The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction
Hernandez, A. et. al. The North Atlantic Oscillation (NAO) is the main atmospheric circulation mode controlling climate variability in the Northern Hemisphere. Instrumental records of the NAO are relatively short, and therefore proxy approaches are essential to understand its evolution over longer t...
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ftcsic:oai:digital.csic.es:10261/132096 2024-02-11T10:06:21+01:00 The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction Hernández, Armand Rubio de Ingles, Maria Jesus Sánchez-López, Guiomar Giralt, Santiago 2015-04-12 http://hdl.handle.net/10261/132096 unknown European Geosciences Union Publisher's version Sí European Geosciences Union General Assembly 2015 Vienna, Austria 12 – 17 April 2015 EGU2015-13201-1 http://hdl.handle.net/10261/132096 open comunicación de congreso http://purl.org/coar/resource_type/c_5794 2015 ftcsic 2024-01-16T10:15:13Z Hernandez, A. et. al. The North Atlantic Oscillation (NAO) is the main atmospheric circulation mode controlling climate variability in the Northern Hemisphere. Instrumental records of the NAO are relatively short, and therefore proxy approaches are essential to understand its evolution over longer time periods. Diatom oxygen isotope ratios are increasingly being used for palaeoclimatic reconstructions in lacustrine sedimentary records. However, application of this proxy to annual-to-decadal resolution lacustrine records is still in its infancy. To our knowledge, oxygen isotope ratios from diatoms at annual-to-decadal resolution has not been attempted, mainly due to the difficulty in obtaining large enough samples suitable for analysis at this temporal scale. Here we present a high-resolution, ca. 200-year-long, proxy record based on 56 oxygen isotope measurements from Lake Santiago (37 ̊ 50’ N – 25 ̊ 47’W, Azores Archipelago, Portugal). This record will be compared to instrumental data of precipitation and NAO index values to test its robustness to conduct an ancient NAO reconstruction. In detail the oxygen isotope data shows an isotope depletion trend (-3 h), with several interannual oscillations, from 1830 cal yr AD until present. The entire record can be divided into two intervals. The interval, from 1830 to 1938 cal yr AD, displays values above the average (+33h), whereas the interval from 1939 to 2012 cal yr AD shows values below the mean. Since Lake Santiago is a hydrologically closed lake, the oxygen isotope variations are mostly related to the precipitation-evaporation ratio. These results exhibit a good agreement with the rainfall instrumental data with an increase of net rainfall amount through the last decades in the Azores archipelago. Besides this, the short-term recorded isotope excursions (3.5h) are related to the rainfall interannual variability.These patterns suggest that the isotope data from diatom silica in Lake Santiago sediments are directly linked to past precipitation changes on the ... Conference Object North Atlantic North Atlantic oscillation Digital.CSIC (Spanish National Research Council) Hernandez ENVELOPE(-62.167,-62.167,-74.500,-74.500) |
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Digital.CSIC (Spanish National Research Council) |
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Hernandez, A. et. al. The North Atlantic Oscillation (NAO) is the main atmospheric circulation mode controlling climate variability in the Northern Hemisphere. Instrumental records of the NAO are relatively short, and therefore proxy approaches are essential to understand its evolution over longer time periods. Diatom oxygen isotope ratios are increasingly being used for palaeoclimatic reconstructions in lacustrine sedimentary records. However, application of this proxy to annual-to-decadal resolution lacustrine records is still in its infancy. To our knowledge, oxygen isotope ratios from diatoms at annual-to-decadal resolution has not been attempted, mainly due to the difficulty in obtaining large enough samples suitable for analysis at this temporal scale. Here we present a high-resolution, ca. 200-year-long, proxy record based on 56 oxygen isotope measurements from Lake Santiago (37 ̊ 50’ N – 25 ̊ 47’W, Azores Archipelago, Portugal). This record will be compared to instrumental data of precipitation and NAO index values to test its robustness to conduct an ancient NAO reconstruction. In detail the oxygen isotope data shows an isotope depletion trend (-3 h), with several interannual oscillations, from 1830 cal yr AD until present. The entire record can be divided into two intervals. The interval, from 1830 to 1938 cal yr AD, displays values above the average (+33h), whereas the interval from 1939 to 2012 cal yr AD shows values below the mean. Since Lake Santiago is a hydrologically closed lake, the oxygen isotope variations are mostly related to the precipitation-evaporation ratio. These results exhibit a good agreement with the rainfall instrumental data with an increase of net rainfall amount through the last decades in the Azores archipelago. Besides this, the short-term recorded isotope excursions (3.5h) are related to the rainfall interannual variability.These patterns suggest that the isotope data from diatom silica in Lake Santiago sediments are directly linked to past precipitation changes on the ... |
format |
Conference Object |
author |
Hernández, Armand Rubio de Ingles, Maria Jesus Sánchez-López, Guiomar Giralt, Santiago |
spellingShingle |
Hernández, Armand Rubio de Ingles, Maria Jesus Sánchez-López, Guiomar Giralt, Santiago The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
author_facet |
Hernández, Armand Rubio de Ingles, Maria Jesus Sánchez-López, Guiomar Giralt, Santiago |
author_sort |
Hernández, Armand |
title |
The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
title_short |
The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
title_full |
The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
title_fullStr |
The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
title_full_unstemmed |
The use of the oxygen isotopes from diatom silica as a proxy for North Atlantic Oscillation reconstruction |
title_sort |
use of the oxygen isotopes from diatom silica as a proxy for north atlantic oscillation reconstruction |
publisher |
European Geosciences Union |
publishDate |
2015 |
url |
http://hdl.handle.net/10261/132096 |
long_lat |
ENVELOPE(-62.167,-62.167,-74.500,-74.500) |
geographic |
Hernandez |
geographic_facet |
Hernandez |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Publisher's version Sí European Geosciences Union General Assembly 2015 Vienna, Austria 12 – 17 April 2015 EGU2015-13201-1 http://hdl.handle.net/10261/132096 |
op_rights |
open |
_version_ |
1790603995567357952 |