translate English to French: During theperiod between 1920 and 1960, concentrations of sulphate aerosols in the stratosphere due to such eruptions were below average, thus allowing more sunlight to reach the earthâ€™s surface.
Entre 1920 et 1960, les concentrations d â€™ a é r o s o ls sulfatés dans la s t r a t o s p h è r e imputables à ce genre dâ€™éruptions ont été inférieures à la moyenne, ce qui a laissé davantage de rayonnement solaire atteindre la surface de la Terre.