by Dr M. Wielicki, May 24, 2023 in ClimateChangeDispatch

First, do we really know the temperature and thus heat content of the ocean?

The ocean is vast and covers ~70% of the Earth’s surface, making it the largest system on the planet. Despite its size, only a small portion of the ocean has been explored and mapped in detail.

It is estimated that <20% of the world’s oceans have been mapped and explored to date. [emphasis, links added]

This is largely due to the difficulties and challenges associated with ocean exploration, such as the high pressure and extreme environments found in the deep ocean, as well as the high cost of research vessels, equipment, and technology.

Most of the ocean that has been explored in detail is located near the coasts or in shallow waters, where it is more accessible to research vessels and equipment, but usually far away from the heat sources of mid-ocean ridges.

The deep ocean, which makes up the majority of the ocean’s volume, remains largely unexplored, with less than 5% of the ocean floor having been mapped in high resolution.

Advances in technology, such as underwater drones and submersibles, are helping to improve our understanding of the ocean and its ecosystems, and it is likely that our knowledge of the ocean will continue to expand in the coming decades.

Temperature measurements in the ocean are typically taken using a variety of instruments. These instruments can be deployed from research vessels or from moored or drifting buoys, and they collect temperature data at different depths throughout the ocean.

The amount of the ocean that is measured for temperature varies depending on the method of measurement and the specific objectives of the research.

However, it is estimated that significantly less than 10% of the world’s oceans have been sampled for temperatures at depths greater than 2,000 meters.

Despite the relatively limited coverage of temperature measurements in the deep ocean, there are ongoing efforts to improve our understanding of the ocean’s temperature structure and variability.

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