LOWER TROPOSPHERE OBSERVING SYSTEM (LOTOS) - Advancing PBL Observations

The National Center for Atmospheric Research Earth Observing Laboratory (EOL) proposes developing the Lower Troposphere Observing System (LOTOS), an integration of instrumentation that offers the potential for a transformative understanding of the lower atmosphere and its coupling to the Earth's surface. The goals of LOTOS are to enhance thermodynamic profiling and land-atmosphere exchange process observations to: i) study physical processes in the atmospheric surface layer, boundary layer, and lower troposphere; ii) investigate the coupling between the atmosphere and the underlying land surface; and iii) assimilate data into numerical models for various weather forecasting, surface flux representation, and hydrological applications.

The LOTOS instrumentation network is designed to allow simultaneous and coordinated sampling both vertically, through the atmospheric planetary boundary layer, and horizontally, across the surrounding landscape. It focuses on the land-atmosphere interface and its coupling with the overlying free troposphere.

LOTOS will be a modular and flexible system designed to meet the scientific objectives of the investigators. Deployment options could include up to five profiling nodes with instrumentation comprised of: i) radar wind profiler for measuring wind profiles throughout the lower troposphere; ii) Doppler wind lidar for high-resolution wind profiles near the ground; iii) micropulse DIAL (Differential Absorption Lidar: MPD) for measuring profiles of water vapor and temperature; iv) Infrared spectrometer for retrieving profiles of water vapor and temperature from 5 m to 3 km; iv) 30-meter flux tower and greenhouse gas sensors for measuring carbon dioxide, methane, and water vapor concentrations at multiple tower heights; v) radiosonde sounding system; vi) Ka-band vertical pointing cloud radar; vii) a surface network of up to 15 flux stations surrounding each node; and viii) partnerships for UAS (Unmanned Aircraft Systems) in situ measurements to fill the gap between surface sensors and remote sensing instruments.

The combination and modularity of instruments and sensors in LOTOS will allow for a flexible approach to meeting the unique needs of field programs. The integration of data from various sensors and instruments aims to have common data formats and data quality control capabilities, where the complete dataset will be considerably greater than the sum of its parts. The capability of LOTOS will only be possible through strong partnerships with the community. We are seeking partners to collaborate on instrumentation, including UAS, data processing, and algorithm development, to produce an integrated data product using LOTOS observations' common data formats and tools, creating value-added data products for the community.

It is envisioned that LOTOS will become part of the deployable NSF Lower Atmosphere Observing Facilities (LAOF), thus being available to a broad base of NSF users for various scientific applications, including microscale meteorology, mesoscale meteorology, biogeochemistry, hydrology, urban meteorology, wind energy, and fire meteorology. LOTOS will provide abundant data not only for process studies but also for assimilation and improvement of advanced numerical weather prediction models. LOTOS offers the potential for a transformative understanding of the Earth and its atmosphere as a coupled system. This presentation will describe the instrumentations, potential data products, and scientific motivation.