AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS
An analysis of the variability of the North Atlantic Oscillation (NAO) since the beginning of the 19th century has been carried out using monthly pressure series from Gibraltar, Lisbon, The Azores and Iceland. In the first part, the combinations of stations that best monitor the NAO at different tim...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.378.973 2023-05-15T16:51:39+02:00 AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS D. Pozo-vázqueza M. J. Esteban-parrab F. S. Rodrigoc Y. Castro-díezb A The Pennsylvania State University CiteSeerX Archives 1999 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.378.973 http://hera.ugr.es/doi/15024210.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.378.973 http://hera.ugr.es/doi/15024210.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://hera.ugr.es/doi/15024210.pdf text 1999 ftciteseerx 2016-09-18T00:15:06Z An analysis of the variability of the North Atlantic Oscillation (NAO) since the beginning of the 19th century has been carried out using monthly pressure series from Gibraltar, Lisbon, The Azores and Iceland. In the first part, the combinations of stations that best monitor the NAO at different time intervals (monthly, seasonal and winter-annual) are analysed based on a signal/noise approach. The stability through time of the relationship between the pressures at the different stations is also studied. Based on this analysis, proxy indices of the NAO are obtained and compared with the NAO index resulting from a principal component analysis (PCA) of gridded sea level pressure (SLP) data. In the second part, the cross-spectral characteristics of the data of the northern and southern stations are studied in order to determine for which ranges of periods the pressure undergoes simultaneous coherent and out-of-phase variations. Based on the cross-spectral analysis, several filters are proposed to be applied to the pressure series prior to calculating the NAO index, in order to improve the reliability of the NAO index as an indicator of the NAO. Results show that for a monthly or seasonal index, The Azores must be selected as the southern station, but the strongest relationship is found for winter using Gibraltar as the southern station. The cross-spectral analysis shows, firstly, that the periods that are mainly responsible for coherent and out-of-phase variations are 6 months, 1 year, 2 years and 8 years (the most important). Secondly, several ranges of periods, mainly from 3 to 4 years and less than Text Iceland North Atlantic North Atlantic oscillation Unknown |
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Open Polar |
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English |
description |
An analysis of the variability of the North Atlantic Oscillation (NAO) since the beginning of the 19th century has been carried out using monthly pressure series from Gibraltar, Lisbon, The Azores and Iceland. In the first part, the combinations of stations that best monitor the NAO at different time intervals (monthly, seasonal and winter-annual) are analysed based on a signal/noise approach. The stability through time of the relationship between the pressures at the different stations is also studied. Based on this analysis, proxy indices of the NAO are obtained and compared with the NAO index resulting from a principal component analysis (PCA) of gridded sea level pressure (SLP) data. In the second part, the cross-spectral characteristics of the data of the northern and southern stations are studied in order to determine for which ranges of periods the pressure undergoes simultaneous coherent and out-of-phase variations. Based on the cross-spectral analysis, several filters are proposed to be applied to the pressure series prior to calculating the NAO index, in order to improve the reliability of the NAO index as an indicator of the NAO. Results show that for a monthly or seasonal index, The Azores must be selected as the southern station, but the strongest relationship is found for winter using Gibraltar as the southern station. The cross-spectral analysis shows, firstly, that the periods that are mainly responsible for coherent and out-of-phase variations are 6 months, 1 year, 2 years and 8 years (the most important). Secondly, several ranges of periods, mainly from 3 to 4 years and less than |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
D. Pozo-vázqueza M. J. Esteban-parrab F. S. Rodrigoc Y. Castro-díezb A |
spellingShingle |
D. Pozo-vázqueza M. J. Esteban-parrab F. S. Rodrigoc Y. Castro-díezb A AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
author_facet |
D. Pozo-vázqueza M. J. Esteban-parrab F. S. Rodrigoc Y. Castro-díezb A |
author_sort |
D. Pozo-vázqueza |
title |
AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
title_short |
AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
title_full |
AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
title_fullStr |
AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
title_full_unstemmed |
AN ANALYSIS OF THE VARIABILITY OF THE NORTH ATLANTIC OSCILLATION IN THE TIME AND THE FREQUENCY DOMAINS |
title_sort |
analysis of the variability of the north atlantic oscillation in the time and the frequency domains |
publishDate |
1999 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.378.973 http://hera.ugr.es/doi/15024210.pdf |
genre |
Iceland North Atlantic North Atlantic oscillation |
genre_facet |
Iceland North Atlantic North Atlantic oscillation |
op_source |
http://hera.ugr.es/doi/15024210.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.378.973 http://hera.ugr.es/doi/15024210.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766041773907378176 |