Nonlinear Processes in Geosciences

A few reasons making the June 2022 French Heatwave too hot & too soon

Davide Faranda June 17, 2022

Picture (by Chris Walts): original way to stay cool during hot days in Paris.

Too hot, Too soon: the thermometer has reached unprecedented temperature for a month of June in France, with the 40°C mark crossed by Friday June 17 in part of France. The IPCC AR6 report now clearly states that the probability of heatwave events such as this one has increased by a factor 3 to 5 in the present climate with respect to a counterfactual world not affected by anthropogenic greenhouse ...[Read More]

ClimarisQ: A game on the complexity of the climate systems and the extreme events

Davide Faranda May 26, 2022

ClimarisQ is a smartphone/web game from a scientific mediation project that highlights the complexity of the climate system and the urgency of collective action to limit climate change. It is available in four languages: English, French, Spanish and Italian. It is an app-game where players must make decisions to limit the frequency and impacts of extreme climate events and their impacts on human s ...[Read More]

NPG Paper of the Month: “Inferring the instability of a dynamical system from the skill of data assimilation exercises”

Yumeng Chen April 25, 2022

Scatter plots of the largest Lyapunov exponent (left) and Kolmogorov-Sinai entropy (right) against the skill of DA measured as the RMSE of the analysis. The experiments are done with model configurations displaying fully developed chaos (main panels) and with weakly chaotic configurations (insets). In all cases a strong observational constraint is applied: we measure the entire state vector at each time step. The theoretical error upper bound are also displayed (red markers).

The NPG paper of the month was awarded to “Inferring the instability of a dynamical system from the skill of data assimilation exercises” by Yumeng Chen, Alberto Carrassi, and Valerio Lucarini. Geophysical systems are usually described by a set of dynamical equations that are often non-linear and chaotic (Ghil and Lucarini, 2020). Errors about the initial state can grow, shrink, or sta ...[Read More]

When weather extremes meet climate change: how do scientists attribute single events to climate change?

Davide Faranda February 25, 2022

Tropical Cyclone Batsirai landfalled in Madagascar on February 5-6 2022, causing extended floding, visible on February 10 (right) when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite passed over. In this comparison of false-color imagery, which uses MODIS bands 7-2-1, areas flooded with sediment-laden water appear blue. The same area is shown on January 30, between recent storms (left panel). Credits: NASA Earth Observatory.

One of the main new points of the IPCC reports AR6 with respect to the previous ones is the increased confidence that global climate change induced by anthropogenic emissions is critically affecting the dynamics of weather extremes. For summer, and specifically over Europe, the AR6 report states that we are already observing prolonged periods of extremely warm conditions with increased droughts bo ...[Read More]