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Raindrop size distribution （RSD） is fundamental in understanding the precipitation microphysics and quantitative precipitation estimation， especially in complex terrain with complicated rainfall mechanism and high spatial and temporal variability.In this paper， the RSD characteristics of different rainfall rates and rain types in the mountainous and plain areas of the Ili River Valley during the summer of 2020 -2022 are investigated using Parsivel2 disdrometer.The results show that the precipitation in the mountainous and plain areas is mainly composed of small raindrops， and medium raindrops are the largest contribution to the rainfall rate R.Precipitation in the mountainous and plain areas mainly occurs during the late afternoon and early evening， and the concentration of large and medium-sized raindrops is higher in the mountainous areas in all time periods.The spectral width and the concentration of drops with diameters increase with increasing rainfall rate.The number concentration of medium and large particles in the mountainous areas is obviously higher than that in the plain areas during light rain and heavy rain.For the same rainfall rate and rain type， precipitation in the mountainous areas has higher mass-weighted mean diameter （Dm） and lower normalized intercept parameter （log10Nw）.In addition， the convective rain spectrum in the mountainous and plain areas of the Ili River Valley tend to be “continental-like convective cluster”.It is found that there are also significant differences in the μ-Λ relationship and Z-R relationship of precipitation between the two areas， and the empirical relationship of Z =300R1.40 clearly overestimates precipitation.The results reveal the microphysical characteristics of precipitation under different terrain conditions in the Ili River Valley， and provide a reliable factual basis for the subsequent retrieval of precipitation using radar data.

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Using the ITU-R rain attenuation forecasting model,and based on the rainfall data and the geographic location parameters of main cities in our country,the isograms of rain attenuation distribution for the communication satellite with the orbital location 92° E in Ka band（30/20GHz）was presentd.A further analysis was made on the rain attenuation char-acteristic of the Ka band satellite communication system by integrating with the landform and the climate distribution pattern in our country.The results could be used as the theoretical basis when designing the Ka band satellite communica-tion system.

Copyright of Journal of Tropical Meteorology (1004-4965) is the property of Guangzhou Institute of Tropical & Oceanic Meteorology, China Meteorological Administration and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Tropical Meteorology (1004-4965) is the property of Guangzhou Institute of Tropical & Oceanic Meteorology, China Meteorological Administration and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Tropical Meteorology (1004-4965) is the property of Guangzhou Institute of Tropical & Oceanic Meteorology, China Meteorological Administration and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the hourly precipitation data at 124 stations from 1977 to 2017, the basic climatological characteristics of night rainfall rate, frequency and intensity in Yunnan province are analyzed by using the statistical methods such as time and space averaging. The results show that: (1) Night rain accounts for a large proportion of daily precipitation in Yunnan, which can exceed 50% in most areas for all seasons, and has significant regional differences. The annual variation of night rainfall rate has a complex and special three-peak pattern. (2) The annual frequency of night rain in Yunnan is more in the east and west than in the middle, which mainly comes from the contribution of the typical high frequency area of night rain in the east and west of Yunnan in spring and winter. In winter and spring, the high frequency area of night rain in eastern and western Yunnan is affected by the southwesterly wind system, Kunming quasi-stationary front and Yunnan topography. (3) The northern and southern margins of Yunnan province are the high value areas of night rainfall intensity in most of the year, while the middle part is relatively weak. In most areas of Yunnan, the intensity of night rain in summer and autumn is higher than that in spring and winter, but the intensity of night rain in winter and spring in northwest margins of Yunnan is higher than that in summer and autumn.

