scholarly journals East European chironomid-based calibration model for past summer temperature reconstructions

2019 ◽  
Vol 77 (1) ◽  
pp. 63-76 ◽  
Author(s):  
TP Luoto ◽  
B Kotrys ◽  
M Płóciennik
Keyword(s):  
Summer Temperature ◽  
Calibration Model ◽  
East European ◽  
Temperature Reconstructions ◽  
Past Summer

The relationship between water and air temperature in chironomid-based paleoclimate reconstructions: Records from boreal and subarctic Finland

The Holocene ◽  
2014 ◽  
Vol 24 (11) ◽  
pp. 1584-1590 ◽  
Author(s):  
Tomi P Luoto ◽  
Marjut Kaukolehto ◽  
Liisa Nevalainen
Keyword(s):  
Water Temperature ◽  
Air Temperature ◽  
Sediment Cores ◽  
Regional Scale ◽  
Calibration Model ◽  
Related Factors ◽  
Temperature Reconstructions ◽  
Close Relationship ◽  
Performance Statistics ◽  
Temperature Optima

Fossil remains of larval chironomids are one of the most useful paleolimnological proxies to reconstruct Holocene paleoclimate. We investigate the within-lake distribution of chironomids in relation to water temperature and test the usability of intralake calibration in chironomid-based temperature reconstructions. We compare our findings against the traditional multilake calibration technique in Holocene sediment cores from Finland. The results show that intralake water temperature optima of common taxa correspond closely with mean July air temperature optima in a regional multilake dataset, with exception of a few vegetation-associated taxa. A calibration model based on intralake water temperatures shows performance statistics that correspond to the general performance statistics level of multilake calibration models. However, the intralake model has somewhat increased prediction error. Despite the fact that the intralake model is sensitive to poor modern analogues, it shows correlation with the results using the multilake calibration approach in the Holocene reconstructions. Our results confirm that the within-lake distribution of chironomids along a water depth gradient is closely linked with water temperature gradient. This provides evidence for the close relationship between chironomids and temperature in general and suggests that, in addition to the regional scale, water temperature is a key variable in determining chironomid distribution at the site-specific scale. However, long-term changes in intralake gradients in other depth-related factors, such as hypolimnetic oxygen conditions, extent of photic zone and habitat distribution, may hamper the quantitative accuracy of chironomid-based temperature reconstructions, though the results also suggest that these changes are likely to have little general impact on the trends of chironomid-based air temperature reconstructions.

A pre-deforestation pollen-climate calibration model for New Zealand and quantitative temperature reconstructions for the past 18 000 years BP

2007 ◽  
Vol 22 (5) ◽  
pp. 535-547 ◽  
Author(s):  
Janet M. Wilmshurst ◽  
Matt S. McGlone ◽  
John R. Leathwick ◽  
Rewi M. Newnham
Keyword(s):  
New Zealand ◽  
Calibration Model ◽  
The Past ◽  
Temperature Reconstructions

scholarly journals Blue intensity and density from northern Fennoscandian tree rings, exploring the potential to improve summer temperature reconstructions with earlywood information

2014 ◽  
Vol 10 (2) ◽  
pp. 877-885 ◽  
Author(s):  
J. A. Björklund ◽  
B. E. Gunnarson ◽  
K. Seftigen ◽  
J. Esper ◽  
H. W. Linderholm
Keyword(s):  
Tree Ring ◽  
Wood Density ◽  
Lignin Content ◽  
Warm Season ◽  
Summer Temperature ◽  
Latewood Density ◽  
Radiographic Measurements ◽  
Temperature Reconstructions ◽  
June July ◽  
Blue Intensity

