Tag: South Indian Ocean

Researchers Find Rapid Global Warming Phase At End Of Last Ice Age (Ca.18,000 Years Ago)

Glacial oceans had stronger stratification with saltier, denser deep waters helping sequester CO₂. Deglaciation disrupted this, leading to mixing that brought both heat and salt (and CO₂) upward. The “salty blob” in the deep Indian Ocean acted as a reservoir that influenced surface properties when ventilation increased.

From NoTrickZone

By P Gosselin

The Germany-based European Institute for Climate and Energy (EIKE) has posted its latest Klimaschau video, titled “Prähistorische Ozeanschichten als möglicher Faktor der Erwärmung (Prehistoric Ocean Layers as a Possible Factor in Warming):

The new video highlights a study from Rutgers University published in Nature Geoscience.

Researchers found that the rapid global warming phase at the end of the last ice age (around 18,000 years ago) coincided with the release of highly saline water—a “salt blob”—that had previously been trapped in the deep ocean.

Scientists have long suspected a link between deep ocean salinity and atmospheric CO2 levels during ice age cycles. Colder water holds more dissolved CO2. When marine organisms die, their carbon-rich remains sink into the deep sea. Variations in salinity act as a barrier, trapping this carbon in the deep ocean layers and preventing it from easily escaping back into the atmosphere.

Ocean currents and shifting layers can transport these deep, carbon-rich waters back to the surface. Once there, they oxidize and release large amounts of CO2 into the atmosphere, rapidly triggering a warming phase.

The Asymptotic Nature of Greenhouse Gases

The video notes that climate alarmists might equate this prehistoric CO2 release to modern industrial emissions. However, it argues this is oversimplified, asserting that greenhouse gases (like CO2 and methane) absorb radiation asymptotically—meaning their warming effect peaks at a certain limit rather than increasing indefinitely.

Historical Context (“Snowball Earth”)

It touches on the “Snowball Earth” phenomenon from 580 million years ago, when low atmospheric CO2 levels likely caused a super ice age.

The video concludes that because Earth’s current CO2 levels are historically low compared to the last half-billion years, even a slight drop can trigger cooling phases, whereas sudden releases of trapped ocean gases can quickly reverse this and instigate warm periods.

Watch the entire video (in German) on YouTube: https://www.youtube.com/watch?v=5NIx28vEstQ.

Decreasing Trend in South Indian Ocean TC Intensity Since mid–1990s

Tropical cyclone activity often leads to many adverse impacts and assessing their destructiveness is a crucial scientific concern.

From NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood

And here’s the study:

Abstract

Tropical cyclone activity often leads to many adverse impacts and assessing their destructiveness is a crucial scientific concern.

Here we investigated changes in the destructiveness of tropical cyclones worldwide using the power dissipation index and found that there is no clear trend in most basins, but a significant decrease in power dissipation index has been detected in the South Indian Ocean basin since 1994, which is almost entirely due to a decrease in both tropical cyclone frequency and duration in this basin.

The decrease in tropical cyclone frequency is influenced by increased atmospheric stability. The decrease in tropical cyclone duration can be attributed to the changes in tropical cyclone locations. In addition, the weakened subtropical high is only observed in the South Indian Ocean (i.e., the Mascarene High), which is also associated with the decrease in tropical cyclone destructiveness.

These findings have implications for assessing the destructive potential of future tropical cyclones.

Fig. 1: Time series of the cumulative power dissipation index (PDI) of tropical cyclones (TCs) for each basin and the global.

https://www.nature.com/articles/s43247-024-01683-2
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