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Marine & coastal Multi-level ocean projections

Projections of future changes in sub-surface marine variables around the UK, are available as maps, and the underlying data from the UKCP09 User Interface (external website). They provide:

  • Projections of changes (and future absolute climate) in water temperature, salinity, the stability of the water column, and currents.
  • For 34 depth levels (from water surface to sea bed) available from the Multi-level ocean data from the LINK website on registration, and only 2 levels available on the UKCP09 User Interface.
  • For 12 km marine grid squares.
  • For the 30-year time period of 2070–2099. It is also possible to produce maps for the baseline period of 1961–1990.
  • For the UKCP09 medium emissions scenario (IPCC SRES: A1B).

Details of the preparation of the multi-level ocean projections are provided in Chapter 6 of the Marine & coastal projections report.

They are the first national marine climate change scenarios. The shelf seas model has been found to validate well.

  • What should I use them for?

  • To explore spatial and temporal variation in the variables of interest.

The multi-level ocean projections can be mapped in the UKCP09 User Interface.  This permits the exploration of spatial and temporal variation in the variables of interest.

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  • Benefits

  • They are the first national marine climate change scenarios

It is the first time that potential implications of climate change on the marine environment has been reported in such detail and as part of UK climate change scenarios.

  • The shelf seas model has been found to validate well

The POLCOMS shelf sea model has been used operationally by the UK Met Office since 2002, and has been validated with observations from marine weather stations ( Met Office validation page on the Met Office website) and the ICES database (external website). See Chapter 6 of the Marine & coastal projections report for more information on model validation.

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  • Main assumptions

  • That meteorological outputs from the regional climate model can be used to drive a shelf seas model

The multi-level ocean projections are based on the assumption that future changes in driving climate variables can be simulated with sufficient reliability that they make useful inputs into the POLCOMS shelf-seas model.

This is particularly significant with regard to future changes in wind and storminess, which are an important and necessary input to simulate future sub-surface marine conditions, but in which we have relatively low confidence.

Details of further assumptions and choices made in the preparation of the multi-level ocean projections are provided in Chapter 6 of the Marine & coastal projections report.

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  • What to be aware of

  • They are based on a single model run

Unlike some other components of UKCP09, the multi-level ocean projections are provided based on a single simulation. No attempt has been made to quantify the range of future changes meaning that no statements can be made about a range of uncertainty.

  • Results from other climate models are not incorporated

Unlike some other components of UKCP09, the results of other driving climate models (such as from the IPCC AR4) are not considered. This is because most other global climate models do not have the necessary spatial and temporal detail to drive the POLCOMS Atlantic Margin application model.

  • They only provide projections for one future time period

UKCP09 multi-level ocean projections are only provided for the 2070 to 2099 time period, meaning that consideration of the evolution of changes through time is not possible.

  • They only provide projections for one emissions scenario

The UKCP09 multi-level ocean projections are only provided for the medium (IPCC SRES: A1B) emissions scenario, meaning that the uncertainties associated with future emissions is not addressed.

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