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Glaciers and Paleorecords Tell Us How Atmospheric Circulation Changes and Successive Cooling Periods Occurred in the Fennoscandia during the Holocene
- Source :
- Journal of Marine Science and Engineering, Volume 9, Issue 8, Journal of Marine Science and Engineering, Vol 9, Iss 832, p 832 (2021)
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Two major climatic phenomena that occurred during the Holocene are interpreted from the resonance in subharmonic modes of long-period Rossby waves winding around the North Atlantic gyre, the so-called gyral Rossby waves (GRWs). These are, on the one hand, the change in atmospheric circulation that occurred in the North Atlantic in the middle Holocene, and, on the other hand, the occurrence of abrupt cooling events more frequently than what is generally accepted. The amplitude of GRWs is deduced by filtering, within bands characteristic of various subharmonic modes, climate records from the Greenland ice sheet, pollen, and tree rings in northern Fennoscandia, and from two Norwegian glaciers in northern Folgefonna and on the Lyngen peninsula. While the subharmonic modes reflect the acceleration/deceleration phases of the western boundary current, an anharmonic mode is evidenced in the 400–450 year band. Abrupt cooling events of the climate are paced by this anharmonic mode while the western boundary current is decelerating, and the northward heat advection of air favors the melting of the pack ice. Then, the current of the northernmost part of the North Atlantic gyre cools before branching off to the north, which alters its buoyancy. On the other hand, according to high subharmonic modes, high-pressure systems prevailed over the North Atlantic in the first half of the Holocene while low-pressure systems resulted from baroclinic instabilities of the atmosphere dominate during the second half, favoring the growth of glaciers in Scandinavia by a better snowfall in winter and cooler summers.
- Subjects :
- North Atlantic gyre
subharmonic modes
010506 paleontology
010504 meteorology & atmospheric sciences
Atmospheric circulation
Naval architecture. Shipbuilding. Marine engineering
VM1-989
Greenland ice sheet
Ocean Engineering
GC1-1581
Oceanography
01 natural sciences
glacier fluctuations
Ocean gyre
Holocene
0105 earth and related environmental sciences
Water Science and Technology
Civil and Structural Engineering
geography
geography.geographical_feature_category
North Atlantic
Rossby wave
Glacier
Arctic ice pack
Boundary current
Climatology
Geology
Subjects
Details
- ISSN :
- 20771312
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- Journal of Marine Science and Engineering
- Accession number :
- edsair.doi.dedup.....eb3f0aa8604cb60912c77942bcdcf393