Geochemical reconstruction of Pacific decadal variability from the eastern North Pacific during the HoloceneThis article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.

2008 ◽  
Vol 45 (11) ◽  
pp. 1317-1329 ◽  
Author(s):  
Tara S. Ivanochko ◽  
Stephen E. Calvert ◽  
Richard E. Thomson ◽  
Thomas F. Pedersen
Keyword(s):  
North Pacific ◽  
Decadal Variability ◽  
High Elevation ◽  
Early Holocene ◽  
Aleutian Low ◽  
Polar Climate ◽  
Climate Stability ◽  
The Pacific ◽  
Age Model ◽  
Effingham Inlet

Determining climate variations over the Holocene requires high-resolution records with well-developed age models. A 40 m long marine sediment core raised from Effingham Inlet, an anoxic fjord on the west coast of Vancouver Island, British Columbia, Canada, yields such a record. Forty six 14C accelerator mass spectrometry (AMS) dates determined from terrestrial plant material form the age model. Downcore sampling at both 5 cm (20 year) and 1.5 cm (7 year) resolution indicates that high-frequency oceanographic variability has prevailed at this site over the last 10 000 years. Spectral analysis of wt.% opal, a proxy for diatom productivity in the basin, reveals the bidecadal and pentadecadal periods of the Pacific decadal oscillation (PDO) – North Pacific index (NPI) that are related to changes in the strength of the Aleutian Low. Coherence analysis between the Effingham Inlet data and δ18O records from Jellybean Lake (a high elevation site in southwest Yukon) indicates regional coherence at periods of 45, 70, and 510 years between productivity in Effingham Inlet and changes in the Aleutian Low strength. Over the entire Holocene, the strength of decadal variability has changed. Both 20- and 50-year periods are present to some degree in the early Holocene, and only the 50 year period is evident in the late Holocene. These data imply that regime shifts would have been more frequent in the early Holocene relative to the last several thousand years.

North Pacific Subtropical Mode Water Controlled by the Atlantic Multi-Decadal Variability

2020 ◽  
Author(s):  
Baolan wu ◽  
Xiaopei lin ◽  
Lisan yu
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Decadal Variability ◽  
Heat Content ◽  
Northwestern Pacific ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
Mean Temperature ◽  
The Pacific

<p><strong>The North Pacific Subtropical Mode Water (mode water hereafter) is a vertically homogeneous thermocline water mass, occupying the entire subtropical Western Pacific Ocean. By transporting mass, heat and nutrients from the surface into the subsurface ocean, it provides memory of climate variability and is a potential source of predictability. Previous studies attributed decadal variability of the mode water mean temperature to the Pacific Decadal Oscillation (PDO). Using available observations and reanalysis data, here we show that decadal to multi-decadal variability of the mode water mean temperature is controlled by the Atlantic Multi-Decadal Variability (AMV) instead. During an AMV positive phase, warm sea surface temperatures (SSTs) in the north Atlantic Ocean weaken the subtropical North</strong> <strong>Pacific westerlies, and the anomalous easterlies in the subtropical west Pacific drive an anomalous northward Ekman transport of warm water into the mode water formation area. </strong><strong>This increases the mode water temperature through subduction</strong><strong>, driving variability of the upper-layer ocean heat content and fish catches in the Northwestern Pacific. This mechanism is supported by a long pre-industrial model simulation with multiple AMV cycles and by a Pacemaker model experiment, in which the AMV forcing alone is shown to drive the variability of the mode water. Our finding suggests that the AMV is an important driver for decadal climate and ecosystem variability and provides memory for prediction in the Pacific Ocean.</strong></p>

scholarly journals A database of paleoceanographic sediment cores from the North Pacific, 1951–2016

2017 ◽  
Author(s):  
Marisa Borreggine ◽  
Sarah E. Myhre ◽  
K. Allison S. Mislan ◽  
Curtis Deutsch ◽  
Catherine V. Davis
Keyword(s):  
North Pacific ◽  
Planktonic Foraminifera ◽  
Sediment Cores ◽  
Model Development ◽  
Data Set ◽  
Sedimentary Sequences ◽  
The North ◽  
The Pacific ◽  
Age Model ◽  
The North Pacific

Abstract. We assessed sediment coring, data acquisition, and publications from the North Pacific (north of 30˚ N) from 1951–2016. There are 2134 sediment cores collected by American, French, Japanese, Russian, and international research vessels across the North Pacific (including the Pacific Subarctic Gyre, Alaskan Gyre, Japan Margin, and California Margin, 1391 cores), Sea of Okhotsk (271 cores), Bering Sea (123 cores), and Sea of Japan (349 cores) reported here. All existing metadata associated with these sediment cores are documented, including coring date, location, core number, cruise number, water depth, vessel metadata, and coring technology. North Pacific age models are based on isotope stratigraphy, radiocarbon dating, magnetostratigraphy, biostratigraphy, tephrochronology, % opal, color, and lithophysical proxies. Here, we evaluate the iterative generation of each published age model and provide documentation of each dating technique used, as well as sedimentation rates and age ranges. We categorized cores according to availability of a variety of proxy evidence, including biological (e.g. benthic and planktonic foraminifera assemblages), geochemical (e.g. heavy metal concentrations), isotopic (e.g. bulk sediment nitrogen and carbon isotopes), and stratigraphic (e.g. preserved laminations) proxies. This database is a unique resource to the paleoceanographic and paleoclimate communities, and provides cohesive accessibility to sedimentary sequences, age model development, and proxies. The data set is publicly available through PANGAEA at https://doi.org/10.1594/PANGAEA.875998.

The Forcing of the Pacific Decadal Oscillation*

2005 ◽  
Vol 18 (21) ◽  
pp. 4355-4373 ◽  
Author(s):  
Niklas Schneider ◽  
Bruce D. Cornuelle
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Pacific Decadal Oscillation ◽  
North Pacific ◽  
Sea Surface ◽  
Aleutian Low ◽  
The Pacific ◽  
Sea Surface Temperature Anomalies ◽  
Zonal Advection ◽  
The Kuroshio

Abstract The Pacific decadal oscillation (PDO), defined as the leading empirical orthogonal function of North Pacific sea surface temperature anomalies, is a widely used index for decadal variability. It is shown that the PDO can be recovered from a reconstruction of North Pacific sea surface temperature anomalies based on a first-order autoregressive model and forcing by variability of the Aleutian low, El Niño–Southern Oscillation (ENSO), and oceanic zonal advection anomalies in the Kuroshio–Oyashio Extension. The latter results from oceanic Rossby waves that are forced by North Pacific Ekman pumping. The SST response patterns to these processes are not orthogonal, and they determine the spatial characteristics of the PDO. The importance of the different forcing processes is frequency dependent. At interannual time scales, forcing from ENSO and the Aleutian low determines the response in equal parts. At decadal time scales, zonal advection in the Kuroshio–Oyashio Extension, ENSO, and anomalies of the Aleutian low each account for similar amounts of the PDO variance. These results support the hypothesis that the PDO is not a dynamical mode, but arises from the superposition of sea surface temperature fluctuations with different dynamical origins.

Postglacial evolution of a Pacific coastal fjord in British Columbia, Canada: interactions of sea-level change, crustal response, and environmental fluctuations — results from MONA core MD02-2494This article is one of a series of papers published in this Special Issue on the theme Polar Climate Stability Network.

2008 ◽  
Vol 45 (11) ◽  
pp. 1345-1362 ◽  
Author(s):  
Audrey Dallimore ◽  
Randolph J. Enkin ◽  
Reinhard Pienitz ◽  
John R. Southon ◽  
Judith Baker ◽  
...  
Keyword(s):  
British Columbia ◽  
Sea Level ◽  
Radiocarbon Dates ◽  
Polar Climate ◽  
The Core ◽  
Mantle Viscosity ◽  
Climate Stability ◽  
Viscosity Models ◽  
New Information ◽  
Effingham Inlet

The sedimentary record in a 40.9 m giant (Calypso) piston core (MD02-2494) raised from the inner basin within Effingham Inlet, British Columbia, Canada, during the 2002 Marges Ouest Nord Américaines (MONA) campaign, spans from 14 360 14C years BP (17 300 calibrated calendar (cal.) years BP) to about nine centuries before present. The core archives changes in sedimentation and sea level immediately following deglaciation of the Late Wisconsin Fraser Glaciation, which peaked about 15 000 14C years BP. The presence of the Mazama Ash in the core anchors a detailed chronology based on 49 radiocarbon dates and seven Pleistocene paleomagnetic secular variation correlations. Diatom assemblages identify a marine–freshwater–marine transition in the basin, which occurred 11 630 14C years BP (13 500 cal. years BP). At this time, a bedrock sill, presently at 46 m depth, was briefly exposed as sea level fell and then rose again during isostatic crustal adjustments. These data constrain a new sea-level curve for the outer coast of Vancouver Island covering the past 12 000 14C years BP (14 000 cal. years BP), providing new information on the nature of deglaciation along the west coast of Canada and informing interpretations of regional paleoceanographic records and mantle viscosity models.

