An investigation into the relationship between liquid water content and cloud number concentration in the stratiform clouds over north China

2014 ◽  
Vol 139 ◽  
pp. 137-143 ◽  
Author(s):  
Jin-Fang Yin ◽  
Dong-Hai Wang ◽  
Guo-Qing Zhai ◽  
Huan-Bin Xu
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
North China ◽  
Liquid Water Content ◽  
Number Concentration ◽  
Stratiform Clouds ◽  
The Relationship

scholarly journals Modelling the relationship between liquid water content and cloud droplet number concentration observed in low clouds in the summer Arctic and its radiative effects

2020 ◽  
Vol 20 (1) ◽  
pp. 29-43
Author(s):  
Joelle Dionne ◽  
Knut von Salzen ◽  
Jason Cole ◽  
Rashed Mahmood ◽  
W. Richard Leaitch ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Water Content ◽  
Liquid Water ◽  
Cloud Droplet ◽  
Liquid Water Content ◽  
Number Concentration ◽  
Radiative Effect ◽  
Low Clouds ◽  
Cloud Radiative Effect ◽  
Cloud Droplet Number Concentration

Abstract. Low clouds persist in the summer Arctic with important consequences for the radiation budget. In this study, we simulate the linear relationship between liquid water content (LWC) and cloud droplet number concentration (CDNC) observed during an aircraft campaign based out of Resolute Bay, Canada, conducted as part of the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments study in July 2014. Using a single-column model, we find that autoconversion can explain the observed linear relationship between LWC and CDNC. Of the three autoconversion schemes we examined, the scheme using continuous drizzle (Khairoutdinov and Kogan, 2000) appears to best reproduce the observed linearity in the tenuous cloud regime (Mauritsen et al., 2011), while a scheme with a threshold for rain (Liu and Daum, 2004) best reproduces the linearity at higher CDNC. An offline version of the radiative transfer model used in the Canadian Atmospheric Model version 4.3 is used to compare the radiative effects of the modelled and observed clouds. We find that there is no significant difference in the upward longwave cloud radiative effect at the top of the atmosphere from the three autoconversion schemes (p=0.05) but that all three schemes differ at p=0.05 from the calculations based on observations. In contrast, the downward longwave and shortwave cloud radiative effect at the surface for the Wood (2005b) and Khairoutdinov and Kogan (2000) schemes do not differ significantly (p=0.05) from the observation-based radiative calculations, while the Liu and Daum (2004) scheme differs significantly from the observation-based calculation for the downward shortwave but not the downward longwave fluxes.

scholarly journals A study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain

2014 ◽  
Vol 14 (12) ◽  
pp. 6417-6426 ◽  
Author(s):  
Y. X. Bian ◽  
C. S. Zhao ◽  
N. Ma ◽  
J. Chen ◽  
W. Y. Xu
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Liquid Water ◽  
North China Plain ◽  
North China ◽  
Liquid Water Content ◽  
High Relative Humidity ◽  
The North ◽  
The North China Plain ◽  
Thermodynamic Equilibrium Model

Abstract. Water can be a major component of aerosol particles, also serving as a medium for aqueous-phase reactions. In this study, a novel method is presented to calculate the aerosol liquid water content at high relative humidity based on measurements of aerosol hygroscopic growth factor, particle number size distribution and relative humidity in the Haze in China (HaChi) summer field campaign (July–August 2009) in the North China Plain. The aerosol liquid water content calculated using this method agreed well with that calculated using a thermodynamic equilibrium model (ISORROPIA II) at high relative humidity (>60%) with a correlation coefficient of 0.96. At low relative humidity (<60%), an underestimation was found in the calculated aerosol liquid water content by the thermodynamic equilibrium model. This discrepancy mainly resulted from the ISORROPIA II model, which only considered limited aerosol chemical compositions. The mean and maximum values of aerosol liquid water content during the HaChi campaign reached 1.69 × 10−4 g m−3 and 9.71 × 10−4 g m−3, respectively. A distinct diurnal variation of the aerosol liquid water content was found, with lower values during daytime and higher ones at night. The aerosol liquid water content depended strongly on the relative humidity. The aerosol liquid water content in the accumulation mode dominated the total aerosol liquid water content.

scholarly journals A~study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain

2014 ◽  
Vol 14 (3) ◽  
pp. 4089-4118
Author(s):  
Y. X. Bian ◽  
C. S. Zhao ◽  
N. Ma ◽  
J. Chen ◽  
W. Y. Xu
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Liquid Water ◽  
North China Plain ◽  
North China ◽  
Liquid Water Content ◽  
High Relative Humidity ◽  
The North ◽  
The North China Plain ◽  
Thermodynamic Equilibrium Model

