Back to opportunities | Category Index
These are the intended use-case/justification for one or multiple variable groups. Opportunities are linked to relevant experiment groups. Identifying opportunities helps to provide a structure to map variables against requirements. Each opportunity description will convey why this combination of variables and experiments is important and how they contribute to impact.
| Attribute | Value |
|---|---|
| description | The ocean is a key component of the climate system, storing 90% of the excess energy trapped in the earth system and absorbing about 25% of the CO2 emitted by human activities. Large-scale ocean circulation systems transport heat across latitudes, basins, and depths. Consequently, changes in the ocean circulation, heat content, and its capacity to store CO2 impact the atmospheric and land warming. Physical ocean changes, especially warming and salinification/freshening, drive sea level rise and impact ocean ecosystems. It is essential to understand changes in ocean properties and circulations, and to evaluate rigorously the budgets of heat and salt. Of special interest are a few key processes.is the The Meridional Ocean Circulation (MOC) is one, because its rate of decrease in the future climate is highly uncertain and a complete shutdown of the Atlantic MOC would have huge consequences on climate worldwide. The ocean mixed layer depth (MLD) is another, because it is the conduit for communication between the ocean and atmosphere. Properties of the polar oceans are another, because these regions are part of the Polar Amplification processes where the climate change signal is strongest. Key roles for the oceans in the global climate system are acting as a reservoir for the carbon and energy budgets. Tropical variability, such as ENSO, is a dominant process in determining ensemble spread and internal variability in energy budgets as well as dominant patterns of air-sea exchanges. Changes to other ocean transports can also be important (e.g., gyres, boundary currents, interbasin exchanges), which should be compared in effect to changes to the stratification and regional properties of the oceans (e.g., temperature and salinity). Finally, thermosteric and halosteric sea level are key components of total sea level, and often set the regional patterns of variability. |
| expected_impacts | The understanding of the mechanisms driving ocean changes is key for climate projections. For example, how does the strength of the Antarctic Circumpolar current relate to the absorption of CO2 in the Southern Ocean; how do the heat exchanges between the North Atlantic and the Arctic impact sea-ice and land-ice melt and the stability of ice shelves; how does the ocean stratification in eastern boundary upwelling systems evolve and affect the vertical transport of nutrients that feed this rich ecosystems; what is the status of ocean sinks; etc. A better understanding of these mechanisms is key to project future sea-ice, regional sea level rise, atmosphere-ocean interaction, ocean biogeochemistry and sea life. |
| justification_of_resources | Understanding changes in the ocean is critical for understanding their impacts. This goes beyond assessing the energy and salinity budget at the global scale: variables are needed over the full depth of the ocean to understand the links between circulation and water mass properties: transports of key ocean currents; individual components of meridional fluxes, due to resolved velocities as well as parameterized processes; thermohaline circulation; heat transports to help understand how the ocean redistributes heat and its impact; transports of salt to understand the impact of the global water mass cycle on the salinity distribution. Higher resolution ocean models that allow the development of mesoscale dynamics will improve our understanding of ocean variability and provide more realistic assessments of uncertainties in the heat and salt budgets. The ocean model intercomparisons and related papers are relevant both to assessment reports and model development. In this case, the collection of compatible variables in CMIP runs as in forced runs provides opportunities for a broad perspective on these models. These are the fundamental comparison variables for ocean model intercomparison. As OMIP is not part of the Fast Track, it is critical that these variables be retained in key Fast Track experiments. |
| lead_theme | Ocean & Sea-Ice |
| minimum_ensemble_size | 1 |
| name | Ocean Changes, Drivers and Impacts |
| opportunity_id | 47 |
| data_request_themes | Impacts & Adaptation, Atmosphere, Ocean & Sea-Ice, Earth System |
| experiment_groups | scenarios_extensions, deck, fast-track, scenarios, historical |
| mips | DCPP, PMIP, DAMIP |
| time_subsets | 80ac3156-a698-11ef-914a-613c0433d878 |
| variable_groups | int_ocean_budgets, ocean_grid_low_priority, baseline_fixed, baseline_monthly, ocean_grid ... and 13 moreint_ocean_budgets, ocean_grid_low_priority, baseline_fixed, baseline_monthly, ocean_grid, ocean_meridional_overturning_streamfunctions, ocean_mesoscale, omip_budgets, omip_momentum_fluxes_high_priority, omip_parameterizations, omip_scalars_high_priority, omip_scalars_low_priority, omip_surface_fluxes_high_priority, omip_surface_fluxes_medium_priority, omip_transports_high_priority, omip_transports_low_priority, omip_transports_medium_priority, omip_vectors_high_priority |