Temperature changes along the Gulf of Alaska and the Pacific Northwest coast modeled from coastal tree rings

1996 ◽  
Vol 26 (3) ◽  
pp. 474-481 ◽  
Author(s):  
Gregory C. Wiles ◽  
Rosanne D. D'Arrigo ◽  
Gordon C. Jacoby
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Ring Width ◽  
Warm Season ◽  
Gulf Of Alaska ◽  
Maximum Latewood Density ◽  
Pacific Northwest Coast ◽  
Latewood Density ◽  
The Pacific ◽  
Temperature Records

Warm-season (April–September) temperature models based on a network of coastal ring-width and maximum latewood density tree-ring chronologies are the first reconstructions for coastal stations along the Gulf of Alaska and the Pacific Northwest. These well-verified temperature models are consistent with long climatic series from coastal stations and other proxy data from the Pacific coast. Cool summers during the 1850s and late 1800s in the Gulf of Alaska correspond to general glacier advance from the region. The Pacific Northwest reconstruction shows summer temperatures cooling in the early 1800s, coincident with a maximum of glacier activity in the coastal Olympic Mountains, Washington. The two warm-season temperature records show intervals when anomalies are opposite in sign, most notably during the 1850s, when cooling is inferred for the Gulf and warming is inferred for the Pacific Northwest. The records are coherent, however, during other intervals, with both showing cooling in the early 1800s and warming around 1870. The phase of these two records may reflect decadal changes in large-scale circulation in the northeastern Pacific. These land temperature reconstructions are strongly correlated with nearby sea surface temperatures, indicating large-scale oceanic–atmospheric influences.

Boreal temperature variability inferred from maximum latewood density and tree-ring width data, Wrangell Mountain region, Alaska

2003 ◽  
Vol 60 (3) ◽  
pp. 252-262 ◽  
Author(s):  
Nicole K. Davi ◽  
Gordon C. Jacoby ◽  
Gregory C. Wiles
Keyword(s):  
20Th Century ◽  
Ring Width ◽  
Warm Season ◽  
Principal Component ◽  
Volcanic Eruptions ◽  
Moisture Stress ◽  
Mountain Region ◽  
Temperature History ◽  
Maximum Latewood Density ◽  
Latewood Density

AbstractVariations in both width and density of annual rings from a network of tree chronologies were used to develop high-resolution proxies to extend the climate record in the Wrangell Mountain region of Alaska. We developed a warm-season (July–September) temperature reconstruction that spans A.D. 1593–1992 based on the first eigenvector from principal component analysis of six maximum latewood density (MXD) chronologies. The climate/tree-growth model accounts for 51% of the temperature variance from 1958 to 1992 and shows cold in the late 1600s–early 1700s followed by a warmer period, cooling in the late 1700s–early 1800s, and warming in the 20th century. The 20th century is the warmest of the past four centuries. Several severely cold warm-seasons coincide with major volcanic eruptions. The first eigenvector from a ring-width (RW) network, based on nine chronologies from the Wrangell Mountain region (A.D. 1550–1970), is correlated positively with both reconstructed and recorded Northern Hemisphere temperatures. RW shows a temporal history similar to that of MXD by increased growth (warmer) and decreased growth (cooler) intervals and trends. After around 1970 the RW series show a decrease in growth, while station data show continued warming, which may be related to increasing moisture stress or other factors. Both the temperature history based on MXD and the growth trends from the RW series are consistent with well-dated glacier fluctuations in the Wrangell Mountains and some of the temperature variations also correspond to variations in solar activity.

Blue Intensity for dendroclimatology: The BC blues: A case study from British Columbia, Canada

The Holocene ◽  
2014 ◽  
Vol 24 (11) ◽  
pp. 1428-1438 ◽  
Author(s):  
Rob Wilson ◽  
Rohit Rao ◽  
Miloš Rydval ◽  
Cheryl Wood ◽  
Lars-Åke Larsson ◽  
...  
Keyword(s):  
British Columbia ◽  
Tree Ring ◽  
Large Scale ◽  
Ring Width ◽  
Frequency Information ◽  
Maximum Latewood Density ◽  
Latewood Density ◽  
Summer Temperatures ◽  
Two Parameters ◽  
Blue Intensity

Maximum latewood density (MXD) is a strong proxy of summer temperatures. Despite this, there is a paucity of long MXD chronologies in the Northern Hemisphere, which limits large-scale tree-ring-based reconstructions of past temperature which are dominated by ring-width (RW) data – a weaker temperature proxy at inter-annual time-scales. This paucity likely results from the relative expense of measuring MXD and the lack of laboratories with the facilities to measure it. Herein, we test the ability of a relatively new, less expensive, tree-ring parameter, Blue Intensity (BI), to act as a surrogate parameter for MXD. BI was measured on Engelmann spruce samples from British Columbia where MXD had previously been measured to allow direct comparison between the two parameters. Signal strength analyses indicate that 8 MXD series were needed to acquire a robust mean chronology while BI needed 14. Utilising different detrending methods and parameter choices (RW + MXD vs RW + BI), a suite of reconstruction variants was developed. The explained variance from the regression modelling (1901–1995) of May–August maximum temperatures ranged from 52% to 55%. Validation tests over the earlier 1870–1900 period could not statistically distinguish between the different variants, although spectral analysis identified more lower frequency information extant in the MXD-based reconstructions – although this result was sensitive to the detrending method used. Ultimately, despite the MXD-based reconstruction explaining slightly more of the climatic variance, statistically robust reconstructions of past summer temperatures were also derived using BI. These results suggest that there is great potential in utilising BI for dendroclimatology in place of MXD data. However, more experimentation is needed to understand (1) how well BI can capture centennial and lower frequency information and (2) what biases may result from wood discolouration, either from species showing a distinct heartwood/sapwood boundary or from partly decayed sub-fossil samples.

scholarly journals Untangling cultural inheritance: language diversity and long-house architecture on the Pacific northwest coast

2010 ◽  
Vol 365 (1559) ◽  
pp. 3875-3888 ◽  
Author(s):  
Peter Jordan ◽  
Sean O'Neill
Keyword(s):  
Pacific Northwest ◽  
Cultural Transmission ◽  
Large Scale ◽  
Vernacular Architecture ◽  
Northwest Coast ◽  
Small Scale ◽  
Cultural Inheritance ◽  
Pacific Northwest Coast ◽  
The Pacific ◽  
Macro Scale

Many recent studies of cultural inheritance have focused on small-scale craft traditions practised by single individuals, which do not require coordinated participation by larger social collectives. In this paper, we address this gap in the cultural transmission literature by investigating diversity in the vernacular architecture of the Pacific northwest coast, where communities of hunter–fisher–gatherers constructed immense wooden long-houses at their main winter villages. Quantitative analyses of long-house styles along the coastline draw on a range of models and methods from the biological sciences and are employed to test hypotheses relating to basic patterns of macro-scale cultural diversification, and the degree to which the transmission of housing traits has been constrained by the region's numerous linguistic boundaries. The results indicate relatively strong branching patterns of cultural inheritance and also close associations between regional language history and housing styles, pointing to the potentially crucial role played by language boundaries in structuring large-scale patterns of cultural diversification, especially in relation to ‘collective’ cultural traditions like housing that require substantial inputs of coordinated labour.

Use of Oyster Shell to Enhance Intertidal Habitat and Mitigate Loss of Dungeness Crab (Cancer magister) Caused by Dredging

1993 ◽  
Vol 50 (2) ◽  
pp. 381-390 ◽  
Author(s):  
Brett R. Dumbauld ◽  
David A. Armstrong ◽  
Trent L. McDonald
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Oyster Shell ◽  
The United States ◽  
Dungeness Crab ◽  
Cancer Magister ◽  
Pacific Northwest Coast ◽  
Intertidal Crab ◽  
The Pacific ◽  
Scale 8

Juvenile Dungeness crab (Cancer magister) recruit to intertidal areas in estuaries along the Pacific Northwest coast of the United States in May and June of each year and survive best through their first summer in shell or eelgrass habitat. Experiments were initiated in Grays Harbor, Washington, to investigate the potential of using shell to enhance intertidal crab habitat as a means to augment the crab resource and mitigate losses from the subtidal population that occur during dredging. Experimental plots (225 m2) were constructed prior to crab settlement at each of three intertidal locations using three configurations of oyster shell (heavy layer, light scattering, and small piles of shell). Resulting crab densities were comparable with those found in naturally occurring shell with high numbers (20–60 crab∙m−2) observed during settlement that declined to a relatively stable density of 10 crab∙m−2 in July and August. Crab survival was highest in both heavy and pile configurations, but the heavy shell configuration remained intact the longest. This enhancement experiment has become the impetus for a large-scale (8 ha) mitigation program in 1992 as part of a dredging project completed in 1990 in Grays Harbor.

