E-Thesis 289 views 75 downloads
Stable isotope dendroclimatology at Forfjorddalen in northwestern Norway. / Giles Hugh Findlay Young
Swansea University Author: Giles Hugh Findlay Young
Abstract
Climate change has become a key issue for the 21st century and producing future climatic scenarios has become a priority. However, to model future climate scenarios successfully and to understand their implications it is important to have a clear picture of past climate. Stable isotopes from tree ri...
| Published: |
Swansea
2008
|
|---|---|
| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa42414 |
| Abstract: |
Climate change has become a key issue for the 21st century and producing future climatic scenarios has become a priority. However, to model future climate scenarios successfully and to understand their implications it is important to have a clear picture of past climate. Stable isotopes from tree rings may have the potential to reconstruct past climate at all temporal frequencies. This thesis presents a reconstruction of temperature (AD 1394- 2001) and precipitation (AD 1765-2001) from Forfjorddalen in northwest Norway based on and delta13C and delta18O, respectively. Tree cores were dated and the annual growth rings cut and extracted to alpha-cellulose, measurements of delta13C and delta18O and were then made. Corrected delta13C[pin] was calibrated with temperature (r = 0.71) and delta18O with precipitation (r = 0.57). A conceptual model of the relationship between delta13C and delta18O and temperature and precipitation is presented to explain a period of non-linearity in the relationship between delta13C and temperature. The delta13C temperature reconstruction suggests periods with warmer summer temperatures than the late twentieth century during the mid 18th and early 17th centuries; the coldest periods occur in the early 15th and late 19th centuries. This reconstruction compares favorably with long Scandinavian temperature records form Tornedalen (AD 1802) and Uppsala (AD 1722) and a recent tree-ring density based reconstruction from Tornetrask. It also exhibits much greater multi-decadal variability than the previous, ring-width based, Forfjorddalen temperature reconstruction. A precipitation reconstruction (AD 1765 to 2001) shows wet conditions during the late 18th and early 19th centuries followed by a dry period in the late 19th century, becoming wetter again through the 20th century. Spatial field correlations demonstrate the potential for proxy data from Forfjorddalen to reconstruct climate on a regional scale; combination with data from Tornetrask yields correlations > r=0.70 with much of northwestern Scandinavian temperature. |
|---|---|
| Keywords: |
Biogeochemistry, Paleoclimate science, Climate change |
| College: |
Faculty of Science and Engineering |