Raindrop size distribution (DSD) is a basic characteristic for describing the microphysical process of rainfall. A better understanding of DSD and its variations is not only crucial for improving microphysical parameterization schemes in numerical weather forecasting models, but also important for radar quantitative precipitation estimation. It shows that DSD characteristics are not only related to geographical location, climate, terrain, and humidity, but also vary among different rainfall types and rain rate in the same region. At present, there are still some uncertainties and limitations in the understanding of microphysical characteristics of rainfall in Northeast China, and the microphysical parameterization scheme still lacks accurate description of rainfall microphysical process. Based on observations of the precipitation phenomenon instrument at Xinmin of Liaoning Province in summer, DSD characteristics of different rainfall rate classes are investigated and compared with those of other regions in China. Spectral width of DSD increases with an increase in rain rate (R). The spectral width of raindrops is close to 8 mm when R>20 mm·h-1. Small drops are predominant in rainfall of Xinmin, but moderate drops make the most significant contribution to total rainfall. Observed DSD samples are also categorized into convective and stratiform rainfall types. The convective rainfall at Xinmin has large raindrop size and low raindrop concentration. Convective rainfall can be identified as continental clusters, with average Dm and lgNw of 2.14 mm and 3.40, while average Dm and lgNw of stratiform rainfall at Xinmin are 1.23 mm and 3.30, respectively. The μ-Λ and Z-R relationships for convective and stratiform rainfall at Xinmin are thus fitted. Fitted μ-Λ relationship at Xinmin is similar to that in other regions fitted with data observed by PARSIVEL disdrometers, but different from the empirical relationship fitted from two-dimensional video raindrop spectrometers (2DVD) observations in other regions, and the difference of instruments is the main cause for the discrepancies of μ-Λ relationships. Compared with East China and North China, Xinmin rainfall has larger Dm, lower lgNw, and higher exponent value of fitted Z-R power-law relationship for convective rainfall, indicating that the radar reflectivity factor at Xinmin increases more rapidly with the increase of rain rate. Using the Z-R empirical formula fitted at Xinmin can reduce the error of radar-based quantitative precipitation estimation. Results would contribute to the understanding of microphysical characteristics of rainfall in Northeast China and the accuracy of radar quantitative precipitation estimation.

The interaction between rainfall and aircraft wake vortices changes their dynamic characteristics, and the dynamic evolution of wake vortices, which has an important impact on the safety of wake encounters. Aiming at the interaction between wake vortices and rainfall, this study investigates the evolution characteristics of wake vortices in rainy conditions based on the Euler-Euler multiphase flow model. For the air phase simulation in the multiphase flow model, the large eddy simulation turbulence model is used. The dynamic transport of rain phase is controlled by two scalar equations. The two phases are coupled through the momentum source term to realize the energy transfer. The influence of rainfall rate on the evolution characteristics of wake vortices, such as circulation, vorticity, velocity distribution near the vortex core and sinking velocity, is analyzed. The results show that rainfall accelerates the decay of the circulation, reduces the maximum vorticity of the vortex core, smooths the velocity distribution, and affects the descent process of wake vortices. In addition, the presence of wake vortices also affects the trajectory and concentration distribution of rain. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective Geological, climatic, and topographical conditions control regional groundwater flow systems. Previous researchers have made significant advancements in developing the theory of groundwater flow systems under steady-state climatic conditions. However, there has been limited progress in comprehensively understanding transient groundwater flow systems. Methods To address this gap, we constructed a two-dimensional numerical model that couples groundwater and surface water using HydroGeoSphere. We then examined the relationships among the subsystems of transient groundwater flow systems in response to variations in rainfall. Results The results demonstrate that the areas occupied by subsystems change with rainfall fluctuations. Local groundwater flow systems may neither expand during wet seasons nor contract during dry seasons. The relationships among the penetration depths, which indicate the elevation of the lowest point in a local flow system, can be positive, negative, or unrelated. This variation mainly arises from the high activity of intermediate groundwater flow systems under transient conditions, where their inputs, outputs, flow paths, and areas of recharge and discharge vary with rainfall fluctuations. These relationships are also sensitive to factors such as geology (hydraulic conductivity, specific storage), climate (rainfall rate), and topography (local and regional). Conclusion Based on a sensitivity analysis of five scenarios, changes in local flow systems are more influenced by aquifer anisotropy. Future research should prioritize conducting a more comprehensive analysis of the non-steady-state response patterns exhibited by groundwater flow systems, considering climate fluctuations on a seasonal scale, over multiple years, and even across centuries.

