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Global Ocean Accounts Partnership Technical Guidance

Physical Condition Measurement

Circular ID TG-4.8
Version 6.0
Badge Applied
Status Draft
Last Updated May 2026

Framework position: TG-4.8 sits in the data methods layer. It provides the measurement protocols and variable selection guidance for physical state variables that feed upstream into the ecosystem condition indicators described in TG-2.1 and TG-2.8, and from there into asset accounts compiled under TG-3.1. Users compiling condition accounts should read this Circular alongside TG-4.9 Biological Condition Measurement, which covers the biotic counterpart to the abiotic variables described here.

1. Outcome

1This Circular provides guidance on measuring the physical condition of ocean and coastal ecosystems for use in SEEA EA ecosystem condition accounts. On completing this Circular, users will be able to select appropriate physical state variables, establish reference conditions, rescale variables to dimensionless condition indicators on a 0—1 scale, and integrate physical condition data into the asset account structure defined in TG-3.1 Asset Accounts.

2Physical condition measurement addresses the abiotic subset of ecosystem condition (temperature, salinity, dissolved oxygen, pH, turbidity, nutrients, and light attenuation), corresponding to ECT Classes A and B as defined in SEEA EA Table 5.1. This Circular does not cover biological condition variables (covered by TG-4.9) or the compilation of condition account tables (covered by TG-3.1).

2. Requirements

1Users should be familiar with the following circulars before working through this guidance:

3. Guidance Material

3.1 Conceptual Framework

1Physical condition measurement is anchored in SEEA EA Chapter 5, which establishes the Ecosystem Condition Typology (ECT), the concept of reference condition, and the rescaling of state variables to dimensionless condition indicators on a 0—1 scale. Physical condition captures the abiotic state of the ocean environment, corresponding to two ECT classes defined in SEEA EA Table 5.1:

  • 2ECT Class A — Physical and chemical characteristics: variables describing the thermal, chemical, and optical properties of the water column (temperature, salinity, pH, dissolved oxygen, turbidity).
  • 3ECT Class B — Hydrological and hydrochemical characteristics: variables describing water circulation, stratification, nutrient dynamics, and light penetration relevant to ecosystem functioning.

4Physical condition is distinct from biological condition (TG-4.9 Biological Condition Measurement): physical variables measure the abiotic habitat envelope within which organisms live, whilst biological variables capture the biotic response of living organisms to that environment. Both are components of ecosystem condition as defined by SEEA EA Chapter 5 and both feed into asset accounts (TG-3.1 Asset Accounts).

5Reference condition is the baseline against which current state is compared. SEEA EA paras 5.65—5.75 and Appendix A5.2 establish four approaches, and this framework is canonical for both physical and biological condition accounts (TG-4.9 cross-refers here).

ApproachDescription
Historical / pre-impact baselineEarliest available consistent dataset for the accounting unit (national monitoring series, paleoecological records, legacy survey data).
Pristine or least-disturbed reference siteMinimally impacted contemporary site of equivalent ecosystem type, biogeographic region, and depth range.
Modelled natural stateModel-derived estimate calibrated on undisturbed sites; used where empirical references are unavailable.
Regulatory or management targetPolicy-defined value (e.g., MPA recovery target, CBD Kunming-Montreal GBF Target 3); least preferred, flag explicitly.

6Fixed reference condition for time-series accounts. For time-series accounting, the reference condition value for each indicator must be fixed at the start of the series and held constant across all subsequent periods. Revisions are permitted only at a formally documented major methodological review and require complete re-compilation of the historical series from the new baseline. Document the reference-condition vintage (year established) in account metadata. New accounting units introduced mid-series establish their own baseline at first measurement, and are flagged as a new series start.

