Wednesday, April 2, 2014

New paper finds another amplification mechanism by which the Sun controlled Arctic climate

A paper published today in Geophysical Research Letters finds evidence of a response of the Bering Sea to 11-year solar cycles during the Bølling-Allerød period [14,700 to 12,700 years ago]. The authors find an 11-year cycle of fresh meltwater input and early sea-ice retreat in spring under the solar irradiance maximum which follows the positive phase of Arctic Oscillation [AO]. They also find the strength of this 11-year solar irradiance effect might be further regulated by the pressure patterns of PDO [Pacific Decadal Oscillation] and/or ENSO [El Nino Southern Oscillation] variability [both of which have also been linked to solar activity].

Climate scientists claim the tiny 0.1% variation in total solar irradiance during 11-year solar cycles cannot influence climate on decadal timescales, but this paper and many hundreds of others demonstrate solar activity does have large-scale, short and long-term effects on climate via amplification mechanisms including ocean and atmospheric oscillations.

Response of the Bering Sea to 11-year solar irradiance cycles during the Bølling-Allerød

Kota Katsuki et al


Previous studies find decadal climate variability possibly related to solar activity, although the details regarding the feedback with the ocean environment and ecosystem remain unknown. Here, we explore the feedback system of solar irradiance change during the Bølling-Allerød period [14,700 to 12,700 years ago], based on laminated sediments in the northern Bering Sea. During this period, well-ventilated water was restricted to the upper intermediate layer, and oxygen-poor lower intermediate water preserved the laminated sediment. An 11-year cycle of diatom and radiolarian flux peaks was identified from the laminated interval. Increased fresh meltwater input and early sea-ice retreat in spring under the solar irradiance maximum follow the positive phase of Arctic Oscillation which impacted the primary production and volume of upper intermediate water production in the following winter. Strength of this 11-year solar irradiance effect might be further regulated by the pressure patterns of PDO and/or ENSO variability.

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