Next Article in Journal / Special Issue
Entropy-Based Experimental Design for Optimal Model Discrimination in the Geosciences
Previous Article in Journal
Thermodynamics of Noncommutative Quantum Kerr Black Holes
Previous Article in Special Issue
Fuzzy Shannon Entropy: A Hybrid GIS-Based Landslide Susceptibility Mapping Method
Article Menu
Issue 11 (November) cover image

Export Article

Open AccessArticle
Entropy 2016, 18(11), 408; doi:10.3390/e18110408

Global Atmospheric Dynamics Investigated by Using Hilbert Frequency Analysis

1
Departament de Física, Universitat Politècnica de Catalunya, Edifici Gaia, Terrassa, Barcelona 08222, Spain
2
Instituto de Física, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo 11400, Uruguay
*
Author to whom correspondence should be addressed.
Academic Editors: Raúl Alcaraz Martínez and Kevin H. Knuth
Received: 7 September 2016 / Revised: 19 October 2016 / Accepted: 14 November 2016 / Published: 16 November 2016
(This article belongs to the Special Issue Applications of Information Theory in the Geosciences)
View Full-Text   |   Download PDF [914 KB, uploaded 16 November 2016]   |  

Abstract

The Hilbert transform is a well-known tool of time series analysis that has been widely used to investigate oscillatory signals that resemble a noisy periodic oscillation, because it allows instantaneous phase and frequency to be estimated, which in turn uncovers interesting properties of the underlying process that generates the signal. Here we use this tool to analyze atmospheric data: we consider daily-averaged Surface Air Temperature (SAT) time series recorded over a regular grid of locations covering the Earth’s surface. From each SAT time series, we calculate the instantaneous frequency time series by considering the Hilbert analytic signal. The properties of the obtained frequency data set are investigated by plotting the map of the average frequency and the map of the standard deviation of the frequency fluctuations. The average frequency map reveals well-defined large-scale structures: in the extra-tropics, the average frequency in general corresponds to the expected one-year period of solar forcing, while in the tropics, a different behaviour is found, with particular regions having a faster average frequency. In the standard deviation map, large-scale structures are also found, which tend to be located over regions of strong annual precipitation. Our results demonstrate that Hilbert analysis of SAT time-series uncovers meaningful information, and is therefore a promising tool for the study of other climatological variables. View Full-Text
Keywords: time-series analysis; Hilbert transform; atmospheric phenomena; climate dynamics; variability; complex systems; external forcing; noise time-series analysis; Hilbert transform; atmospheric phenomena; climate dynamics; variability; complex systems; external forcing; noise
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Zappalà, D.A.; Barreiro, M.; Masoller, C. Global Atmospheric Dynamics Investigated by Using Hilbert Frequency Analysis. Entropy 2016, 18, 408.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Entropy EISSN 1099-4300 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top