7Ecosystem-specific physical priorities vary by habitat type:

Habitat typeKey physical condition variablesNotes
Coral reefSST anomaly, pH/Ωaragonite, turbidityThermal bleaching and acidification are primary stressors; see §3.2 for coral-specific SST rescaling
Seagrass and saltmarshWater clarity (Kd490), dissolved inorganic nutrients, salinityLight availability governs productivity
MangroveSalinity, turbidity, tidal inundation frequencySalinity tolerance range defines condition envelope
Open ocean / pelagicSST, dissolved oxygen, mixed layer depthOxygen minimum zone expansion is a key condition trend; see §3.2 for MLD guidance

8For detailed habitat-specific guidance, see TG-6.1 Coral Reef Ecosystem Accounting, TG-6.2 Mangrove and Coastal Wetland Accounting, TG-6.3 Seagrass Ecosystem Accounting, and TG-6.5 Pelagic and Open Ocean Accounting.

3.2 Indicator Selection

1Indicators are selected according to four criteria set out in SEEA EA paras 5.22—5.27. Table 3.2.1 below summarises these criteria.

CriterionDescription
MeasurabilityThe variable can be quantified with available technology at the required spatial and temporal resolution.
Ecological relevanceIt reflects a key aspect of ecosystem functioning or integrity for the habitat type in question.
Sensitivity to changeIt responds detectably to the pressures of concern within the accounting period.
Data availabilityConsistent national or regional time series exist or can be established within the capacity of the compiling agency.

2Recommended physical condition indicators by ECT class

3ECT Class A — Physical and chemical characteristics

  • 4Sea Surface Temperature (SST): primary indicator of thermal stress and climate forcing. Unit: °C. Reference condition: long-term climatological mean (e.g., 1985—2014 NOAA OISST baseline). Where the full 1985—2014 period is unavailable nationally, use the longest consistent national record as the reference baseline, document the period explicitly in metadata, and note the departure from the global standard baseline. Rescaling: temperature anomaly relative to baseline. The condition indicator decreases as anomaly increases above the reference variability range. For coral reef accounting units: threshold-based rescaling using the Maximum Monthly Mean (MMM) climatology is the preferred approach. When sea surface temperature exceeds the MMM, Degree Heating Weeks (DHW) begin to accumulate, and DHW ≥ 8°C-weeks corresponds to significant bleaching risk. The MMM/DHW method is the global operational standard for bleaching heat-stress monitoring. NOAA Coral Reef Watch provides ready-to-use global 5-km DHW and MMM products.1 The same indices can equally be derived from Copernicus Marine Service (CMEMS) or ESA Climate Change Initiative (CCI) SST inputs where an alternative provider is preferred.
  • 5Salinity: indicator for estuarine and coastal boundary zones. Unit: practical salinity units (PSU). Reference condition: long-term climatological mean from WOA or ARGO programme for the accounting unit.
  • 6Ocean pH / aragonite saturation (Ω): indicator of ocean acidification state. Unit: pH units (dimensionless Ω). Reference condition: pre-industrial pH (~8.18) or a regional multi-decadal baseline from SOCAT/GLODAP. Condition indicator decreases as pH declines or Ω falls below the aragonite saturation threshold (Ω = 1), below which shell-forming organisms cannot maintain calcified structures.
  • 7Dissolved oxygen (DO): indicator of habitat viability and eutrophication stress. Unit: mg/L or % saturation. Hypoxia threshold: <2 mg/L (below which most marine fauna cannot persist). Reference condition: site-specific or regional historical baseline.

8ECT Class B — Hydrological and hydrochemical characteristics

  • 9Water clarity / light attenuation (Kd490): relevant for seagrass and coral light requirements. Unit: m⁻¹. Reference condition: site-specific long-term mean from satellite ocean colour products. Condition indicator decreases as Kd490 increases beyond the reference level (higher attenuation = reduced light penetration = poorer condition).
  • 10Dissolved inorganic nutrients (NO₃, PO₄): eutrophication indicators for coastal zones. Unit: μmol/L. Reference condition: oligotrophic background level for the relevant ocean region. Condition indicator decreases as nutrient concentrations exceed reference levels.
  • 11Mixed layer depth (MLD): indicator of ocean stratification and vertical mixing, relevant for pelagic and open-ocean accounting units. Unit: metres. Reference condition: long-term climatological mean MLD from ARGO programme or CMEMS reanalysis. Shoaling of MLD beyond the climatological range indicates increased stratification, which constrains nutrient upwelling and affects productivity. Condition indicator decreases as MLD shoals beyond the climatological reference range. Source: ARGO programme density profiles; CMEMS physical reanalysis products. See TG-6.5 Pelagic and Open Ocean Accounting for guidance on MLD in pelagic condition accounts.

12Tiered indicator selection approach

13Indicator selection follows a three-tier framework based on data availability. The tiering draws on the graduated capacity framework described in TG-0.7 Quality Assurance Principles. Table 3.2.2 below summarises the three tiers.

TierDescription
Tier 1Variables with nationally monitored, consistent time series of at least 10 years. These are the preferred source for condition trend assessment. In-situ networks and national survey programmes are the primary data source.
Tier 2Variables derived from model output or regional satellite products where in-situ series are absent or incomplete. The CMEMS Physical Analysis and Forecast System and satellite-derived ocean colour composites are typical Tier 2 sources. Trend assessment requires the full 1993—present satellite altimetry era where possible.
Tier 3Data-poor contexts where global reanalysis climatologies (WOA 5-year periods, ERA5-ocean) provide the only available series. Tier 3 variables carry the highest uncertainty and should be flagged as such in condition account metadata.

14Rescaling and aggregation pathway

15The transition from raw measurement to reported condition indicator follows three steps, consistent with SEEA EA paras 5.44—5.58. Figure 4.8.1 traces the pathway from a raw ECT Class A or B variable, through quality control and benchmarking against the reference condition, to a rescaled and aggregated SEEA EA Table 5.2 condition account row. Table 3.2.3 below summarises these steps.

TG-4.8 -- Physical condition indicator construction pathway The physical condition measurement pathway runs left-to-right. A raw Ecosystem Condition Typology (ECT) Class A or B variable is combined with a reference condition drawn from one of four approaches -- historical benchmark, reference site, modelled potential, or a regulatory / management target (flagged least preferred) -- at a fan-in junction. The combined signal is rescaled to a unitless 0--1 condition index, then aggregated across indicators, and the result is entered as a row in the SEEA EA Table 5.2 ecosystem condition account. Nodes are coloured by data role: raw input (cyan/secondary), compilation or transformation step (emerald/process), and account output (teal/anchor). Condition indicator construction pathway Reference condition (choose one approach) Historical Pre-disturbance benchmark value Reference site Least-disturbed analogous site Modelled Simulated potential condition estimate Regulatory target Policy-defined (MPA recovery, GBF Target 3) least preferred Raw ECT variable Class A or B indicator from monitoring data Quality check IOC-UNESCO/IODE QA/QC screen Rescale to 0--1 index Dimensionless condition score vs reference Aggregate Weighted mean across ECT characteristic groups SEEA EA Table 5.2 row Condition account entry for reporting input passed index score reference (V_ref) Raw input Quality gate Compilation / transformation Account output (SEEA EA)

Figure 4.8.1 Pathway from an ECT Class A or B variable through quality check, reference benchmarking, rescaling, and aggregation to a SEEA EA Table 5.2 row. Four reference-condition approaches; regulatory or management target is least preferred. Source: TG-4.8, §3.1--3.5 (conceptual framework, indicator selection, measurement & integration); ECT Class A/B structure per SEEA EA 2024 Table 5.1; reference-condition approaches per SEEA EA 2024 §§5.65--5.75 and Appendix A5.2.

StepDescription
Raw variable normalisationStandardise units, apply quality flags, and aggregate to the spatial and temporal resolution of the accounting unit.
Rescaling to 0—1 condition indicatorApply the rescaling function (see §3.5 for the explicit formula) to map the variable onto the 0—1 condition scale relative to the reference condition.
ECT-class and composite indicesAggregate individual condition indicators within each ECT class to produce class-level and whole-ecosystem condition indices, following the weighting approach documented by the compiling agency. Cross-reference TG-2.1 Aggregate Biophysical Indicators of Environmental State for indicator aggregation methods.

3.3 Measurement Protocols

1In-situ measurement

2CTD (conductivity-temperature-depth) casts provide vertical profiles of temperature, salinity, and (where equipped) dissolved oxygen and fluorescence. Moored buoys record continuous surface and sub-surface time series. ARGO profiling floats provide open-ocean profiles to 2,000 m depth with near-real-time transmission. Repeat hydrography programmes (WOCE/GO-SHIP sections) supply basin-scale reference data for calibration.

3For coastal and estuarine zones, national tide gauge networks, fixed moored sensors, and periodic survey cruises provide the primary in-situ data. Water sampling for nutrient and pH analysis should follow IOC-UNESCO/IODE standard operating procedures, including certified reference materials for pH (NOAA-distributed CRMs) and oxygen (Winkler titration).

4Remote sensing

5Satellite-derived SST (MODIS Aqua, AVHRR, Sentinel-3 SLSTR) provides daily global coverage with approximately 1 km spatial resolution. Ocean colour products (MODIS Aqua, SeaWiFS, Sentinel-3 OLCI) deliver Kd490 and turbidity estimates at 300 m — 4 km resolution. Gap-filling via optimal interpolation (OI) is standard for SST products (NOAA OISST, CMEMS, GHRSST Level 4). See TG-4.1 Remote Sensing and Geospatial Data for sensor selection and pre-processing protocols.

6Tiered minimum time requirements

7Table 3.3.1 below summarises the minimum time-coverage requirements for each tier.

TierMinimum time requirement
Tier 1A minimum of 10 years of consistent observations is required for trend-reliable condition assessment; longer series should be used where available to capture multi-decadal variability.
Tier 2Satellite-era products should span the full 1993—present period where possible; where national capacity limits coverage, use the longest available continuous record and document the gap in metadata.
Tier 3WOA 5-year climatological periods are the minimum standard. The WOA 2018 edition (Boyer et al. 2018)2 is the current default; report the specific WOA edition and climatological period used in all metadata.

8Abiotic SOP references

9The standards listed in Table 3.3.2 are the canonical SOPs for the abiotic variables enumerated in Section 3.2. Compiling agencies should record the cited standard (and its version/year) in metadata for each variable per TG-0.7 Quality Assurance Principles. Documented departures from the SOP (sampling depth, replication, gear substitution) should be recorded alongside the measurement. Satellite-derived alternatives are listed in the remote-sensing subsection above and in Table 3.4.

VariableMeasurement / sample typeStandard protocolSource
Temperature, salinity (profile)CTD cast, WOCE/GO-SHIP-compatible QAGO-SHIP repeat-hydrography protocol; IOC-UNESCO/IODE Manuals & Guides 5434go-ship.org
Dissolved oxygen (discrete)Winkler titration on bottle samplesIOC-UNESCO/IODE Manual; ISO 5813 / ISO 58145IOC-UNESCO; ISO
Dissolved oxygen (in-situ profile)Calibrated optode on CTD or BGC-ArgoBGC-Argo Quality Control Manual6Argo Data Management Team
pH / pCO₂ / aragonite saturationDiscrete bottle samples; CRM-referenced spectrophotometric pHDickson et al. (2007) Guide to Best Practices for Ocean CO₂ Measurements; SOCAT and GLODAP submission protocols7PICES Special Publication 3
Nutrients (NO₃, PO₄, SiO₄)Auto-analyser on filtered water samplesGO-SHIP nutrient protocol; ISO 13395 (nitrate); ISO 6878 (phosphate)48IOC/GO-SHIP; ISO
Turbidity / Kd490 (in-situ)Secchi depth; PAR profilerIOC-UNESCO ocean optics protocols (Mueller & Fargion 2003)9NASA Ocean Optics Protocol Revisions
Sediment grain size, organic carbonSediment grab/core; sieving and loss-on-ignition or elemental analyserISO 16665 (marine benthos sampling); ISO 11464 (sample pretreatment)10ISO

10Quality control and data-poor contexts

11Apply IOC-UNESCO/IODE QA procedures (anomaly flagging, measurement precision, gap-filling documentation) within the TG-0.7 framework. All stations georeferenced to WGS84. Annual composites are the minimum for accounts. Where national in-situ programmes are limited, global reanalysis (CMEMS, ERA5-ocean, WOA) is a viable Tier 3 alternative. Document source, version, and known biases, especially in shallow coastal and enclosed seas. Supplement with TG-4.4 Citizen Science data where coverage is sparse.

