Schließungsstudien von Aerosol/Wolkenwechselwirkungen anhand von Lidar- und Radarbeobachtungen während MOASiC

<p>Während MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) wurden verschiedene Aerosol- und Wolkentypen mit einem Mehrwellenlängen-Polarisations-Raman-Lidar (Polly-XT) der OCEANET-Atmosphere-Plattform und mit dem KAZR-Wolkenradar der ARM (Atmospheric Radiation Measurement user facility) an Bord des Eisbrechers POLARSTERN beobachtet. Im Winterhalbjahr (2019/20) wurden dafür in der zentralen Arktis regelmäßig Aerosole in Oberflächennähe bis in 4-6 km Höhe (arktischer Dunst) und in der oberen Troposphäre und unteren Stratosphäre (Waldbrandrauch, bis in 18 km Höhe) beobachtet. Neu entwickelte Methoden der Fernerkundung ermöglichen die Bestimmung der Konzentrationen von Wolkenkondensationskernen (CCNC), der Wolkentröpfchenanzahl (CDNC), der eiskeimbildenden Partikel (INPC) und sogar, mit Hilfe von Dopplerradarbeobachtungen, der Eiskristallzahl (ICNC). Gleichzeitig sind Profile der relativen Luftfeuchtigkeit und der Temperatur aus Raman-Lidar, Mikrowellen-Radiometer und Radiosondierungen verfügbar. Mit Hilfe dieses einzigartigen Datensatzes präsentieren wir eine Aerosol-Wolkenschlussstudie, in der wir zeigen, dass CCNC und CDNC sowie INPC und ICNC miteinander verknüpft werden können. Die Ergebnisse können verwendet werden, um zu testen, welche CCN- und INP-Parametrisierungen (aus idealisierten Labormessungen) im arktischen Regime am besten zutreffen. <br>In Anlehnung an diese Methoden werden im zukünftigen Projekt SCiAMO (Smoke Cirrus interaction in the Arctic during MOSAiC) etwa 65 beobachtete Zirren im Hinblick auf Eisnukleationsprozesse in Abhängigkeit vom Auftreten von Rauchpartikeln in der Winter- und Sommersaison analysiert und verglichen.</p>

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

During the launch and return of a spacecraft, the intense combustion of propellants generates strong electromagnetic radiation, which interferes with the operation of electronic equipment in the spacecraft. To improve the electromagnetic compatibility of electronic equipment in spacecraft, it is necessary to study the electromagnetic radiation characteristics of rocket fuel. An electromagnetic radiation measurement system based on antennas is designed to measure the electromagnetic radiation generated by rocket fuel, and the electromagnetic radiation characteristics are obtained through data analysis. The mechanism of the electromagnetic radiation generated by rocket fuel is comprehensively analysed through the spatial, time-domain, frequency-domain, and energy-domain characteristics. A characterization model is established to provide a reliable scheme for evaluating the influence of rocket fuel electromagnetic radiation on electronic equipment in spacecraft.

Laboratory characterisations and intercomparison sounding test of dual thermistor radiosondes for radiation correction

A dual thermistor radiosonde (DTR) comprising two (white and black) sensors with different emissivities was developed to correct the effects of solar radiation on temperature sensors based on in-situ radiation measurements. Herein, the DTR performance is characterised in terms of the uncertainty via a series of ground-based facilities and an intercomparison sounding test. The DTR characterisation procedure using laboratory facilities is as follows: individually calibrate the temperature of the thermistors in a climate chamber; test the effect of temperature on the resistance reading using radiosonde boards in the climate chamber; individually perform radiation tests on thermistors; and perform parameterisation of the radiation measurement and correction formulas using an upper air simulator with varying temperature, pressure and ventilation speed. These results are combined and applied to the DTR sounding test conducted in July, 2021. Thereafter, the effective irradiance is measured using the temperature difference between the white and black sensors of the DTR. The measured irradiance is then used for the radiation correction of the DTR white sensor. The radiation-corrected temperature of the DTR is mostly consistent with that of a commercial radiosonde (Vaisala, RS41) within the expanded uncertainty (~0.35 ℃) of the DTR at the coverage factor k = 2. Furthermore, the components contributing to the uncertainty of the radiation measurement and correction are analysed. The DTR methodology can improve the accuracy of temperature measurement in the upper air within the framework of the traceability to the International System of Units.

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

During the launch and return of a spacecraft, the intense combustion of propellants generates strong electromagnetic radiation, which interferes with the operation of electronic equipment in the spacecraft. To improve the electromagnetic compatibility of electronic equipment in spacecraft, it is necessary to study the electromagnetic radiation characteristics of rocket fuel. An electromagnetic radiation measurement system based on antennas is designed to measure the electromagnetic radiation generated by rocket fuel, and the electromagnetic radiation characteristics are obtained through data analysis. The mechanism of the electromagnetic radiation generated by rocket fuel is comprehensively analysed through the spatial, time-domain, frequency-domain, and energy-domain characteristics. A characterization model is established to provide a reliable scheme for evaluating the influence of rocket fuel electromagnetic radiation on electronic equipment in spacecraft.

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

During the launch and return of a spacecraft, the intense combustion of propellants generates strong electromagnetic radiation, which interferes with the operation of electronic equipment in the spacecraft. To improve the electromagnetic compatibility of electronic equipment in spacecraft, it is necessary to study the electromagnetic radiation characteristics of rocket fuel. An electromagnetic radiation measurement system based on antennas is designed to measure the electromagnetic radiation generated by rocket fuel, and the electromagnetic radiation characteristics are obtained through data analysis. The mechanism of the electromagnetic radiation generated by rocket fuel is comprehensively analysed through the spatial, time-domain, frequency-domain, and energy-domain characteristics. A characterization model is established to provide a reliable scheme for evaluating the influence of rocket fuel electromagnetic radiation on electronic equipment in spacecraft.

A Fast Storage Method for Drone-Borne Passive Microwave Radiation Measurement

A drone-borne microwave radiometer requires a high sampling frequency and a continuous acquisition capability to detect and mitigate radio frequency interference (RFI), but existing methods cannot store such a large amount of data. In this paper, the dual polling write method (DPSM) for secure digital cards triggered by a timer under a multitask framework based on STM32 MCU is proposed to meet the requirements of continuous data storage. The card programming step was changed from a query waiting structure to a polling query flag bit structure, and time-sharing processing and parallel processing were used to simulate multithreading. The experimental results were as follows: (1) the time consumption of the whole storage procedure was reduced from 4000 microseconds to 200–400 microseconds; (2) the time consumption of the card programming step was reduced from 3000 microseconds in the first block and 1000 microseconds in the second and subsequent blocks to 17–174 microseconds and 18–71 microseconds, respectively, compared with the existing method; (3) the delay in the whole sampling cycle was reduced from 3942 microseconds to 0 microseconds. The results of this paper can meet the data storage requirements of a drone-borne microwave radiometer and be applied to the high-speed storage of other devices.