Recognition of composition and of microphysical characteristics of aerosol clouds in multifrequency sounding

Bravy, B. G.; Vasiliev, G K; Agroskin, V. Ya.

doi:10.1117/12.454419

Cited by 5 publications

(3 citation statements)

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“…The parameters of the Gaussian distribution for different cloud top pressure intervals are jointly estimated using an evolutionary algorithm (EA) [ Eiben and Smith , ; Goldberg , ]. EAs have been previously applied to problems in meteorology and cloud physics [ Babb et al , ; Bravy et al , ; Cerdeña et al , ; Pallavi and Vaithiyanathan , ; Ahn and Lee , ], but to the best of our knowledge, they have not been yet considered in applications related to CGT analysis. In this case, classical approaches are not straightforward to be applicable to this nonlinear problem, whereas EAs are known to be very effective independently of the type of objective function, and they can cope with the integral formulation of the proposed model and the large number of parameters to be optimized.…”

Section: Introductionmentioning

confidence: 99%

Cloud glaciation temperature estimation from passive remote sensing data with evolutionary computing

et al. 2016

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The phase partitioning between supercooled liquid water and ice in clouds in the temperature range between 0 and −37°C influences their optical properties and the efficiency of precipitation formation. Passive remote sensing observations provide long‐term records of the cloud top phase at a high spatial resolution. Based on the assumption of a cumulative Gaussian distribution of the ice cloud fraction as a function of temperature, we quantify the cloud glaciation temperature (CGT) as the 50th percentile of the fitted distribution function and its variance for different cloud top pressure intervals, obtained by applying an evolutionary algorithm (EA). EAs are metaheuristics approaches for optimization, used in difficult problems where standard approaches are either not applicable or show poor performance. In this case, the proposed EA is applied to 4 years of Pathfinder Atmospheres‐Extended (PATMOS‐x) data, aggregated into boxes of 1° × 1° and vertical layers of 5.5 hPa. The resulting vertical profile of CGT shows a characteristic sickle shape, indicating low CGTs close to homogeneous freezing in the upper troposphere and significantly higher values in the midtroposphere. In winter, a pronounced land‐sea contrast is found at midlatitudes, with lower CGTs over land. Among this and previous studies, there is disagreement on the sign of the land‐sea difference in CGT, suggesting that it is strongly sensitive to the detected and analyzed cloud types, the time of the day, and the phase retrieval method.

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Section: Introductionmentioning

confidence: 99%

Cloud glaciation temperature estimation from passive remote sensing data with evolutionary computing

et al. 2016

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“…For different process of chemical reaction comparing with the chain HF laser, it can be operated on high pulse repetition-rate with high peak power [1,2] . With above properties, the non-chain HF laser has possible applications for various science and technology purposes, such as detection of atmospheric pollution, medicine, and processing of materials [3,4] .…”

Section: Introductionmentioning

confidence: 98%

Discharge pumped non-chain repetitively pulsed HF laser

Huang

Tang

et al. 2013

SPIE Proceedings

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The design and performance of a closed cycle, repetitively pulsed HF laser is described. The homogeneous glow discharge is formed with UV pre-ionization and transverse discharge structure. The optimal output parameters of single pulse operation are given by the investigation of discharge characteristics in SF 6 /C 2 H 6 gas mixture and output characteristics of laser pulse. The repetitively pulse energy stability of laser device are checked with different conditions of gas flowing velocity, charging voltage and total pressure of gas mixture. It is shown that the maximal output energy of laser pulse of 0.6J, peak power 3MW are obtained. Total efficiency of laser device is about 2.4%. When the gas mixture circulating with 4m/s flowing velocity, the maximal running frequency of 50Hz are obtained and operating stability keep well. Under these conditions, the laser pulse energy keeps stable and the average output power is 18W.

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Section: Introductionmentioning

confidence: 98%

<title>Discharge characteristics and laser performance of non-chain HF laser</title>

Huang

Tang

et al. 2010

SPIE Proceedings

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The experimental setup and performance of a non-chain transverse excited HF laser with UV pre-ionization is described.Electric discharge characteristics in gas mixture of SF 6 /C 2 H 6 are investigated for various initial conditions by recording the discharge plasma fluorescence intensity and temporal evolution of discharge current and voltage. The laser pulse energy is studied in different charging voltage, gas mixture pressure and concentration. It is shown that the process of discharge in gas mixture has three phases: glow discharge, voltage plateau and arc discharge. The optimal energy deposition obtained at the critical point that the voltage plateau just disappears. Maximal output energy of 0.6J and electrical efficiency of 2.5% are obtained.

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Recognition of composition and of microphysical characteristics of aerosol clouds in multifrequency sounding

Cited by 5 publications

References 0 publications

Cloud glaciation temperature estimation from passive remote sensing data with evolutionary computing

Cloud glaciation temperature estimation from passive remote sensing data with evolutionary computing

Discharge pumped non-chain repetitively pulsed HF laser

<title>Discharge characteristics and laser performance of non-chain HF laser</title>

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