Transfer Entropy between South Atlantic Anomaly and Global Sea Level for the last 300 years

Campuzano, Saioa A.; Santis, Angelo De; Pavón‐Carrasco, F. J.; Osete, María Luisa; Qamili, Enkelejda

doi:10.5194/nhess-2016-56

Cited by 2 publications

(3 citation statements)

References 50 publications

(79 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result is in agreement with the argument made by Svensmark (2007). However, there are few works reporting the possible indirect influence of the geomagnetic field on climatic variations during the last century (e.g., Vieira and da Silva, 2006;Courtillot et al, 2007;Frigo et al, 2013;Campuzano et al, 2016). Frigo et al (2013) investigated the spectral coherence between the 11-and 22-year solar activity cycles and the yearly average temperatures recorded during the last century at four weather stations located in southern Brazil's coastal region.…”

Section: Introductionsupporting

confidence: 86%

“…Some of these works suggest that climatic modulation occurs indirectly, through the action of galactic cosmic rays (GCRs) (e.g., Svensmark and Friis-Christensen, 1997). GCRs are predominantly positively electrically charged particles; although these contribute very little to the energy input, they are very important in the ionization processes in the Earth's atmosphere (Carslaw et al, 2002). The entrance of GCRs to the atmosphere is modulated by the magnetic fields of the Sun and the Earth.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil

et al. 2018

View full text Add to dashboard Cite

Quasi-periodic variations in solar activity and galactic cosmic rays (GCRs) on decadal and bidecadal timescales have been suggested as a climate forcing mechanism for many regions on Earth. One of these regions is southern Brazil, where the lowest values during the last century were observed for the total geomagnetic field intensity at the Earth's surface. These low values are due to the passage of the center of the South Atlantic Magnetic Anomaly (SAMA), which crosses the Brazilian territory from east to west following a latitude of ∼ 26 • . In areas with low geomagnetic intensity, such as the SAMA, the incidence of GCRs is increased. Consequently, possible climatic effects related to the GCRs tend to be maximized in this region. In this work, we investigate the relationship between the ∼ 11year and ∼ 22-year cycles that are related to solar activity and GCRs and the annual average temperature recorded between 1936 and 2014 at two weather stations, both located near a latitude of 26 • S but at different longitudes. The first of these stations (Torres -TOR) is located in the coastal region, and the other (Iraí -IRA) is located in the interior, around 450 km from the Atlantic Ocean. Sunspot data and the solar modulation potential for cosmic rays were used as proxies for the solar activity and the GCRs, respectively. Our investigation of the influence of decadal and bidecadal cycles in temperature data was carried out using the wavelet transform coherence (WTC) spectrum. The results indicate that periodicities of 11 years may have continuously modulated the climate at TOR via a nonlinear mechanism, while at IRA, the effects of this 11-year modulation period were intermittent. Four temperature maxima, separated by around 20 years, were detected in the same years at both weather stations. These temperature maxima are almost coincident with the maxima of the odd solar cycles. Furthermore, these maxima occur after transitions from even to odd solar cycles, that is, after some years of intense GCR flux. The obtained results offer indirect mathematical evidence that solar activity and GCR variations contributed to climatic changes in southern Brazil during the last century. A comparison of the results obtained for the two weather stations indicates that the SAMA also contributes indirectly to these temperature variations. The contribution of other mechanisms also related to solar activity cannot be excluded.

show abstract

Section: Introductionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Their results suggested that greenhouse gases are primary contributors to the recent climate variability. The authors of [ 23 ] studied the information exchange between the South Atlantic anomaly and global sea level for the last 300 years using TE and concluded that larger information is exchanged from the south Atlantic anomaly to global sea-level rise than vice versa. However, these studies relied only on a single TE estimation technique (binning).…”

Section: Introductionmentioning

confidence: 99%

Quantification of Information Exchange in Idealized and Climate System Applications

Pothapakula

Primo

Ahrens

2019

Entropy

View full text Add to dashboard Cite

Often in climate system studies, linear and symmetric statistical measures are applied to quantify interactions among subsystems or variables. However, they do not allow identification of the driving and responding subsystems. Therefore, in this study, we aimed to apply asymmetric measures from information theory: the axiomatically proposed transfer entropy and the first principle-based information flow to detect and quantify climate interactions. As their estimations are challenging, we initially tested nonparametric estimators like transfer entropy (TE)-binning, TE-kernel, and TE k-nearest neighbor and parametric estimators like TE-linear and information flow (IF)-linear with idealized two-dimensional test cases along with their sensitivity on sample size. Thereafter, we experimentally applied these methods to the Lorenz-96 model and to two real climate phenomena, i.e., (1) the Indo-Pacific Ocean coupling and (2) North Atlantic Oscillation (NAO)–European air temperature coupling. As expected, the linear estimators work for linear systems but fail for strongly nonlinear systems. The TE-kernel and TE k-nearest neighbor estimators are reliable for linear and nonlinear systems. Nevertheless, the nonparametric methods are sensitive to parameter selection and sample size. Thus, this work proposes a composite use of the TE-kernel and TE k-nearest neighbor estimators along with parameter testing for consistent results. The revealed information exchange in Lorenz-96 is dominated by the slow subsystem component. For real climate phenomena, expected bidirectional information exchange between the Indian and Pacific SSTs was detected. Furthermore, expected information exchange from NAO to European air temperature was detected, but also unexpected reversal information exchange. The latter might hint to a hidden process driving both the NAO and European temperatures. Hence, the limitations, availability of time series length and the system at hand must be taken into account before drawing any conclusions from TE and IF-linear estimations.

show abstract

Transfer Entropy between South Atlantic Anomaly and Global Sea Level for the last 300 years

Cited by 2 publications

References 50 publications

Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil

Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil

Quantification of Information Exchange in Idealized and Climate System Applications

Contact Info

Product

Resources

About