Leona Libby’s Isotopic Tree Thermometers was published 40 years ago.
Her paper was extraordinary in many ways.
Firstly, Leona Libby applied an objective scientific methodology to dendrochronology.
Long term isotope changes in precipitation, caused by changes in climatic temperatures, are well documented in polar ice caps -the heavier of the stable isotopes is depleted in ice laid down in the ice age by comparison with present-day ice.
In 1970 we extended this concept to trees, suggesting that they are also thermometers, and undertook measurements to test the idea.
In trees which use atmospheric precipitation to manufacture their rings, isotope variations in the rings should be climate indicators because the isotope composition in the rain and C02 varies with temperature.
Isotopic tree thermometers – Leona Libby – Nature Vol. 261 May 27 1976
Secondly, Leona Libby demonstrated [for example] the Deuterium Ratio from the German Oak chronology correlated well with the English Winter Temperatures (30-yr running averages) going back to the late 1700s when mercury thermometers were introduced.
A Thermometer is a device that measures temperature or a temperature gradient.
The first person to put a scale on a thermoscope is variously said to be Francesco Sagredo (1571–1620) or Santorio Santorio in about 1611 to 1613.
However, each inventor and each thermometer was unique – there was no standard scale.
Finally in 1724, Daniel Gabriel Fahrenheit (1686–1736) produced a temperature scale which now (slightly adjusted) bears his name. He could do this because he manufactured thermometers, using mercury (which has a high coefficient of expansion) for the first time and the quality of his production could provide a finer scale and greater is reproducibility, leading to its general adoption.
In 1742, Anders Celsius (1701–1744) proposed a scale with zero at the boiling point and 100 degrees at the freezing point of water, though the scale which now bears his name has them the other way around.
However, after forty years of Settled Science its difficult to reconcile modern English Temperature datasets with the English Winter Temperature data used by Leona Libby.
Thirdly, Leona Libby produced an Isotopic Chronology from a single Old Japanese Cedar Tree that indicated temperatures had fallen by ~1.5 °C in 1,800 years.
We have shown that the temperature records in three modern trees seem to follow the local mercury thermometer records, and have found that a Japanese cedar indicates a temperature fall of ~1.5°C in the past 1,800 yr.
Isotopic tree thermometers – Leona Libby – Nature Vol. 261 May 27 1976
Fourthly, Leona Libby identified a dramatic decline in temperatures at the Arabian Horizon.
The step change [in surface temperatures] at the Arabian Horizon were moderated by “the tremendous heat capacity of the oceans”.
The tremendous heat capacity of the oceans moderates the planet’s climate, and its absorption of various gases affects the composition of the atmosphere.
In theory, the moderating influence of the oceans should slowly oscillate with a period of about 1,000 years as the oceans complete one full Thermohaline Circulation cycle.
Thermohaline circulation (THC) is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.
Wind-driven surface currents (such as the Gulf Stream) travel polewards from the equatorial Atlantic Ocean, cooling en route, and eventually sinking at high latitudes (forming North Atlantic Deep Water). This dense water then flows into the ocean basins. While the bulk of it upwells in the Southern Ocean, the oldest waters (with a transit time of around 1000 years) upwell in the North Pacific.
The Old Japanese Cedar Tree chronology broadly supports this theory because the long term temperature trend rises and falls over [about] 1,050 years i.e. 675 through 1725 CE.
The decline of this long term trend [into 1725 CE] appears to have exacerbated the The Little Ice Age [between 1600 and 1850 AD] when the Thermohaline Circulation recirculated the oceanic water that had dramatically released its heat at the Arabian Horizon.
The subsequent rebound in temperatures [and CO2 levels] follows the Thermohaline Circulation as the moderating influence of the oceans gets back to business as usual as it slowly oscillates around [and adjusts to] the stepped down equilibrium point established at the Arabian Horizon.
François Matthes introduced The Little Ice Age into the mainstream narrative in 1939 and within a decade the storyline of The Little Ice Age was firmly established as a period of glacier advances between 1600 and 1850 AD.
In other words:
The catastrophic downward spike in surface temperatures at the Arabian Horizon triggered a spike in released oceanic heat and water vapour which [in their turn] caused a dramatic short term spike in precipitation [aka Deluge].
Roughly 97% of the planet’s water is in its oceans, and the oceans are the source of the vast majority of water vapor that condenses in the atmosphere and falls as rain or snow on the continents.
