[meteorite-list] Oceanic and Atmospheric Cooling Started Before Start of Younger Dryas

[Paul]

Hi,

While reading on a slow Friday afternoon,
I came across the below paper.

Levac, E., Sandercombe, S. and Chmura, G.L., 2018.
The Younger Dryas in palynological records from
the northern Northwest Atlantic: Does the terrestrial
record lag the marine and air records?.
Palaeogeography, Palaeoclimatology, Palaeoecology,
  490, pp.269-279.
https://www.sciencedirect.com/science/article/pii/S0031018217307514

In part the the abstract states:

“Major changes in both pollen and dinocyst
assemblages are recorded during the Younger
Dryas in Bay of Islands and are associated with
large drops in air and sea surface temperatures,
and sea surface salinity. The changes in
vegetation are similar with those observed at
other sites in Newfoundland.”

“Sea-surface and air temperatures started
cooling 250 and 110 years before the start of
the YD, hence there is a 140 years delay
between ocean and atmosphere.”

On page 277 of Levac et al. (2018):

“However, we were not expecting a cooling trend
(in sea-surface and air temperatures) that started
before the recorded YD period.”

and

“Not only did sea-surface and air temperatures start
to deteriorate before the start of the YD (respectively
250 years and 110 years before the YD), we also
see a 110 year-lag between the changes in air
temperatures and pollen assemblages.”

and

..and we suggest that the decrease in air
temperatures in eastern Canada started before
the YD period.”

Basically, the cooling trend associated with the
Younger Dryas (YD) actually started before the
official start of the YD period, the time of
the hypothesized YD impact.

How can an extraterrestrial impact effect climate
before it even happens?

Yours,

Paul H.