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Identification of the driving forces of climate change using the longest instrumental temperature record

View Article: PubMed Central - PubMed

ABSTRACT

The identification of causal effects is a fundamental problem in climate change research. Here, a new perspective on climate change causality is presented using the central England temperature (CET) dataset, the longest instrumental temperature record, and a combination of slow feature analysis and wavelet analysis. The driving forces of climate change were investigated and the results showed two independent degrees of freedom —a 3.36-year cycle and a 22.6-year cycle, which seem to be connected to the El Niño–Southern Oscillation cycle and the Hale sunspot cycle, respectively. Moreover, these driving forces were modulated in amplitude by signals with millennial timescales.

No MeSH data available.


The band-pass filtering for S1-S8, where the black curves indicate the filter signals themselves, while the blue.red and green curves indicate their modulating signals from M1 to M8.This figure was produced by using the MATLAB version R2010a software (http://cn.mathworks.com).
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f4: The band-pass filtering for S1-S8, where the black curves indicate the filter signals themselves, while the blue.red and green curves indicate their modulating signals from M1 to M8.This figure was produced by using the MATLAB version R2010a software (http://cn.mathworks.com).

Mentions: To investigate each scale in detail, Fig. 4 shows the variation of the individual scale components (S1–S8 in Fig. 4) from band-pass filtering, which indicates the features of the driving forces in the time domain. Figure 4 indicates that all the signals are all strongly amplitude and phase modulated. The band-pass filters for the decomposed scale components, termed S1 to S8 from low to high frequency, were modulated in amplitude, suggesting that these signals are modulated by other signals with longer timescales. For fitting the envelopes of each filtered signal, the modulating signals, named M1 to M8, are presented using sine functions. The modulating signals can be approximately expressed as:


Identification of the driving forces of climate change using the longest instrumental temperature record
The band-pass filtering for S1-S8, where the black curves indicate the filter signals themselves, while the blue.red and green curves indicate their modulating signals from M1 to M8.This figure was produced by using the MATLAB version R2010a software (http://cn.mathworks.com).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384247&req=5

f4: The band-pass filtering for S1-S8, where the black curves indicate the filter signals themselves, while the blue.red and green curves indicate their modulating signals from M1 to M8.This figure was produced by using the MATLAB version R2010a software (http://cn.mathworks.com).
Mentions: To investigate each scale in detail, Fig. 4 shows the variation of the individual scale components (S1–S8 in Fig. 4) from band-pass filtering, which indicates the features of the driving forces in the time domain. Figure 4 indicates that all the signals are all strongly amplitude and phase modulated. The band-pass filters for the decomposed scale components, termed S1 to S8 from low to high frequency, were modulated in amplitude, suggesting that these signals are modulated by other signals with longer timescales. For fitting the envelopes of each filtered signal, the modulating signals, named M1 to M8, are presented using sine functions. The modulating signals can be approximately expressed as:

View Article: PubMed Central - PubMed

ABSTRACT

The identification of causal effects is a fundamental problem in climate change research. Here, a new perspective on climate change causality is presented using the central England temperature (CET) dataset, the longest instrumental temperature record, and a combination of slow feature analysis and wavelet analysis. The driving forces of climate change were investigated and the results showed two independent degrees of freedom —a 3.36-year cycle and a 22.6-year cycle, which seem to be connected to the El Niño–Southern Oscillation cycle and the Hale sunspot cycle, respectively. Moreover, these driving forces were modulated in amplitude by signals with millennial timescales.

No MeSH data available.