3.4 Data Requirements and Sources

1The following matrix specifies the minimum data requirements for each recommended physical condition indicator:

VariableUnitPrimary SourceUpdate Frequency (accounts: annual composite recommended)Data-Poor Alternative
Sea Surface Temperature°CNOAA OISST / CMEMS SSTDaily source; monthly composites; annual mean for accountsHadISST reanalysis (monthly, 1°×1°)
SalinityPSUARGO programme / national CTD surveysMonthly profiles; annual climatology for accountsWorld Ocean Atlas (5-year climatology)
Dissolved Oxygenmg/LARGO BGC floats / moored sensorsNear-real-time profiles; annual composite for accountsWorld Ocean Database reanalysis fields
pH / ΩaragonitepH / dimensionlessSOCAT, GLODAP, ARGO BGCSOCAT/GLODAP: annual update; ARGO BGC: near-real-time; annual composite for accountsCMEMS biogeochemical analysis and forecast
Water clarity (Kd490)m⁻¹MODIS Aqua / Sentinel-3 OLCIMonthly composites; annual mean for accountsCMEMS ocean colour multi-observation product
Dissolved inorganic nutrientsμmol/LNational marine surveys / ICES Data CentreAnnual survey; near-real-time for some ICES regions; annual composite for accountsWorld Ocean Atlas (5-year climatology)
Mixed layer depthmARGO programme density profiles / CMEMS physical reanalysisMonthly profiles; annual mean for accountsCMEMS global ocean reanalysis (GLORYS12)

2Key institutional data sources: Copernicus Marine Service (CMEMS), NOAA CoastWatch, NOAA Coral Reef Watch, IMOS (Australia), ICES Data Centre, IOC-UNESCO IODE, national oceanographic institutes, national meteorological services, Argo Data Assembly Centres (GDAC).

3Known data limitations:

  • 4Sparse in-situ coverage in developing-country EEZs creates reliance on Tier 2—3 products with higher uncertainty.
  • 5Satellite retrievals are degraded by cloud cover, sun glint, river plumes, and coastal adjacency effects within approximately 1 km of the shoreline.
  • 6Reanalysis products may not resolve sub-mesoscale processes in enclosed seas, shallow bays, or areas of strong tidal forcing.
  • 7BGC-ARGO pH and oxygen profiles are sparse in coastal and shelf regions, whilst WOD/GLODAP cover is more complete in the open ocean.
  • 8MLD estimates from density profiles are sensitive to the threshold criterion applied (density or temperature criterion), and the criterion used must be documented for reproducibility.

9Compiling agencies should document data source, product version, spatial resolution, and temporal coverage for every variable in the condition account metadata. See TG-4.6 Data Harmonisation and Interoperability for guidance on integrating data from multiple sources.

3.5 Reporting and Integration

1Reporting format

2Physical condition indicators feed directly into the ecosystem condition account (TG-3.1 Asset Accounts) as rows in the SEEA EA Table 5.2 format, with the following fields for each variable: ECT class, variable name, unit of measurement, reference condition value, current condition value, and rescaled condition indicator (0—1 scale).

3Rescaling formula

4For variables where higher values indicate better condition (e.g., dissolved oxygen, aragonite saturation):

CI = (V — V_min) / (V_ref — V_min)

5For variables where lower values indicate better condition (e.g., temperature anomaly, nutrient loading, turbidity):

CI = 1 — [(V — V_min) / (V_max — V_min)]

6Where:

  • 7CI = condition indicator (0—1 scale; 1 = at or above reference condition; 0 = fully degraded or absent)
  • 8V = observed variable value for the accounting period
  • 9V_ref = reference condition value (the value of the variable under the chosen reference condition)
  • 10V_min = minimum observed value or ecologically meaningful lower bound (e.g., 0 mg/L for dissolved oxygen; Ωaragonite = 0; pH = 7.75). Examples by variable: dissolved oxygen V_min = 0 mg/L; Ωaragonite V_min = 0; pH V_min = 7.75; temperature anomaly V_min = 0. Compiling agencies must document the V_min and V_max values applied for each variable in condition account metadata.
  • 11V_max = maximum observed value or ecologically meaningful upper bound (used in negative-condition formula only)