In order to enhance the understanding of rainfall observation performance of micro-smart (integrated) weather stations and to promote the application in rainfall observation operations, a comparative experiment for the rainfall observation of radar, photoelectric, piezoelectric and tipping bucket micro-smart weather stations is carried out by Hebei Xiong'an New Area Meteorological Service from June to November in 2021. The rainfall observation capability of micro-smart weather stations with different rainfall observation principles are analyzed in terms of total rainfall, rainfall intensity, percentage of rainfall intensity and temporal characteristics. It shows that when the accumulated precipitation exceeds 10 mm, the precipitation measured by the tipping bucket micro-smart weather station can meet observation error control requirements compared with the precipitation observed by the standard station, while results of the radar micro-smart weather station are large and results of the photoelectric and piezoelectric micro-smart weather stations are small. When the cumulative precipitation is less than 10 mm, results of the tipping bucket and piezoelectric micro-smart weather stations can meet observation error control requirements, while results of radar micro-smart weather stations are large and results of photoelectric micro-smart weather stations are small. In terms of rainfall intensity, the double tipping bucket station is suitable for monitoring rainfall extreme, while photovoltaic and piezoelectric stations underestimate the extreme. Radar-based micro-smart weather stations can be calibrated and revised for rainfall extreme monitoring by adjusting internal parameters. Analysis of different rainfall intensities and their corresponding rainfall ratios show that the rain intensity corresponding to a rain intensity accumulation ratio greater than 95% at each micro-smart weather station is[0.3 mm·min-1, 0.6 mm·min-1] and the rain intensity corresponding to a rainfall accumulation ratio greater than 50% is[0.1 mm·min-1, 0.4 mm·min-1]. It shows that within 0.4 mm·min-1, the proportion of rainfall measured by any type of rain sensor accounts for more than half of the total rainfall, so more attention should be paid to accuracy for small rain intensity in the operational rain sensor rate determination. As the resolving capacity increases, the tipping bucket type micro-smart weather station becomes less sensitive to the starting time and will identify the ending time earlier. The radar type micro-smart weather station responds to rainfall relatively more quickly. Finer resolving capacity of the rain sensor will enhance the monitoring effectiveness of fine rainfall and the effective rainfall rate.

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Tropical Meteorology (1004-4965) is the property of Guangzhou Institute of Tropical & Oceanic Meteorology, China Meteorological Administration and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It's of great significance to study features of raindrop size distribution (DSD) during different stages of the summer monsoon for understanding the precipitation mechanism, which is regarded as credible reference to improve and refine ainfall retrieval algorithms based on satellite and radar observations and the parameterization of microphysics scheme in numerical model. Characteristics of DSD during summer (June to August) of 2015-2017 are investigated using measurements from a ground-based disdrometer in Nanjing. Results show different micro and macro precipitation characteristics among three stages of summer monsoon. Precipitation before Meiyu is characterized by the highest (among the three stages) mean mass-weighted raindrop diameter, average minutely rainfall rate, and intense minutely and strong hourly rainfall occurrences. Despite generally weak convection intensity in this stage, the persistent support from large-scale synoptic conditions, sufficient condensation and the weakened influence from evaporation, breaking-up and entrainment processes are beneficial to produce large raindrops and improve precipitation efficiency. In contrast, precipitation after Meiyu is identified with the greatest frequency of large raindrop and extreme minutely rainfall occurrences. This is mainly caused by severe convective activities under hot and humid atmospheric conditions. Stronger convection is also associated with higher frequency of smaller raindrops. In pace with the northward advancement of the summer monsoon, the convection intensity enhances gradually and breaking-up processes of raindrops heighten as well, which lead to higher ratio of small-raindrop samples with the largest value during the stage after Meiyu. From many aspects of these raindrop and rainfall characteristics, convective precipitation during Meiyu is inferior comparing to that in the other two stages. However, rainfall rates are highest and raindrops are largest during stratiform precipitation due to sufficient coalescence processes under favorable synoptic forcing conditions. The concentration of small raindrops is usually high but the ratio of small raindrops is the lowest in this stage. Among three stages, the binomial relationship between the shape index and slope parameter also differ significantly, depending on the value of the shape index. Compared with Meiyu of 2009-2011, the frequency of intense rainfall occurrence and its contribution to total precipitation decrease while those for weak rainfall increase in terms of both minutely and hourly rainfall. Simultaneously, the binomial relationship of the shape index and slope parameter changes significantly as well.

