Risto Jalkanen
Biographic Data
| ID | 6384163 |
|---|---|
| NAME | Risto Jalkanen |
| GIVEN NAMES | Risto |
| FAMILY NAME | Jalkanen |
| SIGNATURE | JALKANEN R |
| AFFILIATIONS | Metla, Rovaniemi Research Unit, Finland |
| ORCID | 0000-0002-8189-2295 |
| VERIFIED | Yes |
| TOTAL WORKS | 8 |
| TOTAL CITATIONS | 37 |
| WORKS AS AUTHOR | 8 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 2003 |
| LATEST PUBLICATION YEAR | 2021 |
| H-INDEX | 4 |
Solar-type periodicities in the climate variability of Northern Fennoscandia during the last three centuries
Fifteen proxy records of summer temperature in Fennoscandia, Northern Europe and in Yamal and Taymir Peninsulas (Western Siberia) were analyzed for the AD 1700–2000 period. Century-long (70–100 year) and quasi bi-decadal periodicities were found from proxy records representing different parts of Fennoscandia. Decadal variation was revealed in a smaller number of records. Statistically significant correlations were revealed between the timescale-d…
A 1200-year multiproxy record of tree growth and summer temperature at the northern pine forest limit of Europe
Combining nine tree growth proxies from four sites, from the west coast of Norway to the Kola Peninsula of NW Russia, provides a well replicated (> 100 annual measurements per year) mean index of tree growth over the last 1200 years that represents the growth of much of the northern pine timberline forests of northern Fennoscandia. The simple mean of the nine series, z-scored over their common period, correlates strongly with mean June to August …
Subcentury scale variability in height-increment and tree-ring width chronologies of Scots pine since ad 745 in northern Fennoscandia
Height-increment and tree-ring width data of Scots pine from northern Fennoscandia were updated and their sample replication increased considerably. Standard chronologies as well as low-frequency chronologies were built and compared during their common period in ad 745–2007. The two chronologies correlate significantly ( r = 0.58) with each other and have several extreme years in common, e.g. 1089 and 1601. The low-frequency chronologies indicate…
The height-increment record of summer temperature extended over the last millennium in Fennoscandia
New data have allowed us to extend a previous height-increment chronology of Scots pine ( Pinus sylvestris L.) at the northern Fennoscandian timberline 817 years backwards in time, from 1561 to 745. Our final transfer model accounts for 31% of the dependent instrumental (mean June—August) temperature variance between 1908 and 2007. According to the 1263 yr long summer temperature proxy, the most severe summers were experienced in 1601, 1790 and 7…
A summer temperature proxy from height increment of Scots pine since 1561 at the northern timberline in Fennoscandia
Height increments of 60 Scots pine trees were used to reconstruct mean June—August temperature variability at interannual to decadal scales from 1561 to 2004. Three standardization methods (67%, 33% flexible splines, and a fixed 22 years spline) were compared in building chronologies in order to optimize the frequency response in relation to major climatic forcing factors. The height-growth chronology built using the 33% spline standardization pr…
Exorcising the `segment length curse
Stable carbon isotope ratios from the latewood cellulose of 12 trees from two sites in northern Finland are used to construct an isotope chronology covering AD 1640 to 2002. By measuring isotopic ratios of every sample independently it is possible to identify and remove the juvenile portion of each δ 13 C series, correct the individual series for anthropogenic changes in atmospheric carbon dioxide isotopic ratios and concentrations, and to quanti…
Blue intensity in Pinus sylvestris tree-rings
Minimum blue intensity measurements of resin-extracted Pinus sylvestris (L.) samples, conducted using a flat-bed scanner and commercially available software, are shown to provide a robust and reliable surrogate for maximum latewood density. Blue intensity data from 15 trees, from three stands, are reported relative to a standard blue-scale in a manner similar to grey-scale calibration in x-ray densitometry. The resulting time series are highly co…
Multiproxy dendroclimatology
Ten potential proxy measures of past climate were recovered from Scots pine (Pinus sylvestris) at three sites on a latitudinal transect close to the pine limit in northern Finland (earlywood, latewood and annual ring width; earlywood, latewood and maximum density; stable carbon isotope ratio; height increment; needle production; pollen deposition). Cambium dynamics were also monitored. The aim was to determine how climate influences each potentia…
A 1200-year multiproxy record of tree growth and summer temperature at the northern pine forest limit of Europe
Combining nine tree growth proxies from four sites, from the west coast of Norway to the Kola Peninsula of NW Russia, provides a well replicated (> 100 annual measurements per year) mean index of tree growth over the last 1200 years that represents the growth of much of the northern pine timberline forests of northern Fennoscandia. The simple mean of the nine series, z-scored over their common period, correlates strongly with mean June to August …
Blue intensity in Pinus sylvestris tree-rings
Minimum blue intensity measurements of resin-extracted Pinus sylvestris (L.) samples, conducted using a flat-bed scanner and commercially available software, are shown to provide a robust and reliable surrogate for maximum latewood density. Blue intensity data from 15 trees, from three stands, are reported relative to a standard blue-scale in a manner similar to grey-scale calibration in x-ray densitometry. The resulting time series are highly co…
Multiproxy dendroclimatology
Ten potential proxy measures of past climate were recovered from Scots pine (Pinus sylvestris) at three sites on a latitudinal transect close to the pine limit in northern Finland (earlywood, latewood and annual ring width; earlywood, latewood and maximum density; stable carbon isotope ratio; height increment; needle production; pollen deposition). Cambium dynamics were also monitored. The aim was to determine how climate influences each potentia…
