Comparison of techniques for detection of discontinuities in temperature series

Ducré-Robitaille, Jean-François; Vincent, Lucie A.; Boulet, Gilles

doi:10.1002/joc.924

Cited by 156 publications

(155 citation statements)

References 11 publications

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“…This calls for sequential tests where the existence of a regime shift is tested for at every point in time, and which must be characterized by higher critical values of the test statistic than in classical statistical methods (cf. Box 2) due to the so-called The most commonly investigated regime shift hypothesis is a step change in mean level using parametric [40,42,43] development of threshold detection methods in econometrics and climate research (often > 100 time steps). As change-points occurring at the extremes of a time series do not lend much power to hypothesis testing, it is only those change-points located near the middle of the time series that can be detected with confidence.…”

Section: Inferential Statistics and Hypothesis Testingmentioning

confidence: 99%

“…This calls for sequential tests where the existence of a regime shift is tested for at every point in time, and which must be characterized by higher critical values of the test statistic than in classical statistical methods (cf. Box 2) Critical values at different significance levels are tabularized for regularly observed data points, typically time series [38] The most commonly investigated regime shift hypothesis is a step change in mean level using parametric [40,42,43] or non-parametric [44] methods. Regime shift detection methods involving changing variance, shift in the frequencies of fluctuations, or even simultaneous interrelated shifts in several ecosystem components at a particular point have also been proposed [45], but their application to practical data analysis has so far been limited.…”

Section: Inferential Statistics and Hypothesis Testingmentioning

confidence: 99%

See 1 more Smart Citation

Ecological thresholds and regime shifts: approaches to identification

Andersen

Carstensen²,

Hernández-Garcı́a

et al. 2009

Trends in Ecology & Evolution

656

519

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There is an apparent gap between the prominence of present theoretical frameworks involving ecological thresholds and regime shifts, and the paucity of efforts to conduct simple tests and quantitative inferences on the actual appearance of such phenomena in ecological data. There is a wide range of statistical methods and analytical techniques now available that render these questions tractable, some of them even dating half a century back. Yet, their application has been sparse and confined within a narrow subset of cases of ecological regime shifts. Our objective is to raise awareness on the range of techniques available, and to their principles and limitations, in order to promote a more operational approach to the analysis of ecological thresholds and regime shifts. The observation that managed ecosystems often fail to respond smoothly to changing pressures has generated perplexity and eventually lead researchers to draw parallels between the behaviour of ecological systems and other complex systems with non-linear dynamics, such as the global climate, the human immune system, and the world economy (cf.[1] for a popular account). Initial reports of kelp forest disturbance and recovery [2], freshwater ecosystem shifts engineered by beavers [3], and vegetation shifts affected by fire [4] have lead on to an ever-growing research effort on ECOLOGICAL THRESHOLDS and REGIME SHIFTS (see Glossary), whose underlying theoretical framework [5,6] (Box 1) has been shown to be applicable to a broad range of ecosystems from coral reefs to forests and lakes [7,8]. These concepts are now also making their way into the minds and discussions of policy makers and might soon be translated into legislative frameworks [9].Ecological regime shifts can be defined as abrupt changes on several trophic levels [10], leading to rapid ecosystem reconfiguration between alternative states. These shifts are generally thought to be driven by external perturbations (e.g. climatic fluctuations, overexploitation, eutrophication, and invasive species), but the exact mechanism is often unclear. The subject has become a fast growing scientific discipline, manifested by a 12-fold increase in publications between 1991 and 2006, twice as fast as the growth rate of research effort in ecology as a whole (7.7 % year -1 , ISI Web of Science). Most of the reported cases of ecological regime shifts are inferred from time series of monitoring data, while direct evidence by controlled experiments of the existence of alternative states is difficult to find [11]. Surprisingly, the general techniques available to test for regime shifts and thresholds have only to a limited extent been applied to these data sets. As formal tests of regime shifts have a long history in the context of climate change research (e.g. that formal statistical tests for ecological regime shifts have mostly been restricted to the effects of climate change on marine communities [13]. These observations suggest that there is a need to increase the awareness of ecologists on the availability...

