Nonlinear Processes in Geosciences

NPG Paper of the Month: “Detecting dynamical anomalies in time series from different palaeoclimate proxy archives using windowed recurrence network analysis”

Tommaso Alberti June 30, 2020

Recurrence network transitivity (colour-coded) for a Lorenz-63 system with linear parameter drift as input signal, and the output of four different proxy system models with an areawise significance test (contours). The vertical lines denote the approximate positions of transient bifurcations between different types of dynamics at b = 161.0 and b = 166.5 as described in Donges et al., Nonlin. Processes Geophys., 2011. Credits: Detecting dynamical anomalies in time series from different palaeoclimate proxy archives using windowed recurrence network analysis (https://npg.copernicus.org/articles/27/261/2020/).

This month the NPG Paper of the Month award is achieved by Jaqueline Lekscha and Reik Donner for their paper “Detecting dynamical anomalies in time series from different palaeoclimate proxy archives using windowed recurrence network analysis” (https://npg.copernicus.org/articles/27/261/2020/). Jaqueline Lekscha did her PhD in physics at the Potsdam Institute for Climate Impact Research and Humbold ...[Read More]

COVID-19-related drop in anthropogenic aerosol emissions in China and corresponding cloud and climate effects

Anna von der Heydt May 29, 2020

Observed reduced NO2 concentration above China in February 2020. Shown is the difference between February 2020 and the average of February 2018 and 2019. Figure from https://doi.org/10.31223/osf.io/z5dm8.

While a previous blog entry dealt with the question whether we can use lessons from the nonlinear nature of climate for projections of the Covid-19 pandemic, there is now a first example of how the pandemic can teach us something on climate. The several weeks long lockdown of China made February 2020 an exceptional month in terms of air quality; aerosol emissions were tremendously reduced leading ...[Read More]

NP Interviews: the 2020 Lewis Fry Richardson Medal Valerio Lucarini

Tommaso Alberti April 29, 2020

The 2020 Lewis Fry Richardson Medal Valerio Lucarini.

Today’s NP Interviews hosts the 2020 Lewis Fry Richardson Medal Valerio Lucarini. Valerio (b. Ancona, Italy, 1976) is the Director of the Centre for the Mathematics of Planet Earth and Professor of Statistical Mechanics at the University of Reading, and former Professor of Theoretical Meteorology at the University of Hamburg. His main expertise is in Climate Dynamics, Extreme Events, Statist ...[Read More]

NPG Paper of the Month: “Application of a local attractor dimension to reduced space strongly coupled data assimilation for chaotic multiscale systems”

Tommaso Alberti April 23, 2020

Local dynamical properties of a segment of an example run for the coupled Lorenz system. (a) Alignment of directions of error growth plotted along the x coordinate of the ocean subsystem. Large orange stars indicate high alignment of error growth in the unstable or neutral subspaces. (b) Finite-time Lyapunov exponents (FTLEs) computed over window τ = 4. (c) Local Kaplan-Yorke dimension calculated from FTLEs. (Source: Quinn, O’Kane, and Kitsios, Application of a local attractor dimension to reduced space strongly coupled data assimilation for chaotic multiscale systems, Nonlin. Processes Geophys., 27, 51–74, 2020, https://www.nonlin-processes-geophys.net/27/51/2020/. License: https://creativecommons.org/licenses/by-nc-nd/4.0/.

This month the NPG Paper of the Month award is achieved by Courtney Quinn for her paper “Application of a local attractor dimension to reduced space strongly coupled data assimilation for chaotic multiscale systems” (https://www.nonlin-processes-geophys.net/27/51/2020/). Dr. Courtney obtained her PhD in Mathematics at the University of Exeter (UK) researching critical transitions in dynamical syst ...[Read More]