Nonlinear Processes in Geosciences

Is climate change making the weather more extreme?

Davide Faranda September 11, 2020

NOAA PSL weather forecasts of temperature anomaly at 850hPa (~1500m.a.s.l.) shows a deep negative anomaly on Central US, leading to snowfalls. Credits: NOAA.

Denver, Sept. 06: it is midday and Jonathan and Maria are sunbathing at City Park. They feel uncomfortable as the temperature has already reached 36°C. While they decide to go back home, their favoured weather app displays an unbelievable snowstorm watch for Tuesday Sept. 08. The forecast turns out to be rather accurate as all Colorado experiences one of the earliest snowstorms on record in Septem ...[Read More]

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]

Is planting trees a feasible large-scale solution to mitigate climate change?

Davide Faranda June 8, 2020

In the last few years it has become a common practice to compensate carbon dioxide (CO2) emissions by planting trees. This idea is simple and rooted on a very basic principle: trees get the energy of sunlight, and by photosynthesis they take water from the ground and CO2 from the air, releasing oxygen in the atmosphere. The CO2 is then stored in trees and surrounding soil. Tree planting efforts ar ...[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]