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Section: Inferential Statistics and Hypothesis Testingmentioning

confidence: 99%

“…This calls for sequential tests where the existence of a regime shift is tested for at every point in time, and which must be characterized by higher critical values of the test statistic than in classical statistical methods (cf. Box 2) Critical values at different significance levels are tabularized for regularly observed data points, typically time series [38] The most commonly investigated regime shift hypothesis is a step change in mean level using parametric [40,42,43] or non-parametric [44] methods. Regime shift detection methods involving changing variance, shift in the frequencies of fluctuations, or even simultaneous interrelated shifts in several ecosystem components at a particular point have also been proposed [45], but their application to practical data analysis has so far been limited.…”

Section: Inferential Statistics and Hypothesis Testingmentioning

confidence: 99%

Ecological thresholds and regime shifts: approaches to identification

Andersen

Carstensen²,

Hernández-Garcı́a

et al. 2009

Trends in Ecology & Evolution

656

519

View full text Add to dashboard Cite

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“…Buishand (1982) and Peterson et al (1998a, b)havediscussed in detail the application of relative and absolute tests. Detailed mathematical development of the tests is also discussed in Wijngaard et al (2003), while Ducré-Robitaille et al (2003) provides a comparison between the techniques.…”

Section: Homogeneity Testingmentioning

confidence: 99%

Analysis of mid-twentieth century rainfall trends and variability over southwestern Uganda

Nsubuga

Olwoch

Rautenbach

et al. 2013

Theor Appl Climatol

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A methodology has been applied to investigate the spatial variability and trends existent in a mid-twentieth century climatic time series (for the period recorded by 58 climatic stations in the Albert-Victoria water management area in Uganda. Data were subjected to quality checks before further processing. In the present work, temporal trends were analyzed using Mann-Kendall and linear regression methods. Heterogeneity of monthly rainfall was investigated using the precipitation concentration index (PCI). Results revealed that 53 % of stations have positive trends where 25 % are statistically significant and 45 % of stations have negative trends with 23 % being statistically significant. Very strong trends at 99 % significance level were revealed at 12 stations.

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“…Alexandersson (1986) developed the 'Standard normal homogeneity test' (SNHT), applied to the Swedish precipitation series in subsequent work Moberg and Alexandersson, 1997). The SNHT is one of the most efficient tests for homogeneity, as Ducré-Robitaille et al (2003) recently demonstrated.…”

Section: Introductionmentioning

confidence: 99%

Homogenization of long‐term monthly Spanish temperature data

Staudt

Esteban‐Parra

Castro‐Díez

2007

Intl Journal of Climatology

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Abstract:Reliable time-series is the basic ingredient when analysing climatic changes. However, the errors in real data are frequently of the same order as the signal being sought. Therefore, the available long-term monthly series of Spanish minimum and maximum temperatures have been compiled from the late 19th century on, in order to compile a high-quality data set. The series are organized into climatically homogeneous regional groups and, in each group, the detection and adjustment is based on relative homogeneity and an analysis of the stationarity of the whole set of temperature-difference series. These series are scanned with moving t, Alexandersson, and Mann-Kendall tests. The detected inhomogeneities are adjusted by weighted averages of the regional series. The method is iterative and advances in steps of detection, adjustment, and actualization. Individual inhomogeneous data are discarded and gaps are filled by similar weighted multiple means.For the analysis of the temperature evolution in the Iberian Peninsula, each region is finally represented by one local series and the regional average. The urban effect on minimum temperatures is adjusted by an empirical method, and for Madrid also by a correction derived from new homogenized data. Generally, rigorous homogeneity cannot be achieved because the initial data quality is deficient in many cases and metadata are sparse. Nevertheless, the data homogeneity and quality has been considerably enhanced: the total error margin in a series is of the order of 0.3°C-0.4°C, under consideration of a worst-case error accumulation. On the other hand, the number of inhomogeneities is considerable and their average amplitude is of the order of 1°C reflecting the much larger error margin in the raw data. The homogenized dataset compiled constitutes an important basis for the subsequent detection of thermal changes in Spain in the last 130 years, on a clearly higher confidence level than before.

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Comparison of techniques for detection of discontinuities in temperature series

Cited by 156 publications

References 11 publications

Ecological thresholds and regime shifts: approaches to identification

Ecological thresholds and regime shifts: approaches to identification

Analysis of mid-twentieth century rainfall trends and variability over southwestern Uganda

Homogenization of long‐term monthly Spanish temperature data

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