Archives par mot-clé : Ocean Heat

Where Does Ocean Heat Come From?

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.

Pre-1970s ‘Global’ Sea Surface Temp Measurements Are No More Reliable Or Accurate Than Guessing

by K. Richard, Sept 8, 2022 in NoTricksZone

The accuracy of the long-term global instrumental temperature record – especially the data obtained before the 1970s – wholly rests on the assumption that sailors obtained precisely reliable temperature measurements as they pulled wooden or canvas buckets out of the water from ships at random depths, locations, and times of day. They didn’t.

It has long been known that pulling a bucket out of the water from a ship is rooted in serious error, rendering the sea surface temperature (SST) data obtained nearly useless. Ashford (1948) summarized some of the more salient reliability problems with this method of measurement.

• The initial temperature of the bucket is generally different from that of the sea.

• The water in the bucket may change its temperature before the reading is taken owing to the processes of heat exchange and evaporation.

• The initial temperature of the thermometer is generally different from that of the sample.

• The thermometer is liable to scale errors.

• Owing to thermal lag, the thermometer may take an appreciable time to indicate the true temperature of the sample.

• If the thermometer is removed from the bucket when taking the reading, it may no longer indicate the true water temperature.

• The temperature may be read incorrectly.

Number Of Global Wild Fires Trending Down Since 2003. Northern Ocean Heat Content Drops Since 2010

In his latest video the veteran geologist looks at wild fires worldwide and the CO2 they emit. He reports that both have been decreasing.

Citing the results of the European Copernicus satellite atmosphere monitoring service (CAMS), total wildfires globally have fallen steadily, along with their corresponding CO2 emissions:

New Study Effectively Eliminates Confidence In Human Attribution For Modern Global Warming

by K. Richard, Nov 5, 2020 in NoTricksZone

The forcing uncertainties and lack of observational measurements in the top-to-bottom global ocean preclude an assessment that modern warmth is due to anthropogenic activities.

Key points from a new paper (Gebbie, 2021):

• 93% of the changes to the Earth’s energy budget, manifested as warming of the Earth system, are expressed in the global ocean. Just 1% of global warming is atmospheric.

• Even with the advent of “quasi-global” temperature sampling of the ocean since 2005 (ARGO), these floats “do not measure below 2,000-m depth.” This means that temperature changes in “approximately half the ocean’s volume” are still not being measured today.

• To detect the effects of anthropogenic forcing, it would require energy budget imbalance measurement precision of 0.1 W/m² at the top of the atmosphere (TOA). Uncertainty in the forcing changes affecting climate are ±4 W/m², meaning that uncertainty is about 80 times greater than an anthropogenic signal detection.

• Past changes in global ocean heat content, such as the last deglaciation, have been 20 times larger than modern changes.

• Ocean heat storage during the Medieval Warm Period (Medieval Climate Anomaly, or MCA) was much greater than modern. Modern global ocean heat uptake is “just one-third” of what is required to reach the levels attained during Medieval times.