jueves, 8 de febrero de 2018

El agujero de ozono no se reduce

Pero no en las latitudes altas, donde ya se ha ido corrigiendo, gracias al Protocolo de Montreal, sino en las latitudes medias. Y lo peor es que no sabemos bien por qué.

Desgraciadamente, tampoco se reducen los niveles de ozono troposférico, también causante de daños muy importantes para la salud.

1 comentario:

Fernando Leanme dijo...

Busca este artículo, "Ultraviolet Flux Decrease Under a Grand Minimum from IUE Short-wavelength Observation of Solar Analogs," Astrophysical Journal Letters

Abstract

Abstract
We have identified a sample of 33 Sun-like stars observed by the International Ultraviolet Explorer (IUE) with the short-wavelength spectrographs that have ground-based detections of chromospheric Ca ii H+K activity. Our objective is to determine if these observations can provide an estimate of the decrease in ultraviolet (UV) surface flux associated with a transition from a normal stellar cycle to a grand-minimum state. The activity detections, corrected to solar metallicity, span the range $-5.16\lt \mathrm{log}{R}_{{HK}}^{{\prime} }\lt -4.26$, and eight stars have log ${R}_{{HK}}^{{\prime} }\lt -5.00$. The IUE-observed flux spectra are integrated over the wavelength range 1250–1910 Å, transformed to surface fluxes, and then normalized to solar B − V. These normalized surface fluxes show a strong linear relationship with activity ${R}_{{HK}}^{{\prime} }$ (R 2 = 0.857 after three outliers are omitted). From this linear regression we estimate a range in UV flux of 9.3% over solar cycle 22 and a reduction of 6.9% below solar cycle minimum under a grand minimum. The 95% confidence interval in this grand-minimum estimate is 5.5%–8.4%. An alternative estimate is provided by the IUE observations of τ Cet (HD 10700), a star having strong evidence of being in a grand-minimum state, and this star's normalized surface flux is 23.0 ± 5.7% lower than solar cycle minimum.

Parece ser que estamos entrando en un Mínimo de Dalton y eso puede tener influencia sobre el ozono. También puede ser que reduzca UV por varias décadas.