Flaring Latitudes in Ensembles of Low Mass Stars

The distribution of small-scale magnetic fields in stellar photospheres is an important ingredient in our understanding of the magnetism of low mass stars. Their spatial distribution connects the field generated in the stellar interior with the outer corona and the large scale field, and thereby affects the space weather of planets. Unfortunately, we lack techniques that can locate them on most low-mass stars. One strategy is to localize field concentrations using the flares that occur in their vicinity. We explore a new method that adapts the spot simulation software fleck to study the modulation of flaring times as a function of active latitude. We use empirical relations to construct flare light curves similar to those available from Kepler and the Transiting Exoplanet Survey Satellite (TESS), search them for flares, and use the waiting times between flares to determine the location of active latitudes. We find that the mean and standard deviation of the waiting time distribution provide a unique diagnostic of flaring latitudes as a function of the number of active regions. Latitudes are best recovered when stars have three or less active regions that flare repeatedly, and active latitude widths below 20 deg; when either increases, the information about the active latitude location is gradually lost. We demonstrate our technique on a sample of flaring G dwarfs observed with the Kepler satellite, and furthermore suggest that combining ensemble methods for spots and flares could overcome the limitations of each individual technique for the localization of surface magnetic fields.Comment: 15 pages, 10 figures. Accepted to MNRAS. Repository with source code: https://github.com/ekaterinailin/flare-locations-ensembles-science Repository with data: https://zenodo.org/record/799692

Betting on the best case: higher end warming is underrepresented in research

Abstract: We compare the probability of different warming rates to their mentions in IPCC reports through text mining. We find that there is a substantial mismatch between likely warming rates and research coverage. 1.5 °C and 2 °C scenarios are substantially overrepresented. More likely higher end warming scenarios of 3 °C and above, despite potential catastrophic impacts, are severely neglected

Focus of the IPCC Assessment Reports Has Shifted to Lower Temperatures

Funder: Templeton World Charity FoundationAbstract: We focus on how different global temperature increases represented in IPCC reports have shifted over time. While the first four assessment reports had a roughly equal focus on temperatures above and below 2°C, the more recent fifth and sixth assessment reports have a considerably stronger focus on warming below 2°C. This is concerning as warming above 2°C is more likely given current emissions trajectories and is more influential on climate risk assessments