Ice-Nucleating Particle Concentrations and Sources in Rainwater over the Third Pole, Tibetan Plateau

• Main Authors: Chen, Jie, Wu, Zhijun, Wu, Guangming, Gong, Xianda, Wang, Feng, Chen, Jingchuan, Shi, Guo Liang, Hu, Min, Cong, Zhiyuan
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2020
• Subjects: Ice Nucleating Particle; Rainwater; Tibetan Plateau; Arctic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.923856; https://doi.org/10.1594/PANGAEA.923856

The ice-nucleating particles (INPs) modulate the microphysics and radiative properties of clouds. However, less is known concerning their abundance and sources in the most pristine and climatic sensitive regions, such as the Tibetan Plateau (TP). Here, to our best knowledge, we conduct the first investigation on INPs in rainwater collected in the TP region under mixed-phase cloud conditions. The INP concentrations vary from 0.002 to 0.675 L-1 Air over the temperature range from -7.1 to -27.5 °C, being within the INP spectra derived from precipitation under worldwide geophysical conditions, and are also comparable to those in the Arctic region. The heating-sensitive INPs account for 57%±30% of the observed INPs at -20 °C, and become increasingly important at warmer temperature regime, indicating biogenic particles as major contributors to INPs above -20 °C over the TP, especially, on the day with additional input of biogenic materials carried by dust particles. Chemical analysis demonstrates the rainwater components are mixture of dust particles, marine aerosol, and anthropogenic pollutants. Dust particles transported from the surrounding deserts and originated from ground surface of TP may contribute to the heating-resistant INPs at temperatures below -20 °C.