Above-low-cloud aerosol (ACA) has important impacts on low clouds bellow. Based on the satellite data from 2007 to 2010, this study analyzed the relationship between ACA optical depth (OD), ACA occurrences and low cloud integrated color ratio (CR) over tropic Atlantic region where ACA frequently occurs. The results show that, the integrated attenuated CR (IACR) of low cloud is about 30%-50% larger over smoke region in smoke outbreak seasons than other regions or seasons. However, the IACR of low cloud over dust region shows small difference between dust outbreak seasons and other seasons. It indicates that above-low-cloud smoke aerosol can introduce stronger color effect than dust. The integrated corrected CR (ICCR) of low cloud tends to decrease with increasing above-cloud dust OD, while the low cloud ICCR shows weak relationship with above-low-cloud smoke OD. And, the above-low-cloud dust aerosol could introduce strong microphysics effect, that is, the low cloud droplet size may decrease with increasing burden of dust aerosol above.
This paper studied the marine-type aerosol distribution characteristics with the Wide-range Particle Spectrometer (WPS) obsevations boared on ”Shen Kuo” ship, over the South China Sea from June 21 to July 2, 2019. Particle spectral distributions at different time, fitted by the log-normal distribution method, and compared with the fine particle measurements in Hefei. Results show that the particle distributions over the South China Sea mainly show peaks around 95nm and 480nm respectively, while peaks around 26nm and 100nm in Hefei. The maximum concentration of fine particles in Hefei can reach 13×103 /cm3 , which is much higher than that over the South China Sea with a peak concentration of 6×103 /cm3 .
Because of the special topography surrounded by sea on three sides, the coastal area of Qingdao is greatly affected by the aerosol of sea salt sources, and has a significant maritime climate. Based on the meteorological observation data measured by the Qingdao seaside from September to October 2019, the correlations between the atmospheric conventional meteorological parameters of the typical sea area and the influence of meteorological parameters on the atmospheric aerosol optical parameters were analyzed. The results indicate that,(1) the relative humidity has opposite daily variation to temperature, and the change of atmospheric pressure slightly lags behind the relative humidity;(2) there is a relationship between the change of weather and meteorological parameters, that is, the parameters such as temperature and relative humidity, visibility and particle number density distribution on sunny days are significantly different from those in rainy days;(3) visibility is positively correlated with the daily variation of wind speed and temperature, and is negatively correlated with the daily variation of relative humidity. It shows that conventional meteorological parameters such as relative humidity, temperature, and atmospheric pressure are closely related to optical parameters such as particle size distribution and visibility. The above statistical analysis results have reference value for the establishment of the regional aerosol model in the coastal area of Qingdao.
The altitude of atmospheric medium involved in atmospheric optics has a height range of 100km, and the most complicated variation of atmospheric properties is mainly in the atmospheric boundary layer (ABL). The variety of ABL height is of considerable significance to the distribution of aerosol, cloud, and other processes. Since the research of Chinese marine ABL analysis is limited, in this study, we improved the algorithm by using 532nm total attenuated backscattering (TAB) for retrieving atmospheric boundary layer height (ABLH) from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and verified the results gained from micro-pulse lidar (MPL) and radiosonde over the South China Sea. Finally, we used the validated ABLH algorithm model to retrieve the ABLH against CALIPSO data from Mar. 2018 to Feb.2019 over the South China Sea.
Tibetan Plateau, known as the third pole of the Earth, has an important impact on the atmospheric circulation and weather in East Asia. The detection of meteorological elements in the near-surface layer of the area is of great significance for the in-depth study of the meteorological mechanism of the boundary layer. In this paper, we used multi-rotor UAV (Unmanned Aerial Vehicle) combined with conventional observations to independently design a measurement platform with various sensors, data storage and transmission components, measuring conventional meteorological parameters, and temperature structure constants (Ct2 ). The suitability analysis of the platform was carried out through drone sonde and kite-balloon sonde experiments in Lhasa area (91°08′07′′E, 29°39′36′′N). Comparative analysis of two kinds of data shows that 403MHz wireless transmission adopted by the two methods is stable, and two sounding results of temperature, air pressure and Ct2 have good consistency between each other, with acceptable normal ranges of error. This work provides a new boundary layer detection method, and also has positive significance for scientific research work in meteorology and environmental monitoring.
Lidar has been widely used in remote sensing of atmospheric environment because of its high spatial-temporal resolution and detection sensitivity. As the main noise source in lidar detection, solar background radiation is an important factor to determine target from background. The background noise, which is estimated by taking the average value of the lidar echo signal at a certain height, is usually removed directly. However, the background noise also contains some useful information on the whole layer of the atmosphere. In this paper, atmospheric radiation transmission model software MODTRAN 5.0 was used to simulate the lidar background noise under clear sky condition, combined with micro-pulse lidar (MPL) and meteorological element sounding data. The daytime background noise received by lidar were simulated by standard model method and user-defined model method. The standard model method uses standard atmospheric and aerosol model, which is the common way in traditional background radiation simulation. The user-defined model method uses aerosol and meteorological data measured in Maoming, Guangdong Province in October 2018 to build a user-defined atmospheric model. Results shows that the overall trends of the simulated background radiation from two methods are quite similar to the MPL observation. The user-defined model method can produce more consistent results with the observation than the standard model method, mainly due to that standard model cannot be completely consistent with the real experimental environment. The simulation results in this paper can be used to improve the daytime MPL retrieval, and can also be applied to the retrieving of aerosol particle size information and optical characteristics of cloud in further study.