No abstract

Socio-ecological damage from climate-related disasters has increased worldwide, including a type of cold-season disaster (dzud) that is unique to the Eurasian steppes, notably Mongolia. During 2000–2014, dzuds killed approximately 30 million livestock and impacted the Mongolian socio-economy. The contributions of both natural and social processes to livestock mortality were not previously considered across Mongolia. Here, we consider the contribution of both multiple climate hazards (drought, cold temperatures and snow), and socioeconomic vulnerability (herders’ livestock and coping-capacity) to mortality risk. We performed multi-regression analyses for each province using meteorological, livestock and socioeconomic datasets. Our results show that 93.5% of mortality within Mongolia was caused by a combination of multi-hazards (47.3%) and vulnerability (46.2%), suggesting dzuds were both climate- and man-made. However, in high-mortality hotspots, mortality was primarily caused by multi-hazards (drought-induced pasture deficiency and deep-snow). Livestock overpopulation and a lack of coping capacities that caused inadequate preparedness (e.g., hay/forage) were the main vulnerability factors. Frequent and severe multi-hazards greatly increased the mortality risk, while increased vulnerability caused by socioeconomic changes in Mongolia since the 1990s tended to amplify the effects of multi-hazards. Thus, reductions in herder vulnerability within high-mortality hotspots would likely be an effective means of mitigating the risk of future dzuds.

No abstract

In recent years, extreme cold air outbreak events (COEs) in winter have tended to occur more frequently over the mid‐latitudes of Eurasia, including Mongolia, despite marked warming across the continent. In the 2000s, an increase in COEs contributed to huge losses of livestock throughout Mongolia, causing socioeconomic stagnation. This study diagnosed the interdecadal variability of the frequency of COEs during cold season (November–March) using observations from 70 meteorological stations in Mongolia by contrasting a past period (PP:1981–1999) and a recent period (RP:2000–2016). Then, this analysis was extended to characterize the synoptic pattern of each period using ERA‐Interim reanalysis data in terms of the ridge and trough system and cold advection. We defined a COE as an event having at least five continuous days with a daily average air temperature lower than minus one standard deviation from the daily climatology during cold season in 1981–2016. The results revealed that totally 112 COEs could be identified over Mongolia during 1981–2016 with a higher number of events (59) during the RP. Regionally, a slight increase in COEs was observed in the north, whereas no clear change was evident in the south. Composite analyses for each period demonstrated that a trough in the central Eurasian mid‐troposphere was deepened and southwestward advection of cold air enhanced during the RP, in comparison with the PP, which changed the wind direction over northern Mongolia from westerly to northwesterly. In addition, the number of snow cover days have increased slightly in the RP in northern Mongolia, likely acting as a favourable condition for low air temperatures with intensifying surface cooling. These findings suggest that a deepened trough over central Eurasia, strengthened northerly cold advection into Mongolia, and cooling from the snow‐covered surface are most likely to have resulted in the increased frequency of COEs overnorthern Mongolia in the RP.

In this study, we present some of the laboratory measurements of the viability of bioaerosols together with different environmental dust to understand the interaction among those components. Model airborne bacteria, DH5α Escherichia coli, was used to assess the dust affecting a viability reduction rate of the DH5α bacteria in a Teflon reaction chamber. The viability reduction rate of the DH5α model airborne bacteria was measured with a culture method. The DH5 α bacteria were nebulized into the chamber and airborne dust materials 1) Phosphate Buffer Solution (PBS) as a control, 2) desert sand from Mongolia and 3) sludge dust from the coastal area of Japan. The result indicated that the co-existence of DH5α with desert dust from Mongolia significantly decreased the viability and with the sludge dust from Japan significantly increased the viability of the airborne DH5α compare to the control PBS dust (p<0.05). Furthermore, soot as a model air pollutant was generated by a candle and mixed with a model airborne bacteria Mycobacterium smegmatis. The results indicated that the different types of airborne environmental dust influenced the viability of airborne bacteria with the DH5α experiments. Furthermore, the presence of soot indicated a possible protective effect of increasing the survival rate of Mycobacterium smegmatis.