Large‐Scale Circulation Environment and Microphysical Characteristics of the Cloud Systems Over the Tibetan Plateau in Boreal Summer

Chen, Jinghua; Wu, Xiaoqing; Yin, Yan; Lu, Chen

doi:10.1029/2020ea001154

Cited by 10 publications

(4 citation statements)

References 36 publications

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“…Conversion of INP per water volume to INP per air volume ( N INP_air ) is achieved by assuming a cloud water content (CWC) of 0.15 g m −3 averaged over the CWC (ranged from 0.03 to 0.25 g m −3 ) detected in an aircraft measurement over the TP (Chang et al., 2019). This value was consistent with that estimated in precipitating convective clouds using multiyear satellite observation (<0.2 g m −3 ) (Chen et al., 2020). CWC is defined as cloud droplets of 1pL disperse in 1 m 3 of air weigh about 0.15 g, and the corresponding volume of cloud water per volume of air ( F cloud _ air ) was 1.5 × 10 −7 m 3 water m −3 air (Gong et al., 2020).…”

Section: Methodssupporting

confidence: 92%

Ice‐Nucleating Particle Concentrations and Sources in Rainwater Over the Third Pole, Tibetan Plateau

Chen

et al. 2021

JGR Atmospheres

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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 value of INP concentrations varies from 0.002 to 0.675 L−1 air over the temperature range from −7.1 to −27.5°C. This is within the INP spectra derived from precipitation under worldwide geophysical conditions and is also comparable with INP concentrations in the Arctic regions. The heat‐sensitive INPs account for 57% ± 30% of the observed INPs at −20°C and become increasingly important at higher temperatures, indicating biological particles as major contributors to INPs at temperatures above −20°C over the TP, especially on the day with additional input of biogenic materials carried by dust particles. Chemical analysis demonstrates that the rainwater components are mixture of dust particles, marine aerosol, and anthropogenic pollutants. Combined with the backward trajectory analysis, we show that dust particles transported from the surrounding deserts and originated from ground surface of TP may contribute to the heat‐resistant INPs at temperatures below −20°C.

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Section: Methodssupporting

confidence: 92%

Ice‐Nucleating Particle Concentrations and Sources in Rainwater Over the Third Pole, Tibetan Plateau

Chen

et al. 2021

JGR Atmospheres

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“…As "the world water tower," the Tibetan Plateau (TP) tremendously affects water budget in this region, as well as the radiation balance, weather and climate of East Asia (Chen et al, 2020;Fu et al, 2020;Wu et al, 2015;Xu et al, 2008Xu et al, , 2014, and global stratosphere (Bian et al, 2020). In the boreal summer, convection is easy to be triggered, and clouds prevail over TP (Chen et al, 2019;Li et al, 2020;Li & Zhang, 2016;Liu et al, 2015;Wang et al, 2014;Yu et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Parameterizations of Entrainment‐Mixing Mechanisms and Their Effects on Cloud Droplet Spectral Width Based on Numerical Simulations

Luo

Liu

et al. 2020

JGR Atmospheres

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Entrainment-mixing mechanisms significantly affect cloud droplet number concentration, radius, and spectral shape. Quantitative examination of entrainment-mixing effects on cloud droplet spectral width is lacking. This study examines the effects of entrainment-mixing processes on cloud microphysics by 12,218 different setups, each simulated 10 times using the Explicit Mixing Parcel Model (EMPM) driven by the observational data from the Third Tibetan Plateau Atmospheric Scientific Experiment (TIPEX-III) campaign. Parameterizations of entrainment-mixing mechanisms are developed by relating homogeneous mixing degree to transition scale number that depends on the dissipation rate and droplet evaporation time scale. The correlation between relative dispersion of cloud droplet size distribution and homogeneous mixing degree changes from negative to positive with the decreasing homogeneous mixing degree. The different relationships are closely related to the competition between complete and partial droplet evaporation and the number concentration of small droplets, which are quantitatively described by two newly introduced dimensionless numbers. The competition is significantly affected by relative humidity and mixing fraction of entrained air as well as turbulence dissipation rate, but not much by cloud droplet number concentration. Especially, when relative humidity and dissipation rate are high, there is only a negative correlation. This study sheds new light on generalizing the homogeneous/inhomogeneous concept by considering relative dispersion and also provides parameterizations of entrainment-mixing processes and relative dispersion for atmospheric models.

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“…The rainy weather seen over the TP is usually related to water vapor transported by the warm southward current [8]. Precipitation on the TP gradually decreases from southeast to northwest, and summer precipitation accounts for about 60-70% of the total annual precipitation [9].…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of a Typical Convective Precipitation and Its Cloud Microphysical Process in the Yushu Area, Based on the WRF Model

Zhang

Yang

et al. 2022

Atmosphere

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Cloud microphysical processes significantly impact the time variation and intensity of precipitation. However, due to the high altitude of the Tibetan Plateau (TP) and the lack of observational data, the understanding of cloud microphysical processes on the TP is relatively insufficient, affecting the accuracy of precipitation simulations around the TP. To further reveal the characteristics of convective precipitation and cloud microphysical structure over the TP, the mesoscale numerical model, WRF, and various observational data were used to simulate and evaluate typical convective precipitation in the Yushu area, which was recorded from 11 to 12 August 2020. The results showed that the combination of the Lin scheme in the WRF model could effectively reproduce this case’s characteristics and evolution process. In the simulation process, the particles of each phase were distributed at different altitudes, and their mass and density over time reflected the characteristics of surface precipitation changes. Among the particles mentioned above, rainwater contributed the most to the initiation and growth of graupel particles. Further research established that the initiation of graupel was mainly affected by the freezing effect of rainwater and cloud ice, while the growth of graupel was influenced primarily by the collision of graupel particles and rainwater. On the whole, from the evolution characteristics of microphysical processes over time, it was found that the ice phase process plays an essential role in this typical convective precipitation.

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Large‐Scale Circulation Environment and Microphysical Characteristics of the Cloud Systems Over the Tibetan Plateau in Boreal Summer

Cited by 10 publications

References 36 publications

Ice‐Nucleating Particle Concentrations and Sources in Rainwater Over the Third Pole, Tibetan Plateau

Ice‐Nucleating Particle Concentrations and Sources in Rainwater Over the Third Pole, Tibetan Plateau

Parameterizations of Entrainment‐Mixing Mechanisms and Their Effects on Cloud Droplet Spectral Width Based on Numerical Simulations

Numerical Simulation of a Typical Convective Precipitation and Its Cloud Microphysical Process in the Yushu Area, Based on the WRF Model

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