Impact of vertical resolution of PBL measurements on the computation of PBL's interaction with surface and the free atmosphere
Abstract
The 2018 NASA Earth Science Decadal Survey recognized the importance of planetary boundary layer (PBL). PBL has a strong spatial variation from deserts (with an early afternoon PBL height of ~4 km) to polar regions (with a PBL height of hundreds to tens of meters). It also has a strong diurnal cycle, typically varying from ~0.1 km at night to ~1 km during the day. It is a challenge to provide space-based observations that can fully resolve the vertical structure of PBL. The question is then: How does the vertical resolution of PBL measurements affect the computation of PBL's interaction with (land/ocean/ice) surface and with the free atmosphere?
To preliminarily address this question, we take the sampling OSSE (Observing System Simulation Experiment) approach based on the radiosonde data. Specifically, we use radiosonde data over land, small islands, ocean, and sea ice to compute 0.1, 0.3, 0.5, 1, 2, and 3 km vertical averages of temperature, humidity, and horizontal wind vector. Then, we evaluate the impact of different vertical resolutions on: (a) the PBL interaction with the free atmosphere, as represented by the jump of potential temperature and specific humidity across the PBL top, (b) the PBL interaction with the (land/ocean/ice) surface, as represented by the wind magnitude from the bottom layer of the radiosonde data multiplied by the air-surface difference of potential temperature, specific humidity, and wind vector (u, v), and (c) the computation of the PBL height. Besides addressing the above question, this effort will shed some light on when (e.g., daytime versus nighttime) and where (e.g., land versus ocean; different climate regimes) measurements with coarse vertical resolutions can be more useful for PBL process studies. It will also help future tradeoff studies of measurement technologies with different vertical resolutions, as required in the NASA PBL Incubation Program.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A14G..02Z
- Keywords:
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- 3307 Boundary layer processes;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES