Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan) in response to Asian dust events

Abstract

Abstract. Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles) on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events.

Abundance of Biological Ice Nucleating Particles in the Mississippi and Its Major Tributaries

“…Indeed, freshwater bacteria have even been found to dominate the bacterial microbiome of aerosols [41,42]. The same emission mechanism that operates in seawater-bubble bursting-would also facilitate freshwater INPs becoming airborne.…”

High similarity in bacterial bioaerosol compositions between the free troposphere and atmospheric depositions collected at high-elevation mountains

“…We hypothesized a close relationship between bacterial bioaerosols collected on the top of high mountains and the free troposphere bioaerosols. We compared data from bacterial bioaerosols obtained in variety of situations: (i) above the boundary layer by aircraft sampling (DeLeon-Rodriguez et al, 2013;Zweifel et al, 2012); and under the influence of dust episodes (Maki et al, 2017;Yamaguchi et al, 2012); (ii) from the ground surface at high altitude research stations by means of air dynamic samplers (Bowers et al, 2012), and…”

A long-term survey unveils strong seasonal patterns in the airborne microbiome coupled to general and regional atmospheric circulations

“…Spatial surveys of airborne microbe distribution shows geographic patterns in both terrestrial and marine environments (16,17). However, substantial differences in the airborne biological composition are observed when the aeroplankton is collected directly from the troposphere (e.g., by aircraft) (18)(19)(20), although homogeneous distribution has recently been noted in the atmosphere up to 12 km (21). Interestingly, tropospheric microbial communities are much closer to those recovered from high-elevation sites, such as on-ground passive collectors located in high mountain areas, than to lowland sites.…”

“…The matching is even greater for wet aerosols than for dry deposition, probably due to the cleansing of the atmosphere by rain and snow. Thus, although sampling the free troposphere may provide a more accurate view of the longrange transport of microbes while avoiding ground surface contamination (8,19), on-ground sampling of washed-out aerosols in high-elevation mountains would be a cost-effective method of monitoring the long-term intercontinental exchange of the airborne microbiome.…”