Exorcising the `segment length curse
Stable carbon isotope ratios from the latewood cellulose of 12 trees from two sites in northern Finland are used to construct an isotope chronology covering AD 1640 to 2002. By measuring isotopic ratios of every sample independently it is possible to identify and remove the juvenile portion of each δ 13 C series, correct the individual series for anthropogenic changes in atmospheric carbon dioxide isotopic ratios and concentrations, and to quanti…
The height-increment record of summer temperature extended over the last millennium in Fennoscandia
New data have allowed us to extend a previous height-increment chronology of Scots pine ( Pinus sylvestris L.) at the northern Fennoscandian timberline 817 years backwards in time, from 1561 to 745. Our final transfer model accounts for 31% of the dependent instrumental (mean June—August) temperature variance between 1908 and 2007. According to the 1263 yr long summer temperature proxy, the most severe summers were experienced in 1601, 1790 and 7…
A summer temperature proxy from height increment of Scots pine since 1561 at the northern timberline in Fennoscandia
Height increments of 60 Scots pine trees were used to reconstruct mean June—August temperature variability at interannual to decadal scales from 1561 to 2004. Three standardization methods (67%, 33% flexible splines, and a fixed 22 years spline) were compared in building chronologies in order to optimize the frequency response in relation to major climatic forcing factors. The height-growth chronology built using the 33% spline standardization pr…
Multiproxy dendroclimatology
Ten potential proxy measures of past climate were recovered from Scots pine (Pinus sylvestris) at three sites on a latitudinal transect close to the pine limit in northern Finland (earlywood, latewood and annual ring width; earlywood, latewood and maximum density; stable carbon isotope ratio; height increment; needle production; pollen deposition). Cambium dynamics were also monitored. The aim was to determine how climate influences each potentia…
Exorcising the `segment length curse
Stable carbon isotope ratios from the latewood cellulose of 12 trees from two sites in northern Finland are used to construct an isotope chronology covering AD 1640 to 2002. By measuring isotopic ratios of every sample independently it is possible to identify and remove the juvenile portion of each δ 13 C series, correct the individual series for anthropogenic changes in atmospheric carbon dioxide isotopic ratios and concentrations, and to quanti…
Blue intensity in Pinus sylvestris tree-rings
Minimum blue intensity measurements of resin-extracted Pinus sylvestris (L.) samples, conducted using a flat-bed scanner and commercially available software, are shown to provide a robust and reliable surrogate for maximum latewood density. Blue intensity data from 15 trees, from three stands, are reported relative to a standard blue-scale in a manner similar to grey-scale calibration in x-ray densitometry. The resulting time series are highly co…
A summer temperature proxy from height increment of Scots pine since 1561 at the northern timberline in Fennoscandia
Height increments of 60 Scots pine trees were used to reconstruct mean June—August temperature variability at interannual to decadal scales from 1561 to 2004. Three standardization methods (67%, 33% flexible splines, and a fixed 22 years spline) were compared in building chronologies in order to optimize the frequency response in relation to major climatic forcing factors. The height-growth chronology built using the 33% spline standardization pr…
The height-increment record of summer temperature extended over the last millennium in Fennoscandia
New data have allowed us to extend a previous height-increment chronology of Scots pine ( Pinus sylvestris L.) at the northern Fennoscandian timberline 817 years backwards in time, from 1561 to 745. Our final transfer model accounts for 31% of the dependent instrumental (mean June—August) temperature variance between 1908 and 2007. According to the 1263 yr long summer temperature proxy, the most severe summers were experienced in 1601, 1790 and 7…
Subcentury scale variability in height-increment and tree-ring width chronologies of Scots pine since ad 745 in northern Fennoscandia
Height-increment and tree-ring width data of Scots pine from northern Fennoscandia were updated and their sample replication increased considerably. Standard chronologies as well as low-frequency chronologies were built and compared during their common period in ad 745–2007. The two chronologies correlate significantly ( r = 0.58) with each other and have several extreme years in common, e.g. 1089 and 1601. The low-frequency chronologies indicate…
A 1200-year multiproxy record of tree growth and summer temperature at the northern pine forest limit of Europe
Combining nine tree growth proxies from four sites, from the west coast of Norway to the Kola Peninsula of NW Russia, provides a well replicated (> 100 annual measurements per year) mean index of tree growth over the last 1200 years that represents the growth of much of the northern pine timberline forests of northern Fennoscandia. The simple mean of the nine series, z-scored over their common period, correlates strongly with mean June to August …
Solar-type periodicities in the climate variability of Northern Fennoscandia during the last three centuries
Fifteen proxy records of summer temperature in Fennoscandia, Northern Europe and in Yamal and Taymir Peninsulas (Western Siberia) were analyzed for the AD 1700–2000 period. Century-long (70–100 year) and quasi bi-decadal periodicities were found from proxy records representing different parts of Fennoscandia. Decadal variation was revealed in a smaller number of records. Statistically significant correlations were revealed between the timescale-d…
Geography (8 works) · Geology (8 works) · Physical geography (8 works) · Tree-ring climate responses (8 works) · Climatology (7 works) · Environmental Science (7 works) · Plant Water Relations and Carbon Dynamics (7 works) · Geology and Paleoclimatology Research (5 works) · Pinus (5 works) · Proxy (statistics (4 works)