Consistency of Tropospheric Water Vapor between Reanalyses and Himawari-8/AHI Measurements over East Asia

High spatiotemporal resolution radiances from the advanced imagers onboard the new generation of geostationary weather satellites provide a unique opportunity to evaluate the abilities of various reanalysis datasets to depict multilayer tropospheric water vapor(WV),thereby enhancing our understanding of the deficiencies of WV in reanalysis datasets.Based on daily measurements from the Advanced Himawari Imager(AHI)onboard the Himawari-8 satellite in 2016,the bias features of multilayer WV from six reanalysis datasets over East Asia are thoroughly evaluated.The assessments show that wet biases exist in the upper troposphere in all six reanalysis datasets;in particular,these biases are much larger in summer.Overall,we find better depictions of WV in the middle troposphere than in the upper troposphere.The accuracy of WV in the ERA5 dataset is the highest,in terms of the bias magnitude,dispersion,and pattern similarity.The characteristics of the WV bias over the Tibetan Plateau are significantly different from those over other parts of East Asia.In addition,the reanalysis datasets all capture the shift of the subtropical high very well,with ERA5 performing better overall.

Design and parameter optimization of spiral-dragon type straw chopping test rig

In order to address the problems of large chop length,high energy consumption and poor chopping effect that were associated with a horizontal total mixed rations(TMR)mixer,a straw chopping device was designed;further,its structure and working principle were analyzed.In this study,wheat straw was chosen as the test object.The number of processing times,number of fixed blades,cutting speed,number of tooth plates and the inclined angle of the box were considered as the test factors.The standard straw length rate and average power were used as evaluation indices for conducting the orthogonal rotation combination experiment with five factors and five levels of quadratic regression.The experimental results denoted that the order of influencing factors on the standard straw length rate can be given as follows:the number of processing times,number of fixed blades,cutting speed,number of tooth plates and inclined angle of the box.The order of the influence of each factor on the average power can be given as follows:the cutting speed,number of fixed blades and number of tooth plates.Further,the optimum structural and working parameters of the device can be determined as follows:linear cutting speed of 17-20 m/min,box inclined angle of 70°-80°,20-23 fixed blades,5-6 processing times and 4-7 tooth plates.Under such a circumstance,the standard straw length rate reached up to 70.5%-77.4%and the average power was low at 5.8-7 kW.The results can be used as reference for designing a chopping device for a TMR mixer.