edu.ucar.opensky::articles:26908 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T18:58:00.878745 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d72b9353 https://doi.org/10.26023/5Z74-JHT9-JT0X https Related Dataset #1 NCAR/EOL 915MHz Wind Profiler NIMA Winds and Moments. Version 1.0 https://doi.org/10.5065/D6WH2NV0 https Related Dataset #2 NCAR/EOL Quality Controlled Radiosonde Data - ISS2 Rogers Farm Site. Version 1.0 https://doi.org/10.5065/D6ZS2TWW https Related Dataset #3 5 Minute Statistics of ISFF data during CASES-99. Version 1.0 https://doi.org/10.5281/zenodo.10213602 https Related Dataset #4 Dataset for publication: Investigation of Hydrostatic Imbalance with Field Observations Investigation of hydrostatic imbalance with field observations 2024-01-01T00:00:00Z publication https://n2t.org/ark:/85065/d72b9353 https://doi.org/10.1175/JAMC-D-22-0206.1 Sun, J. author Wulfmeyer, V. author Späth, F. author Vömel, Holger author Brown, William O.J. author Oncley, Steven author UCAR/NCAR - Library publisher The hydrostatic equilibrium addresses the approximate balance between the positive force of the vertical pressure gradient and the negative gravity force and has been widely assumed for atmospheric applications. The hydrostatic imbalance of the mean atmospheric state for the acceleration of vertical motions in the vertical momentum balance is investigated using tower, the global positioning system radiosonde, and Doppler lidar and radar observations throughout the diurnally varying atmospheric boundary layer (ABL) under clear-sky conditions. Because of the negligibly small mean vertical velocity, the acceleration of vertical motions is dominated by vertical variations of vertical turbulent velocity variances. The imbalance is found to be mainly due to the vertical turbulent transport of changing air density as a result of thermal expansion/contraction in response to air temperature changes following surface temperature changes. In contrast, any pressure change associated with air temperature changes is small, and the positive vertical pressure-gradient force is strongly influenced by its background value. The vertical variation of the turbulent velocity variance from its vertical increase in the lower convective boundary layer (CBL) to its vertical decrease in the upper CBL is observed to be associated with the sign change of the imbalance from positive to negative due to the vertical decrease of the positive vertical pressure-gradient force and the relative increase of the negative gravity force as a result of the decreasing upward transport of the low-density air. The imbalance is reduced significantly at night but does not steadily approach zero. Understanding the development of hydrostatic imbalance has important implications for understanding large-scale atmosphere, especially for cloud development. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation