Abstract In 2011, the National Oceanic and Atmospheric Administration (NOAA) began a cooperative initiative with the academic community to help address a vexing issue that has long been known as a disconnection between the operational and research realms for weather forecasting and data assimilation. The issue is the gap, more exotically referred to as the “valley of death,” between efforts within the broader research community and NOAA’s activities, which are heavily driven by operational constraints. With the stated goals of leveraging research community efforts to benefit NOAA’s mission and offering a path to operations for the latest research activities that support the NOAA mission, satellite data assimilation in particular, this initiative aims to enhance the linkage between NOAA’s operational systems and the research efforts. A critical component is the establishment of an efficient operations-to-research (O2R) environment on the Supercomputer for Satellite Simulations and Data Assimilation Studies (S4). This O2R environment is critical for successful research-to-operations (R2O) transitions because it allows rigorous tracking, implementation, and merging of any changes necessary (to operational software codes, scripts, libraries, etc.) to achieve the scientific enhancement. So far, the S4 O2R environment, with close to 4,700 computing cores (60 TFLOPs) and 1,700-TB disk storage capacity, has been a great success and consequently was recently expanded to significantly increase its computing capacity. The objective of this article is to highlight some of the major achievements and benefits of this O2R approach and some lessons learned, with the ultimate goal of inspiring other O2R/R2O initiatives in other areas and for other applications.
Stereoscopic perception is a basic requirement for photogrammetric 3D measurement and accurate geospatial data collection. Ordinary stereoscopic techniques require operators wearing glasses or using eyepieces for interpretation and measurement. However, the recent emerging autostereoscopic technology makes it possible to eliminate this requirement. This paper studies the principles and implementation of autostereoscopic photogrammetric measurement and evaluates its performance. We first describe the principles and properties of the parallax barrier-based autostereoscopic display used in this study. As an important metric property, we quantitatively present the autostereoscopic geometry, including viewing zones and the boundary of a viewer’s movement for autostereoscopic measurement. A toolkit AUTO3D is developed that has common photogrammetric functions. The implementation principles are described by addressing the differences compared to the ordinary stereoscopic technology. To evaluate the performance of the autostereoscopic measurement, images at a resolution of 25 � m and 50 � m are measured by a group of seven (7) operators, who are asked to digitize 18 well-defined roof points and 18 ground points. These results are evaluated by comparing the same measurements obtained from a popular stereoscopic photogrammetric workstation. It is shown that the precision of autostereoscopic measurement is about 16 percent to 25 percent lower than the conventional stereo workstation.
The soil matrix, salt crystals, ice crystals, and pore solutions constitute the composite geological material of saturated saline frozen soil. The destruction mode and dynamic constitutive model of saturated saline frozen soil need to be studied because infrastructure construction is increasingly being extended to regions with saturated saline frozen soil. Based on the split Hopkinson pressure bar device, uniaxial impact compression tests were conducted on frozen soil samples with different salt contents under different strain rates. The strain rate of saturated saline frozen soil must be emphasized based on the results. The gradient of the elastic segment and maximum stress of the soil are negatively correlated with the salt content increase. To further explore the failure mechanism, the study examined the damage and failure behavior of saturated saline frozen soil, along with the absorption energy in the failure process. According to the test results, the saturated saline frozen soil was similar to a particle-reinforced composite. Subsequently, the debonding damage of the ice–salt eutectic and the mechanical–chemical damage of the soil matrix were considered. The test results could be predicted accurately from the results of the model, verifying that the influences of the salt content and strain rate are reasonably considered by the constructed model.
The tallgrass prairie in the Flint Hills of Kansas faces woody plant encroachment as one of several incessant threats. Many factors affect woody plant encroachment into prairies, and the effects of climatic variability, including temperature and precipitation, are among the most debated. Plants, in the long term, alter their physical structure and functional capacity to adapt to changes in external environmental conditions. These changes include changes to vascular tissue. We conducted a survey of three habitat types (prairie, a transitional woodland, and a forest edge) to identify the impacts of annual weather on woody plant cell physiology; specifically, lumen area, cell wall thickness, and cell diameter in both earlywood (produced during spring) and latewood (produced during summer). Intraspecific comparisons showed little difference among sites. However, there were differences in earlywood cell lumen area and overall cell diameter with precipitation among sites while latewood showed weak positive correlations. Cell wall thickness showed little or no correlation with precipitation in both earlywood and latewood. Temperature had no impact on our cellular metrics among all habitats, suggesting precipitation is the driving stressor in our species in this prairie setting.
As the largest independent east–west-trending mountain in the world, Mt. Tianshan exerts crucial impacts on climate and pollutant distributions in central Asia. Here, the vertical structures of meteorological elements and black carbon (BC) were first derived at Mt. Tianshan using an unmanned aerial vehicle system (UAVS). Vertical changes in meteorological elements can directly affect the structure of the planet boundary layer (PBL). As such, the influences of topography and meteorological elements’ vertical structure on aerosol distributions were explored from observations and model simulations. The mass concentrations of BC changed slightly with the increasing height below 2300 m above sea level (a.s.l.), which significantly increased with the height between 2300–3500 m a.s.l. and contrarily decreased with ascending altitude higher than 3500 m. Topography and mountain–valley winds were found to play important roles in the distributions of aerosols and BC. The prevailing valley winds in the daytime were conducive to pollutant transport from surrounding cities to Mt. Tianshan, where the aerosol number concentration and BC mass concentration increased rapidly, whereas the opposite transport pattern dominated during nighttime.
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