2013 is now being submitted.
Technology:
moored / autonomous and ship-based sensors
near-surface SST: Remote temperature sensor at hull intake 8 m (for Kilo Moana; 3-5 m for typical R/V)
Profile measurements: Ship-based Sea-Bird CTD continuous profiler 0-4780 m.
Data policy: delayed mode data (Hydrographic data and other cruise data) publicly available, see links below
Data management:
data processing and distribution system: As a general rule, we post our CTD data to our web site within one month of each cruise with preliminary quality control, and biogeochemical analyses are quality controlled and publicly available within a year of the time of collection.
Archiving: Archiving is provided by the US National Oceanographic Data Center via P. Caldwell (NODC Liaison, UH)
Satellite data collection system: Ocean color and spectral imaging operated by OSU including use of SEAWIFS, MODIS, AVHRR
Societal value / Users / customers:
The primary societal value of HOT has been to significantly advance our understanding of the interactions between climate and ecosystem dyanmics in the North Pacific subtropical gyre. Moreover, HOT has contributed substantially to our understanding of the role of biology in driving elemental cycling, most specifcially the carbon cycle, in this ecosystem. HOT observations of pCO2 and pH were used in the IPCC AR-4, for example. The HOT program has set an outstanding example for online sharing of observations and derived information. Thousands of users have downloaded our data resulting in hundreds of publications in peer-reviewed literature sources.
Role in the integrated global observing system:
Station ALOHA observations provide a high-quality calibration point for basin-scale maps of salinity (i.e. derived from Argo floats), as well as a suite of other variables, such as carbon inventories and nutrients. The moored observations on-going at ALOHA comprise an air-sea flux reference point (see WHOTS mooring). HOT provides a strong logistical and scientific framework for ocean technology research and development, and serves as an important calibration/validation point for models of biogeochemical-physical interactions.
Contact Person:
for enquiry about addition of instrumentation or sensors to the site or for possible ancillary measurements during cruises to the site: Matthew Church, David M. Karl, and Roger Lukas (UH), hahana.soest.hawaii.edu/hot/crequest/main.html
for information about the site or data : dataman@soest.hawaii.edu
Links / Web-sites:
www.soest.hawaii.edu/HOT_WOCE
hahana.soest.hawaii.edu/hot/hot.html
hahana.soest.hawaii.edu/hot/hale-aloha
picasso.oce.orst.edu/ORSOO/hawaii
www.soest.hawaii.edu/HOT_WOCE/ftp.html (Cruise data)
uop.whoi.edu/projects/WHOTS/whotsdata.htm (WHOTS Buoy data)
http://www.pmel.noaa.gov/co2/moorings/hot/data_158w_all.htm (HALE-ALOHA/MOSEAN CO2 data)
http://www.opl.ucsb.edu/mosean/realtime_hi.html (HALE-ALOHA/MOSEAN Buoy data)
Compiled by: Fernando Santiago-Mandujano and Matthew Church (March 2005; updated January 2009)
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Figure 1:
Salinity variations near Station ALOHA occur over a broad range of time scales.
(a) A near-surface salinity time series combines historical bucket observations at Koko Head, Oahu, with CTD measurements from ALOHA. The light blue line connects observations, while the red line is a smoothing spline.
(b) Smoothed subsurface salinity observations are plotted against potential density, combining available historical hydrographic station data (Curry, 1996; Macdonald et al., 2001) taken within a 200-km radius with annually averaged salinity profiles from HOT. Times of individual
stations are indicated by red tick marks. The long-term average depths of selected isopycnals are indicated along the right-hand axis. The dashed yellow line indicates an apparent decrease in the potential density of neighboring isohalines.
(c) HOT observations at ALOHA are expanded showing details of variability. The thin black line indicates the density of the surface mixed layer.
(d) Time series of salinity averaged over potential density in the region of the salinity maximum and in the mid-thermocline indicate systematic variations over nearly two decades. Black lines connect cruise-averaged data, while red dots are annual averages. The blue lines are smoothing splines.
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(Figure reproduced from Lukas, R., and F. Santiago-Mandujano, 2008: Interannual to Interdecadal Salinity Variations Observed Near Hawaii: Local and Remote Forcing by Surface Freshwater Fluxes. Oceanography, 21, 46-55.
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Figure 2:
Variability in upper ocean pCO2 and pH at Station ALOHA.
(top), Near-surface ocean pCO2 at Station ALOHA (blue symbols) and atmopsheric (wet-air) pCO2 measured at the Mauna Loa Observatory.
(bottom), Near surface ocean seawater pH (green symbols) determined at Station ALOHA. Seawater pH was calculated from inorganic carbon system measurements (DIC and total alkalinity).
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