The interpretation of short climate records, with comments on the North Atlantic and
This pedagogical note reminds the reader that the interpretation of climate records is dependent upon understanding the behavior of stochastic processes. In particular, before concluding that one is seeing evidence for trends, shifts in the mean, or changes in oscillation periods, one must rule out...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.390.2100 2023-05-15T17:30:23+02:00 The interpretation of short climate records, with comments on the North Atlantic and Carl Wunsch The Pennsylvania State University CiteSeerX Archives 1999 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.390.2100 http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.390.2100 http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf text 1999 ftciteseerx 2016-09-18T00:45:27Z This pedagogical note reminds the reader that the interpretation of climate records is dependent upon understanding the behavior of stochastic processes. In particular, before concluding that one is seeing evidence for trends, shifts in the mean, or changes in oscillation periods, one must rule out the purely random fluctuations expected from stationary time series. The example of the North Atlantic oscillation (NAO) is mainly used here: the spectral density is nearly white (frequency power law ≈ s −0.2) with slight broadband features near 8 and 2.5 yr. By generating synthetic but stationary time series, one can see exhibited many of the features sometimes exciting attention as being of causal climate significance. Such a display does not disprove the hypothesis of climate change, but it provides a simple null hypothesis for what is seen. In addition, it is shown that the linear predictive skill for the NAO index must be very slight (less than 3% of the variance). A brief comparison with the Southern Oscillation shows a different spectral distribution, but again a simulation has long periods of apparent systematic sign and trends. Application of threshold-crossing statistics (Ricean) shows no contradiction to the assumption that the Darwin pressure record is statistically stationary. 1. Text North Atlantic North Atlantic oscillation Unknown |
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This pedagogical note reminds the reader that the interpretation of climate records is dependent upon understanding the behavior of stochastic processes. In particular, before concluding that one is seeing evidence for trends, shifts in the mean, or changes in oscillation periods, one must rule out the purely random fluctuations expected from stationary time series. The example of the North Atlantic oscillation (NAO) is mainly used here: the spectral density is nearly white (frequency power law ≈ s −0.2) with slight broadband features near 8 and 2.5 yr. By generating synthetic but stationary time series, one can see exhibited many of the features sometimes exciting attention as being of causal climate significance. Such a display does not disprove the hypothesis of climate change, but it provides a simple null hypothesis for what is seen. In addition, it is shown that the linear predictive skill for the NAO index must be very slight (less than 3% of the variance). A brief comparison with the Southern Oscillation shows a different spectral distribution, but again a simulation has long periods of apparent systematic sign and trends. Application of threshold-crossing statistics (Ricean) shows no contradiction to the assumption that the Darwin pressure record is statistically stationary. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Carl Wunsch |
spellingShingle |
Carl Wunsch The interpretation of short climate records, with comments on the North Atlantic and |
author_facet |
Carl Wunsch |
author_sort |
Carl Wunsch |
title |
The interpretation of short climate records, with comments on the North Atlantic and |
title_short |
The interpretation of short climate records, with comments on the North Atlantic and |
title_full |
The interpretation of short climate records, with comments on the North Atlantic and |
title_fullStr |
The interpretation of short climate records, with comments on the North Atlantic and |
title_full_unstemmed |
The interpretation of short climate records, with comments on the North Atlantic and |
title_sort |
interpretation of short climate records, with comments on the north atlantic and |
publishDate |
1999 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.390.2100 http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.390.2100 http://ocean.mit.edu/~cwunsch/papersonline/bamsrednoise.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766126753007271936 |