12For binary threshold indicators (e.g., DO hypoxia): CI = 1 if V ≥ threshold (2 mg/L), and CI = 0 if V < threshold (step rescaling). Figure 4.8.2 works a numerical example of these formulas: continuous-variable rescaling (an SST anomaly on a coral reef unit), threshold (step) rescaling (dissolved oxygen about the hypoxia threshold), and weighted aggregation into an ECT Class A condition index recorded as populated SEEA EA Table 5.2 rows.

TG-4.8 -- Worked example: from raw variable to condition account row A three-part worked example. Panel A (continuous-variable rescaling) carries a sea surface temperature anomaly for a coral-reef accounting unit through the SEEA EA negative-condition formula: an observed annual mean of 30.2 degrees Celsius against a maximum-monthly-mean reference of 29.0 gives a +1.2 anomaly, which with bounds V_min 0 and V_max +2.0 rescales to a condition indicator of 0.40 on the 0--1 scale. Panel B (threshold rescaling) shows the binary step rule for dissolved-oxygen hypoxia: condition equals 1 when oxygen is at or above the 2 milligrams-per-litre threshold and 0 when below, illustrated by an oxygenated case of 5.4 and a hypoxic case of 1.3. Panel C (aggregation and reporting) combines three ECT Class A indicators by weighted mean to a class condition index of 0.63 and records the variables as populated SEEA EA Table 5.2 condition-account rows. Worked example: from raw variable to condition account row A. Continuous-variable rescaling What it represents: turning one raw measurement into a dimensionless 0--1 condition score against a reference. Worked variable: sea surface temperature, coral-reef unit. Inputs Observed SST = 30.2 °C Reference (MMM) = 29.0 °C → anomaly V = +1.2 °C V_min = 0 °C (at MMM) V_max = +2.0 °C (reef-collapse) Rescale -- negative-condition form (§3.5) CI = 1 - (V - V_min) / (V_max - V_min) = 1 - (1.2 - 0) / (2.0 - 0) = 1 - 0.60 Lower SST is better → negative form. Condition indicator (CI) CI = 0.40 0 1 0--1 condition scale B. Threshold (step) rescaling What it represents: pass/fail variables that score 1 above an ecological threshold and 0 below it. Worked variable: dissolved oxygen, hypoxia. Rule -- step rescaling (§3.5) CI = 1 if DO ≥ 2 mg/L CI = 0 if DO < 2 mg/L Case 1 -- oxygenated DO = 5.4 mg/L 5.4 ≥ 2 → CI = 1.00 Case 2 -- hypoxic DO = 1.3 mg/L 1.3 < 2 → CI = 0.00 C. Aggregation & reporting What it represents: combining individual indicator scores into an ECT-class index, then recording them as rows of the SEEA EA condition account. Aggregate ECT Class A (weighted mean) SST anomaly CI 0.40 w 0.40 pH / arag. CI 0.72 w 0.30 turbidity CI 0.85 w 0.30 Class A condition index = 0.63 = 0.40×0.40 + 0.72×0.30 + 0.85×0.30 SEEA EA Table 5.2 -- ECT Class A condition rows Variable Unit V_ref Current CI Sea surface temperature °C 29.0 30.2 0.40 Dissolved oxygen mg/L ≥ 2 5.4 1.00 ECT Class A index 0.63 Reference baselines and ecological thresholds follow published literature (see caption). Observed values, and the pH and turbidity scores in Panel C, are illustrative. Raw input Compilation / transformation Threshold rule Below threshold Account output (SEEA EA)

Figure 4.8.2 Three panels show continuous rescaling, threshold rescaling, and weighted aggregation into an ECT Class A condition index. Panels A--C; scores feed SEEA EA Table 5.2. Observed values and weights are illustrative. Source: TG-4.8 §3.5 (rescaling, bounds, binary threshold, weighted aggregation); SEEA EA 2024 §§5.44--5.58 and Table 5.2. Baselines: Liu et al. 2014 (MMM/DHW); IPCC 2018 / Frieler et al. 2013 (+2°C); Diaz & Rosenberg 2008 / Vaquer-Sunyer & Duarte 2008 (2 mg/L hypoxia).

13Where current condition exceeds the reference baseline (CI > 1 in the positive-condition formula), CI is reported as 1.0 in the condition account table and the raw calculated value is recorded in the accompanying metadata. A CI above 1 can arise where recent conservation gains have improved condition above the historical reference.

14Integration with biological condition

15Physical variables establish the abiotic habitat envelope for TG-4.9 indicators. Joint reporting of SST, DO, turbidity, and pH enables attribution analysis (e.g., distinguishing thermal stress from direct anthropogenic impact).

16Uncertainty reporting

17Each indicator requires measurement-uncertainty, representativeness, and model-uncertainty components, plus the data tier (1—3) and gap-filling method. Metadata documentation follows TG-0.7.

4. Acknowledgements

1This Circular has been approved for public circulation and comment by the GOAP Technical Experts Group.

2Authors: [To be confirmed]

3Reviewers: [To be confirmed]

Footnotes

  1. 1

    NOAA Coral Reef Watch (2024). NOAA Coral Reef Watch Version 3.1 Daily Global 5-km Satellite Coral Bleaching Heat Stress Monitoring. NOAA/NESDIS/STAR Coral Reef Watch program. https://coralreefwatch.noaa.gov ↩

  2. 2

    Boyer, T.P. et al. (2018). World Ocean Atlas 2018. NOAA Atlas NESDIS 87. Washington, DC: NOAA. ↩

  3. 3

    IOC-UNESCO/IODE (2010). Ocean Data Standards, Volume 1: Recommendation for a Quality Flag Scheme for the Exchange of Oceanographic and Marine Meteorological Data. IOC Manuals and Guides No. 54, Vol. 1. Paris: UNESCO. ↩

  4. 4

    GO-SHIP (Hood, E.M., Sabine, C.L., Sloyan, B.M., eds., 2010). The GO-SHIP Repeat Hydrography Manual: A Collection of Expert Reports and Guidelines. IOCCP Report 14, ICPO Publication Series 134. https://repository.oceanbestpractices.org/handle/11329/377 ↩ ↩2

  5. 5

    ISO 5813:1983 Water quality — Determination of dissolved oxygen — Iodometric method; ISO 5814:2012 Water quality — Determination of dissolved oxygen — Electrochemical probe method. Geneva: International Organization for Standardization. ↩

  6. 6

    Thierry, V., Bittig, H., and the BGC-Argo team (2021). Argo Quality Control Manual for Dissolved Oxygen Concentration, version 2.1. Argo Data Management. https://doi.org/10.13155/46542 ↩

  7. 7

    Dickson, A.G., Sabine, C.L., Christian, J.R. (eds., 2007). Guide to Best Practices for Ocean CO₂ Measurements. PICES Special Publication 3, IOCCP Report 8. Sidney: North Pacific Marine Science Organization. SOCAT and GLODAP data-submission protocols at https://www.socat.info and https://www.glodap.info. ↩

  8. 8

    ISO 13395:1996 Water quality — Determination of nitrite nitrogen and nitrate nitrogen and the sum of both by flow analysis (CFA and FIA) and spectrometric detection; ISO 6878:2004 Water quality — Determination of phosphorus — Ammonium molybdate spectrometric method. Geneva: ISO. ↩

  9. 9

    Mueller, J.L. and Fargion, G.S. (eds., 2003). Ocean Optics Protocols for Satellite Ocean Color Sensor Validation, Revision 4. NASA/TM-2003-211621. Greenbelt, MD: NASA Goddard Space Flight Center. ↩

  10. 10

    ISO 16665:2014 Water quality — Guidelines for quantitative sampling and sample processing of marine soft-bottom macrofauna; ISO 11464:2006 Soil quality — Pretreatment of samples for physico-chemical analysis. Geneva: ISO. ↩

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