Sea smoke, frost smoke, or steam fog, is fog which is formed when very cold air moves over warmer water.
Arctic sea smoke is sea smoke forming over small patches of open water in sea ice.
Because this type of fog requires very low air temperatures, it is uncommon in temperate climates, but is common in the Arctic and Antarctic.
The Old Japanese Cedar Tree and the Denver Dust Bowl both suggest this Deluge was done and dusted by about 675 CE.
The lower layer of soil “ceased to develop” around 675 AD.
Camp Century ice cores reflect this spike in precipitation at the Arabian Horizon.
A Deuterium Ratio data projection suggests the Greenland Ice Sheet formed [sometime] between 390 CE and 945 CE [mid-point 667.5 CE] whilst pattern matching the Oxygen Ratio data suggests the Greenland Ice Sheet began to form in 550 CE.
The initial deluge of rain and snow associated with the 1st Millennium Minimum [at 654 AD] may explain why the Farm Beneath the Sand [settled centuries before the official arrival of Erik the Red in 986 AD] was found under “1.5m-thick layers of sand and gravel”.
Furthermore, this Arabian Horizon deluge scenario is very similar to the climate scenario envisioned by the mainstream during the Last Glacial Period when a “cooling down” [of about c. 8.4 °C] was associated with a “significant precipitation change”.
Last Glacial Period in the semiarid Andes around Aconcagua and Tupungato
A specially interesting climatic change during glacial times has taken place in the semi-arid Andes.
Beside the expected cooling down in comparison with the current climate, a significant precipitation change happened here.
So, researches in the presently semiarid subtropic Aconcagua-massif (6,962 m) have shown an unexpectedly extensive glacial glaciation of the type “ice stream network”.
The connected valley glaciers exceeding 100 km in length, flowed down on the East-side of this section of the Andes at 32–34°S and 69–71°W as far as a height of 2,060 m and on the western luff-side still clearly deeper.
Where current glaciers scarcely reach 10 km in length, the snowline (ELA) runs at a height of 4,600 m and at that time was lowered to 3,200 m asl, i.e. about 1,400 m.
From this follows that – beside of an annual depression of temperature about c. 8.4 °C – here was an increase in precipitation.
Accordingly, at glacial times the humid climatic belt that today is situated several latitude degrees further to the S, was shifted much further to the N.
Additional support for this step change at the Arabian Horizon is provided by the Islamic and Julian calendars which suggest the Earth’s orbital period increased.
A common purely lunar calendar is the Islamic (or Hijri Qamari) calendar.
A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to 12 days.
The regular calendar had only 355 days, which meant that it would quickly be unsynchronized with the solar year, causing, for example, agricultural festivals to occur out of season.
The Julian year is, therefore, on average 365.25 days long.
Allowing for some intercalary days in the pre-Julian calendar it seems likely [as per Immanuel Velikovsky] that Earth’s orbital period increased from 360 to 365.25 days.
Numerous evidences are preserved which prove that prior to the year of 365¼ days, the year was only 360 days long.
Worlds In Collision – Immanuel Velikovsky – 1950
Intercalation or embolism in timekeeping is the insertion of a leap day, week, or month into some calendar years to make the calendar follow the seasons or moon phases.
An increase in the orbital period by 5.25 days implies [using Kepler’s Third Law of Planetary Motion] the Earth’s orbital distance [from the Sun] increased by 0.97%.
Such a step change would explain why the delta14C values in the Bristlecone Pine and Irish Oaks chronologies change direction at the Arabian Horizon i.e. more 14C was produced in the atmosphere when the Earth was closer to the Sun.
Such a step change in the Earth’s orbital distance would also explain why Leona Libby observed that temperatures had dropped by ~1.5 °C in 1,800 years.
The Solar System appears to be periodically recirculating the space debris that triggered the Arabian Horizon.
The implication being the really catastrophic iron core debris arrived [predominantly] during the first wave and the debris in the subsequent waves was [mainly] rocky and progressively smaller as it slowly disintegrated in space.
And as a final thought:
If the Solar System and the Thermohaline Circulation are roughly synchronised then the The Little Ice Age [classically defined as 1600 to 1850 CE] was a less severe rerun of the Last Glacial Period [whose nadir, appropriately derived from the Arabic, occurred at the Arabian Horizon in 637 CE].