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]

Why Bushfires raged out of control across Australia?

Davide Faranda January 22, 2020

A diagram showing how pyrocumulonimbus clouds are formed. Credits: Bureau of Meteorology, Victoria.

Australian wildfires have burned an impressively large surface and caused the death of at least 24 citizens as well as of numerous animals. This immense disaster raises questions about its linkage with climate change, the possibility of controlling these events and the future of Australian wildlife ecosystems. While the first question will be addressed by soon to come attribution studies, and the ...[Read More]

After Lorenzo and Ophelia, should we prepare European coasts for tropical storms and hurricanes?

Davide Faranda October 15, 2019

probability forecasts of tropical storm force winds issued by the National Hurrican Center issued on 02/10/2019. Source: https://www.nhc.noaa.gov/graphics_at3.shtml?tswind120? .

Autumn is hurricane season in the north tropics and indeed 2019 does not make exception from this point of view. After Dorian hitting Bahamas and North Carolina, the American National Hurricane Center named Lorenzo a tropical depression originating near Capo Verde. On September 25th Lorenzo became a category 1 hurricane, according to the Saffir-Simpson scale. This scale categorizes the hurricanes ...[Read More]