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The application of the Gash model to simulate canopy interception is mostly on the study plot or a specified forest, and the application in a landscape scale is only reported in the Australian Water Resource Assessment system (AWRA-L). This study introduced the AWRA-L model, and aimed to simulate the interception loss of the natural secondary forest of birch (Betula platyphylla Suk.) during 2013 in China. The GLASS LAI data and submerging method were used to get the canopy capacity for different periods. The leaf area index (LAI) value obtained before germination was assumed to be the area of branches and trunks. While the LAI value obtained after germination was the area of the leaves, branches and trunks. The differences between the LAI values after and before germination were the area of leaves when the growing of branches and trunks was ignored. The submerging method showed that the water capacity of leaves and stems per unit area were 0.17 and 0.33 mm, respectively. The capacity of branches and trunks was 0.23 mm. The capacity of leaves was 0.04-0.51 mm. The mean canopy capacity was 0.60±0.14 mm. The intercept method showed the canopy capacity and the trunk capacity were 0.62 and 0.04 mm, respectively. The whole capacity of the birch forest in its over ground parts was 0.66 mm. The canopy capacity by the submerging method and the intercept method was not significantly different (P=0.23). Considering of the high canopy cover fraction of the birch forest, both the simulating results of AWRA-L model based on Van model and the AWRA-L(1979) model based on Gash (1979) model were discussed in the paper. For the 25 rain events measured during the experiment, the simulating errors of the cumulative interception loss obtained from the AWRA-L model and the AWRA-L(1979) model were -9.2 and -1.7 mm, respectively. The relative errors were -14.8% and -2.8%, respectively. Both the AWRA-L model and the AWRA-L(1979) model underestimated the interception loss. When the rain event on June 8 with the biggest simulating error was eliminated, the cumulative simulating errors of the AWRA-L model and the AWRA-L(1979) model were -4.4 and 1.5 mm, respectively. The relative errors were -8.7% and 3.0%, respectively. The mean errors of the simulating interception loss for single rain event by these two models were -0.15 and -0.03 mm, respectively. The simulating value and measured was not significantly different. The results illustrated that the canopy capacity obtained by the data of GLASS LAI and submerging method could be used to determine the canopy capacity and the results could be used for simulating of interception loss by the AWRA-L model. The AWRA-L model is reliable to simulate both the cumulative interception loss for a long period and the interception loss for a single rain event in a landscape scale. [ABSTRACT FROM AUTHOR]

Atmospheric precipitation samples were collected in a representative region of Beijing in summer of 2015 to investigate the physical and chemical characteristics of atmospheric precipitation, the changes and causes of major chemical components in rainwater during the course of typical precipitation, and the impacts of typical precipitation processes on atmospheric pollutants. The volume-weighted mean pH value of rainwater in the representative region of Beijing in summer was 6.21 with the range of 5.15-7.34,and acid rain seldom occurred. The pollution elements Cd, Ca and Mn were moderately enriched, and Cu, Zn, Pb and S were seriously enriched in rainwater, of which Ca and S were main pollution elements, which accounted for 45.43% and 43.93% of the total pollution elements respectively, and Zn, Mn, Cu, Pb and Cd were main heavy metal pollution elements, which accounted for 1.32% of the total pollution elements. Different rates of precipitations could have different impacts on atmospheric pollutants. PM 2.5 could be scavenged by raindrop, and SO 2 , NO 2 and O 3 could be scavenged greatly by raindrop during the precipitation episode at a relatively high rainfall rate, containing four significant stages, such as clear-out of atmospheric pollutants, accumulation, both accumulation and clear-out, and another clear-out of airborne pollutants. Atmospheric pollutants such as PM 2.5 , SO 2 , NO 2 and O 3 could mainly be scavenged by in-cloud scavenging processes during the precipitation episode at a relatively low rainfall rate, including four important stages, such as clear-out, both clear-out and accumulation, accumulation, and another clear-out of atmospheric pollutants. The effect of rainfall at a relatively high rate on atmospheric pollutants was bigger than that of rainfall at a relatively low rate.

Studies on the dynamics of upland field P pool under a long-term application of fertilizer P in yellow soil area and their effects on P concentration in runoff showed that the contents of A1-P, Fe-P and Ca-P in soil cultivated layer increased greatly, and Olsen-P and algae-available P also accumulated obviously. The correlation coefficients of algae-available P content in the high-P soils (Olsen-P > 25 mg.kg-1) with the quantities of A1-P, Fe-P and Ca-P were 0.859**, 0.903** and 0.650*, respectively, of which, Fe-P was the most important. By a 30-min rainfall simulation experiment with a constant rainfall rate of 63.2 mm.h-1, the concentrations of dissolved reactive P and bio-available P in runoff from low-P upland fields (Olsen-P 4.62-15.9 mg.kg-1) were 2.81-4.17 micrograms.L-1 and 0.723-0.876 mg.L-1, respectively, whereas their concentrations in runoff from high-P upland fields (Olsen-P 29.4-59.2 mg.kg-1) were 0.026-0.714 mg.L-1 and 0.996-1.281 mg.L-1, respectively. Therefore, runoff from high-P upland fields could accelerate water eutrophication.