Climate change and decadal to centennial-scale climate periodicities recorded in a late Holocene NE Pacific marine record: Examining the role of solar forcing
J.M. Galloway et al
- Climate proxy data from NE Pacific Late Holocene sediments
- Dry climate interval between 2948-2708 cal. yr BP and c. 1992-1727 cal. yr BP
- The record contains periodicities of c. 42-53, 60-70, 82-89, 241-243, and 380 yrs
- Periodicities are replicated in reconstructed sunspot data
- Periodicities may reflect Gleissberg and Suess/de Vries solar cycles
Abstract: We present a decadal-scale late Holocene climate record based on diatoms, biogenic silica, and grain size from a 12-m sediment core (VEC02A04) obtained from Frederick Sound in the Seymour-Belize Inlet Complex of British Columbia, Canada. Sediments are characterized by graded, massive, and laminated intervals. Laminated intervals are most common between c. 2948-2708 cal. yr BP and c. 1992-1727 cal. yr BP. Increased preservation of laminated sediments and diatom assemblage changes at this time suggest that climate became moderately drier and cooler relative to the preceding and succeeding intervals. Spectral and wavelet analyses are used to test for statistically significant periodicities in time series of proxies of primary production (total diatom abundance, biogenic silica) and hydrology (grain size) preserved in the Frederick Sound record. Periodicities of c. 42-53, 60-70, 82-89, 241-243, and 380 yrs are present. Results are compared to reconstructed sunspot number data of Solanki et al. (2004) using cross wavelet transform to evaluate the role of solar forcing on NE Pacific climate. Significant common power of periodicities between c. 42-60, 70-89, 204-243, and of 380 yrs occur, suggesting that celestial forcing [solar activity] impacted late Holocene climate at Frederick Sound. Replication of the c. 204-243 yr periodicity in sunspot time series is most pronounced between c. 2900 cal. yr BP [before the present] and c. 2000 cal. yr BP, broadly correlative to the timing of maximum preservation of laminated sedimentary successions and diatom assemblage changes. High solar activity at the Suess/de Vries band may have been manifested as a prolonged westward shift and/or weakening of the Aleutian Low in the mid-late Holocene, which would have diverted fewer North Pacific storms and resulted in the relatively dry conditions reconstructed for the Seymour-Belize Inlet Complex.
Obviously the Aleutian Low responds along with all the other air circulation features to the effect of changes in the mix of wavelengths and particles from the sun on the gradient of tropopause height between equator and poles.ReplyDelete
More support fro my New Climate Model.
Your model is more sophisticated than mine, but using only AMO+PDO+sunspot integral is remarkable...Delete
Hi Michael. Calibration has to be considered too. My simple SSN integration with AMO and SOI plus a CO2 factor (Which bears a strong similarity to the NCDC adjustments regime) ;-) replicates HADsst3 well too.Delete
Did my comment go missing?Delete
I'm a one-man operation with a real job on the side so often comments have to wait.. ;)
The correlation you noted back in 2010 serves to illustrate my point very well.
The combination of top down solar and lagging bottom up oceanic forcing is enough to explain all observations without CO2.
I first advanced that proposition here:
in May 2008 and suggested that:
"Before it is safe to attribute a global warming or a global cooling effect to any other factor (CO2 in particular) it is necessary to disentangle the simultaneous overlapping positive and negative effects of solar variation, PDO/ENSO and the other oceanic cycles. Sometimes they work in unison, sometimes they work against each other and until a formula has been developed to work in a majority of situations all our guesses about climate change must come to nought.
So, to be able to monitor and predict changes in global temperature we need more than information about the past, current and expected future level of solar activity.
We also need to identify all the separate oceanic cycles around the globe and ascertain both the current state of their respective warming or cooling modes and, moreover, the intensity of each, both at the time of measurement and in the future.
Once we have a suitable formula I believe that changes in global temperature will no longer be a confusing phenomenon and we will be able to apportion the proper weight to other influencing factors such as the greenhouse effect of CO2."
Since then I have extended my model to a complete chain of cause and effect.
Will have my own site up shortly designed to refine and assess the performance of my model in the light of on going climate events.
Thanks Stephen, looking forward to seeing your site.Delete
High solar activity would be associated with a stronger aleutian low not a weaker Aleutian Low.ReplyDelete
IT HAS BEEN SHOWN THAT WEAKER SOLAR ACTIVITY RESULTS IN A
-AO (ARCTIC OSCILLATION0 WHICH IS A MORE MERIDIONAL ATMOSPHERIC CIRCULATION. THIS TYPE OF CIRCULATION WOULD FEATURE A WAEAK ALEUTIAN LOW, NOT A STRONG ALEUTIAN LOW WHICH WOULD BE INDICATIVE OF A ZONAL ATMOSPHERIC CIRCULATION ASSOCIATED WITH STRONG OR ACTIVR SOLAR CONDITIONS.
They have it backwards.
They may well have it backwards. All my model requires is a more negative AO when the sun is less active and a more positive AO when the sun is more active.ReplyDelete
I haven't studied how that affects the Aleutian Low as a specific feature of the general circulation.