Contrasting Climatic Histories for the Snake River Plain, Idaho, Resulting from Multiple Thermal Maxima

1986 ◽  
Vol 26 (3) ◽  
pp. 321-339 ◽  
Author(s):  
Owen K. Davis ◽  
John C. Sheppard ◽  
Susan Robertson
Keyword(s):  
Pacific Northwest ◽  
Late Quaternary ◽  
High Elevation ◽  
Snake River Plain ◽  
Early Holocene ◽  
Snake River ◽  
Limiting Factor ◽  
Summer Drought ◽  
The Pacific ◽  
River Plain

Ten sites near the Snake River Plain have consistent differences in their climatic histories. Sites at low elevation reflect the “early Holocene xerothermic” of the Pacific Northwest, whereas most climatic chronologies at high elevation indicate maximum warmth or aridity somewhat later, ca. 6000 yr ago. This elevational contrast in climatic histories is duplicated at three sites from the central Snake River Plain. For sites in such close proximity, the different chronologies cannot be explained by changes in atmospheric circulation during the late Quaternary. Rather, the differences are best explained by the autecology of the plants involved and the changing seasonal climate. The seasonal climatic sequence predicted by multiple thermal maxima explains the high- and low-elevation chronologies. During the early Holocene, maximum insolation and intensified summer drought in July forced low-elevation vegetation upward. However, moisture was not a limiting factor at high elevation, where vegetation moved upward in response to increased length of growing season coincident with maximum September insolation 6000 yr ago.

scholarly journals Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

2020 ◽  
Author(s):  
Matías Frugone-Álvarez ◽  
Claudio Latorre ◽  
Fernando Barreiro-Lostres ◽  
Santiago Giralt ◽  
Ana Moreno ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
Sedimentary Facies ◽  
High Elevation ◽  
Early Holocene ◽  
Lake Levels ◽  
Lake Productivity ◽  
Central Chile ◽  
Age Model ◽  
Tephra Layers

Abstract. Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate, seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36° S, 2180 m asl, Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model is based on nine new 14C AMS date, existing 210Pb and 137Cs data and the Quizapú ash horizon (CE 1932). According to this age model, early Holocene were followed by a phase of increased productivity during the mid Holocene and higher lake levels after 4.0 ka BP. Major hydroclimate transitions occurred at ca. 0.5, 4.0, 8.0 and 11 ka BP. Decreased summer insolation and winter precipitation due to a southward shift in the Southern Westerly Winds and a strengthened Pacific Subtropical High could explain early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (~ 8.0 to 6.0 ka) is coeval with a warm-dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to higher frequency of volcanic events. During the late Holocene, the tephra layers shows compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 cal ka BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 cal ka BP, most likely caused by the inception of current ENSO/PDO-like dynamics in central Chile.

scholarly journals Pacific Decadal Variability: Paced by Rossby Basin Modes?

2013 ◽  
Vol 26 (4) ◽  
pp. 1445-1456 ◽  
Author(s):  
Wilbert Weijer ◽  
Ernesto Muñoz ◽  
Niklas Schneider ◽  
François Primeau
Keyword(s):  
Climate Variability ◽  
Time Scales ◽  
Pacific Decadal Oscillation ◽  
North Pacific ◽  
Pressure Field ◽  
Decadal Variability ◽  
Climate System Model ◽  
The North ◽  
The Pacific ◽  
The North Pacific

Abstract A systematic study is presented of decadal climate variability in the North Pacific. In particular, the hypothesis is addressed that oceanic Rossby basin modes are responsible for enhanced energy at decadal and bidecadal time scales. To this end, a series of statistical analyses are performed on a 500-yr control integration of the Community Climate System Model, version 3 (CCSM3). In particular, a principal oscillation pattern (POP) analysis is performed to identify modal behavior in the subsurface pressure field. It is found that the dominant energy of sea surface temperature (SST) variability at 25 yr (the model equivalent of the Pacific decadal oscillation) cannot be explained by the resonant excitation of an oceanic basin mode. However, significant energy in the subsurface pressure field at time scales of 17 and 10 yr appears to be related to internal ocean oscillations. However, these oscillations lack the characteristics of the classical basin modes, and must either be deformed beyond recognition by the background circulation and inhomogeneous stratification or have another dynamical origin altogether. The 17-yr oscillation projects onto the Pacific decadal oscillation and, if present in the real ocean, has the potential to enhance the predictability of low-frequency climate variability in the North Pacific.

scholarly journals Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

2020 ◽  
Vol 16 (4) ◽  
pp. 1097-1125
Author(s):  
Matías Frugone-Álvarez ◽  
Claudio Latorre ◽  
Fernando Barreiro-Lostres ◽  
Santiago Giralt ◽  
Ana Moreno ◽  
...  
Keyword(s):  
Southern Oscillation ◽  
Late Quaternary ◽  
Sediment Cores ◽  
High Elevation ◽  
Early Holocene ◽  
Lake Levels ◽  
Lake Productivity ◽  
Central Chile ◽  
Age Model ◽  
Tephra Layers

