大气科学学报2025，Vol.48Issue(6)：1004-1013,10.DOI:10.13878/j.cnki.dqkxxb.20241007001
偏振云粒子谱仪(CAS-DPOL)的数据处理和应用
Development of data processing methods for the cloud aerosol spectrometer with depolarization(CAS-DPOL)and their application
摘要
Abstract
Accurate knowledge of the phase of small cloud particles(d＜50 μm)is crucial for understanding cloud microphysical processes and radiative effects,which remain major sources of uncertainty in weather and cli-mate models.In situ measurements provide an effective means of obtaining cloud particle phase information;how-ever,detecting the phase of small particles in airborne cloud physics observations has long been challenging.Utili-zing the polarization properties of cloud particles to distinguish their phase has recently become recognized as an effective approach.This study focuses on the processing and application of polarization parameters measured by the Cloud Aerosol Spectrometer with Depolarization(CAS-DPOL),a commercial instrument developed by Drop-let Measurement Technologies(DMT),USA.The CAS-DPOL was recently introduced into China's meteorological observation system and developed—together with other cloud microphysical probes—aboard the Inner Mongolia weather modification aircraft Y-12.Despite its operational use,no prior studies in China have re-ported the application of polarization information from CAS-DPOL,primarily due to the absence of dedicated data processing methods. To address this limitation,this study integrates and refines a set of algorithms and threshold criteria suitable for processing CAS-DPOL polarization parameters to retrieve cloud particle phase states and related microphysical quantities.Additionally,the inter-arrival time(IAT)and transit time(TT)of detected particles are analyzed to i-dentify shattered and coincidence particles,respectively. Based on these methods and thresholds,the CAS-DPOL data collected during an airborne campaign over Northeast China,23 May 2021—under a cold vortex synoptic pattern—were analyzed.The results show that,the temperature in the detected clouds was between-1 ℃ and-8 ℃,supercooled cloud droplets accounted for ap-proximately 80.18％of the total particle number concentration.The cloud phase was predominantly mixed-phased,although some regions consisted entirely of supercooled water clouds.For this weather system,a particle number concentration greater than 5 cm-3 was found to be a reliable lower threshold indicating the presence of su-percooled droplets,providing a practical reference for determining cloud-seeding suitability.Furthermore,analysis of in-flight natural icing intensity indicated only minimal icing,with no conditions meeting the CCAR-25 Appen-dix C criteria.The preliminary results demonstrate that supercooled liquid droplets can be effectively distinguished from ice crystals using the proposed processing methods in conjunction with CAS-DPOL measurements.Although further validation is needed,the findings highlight the strong potential of CAS-DPOL and the developed algorithms for applications in cloud microphysics research,artificial weather modification,and aircraft icing detec-tion.关键词
偏振云粒子谱仪/东北冷涡/飞机测量/飞机积冰/人工影响天气Key words
cloud aerosol spectrometer with depolarization(CAS-DPOL)/northeast cold vortex/airborne meas-urement/aircraft icing/artificial weather modification引用本文复制引用
黄敏松,李秋柏..偏振云粒子谱仪(CAS-DPOL)的数据处理和应用[J].大气科学学报,2025,48(6):1004-1013,10.基金项目
中国科学院战略性先导科技专项(XDB0760100) （XDB0760100）
中国气象局航空气象重点开放实验室开放研究课题(HKQXM-2024007) （HKQXM-2024007）
中国气象局云降水物理与人工影响天气重点开放实验室创新基金项目(2023CPML-B06) （2023CPML-B06）
南京气象科技创新研究院北极阁开放研究基金项目(BJG202302) （BJG202302）
中国气象局流域强降水重点开放实验室项目(2023BHR-Y22) （2023BHR-Y22）
中国科学院技术支撑人才项目(E3661416) （E3661416）
