Previous studies have recognized reflectivity maxima above the freezing level(RMAF) within stratiform precipitation over mountain slopes, however, quantitative studies are limited due to the lack of adequate identific...Previous studies have recognized reflectivity maxima above the freezing level(RMAF) within stratiform precipitation over mountain slopes, however, quantitative studies are limited due to the lack of adequate identification criteria. Here, we establish an identification method for RMAF precipitation and apply it to the Tropical Rainfall Measuring Mission(TRMM) Precipitation Radar(PR) observations. Using the TRMM 2A25 product from 1998 to 2013, we show that the RMAF structure in reflectivity profiles can be effectively identified. RMAF exists not only in stratiform precipitation but also in convective precipitation. RMAF frequency is positively correlated with elevation, which is thought to be caused by enhanced updrafts in the middle layers of stratiform precipitation, or in the low to middle layers of convective precipitation over mountains. The average RMAF heights in stratiform and convective precipitation were 1.35 and 2.01 km above the freezing level, respectively, which is lower than previous results. In addition, our results indicate that the RMAF structure increased the echo top height and enhanced precipitation processes above the RMAF height, but it suppressed the downward propagation of ice particles and the near-surface rain rate. Future studies of orographic precipitation should take into account the impact of the RMAF structure and its relevant dynamic triggers.展开更多
This study focused on three newly appointed primary school teachers in City D as research subjects.Utilizing research methods such as interviews,text analysis,and observation,the findings revealed that these teachers ...This study focused on three newly appointed primary school teachers in City D as research subjects.Utilizing research methods such as interviews,text analysis,and observation,the findings revealed that these teachers exhibited a substantial grasp of teaching reflection.The predominant emphasis in their teaching reflection levels was observed at the technical reasonable reflection and practical action reflection stages.To enhance the reflection levels of these novice teachers,it is recommended to foster their professional ethics,institute a diverse training system,and enhance the school’s infrastructure and institutional support systems.展开更多
基金supported by the Special Program for Key Research and Development of Guangdong Province (Grant Number 2019B111101002)the Fundamental Research Funds for the Guangzhou Science and Technology Plan project (Grant Number 201903010036)+1 种基金National Natural Science Foundation of China (Grant Numbers 41675043, 41775094, and 42005062)the Fundamental Research Funds for the Central Universities (Grant Number 20lgpy27)。
文摘Previous studies have recognized reflectivity maxima above the freezing level(RMAF) within stratiform precipitation over mountain slopes, however, quantitative studies are limited due to the lack of adequate identification criteria. Here, we establish an identification method for RMAF precipitation and apply it to the Tropical Rainfall Measuring Mission(TRMM) Precipitation Radar(PR) observations. Using the TRMM 2A25 product from 1998 to 2013, we show that the RMAF structure in reflectivity profiles can be effectively identified. RMAF exists not only in stratiform precipitation but also in convective precipitation. RMAF frequency is positively correlated with elevation, which is thought to be caused by enhanced updrafts in the middle layers of stratiform precipitation, or in the low to middle layers of convective precipitation over mountains. The average RMAF heights in stratiform and convective precipitation were 1.35 and 2.01 km above the freezing level, respectively, which is lower than previous results. In addition, our results indicate that the RMAF structure increased the echo top height and enhanced precipitation processes above the RMAF height, but it suppressed the downward propagation of ice particles and the near-surface rain rate. Future studies of orographic precipitation should take into account the impact of the RMAF structure and its relevant dynamic triggers.
文摘This study focused on three newly appointed primary school teachers in City D as research subjects.Utilizing research methods such as interviews,text analysis,and observation,the findings revealed that these teachers exhibited a substantial grasp of teaching reflection.The predominant emphasis in their teaching reflection levels was observed at the technical reasonable reflection and practical action reflection stages.To enhance the reflection levels of these novice teachers,it is recommended to foster their professional ethics,institute a diverse training system,and enhance the school’s infrastructure and institutional support systems.
