• Comprehensive uncertainty estimation of the timing of Greenland warmings in the Greenland ice core records 

      Myrvoll-Nilsen, Eirik; Riechers, Keno; Rypdal, Martin Wibe; Boers, Niklas (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-20)
      Paleoclimate proxy records have non-negligible uncertainties that arise from both the proxy measurement and the dating processes. Knowledge of the dating uncertainties is important for a rigorous propagation to further analyses, for example, for identification and dating of stadial– interstadial transitions in Greenland ice core records during glacial intervals, for comparing the variability in ...
    • Efficient Bayesian analysis of long memory processes applied to climate 

      Myrvoll-Nilsen, Eirik (Doctoral thesis; Doktorgradsavhandling, 2020-05-22)
      Temperature fluctuations can be described by a persistent correlation structure known as long-range dependence (LRD). This is a phenomenon which implies that the autocorrelation function follows a power-law decay and that observations may still be significantly correlated even if the temporal or spatial distance between them is large. Moreover, temperature is known to be influenced by radiative ...
    • Emergent Scale Invariance and Climate Sensitivity 

      Rypdal, Martin Wibe; Fredriksen, Hege-Beate; Myrvoll-Nilsen, Eirik; Rypdal, Kristoffer; Sørbye, Sigrunn Holbæk (Journal article; Peer reviewed, 2018-11-28)
      Earth’s global surface temperature shows variability on an extended range of temporal scales and satisfies an emergent scaling symmetry. Recent studies indicate that scale invariance is not only a feature of the observed temperature fluctuations, but an inherent property of the temperature response to radiative forcing, and a principle that links the fast and slow climate responses. It provides a ...
    • Statistical estimation of global surface temperature response to forcing under the assumption of temporal scaling 

      Myrvoll-Nilsen, Eirik; Sørbye, Sigrunn Holbek; Fredriksen, Hege-Beate; Rue, Håvard; Rypdal, Martin Wibe (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-08)
      Reliable quantification of the global mean surface temperature (GMST) response to radiative forcing is essential for assessing the risk of dangerous anthropogenic climate change. We present the statistical foundations for an observation-based approach using a stochastic linear response model that is consistent with the long-range temporal dependence observed in global temperature variability. We ...
    • Warming trends and long-range dependent climate variability since year 1900: A Bayesian approach 

      Myrvoll-Nilsen, Eirik; Fredriksen, Hege-Beate; Sørbye, Sigrunn Holbek; Rypdal, Martin wibe (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-21)
      Temporal persistence in unforced climate variability makes detection of trends in surface temperature difficult. Part of the challenge is methodological since standard techniques assume a separation of time scales between trend and noise. In this work we present a novel Bayesian approach to trend detection under the assumption of long-range dependent natural variability, and we use estimates of ...