Evaluation of surface temperature and pressure derived from MERRA-2 and ERA5 reanalysis datasets and their applications in hourly GNSS precipitable water vapor retrieval over China

Temperature and pressure play key roles in Global Navigation Satellite System(GNSS) precipitable water vapor(PWV) retrieval. The National Aeronautics and Space Administration(NASA) and European Center for Medium-Range Weather Forecasts(ECMWF) have released their latest reanalysis product: the modern-era retrospective analysis for research and applications, version 2(MERRA-2) and the fifthgeneration ECMWF reanalysis(ERA5), respectively. Based on the reanalysis data, we evaluate and analyze the accuracy of the surface temperature and pressure products in China using the the measured temperature and pressure data from 609 ground meteorological stations in 2017 as reference values.Then the accuracy of the two datasets and their performances in estimating GNSS PWV are analyzed. The PWV derived from the pressure and temperature products of ERA5 and MERRA-2 has high accuracy. The annual average biases of pressure and temperature for ERA5 are-0.07 hPa and 0.45 K, with the root mean square error(RMSE) of 0.95 hPa and 2.04 K, respectively. The annual average biases of pressure and temperature for MERRA-2 are-0.01 hPa and 0.38 K, with the RMSE of 1.08 h Pa and 2.66 K, respectively.The accuracy of ERA5 is slightly higher than that of MERRA-2. The two reanalysis data show negative biases in most regions of China, with the highest to lowest accuracy in the following order: the south,north, northwest, and Tibet Plateau. Comparing the GNSS PWV calculated using MERRA-2(GNSS MERRA-2 PWV) and ERA5(GNSS ERA5 PWV) with the radiosonde-derived PWV from 48 co-located GNSS stations and the measured PWV of the co-location radiosonde stations, it is found that the accuracy of GNSS ERA5 PWV is better than that of GNSS MERRA-2 PWV. These results show the different applicability of surface temperature and pressure products from MERRA-2 and ERA5 data, indicating that both have important applications in meteorological research and GNSS water vapor monitoring in China.

Helping adolescents develop self-realization using art therapy

This report explored psychodynamic developments that adolescents undergo in their process of self-realization and self-identification, including separation-individuation and ego development. The paper maked a case for art therapy as a resource and non-confrontational outlet to guide adolescents through their development and search for their self-identity. The role of the art therapist is presented as an alternative source of support and containment which may be lacking through the adolescents’ peers and parents. The paper ultimately argued that art therapy had many therapeutic qualities that could help the adolescent in their search and consolidation of the self.

Natural overlaying behaviors push the limit of planar cyclic deformation performance in few-layer MoS_(2) nanosheets

As a typical two-dimensional(2D)transition metal dichalcogenides(TMDCs)material with nonzero band gap,MoS_(2)has a wide range of potential applications as building blocks in the field of nanoelectronics.The stability and reliability of the corresponding nanoelectronic devices depend critically on the mechanical performance and cyclic reliability of 2D MoS_(2).Although an in situ technique has been used to analyze the mechanical properties of 2D materials,the cyclic mechanical behavior,that is,fatigue,remains a major challenge in the practical application of the devices.This study was aimed at analyzing the planar cyclic performance and deformation behavior of three-layer MoS_(2)nanosheets(NSs)using an in situ transmission electron microscopy(TEM)variable-amplitude uniaxial low-frequency and cyclic loading-unloading tensile acceleration test.We also elucidated the strengthening effect of the natural overlaying affix fragments(other external NSs)or wrinkle folds(internal folds from the NS itself)on cycling performances and service life of MoS_(2)NSs by delaying the whole process of fatigue crack initiation,propagation,and fracture.The results have been confirmed by molecular dynamics(MDs)simulations.The overlaying enhancement effect effectively ensures the long-term reliability and stability of nanoelectronic devices made of few-layer 2D materials.