Data from: Export of ice nucleating particles from a watershed

Ice nucleating particles (INP) active at a few degrees below 0°C are produced by a range of organisms and released into the environment. They may affect cloud properties and precipitation when becoming airborne. So far, our knowledge about sources of biological INP is based on grab samples of vegetation, soil or water studied in the laboratory. By combining measurements of INP concentrations in river water with river water discharge rates over the course of 16 months, we obtained a lower limit for the production rate of INP in a watershed covering most of Switzerland (4 × 105 INP−8 m−2 d−1). Coincidentally, we found that INP−8 are likely to retain their potential for catalysing ice formation in the natural environment for at least several months before they are mobilized by an intensive rainfall, washed into the river and exported from the watershed.

在低于0℃数摄氏度时具有活性的冰核粒子（Ice nucleating particles, INP）由多种生物产生并释放进入环境。当其悬浮于大气中时，可能会对云的特性与降水过程产生影响。截至目前，我们对生物源冰核粒子来源的认知，均基于实验室中对植被、土壤或水体的瞬时采样研究。通过对16个月内河水中冰核粒子浓度与河流径流量的联合测定，我们得到了覆盖瑞士大部分区域的流域内冰核粒子产生速率的下限值（4×10^5 INP-8·m^-2·d^-1）。巧合的是，我们发现INP-8在自然环境中至少可保留其催化冰晶形成的能力达数月之久，直至强降雨触发其释放，随后被冲刷进入河流并从流域中输出。