While water and sulfuric acid droplets are the main component of stratospheric aerosols, measurements performed for about 30 years have shown that non-sulfate particles (NSPs) are also present. Such particles, released from the Earth mainly through volcanic eruptions, pollution or biomass burning, or coming from space, present a wide variety of compositions, sizes, and shapes. To better understand the origin of NSPs, we have performed measurements with the Light Optical Aerosol Counter (LOAC) during 151 flights under weather balloons in the 2013–2019 period reaching altitudes up to 35 km. Coupled with previous counting measurements conducted over the 2004–2011 period, the LOAC measurements indicate the presence of stratospheric layers of enhanced concentrations associated with NSPs, with a bimodal vertical repartition ranging between 17 and 30 km altitude. Such enhancements are not correlated with permanent meteor shower events. They may be linked to dynamical and photophoretic effects lifting and sustaining particles coming from the Earth. Besides, large particles, up to several tens of μm, were detected and present decreasing concentrations with increasing altitudes. All these particles can originate from Earth but also from meteoroid disintegrations and from the interplanetary dust cloud and comets.

中文翻译：

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用球囊轻型光学气溶胶计数器（LOAC）检测的平流层中非纯硫酸盐颗粒（NSP）的起源和空间分布

尽管水和硫酸滴是平流层气溶胶的主要成分，但进行了约30年的测量表明，还存在非硫酸盐颗粒（NSP）。这些主要通过火山喷发，污染或生物质燃烧从地球释放出来的粒子，或者来自太空的粒子，具有各种各样的组成，大小和形状。为了更好地了解NSP的起源，我们在2013-2019年期间进行了151次气球飞行期间，使用光学气溶胶计数器（LOAC）进行了测量，这些气球达到了35 km的高度。加上先前在2004-2011年期间进行的计数测量，LOAC测量表明存在与NSP相关的浓度升高的平流层，双峰垂直分区范围在17至30公里之间。这些增强与永久性流星雨事件无关。它们可能与动力学和光致效应有关，这些效应可以提升和维持来自地球的粒子。此外，还发现了大到几十微米的大颗粒，并且随着海拔的升高其浓度逐渐降低。所有这些粒子都可以起源于地球，也可以起源于流星体的崩解以及行星际尘埃云和彗星。