Electron scattering by whistler-mode ELF hiss in plasmaspheric plumes

first_imgNonadiabatic loss processes of radiation belt energetic electrons include precipitation loss to the atmosphere due to pitch-angle scattering by various magnetospheric plasma wave modes. Here we consider electron precipitation loss due to pitch-angle scattering by whistler-mode ELF hiss in plasmaspheric plumes. Using wave observations and inferred plasma densities from the Plasma Wave Experiment on the Combined Release and Radiation Effects Satellite (CRRES), we analyze plume intervals for which well-determined hiss spectral intensities are available. We then select 14 representative plumes for detailed study, comprising 10 duskside plumes and 4 nonduskside plumes, with local hiss amplitudes ranging from maximum values of above 300 pT to minimum values of less than 1 pT. We estimate the electron loss timescale τ loss due to pitch-angle scattering by hiss in each chosen plume as a function of L-shell and electron energy; τ loss is calculated from quasi-linear theory as the inverse of the bounce-averaged diffusion rate evaluated at the equatorial loss cone angle. We find that pitch-angle scattering by hiss in plumes can be efficient for inducing precipitation loss of outer-zone electrons with energies throughout the range 100 keV to 1 MeV, though the magnitude of τ loss can be highly dependent on wave power, L-shell, and electron energy. For 100- to 200-keV electrons, typically τ loss ∼ 1 day while the minimum loss timescale (τ loss ) min ∼ hours. For 500-keV to 1-MeV electrons, typically (τ loss ) min ∼ days, while (τ loss ) min < 1 day in the case of large wave amplitude (∼100's pT). Apart from inducing direct precipitation loss of MeV electrons, scattering by hiss in plumes may reduce the generation of MeV electrons by depleting the lower energy electron seed population. Models of the dynamical variation of the outer-zone electron flux should incorporate electron precipitation loss induced by ELF hiss scattering in plasmaspheric plumes.last_img read more

Subscription box launched for ‘wonky’ bakery products

first_imgSource: Earth & WheatJames Eid with an Earth & Wheat subscription boxStudent and fourth generation baker at family-owned Signature Flatbreads James Eid has unveiled a ‘wonky’ bread subscription service.Eid, who is studying at Lancaster University, will distribute bread and baked goods which would otherwise have been disposed of during the production process due to its appearance, size or overproduction.He has started by utilising the ‘wonky’ baked goods from the family firm, which was set up by his grandfather Dr Samir Eid in 1984, with plans to partner with local independent bakeries across the UK as his customer base expands.Customers who subscribe to the Earth & Wheat service on a weekly or bi-weekly basis will pay £6.99 per box, including delivery. The 2.5kg box contains a week’s worth of bread for a family of three or four, with contents including crumpets, sourdough crumpets, tortillas, wholemeal tortillas, butter-flavoured tortillas, pittas, wholemeal pitta, focaccia, scotch pancakes and buttermilk pancakes.For every box ordered, Eid has also pledged to donate a meal’s worth of bread (450g) to food banks to help fight poverty in the UK.“Earth & Wheat’s vision is to ultimately reduce food waste by delivering perfectly fresh wonky bread and supporting local communities when times are tough. We believe no good food should go to waste,” Eid explained.“It’s a subscription model which is quick and easy to use,” he added. “We want to target environmentally conscious people and families with children who want to help make a difference where they can and reduce food waste, and thus build a sustainable future for the next generation. Even our packaging is fully recyclable – it’s wonky bread without wonky practices.”Bakeries, manufacturers and retailers across the UK are working to reduce food waste through a number of means, including partnering with breweries to use leftover loaves to make beer, utilising apps such as Too Good To Go, and sending surplus baked goods to be turned into animal feed.last_img read more