Planning for LOTOS: A New Lower Tropospheric Observing System

To support a community need for enhanced thermodynamic profiling and ground characterization measurements, an EOL proposal is being developed to create the LOwer Tropospheric Observing System. LOTOS will collect measurements i) to study physical processes in the surface layer, boundary layer and lower troposphere; ii) to study the coupling between the atmosphere and the underlying land surface and iii) to be assimilated into numerical weather prediction models to improve short-term forecast skill of severe storms and quantitative precipitation. LOTOS will be an integrated instrumentation platform that will operate in unattended mode to provide remotely sensed profiles of winds, temperature, moisture, clouds and aerosols; in situ measurements of turbulence and surface fluxes; near-surface profiles of meteorological parameters and greenhouse gases and automated radiosonde launches.

The components of LOTOS will include: a surface network of 100 self-contained flux stations to be deployed over a broad range of spatial scales (1 m- 100 km), including 25 greenhouse gas concentration sensors to measure carbon dioxide, methane and water vapor concentrations at multiple heights. One hundred Global Positioning System (GPS) receivers will provide integrated precipitable water vapor (PWV) and potentially tomographic retrievals. Embedded within the surface network, there will be five profiling nodes that are each comprised of i) micropulse DIAL (DIfferential Absorption Lidar: MPD) to measure profiles of water vapor and calibrated aerosol and potentially also temperature from 300 m to the mid-troposphere; ii) Doppler wind lidar to measure high-resolution wind profiles near the ground; iii) radar wind profiler to measure wind profiles throughout the lower troposphere; iv) Ka-band vertical pointing cloud radar to detect first clouds and v) AERI (Atmospheric Emitted Radiance Interferometer) to measure profiles of water vapor and temperature from 5 m- 3 km. Additionally automated radiosonde launches will be available from each of the five nodes. The combination of sensors into the LOTOS package will allow for integration of multiple instruments with common data formats and automated data quality capabilities where the complete data set will be considerably greater than the sum of the parts. User-provided instruments will also be welcome additions to LOTOS, including for example, unmanned aerial systems (UAS).

LOTOS will be available to the community for a wide range of scientific applications, including but not limited, to microscale meteorology, mesoscale meteorology, biogeochemistry, hydrology, urban meteorology, wind energy and fire meteorology. LOTOS will provide a wealth of data not only for process studies but also for assimilation by and use in improving advanced numerical weather prediction models. This presentation will describe the background, plan and timeline for the LOTOS proposal.