Abstract. Water can be a major component of an aerosol particle. Also water serves as a medium for aqueous-phase reactions in aerosols. In this study, a novel method is presented to calculate the aerosol liquid water content at high relative humidity based on measurements of aerosol hygroscopic growth factor, particle number size distribution and relative humidity in the Haze in China (HaChi) summer field campaign (July–August 2009) in the North China Plain. The aerosol liquid water content calculated using this method agreed well with that calculated using a thermodynamic equilibrium model (ISORROPIA II) at high relative humidity (>60 %) with a correlation coefficient of 0.9658. At low relative humidity (<60%), an underestimation was found in the calculated aerosol liquid water content by the thermodynamic equilibrium model. This discrepancy mainly resulted from the ISORROPIA II model, which only considered limited aerosol chemical compositions. The mean and maximum values of aerosol liquid water content during the HaChi campaign reached 1.69 × 10−4; g m−3 and 9.71 × 10−4; g m−3, respectively. A distinct diurnal variation of the aerosol liquid water content was found, with lower values during daytime and higher ones at night. The aerosol liquid water content depended strongly on the relative humidity. The aerosol liquid water content in the accumulation mode dominated the total aerosol liquid water content.

scholarly journals Application of cloud particle sensor sondes for estimating the number concentration of cloud water droplets and liquid water content: case studies in the Arctic region

2021 ◽  
Vol 14 (7) ◽  
pp. 4971-4987
Author(s):  
Jun Inoue ◽  
Yutaka Tobo ◽  
Kazutoshi Sato ◽  
Fumikazu Taketani ◽  
Marion Maturilli
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Arctic Region ◽  
Liquid Water Content ◽  
Cloud Water ◽  
Number Concentration ◽  
The Arctic ◽  
Cloud Particle ◽  
Particle Count ◽  
The Arctic Region

Abstract. A cloud particle sensor (CPS) sonde is an observing system attached with a radiosonde sensor to observe the vertical structure of cloud properties. The signals obtained from CPS sondes are related to the phase, size, and number of cloud particles. The system offers economic advantages including human resource and simple operation costs compared with aircraft measurements and land-/satellite-based remote sensing. However, the observed information should be appropriately corrected because of several uncertainties. Here we made field experiments in the Arctic region by launching approximately 40 CPS sondes between 2018 and 2020. Using these data sets, a better practical correction method was proposed to exclude unreliable data, estimate the effective cloud water droplet radius, and determine a correction factor for the total cloud particle count. We apply this method to data obtained in October 2019 over the Arctic Ocean and March 2020 at Ny-Ålesund, Svalbard, Norway, to compare with a particle counter aboard a tethered balloon and liquid water content retrieved by a microwave radiometer. The estimated total particle count and liquid water content from the CPS sondes generally agree with those data. Although further development and validation of CPS sondes based on dedicated laboratory experiments would be required, the practical correction approach proposed here would offer better advantages in retrieving quantitative information on the vertical distribution of cloud microphysics under the condition of a lower number concentration.

scholarly journals Experimental Study on the Effect of Different Parameters on Rotor Blade Icing in a Cold Chamber

2020 ◽  
Vol 10 (17) ◽  
pp. 5884
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu ◽  
Ning Zhao
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Rotor Blade ◽  
Leading Edge ◽  
Liquid Water Content ◽  
Rotor Design ◽  
Set Up ◽  
Cold Chamber ◽  
Ice Shapes ◽  
The Relationship

Icing phenomenon is an important problem in helicopter rotor design. Conducting experiments in a cold chamber is one of the main methods used to study the law of rotor icing. The purpose of this paper was to analyze the influence of different parameters on the ice shapes of rotor blade and to obtain the relationship between the ice shapes and the input parameters. The icing experimental platform of rotation blade in a cold chamber was set up, and the rotor icing experiments under various conditions were carried out. The ice shapes on the blade were obtained, and the influence of different icing temperatures, rotation speeds, liquid water content, icing times, number of blades on the rotor, and blade materials on the ice shapes were analyzed. The results showed that the ice thickness on the leading edge increased with the increase of liquid water content, rotation speed, and icing time, and the number and material of blades had little effect on icing. The conclusions of this paper can provide a reference for the rotor numerical simulation and future experimental research.

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