Science questions and knowledge gaps to study microbial transport and survival in Asian and African dust plumes reaching North America

The Sahara in North Africa and the Gobi and Taklamakan deserts in Asia are the primary sources of mobilized dust in the atmosphere, with regional or global airborne transport estimated at 2 to 5 billion tonnes per year. Annual Asian dust plumes take about 7 to 10 d to cross the Pacific Ocean, and often reach the northwest USA between late February and May. In contrast, the peak season for the movement of African dust storms to the southeastern USA is typically June to August, and dust plumes take about 5 to 7 d to reach Florida. Although studies have documented that a wide range of bacteria, fungi, archaea, and viruses in dust plumes reach the USA each year, little is known about temporal and spatial variability in the microbial biodiversity in transoceanic dust plumes, or the effect on the deposition environments. A scoping study (called the Transoceanic Aerobiology Biodiversity Study) was conducted to develop field-based campaigns centered on examining the abundance, diversity, survival, and impact of microorganisms in transoceanic dust plumes arriving in the continental USA from Asia and Africa. This effort identified Science Questions (SQs) and Knowledge Gaps (KGs) that are highly relevant toward an understanding of the microbial diversity, transport, survival, and dispersal in transoceanic dusts. Science Questions were defined as broad science topics in transoceanic dust plume microbiology that were underexplored by the aerobiology community. Knowledge Gaps were defined as specific project-level research questions for each SQ that represented important topics in the study of transoceanic aerobiology.