scholarly journals Blue Intensity based experiments for reconstructing North Pacific temperatures along the Gulf of Alaska

2017 ◽  
Author(s):  
Rob Wilson ◽  
Rosanne D'Arrigo ◽  
Laia Andreu-Hayles ◽  
Rose Oelkers ◽  
Greg Wiles ◽  
...  
Keyword(s):  
Tree Ring ◽  
North Pacific ◽  
Large Scale ◽  
Ring Width ◽  
Gulf Of Alaska ◽  
Cool Period ◽  
Latewood Density ◽  
Ocean Atmosphere ◽  
Blue Intensity

Abstract. Climate in the Gulf of Alaska (GOA) reflects large-scale ocean-atmosphere variability of the North Pacific climate system. Ring-width (RW) records from the GOA have yielded a valuable long-term perspective for North Pacific changes on decadal to longer time scales in prior studies, but express a broad winter to late summer seasonal response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the Blue Intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less expensive and labor intensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions at mid-to-high latitudes. Here we highlight the potential for improving tree-ring based reconstructions using combinations of RW and BI-related parameters (latewood BI (LWB) and delta BI (DB)) from an experimental sub-set of samples from eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first such study for the hemlock genus using BI data. We find that using either LWB or DB can improve the amount of explained temperature variance by > 10 % compared to RW alone although the optimal target season changes to June–September, which may have implications for studying ocean-atmosphere variability in the region. However, one challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood, so long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWB data. Using DB appeared to overcome these trend biases resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th/21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling more trees per site (> 20) and more sites to overcome site specific factors effecting climate response while sub-fossil material will extend the reflectance records back over 1000 years. DB appears to capture long term secular trends that agree with other proxy archives in the region but great care is needed when implementing different detrending options. Finally, more experimentation is needed to assess the utility of DB for different conifer species around the Northern Hemisphere.

Annual to decadal-scale variations in northwest Atlantic sector temperatures inferred from Labrador tree rings

1996 ◽  
Vol 26 (1) ◽  
pp. 143-148 ◽  
Author(s):  
Rosanne D. D'arrigo ◽  
Edward R. Cook ◽  
Gordon C. Jacoby
Keyword(s):  
Warm Season ◽  
Temperature Sensitive ◽  
Northwest Atlantic ◽  
Atlantic Sector ◽  
Grand Banks ◽  
Maximum Latewood Density ◽  
Latewood Density ◽  
Scale Temperature ◽  
Decadal Scale ◽  
North Atlantic Climate

Temperature-sensitive maximum latewood density chronologies from sites near tree line in Labrador are used to infer past changes in warm-season surface air and sea surface temperatures for the northwest Atlantic. Temperatures are reconstructed for the Grand Banks region based on density records from southern Labrador, while a density series from near Okak Fiord, northern Labrador, is used to infer past temperature variations for north-coastal Labrador and the adjacent Labrador Sea. The Labrador chronologies show good agreement with annual and decadal-scale temperature fluctuations over the recent period of instrumental record, and extend this temperature information into the past by several centuries. The lowest density value at the Okak site occurs in 1816, known as the "year without a summer" in eastern North America. Spectral analyses reveal statistically significant variations with periods of around 8.7, 18–22, and 45–66 years. These fluctuations are in general agreement with those identified in several instrumental and modeling analyses of North Atlantic climate.

scholarly journals Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1434
Author(s):  
James E. Overland
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Polar Vortex ◽  
The Arctic ◽  
Large Temperature ◽  
Extreme Heat Event ◽  
The Pacific ◽  
Heat Event ◽  
Large Scale Atmospheric Circulation ◽  
The Bering Sea

The extreme heat event that hit the Pacific Northwest (Oregon, Washington, southern British Columbia) at the end of June 2021 was 3 °C greater than the previous Seattle record of 39 °C; larger extremes of 49 °C were observed further inland that were 6 °C above previous record. There were hundreds of deaths over the region and loss of marine life and forests. At the large scale prior to the event, the polar vortex was split over the Arctic. A polar vortex instability center formed over the Bering Sea and then extended southward along the west coast of North America. The associated tropospheric trough (low geopotential heights) established a multi-day synoptic scale Omega Block (west-east oriented low/high/low geopotential heights) centered over the Pacific Northwest. Warming was sustained in the region due to subsidence/adiabatic heating and solar radiation, which were the main reasons for such large temperature extremes. The seasonal transition at the end of spring suggests the possibility of a southern excursion of a polar vortex/jet stream pair. Both the Pacific Northwest event in 2021 and the Siberian heatwave climax in June 2020 may be examples of crossing a critical state in large-scale atmospheric circulation variability.

scholarly journals Autumn migratory orientation and route choice in early and late dunlins Calidris alpina captured at a stopover site in Alaska

Biology Open ◽  
2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Susanne Åkesson ◽  
Johanna Grönroos ◽  
Giuseppe Bianco
Keyword(s):  
East Asia ◽  
Pacific Northwest ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
Stopover Site ◽  
Migratory Activity ◽  
Calidris Alpina ◽  
Migratory Orientation ◽  
The Pacific ◽  
Wintering Areas

ABSTRACT We investigated the migratory orientation of early and late captured dunlins, Calidris alpina, by recording their migratory activity in circular orientation cages during autumn at a staging site in southwest Alaska and performed route simulations to the wintering areas. Two races of dunlins breeding in Alaska have different wintering grounds in North America (Pacific Northwest), and East Asia. Dunlins caught early in autumn (presumably Calidris alpinapacifica) oriented towards their wintering areas (east-southeast; ESE) supporting the idea that they migrate nonstop over the Gulf of Alaska to the Pacific Northwest. We found no difference in orientation between adult and juveniles, nor between fat and lean birds or under clear and overcast skies demonstrating that age, energetic status and cloud cover did not affect the dunlins’ migratory orientation. Later in autumn, we recorded orientation responses towards south-southwest suggesting arrival of the northern subspecies Calidris alpinaarcticola at our site. Route simulations revealed multiple compass mechanisms were compatible with the initial direction of early dunlins wintering in the Pacific Northwest, and for late dunlins migrating to East Asia. Future high-resolution tracking would reveal routes, stopover use including local movements and possible course shifts during migration from Alaska to wintering sites on both sides of the north Pacific Ocean.

A Preliminary Reconstruction of Rainfall in North-Central China since A.D. 1600 from Tree-Ring Density and Width

1994 ◽  
Vol 42 (1) ◽  
pp. 88-99 ◽  
Author(s):  
Malcolm K. Hughes ◽  
Wu Xiangding ◽  
Shao Xuemei ◽  
Gregg M. Garfin
Keyword(s):  
Tree Ring ◽  
Spectral Power ◽  
Singular Spectrum Analysis ◽  
Ring Width ◽  
Central China ◽  
North Central ◽  
Ring Density ◽  
Maximum Latewood Density ◽  
Documentary Sources ◽  
Latewood Density

AbstractMay-June (MJ) and April-July (AJ) precipitation at Huashan in north-central China has been reconstructed for the period A.D. 1600 to 1988 using tree-ring density and width fromPinus armandii. MJ precipitation (based on ring width and maximum latewood density) calibrated and cross-validated against local instrumental data more strongly than AJ precipitation (based only on ring width). A major drought was reconstructed for the mid- and late 1920s, confirmed by local documentary sources. This drought (culminating in 1929) was the most severe of the 389-yr period for MJ and second most severe for AJ, after an event ending in 1683. Neither reconstruction shows much spectral power at frequencies lower than 1 in 10 yr, but both show concentrations of power between 2.1 and 2.7 yr and 3.5 to 9 yr. There are significant correlations between the two reconstructions and a regional dryness/wetness index (DW) based on documentary sources, particularly at high frequencies. These correlations are focused in the 7.6- to 7.3-, 3.8- to 3.6-, and 2.5-yr periods. Using singular spectrum analysis, quasiperiodic behavior with a period close to 7.2 yr was identified in the MJ precipitation reconstruction and in the DW index based on documents.

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