Abstract. Here we explore two new tree-ring parameters, derived from measurements of wood density and blue intensity (BI). The new proxies show an increase in the interannual summer temperature signal compared to established proxies, and present the potential to improve long-term performance. At high latitudes, where tree growth is mainly limited by low temperatures, radiodensitometric measurements of wood density, specifically maximum latewood density (MXD), provides a temperature proxy that is superior to that of tree-ring widths. The high cost of developing MXD has led to experimentation with a less expensive method using optical flatbed scanners to produce a new proxy, herein referred to as maximum latewood blue absorption intensity (abbreviated MXBI). MXBI is shown to be very similar to MXD on annual timescales but less accurate on centennial timescales. This is due to the fact that extractives, such as resin, stain the wood differentially from tree to tree and from heartwood to sapwood. To overcome this problem, and to address similar potential problems in radiodensitometric measurements, the new parameters Δblue intensity (ΔBI) and Δdensity are designed by subtracting the ambient BI/density in the earlywood, as a background value, from the latewood measurements. As a case-study, based on Scots pine trees from Northern Sweden, we show that Δdensity can be used as a quality control of MXD values and that the reconstructive performance of warm-season mean temperatures is more focused towards the summer months (JJA – June, July, August), with an increase by roughly 20% when also utilising the interannual information from the earlywood. However, even though the new parameter ΔBI experiences an improvement as well, there are still puzzling dissimilarities between Δdensity and ΔBI on multicentennial timescales. As a consequence, temperature reconstructions based on ΔBI will presently only be able to resolve information on decadal-to-centennial timescales. The possibility of trying to calibrate BI into a measure of lignin content or density, similarly to how radiographic measurements are calibrated into density, could be a solution. If this works, only then can ΔBI be used as a reliable proxy in multicentennial-scale climate reconstructions.

Pollen-based summer temperature reconstructions for the eastern Canadian boreal forest, subarctic, and Arctic

2004 ◽  
Vol 23 (18-19) ◽  
pp. 1901-1924 ◽  
Author(s):  
Michael W. Kerwin ◽  
Jonathan T. Overpeck ◽  
Robert S. Webb ◽  
Katherine H. Anderson
Keyword(s):  
Boreal Forest ◽  
Summer Temperature ◽  
Temperature Reconstructions ◽  
Canadian Boreal Forest

scholarly journals A Millennial Summer Temperature Reconstruction for the Eastern Tibetan Plateau from Tree-Ring Width*

2015 ◽  
Vol 28 (13) ◽  
pp. 5289-5304 ◽  
Author(s):  
Jianglin Wang ◽  
Bao Yang ◽  
Fredrik Charpentier Ljungqvist
Keyword(s):  
Tibetan Plateau ◽  
Tree Ring ◽  
Ring Width ◽  
Summer Temperature ◽  
Temperature Variability ◽  
Tree Ring Width ◽  
Eastern Tibetan Plateau ◽  
The Past ◽  
Temperature Reconstructions ◽  
Past Millennium

Abstract Although tree-ring-width-based temperature reconstructions of centennial-to-millennial length have previously been published for many parts of the eastern Tibetan Plateau (ETP), a millennium-long regional-scale composite reconstruction with annual resolution has so far been lacking. Here, the authors present a reconstruction of June–August (JJA) temperature variability over the ETP for the period AD 1000–2005 using a nested composite-plus-scale (CPS) approach to 12 temperature-sensitive tree-ring width chronologies, including 946 individual tree-ring width series. The composite reconstruction reveals warm episodes occurring during much of the sixteenth, nineteenth, and twentieth centuries and cold episodes during much of the eleventh, seventeenth, and eighteenth centuries. The period AD 1996–2005 is likely the warmest decade in the context of the past millennium. The authors explore the influence of possible forcings, finding only a weak direct relationship of temperature changes over the ETP with solar forcing at multidecadal time scales but a robust in-phase relationship with the Atlantic multidecadal oscillation (AMO) during the past millennium. This suggests that the AMO may play an important role in controlling summer temperature variability over the ETP at multidecadal time scales. A comparison with temperature reconstructions from the higher latitudes of East Asia, central-eastern China, and the whole of the Northern Hemisphere shows that the cold eleventh century and the warm nineteenth century prevailing over ETP are somewhat unique, suggesting regional specific characteristics of the temperature variability in this region. This result highlights the need to further increase the number of millennium-long, high-resolution temperature records from East Asia.

Sign in / Sign up

Export Citation Format

Share Document