Abstract. Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate and seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36∘ S, 2180 m a.s.l., Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model based on nine new 14C AMS dates, existing 210Pb and 137Cs data, and the Quizapú ash horizon (1932 CE). According to this age model, the relatively drier Early Holocene was followed by a phase of increased productivity during the mid-Holocene and higher lake levels after 4.0 ka cal BP. Major hydroclimate transitions occurred at ca. 11, 8.0, 4.0 and 0.5 ka cal BP. Decreased summer insolation and winter precipitation due to a southward shift in the southern westerly winds and a strengthened Pacific Subtropical High could explain Early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (∼8.0 to 6.0 ka cal BP) is coeval with a warm–dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to a higher frequency of volcanic events. During the Late Holocene, the tephra layers show compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 ka cal BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 ka cal BP, most likely caused by the inception of current El Niño–Southern Oscillation and Pacific Decadal Oscillation (ENSO–PDO) dynamics in central Chile.

scholarly journals South Pacific Decadal Climate Variability and Potential Predictability

2019 ◽  
Vol 32 (18) ◽  
pp. 6051-6069 ◽  
Author(s):  
Jiale Lou ◽  
Neil J. Holbrook ◽  
Terence J. O’Kane
Keyword(s):  
Pacific Decadal Oscillation ◽  
North Pacific ◽  
Decadal Variability ◽  
South Pacific ◽  
The South ◽  
Potential Predictability ◽  
The North ◽  
The Pacific ◽  
The Relationship ◽  
The North Pacific

Abstract The South Pacific decadal oscillation (SPDO) characterizes the Southern Hemisphere contribution to the Pacific-wide interdecadal Pacific oscillation (IPO) and is analogous to the Pacific decadal oscillation (PDO) centered in the North Pacific. In this study, upper ocean variability and potential predictability of the SPDO is examined in HadISST data and an atmosphere-forced ocean general circulation model. The potential predictability of the IPO-related variability is investigated in terms of both the fractional contribution made by the decadal component in the South, tropical and North Pacific Oceans and in terms of a doubly integrated first-order autoregressive (AR1) model. Despite explaining a smaller fraction of the total variance, we find larger potential predictability of the SPDO relative to the PDO. We identify distinct local drivers in the western subtropical South Pacific, where nonlinear baroclinic Rossby wave–topographic interactions act to low-pass filter decadal variability. In particular, we show that the Kermadec Ridge in the southwest Pacific enhances the decadal signature more prominently than anywhere else in the Pacific basin. Applying the doubly integrated AR1 model, we demonstrate that variability associated with the Pacific–South American pattern is a critically important atmospheric driver of the SPDO via a reddening process analogous to the relationship between the Aleutian low and PDO in the North Pacific—albeit that the relationship in the South Pacific appears to be even stronger. Our results point to the largely unrecognized importance of South Pacific processes as a key source of decadal variability and predictability.

scholarly journals ENSO’s Modulation of Water Vapor Transport over the Pacific–North American Region

2015 ◽  
Vol 28 (9) ◽  
pp. 3846-3856 ◽  
Author(s):  
Hye-Mi Kim ◽  
Michael A. Alexander
Keyword(s):  
United States ◽  
El Niño ◽  
North Pacific ◽  
Moisture Transport ◽  
El Nino ◽  
Tropical Pacific ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Southwestern United States ◽  
The Pacific

Abstract The vertically integrated water vapor transport (IVT) over the Pacific–North American sector during three phases of ENSO in boreal winter (December–February) is investigated using IVT values calculated from the Climate Forecast System Reanalysis (CFSR) during 1979–2010. The shift of the location and sign of sea surface temperature (SST) anomalies in the tropical Pacific Ocean leads to different atmospheric responses and thereby changes the seasonal mean moisture transport into North America. During eastern Pacific El Niño (EPEN) events, large positive IVT anomalies extend northeastward from the subtropical Pacific into the northwestern United States following the anomalous cyclonic flow around a deeper Aleutian low, while a southward shift of the cyclonic circulation during central Pacific El Niño (CPEN) events induces the transport of moisture into the southwestern United States. In addition, moisture from the eastern tropical Pacific is transported from the deep tropical eastern Pacific into Mexico and the southwestern United States during CPEN. During La Niña (NINA), the seasonal mean IVT anomaly is opposite to that of two El Niño phases. Analyses of 6-hourly IVT anomalies indicate that there is strong moisture transport from the North Pacific into the northwestern and southwestern United States during EPEN and CPEN, respectively. The IVT is maximized on the southeastern side of a low located over the eastern North Pacific, where the low is weaker but located farther south and closer to shore during CPEN than during EPEN. Moisture enters the southwestern United States from the eastern tropical Pacific during NINA via anticyclonic circulation associated with a ridge over the southern United States.

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