Research

SAIL will deploy more than four dozen advanced atmospheric instruments measuring precipitation, aerosols, clouds, winds, radiation, temperature, and humidity across a wide range of spatial and temporal scales at the East River watershed research site. These data provide opportunities to quantify key physical processes in the Upper Colorado River Basin known for their qualitative impact on mountainous watershed hydrology.

Research Objectives

SAIL focuses on 5 interrelated science objectives in the Upper Colorado River:

Precipitation Processes

SAIL will characterize the spatial distribution of orographic and convective precipitation processes on diurnal to seasonal time-scales and how those processes interact with large-scale circulation by using observations from an X-band scanning precipitation radar and the Ka-Band Zenith Radar (KAZR) at two separate locations to. Radar observations will provide detailed precipitation structure information that will be useful for observing embedded convective structures in wintertime storms, precipitation-type transitions, warm-season orographic convection, and transport of hydrometeors across mountain ridges. Doppler-derived wind fields will also provide useful information on airflow structures over multi-directional ridgelines. Coordinated Range Height Indicator (RHI) scans from the X-band scanning precipitation radar and the KAZR will yield multi-wavelength polarimetric radar observations to probe how hydrometeor microphysics and dynamics interact.

Sublimation and Wind Redistribution

SAIL will quantify cold-season land-atmosphere interactions that alter snowpack mass balance through wind redistribution and sublimation and the spatial scaling of those processes by using vertical and horizontally distributed wind field measurements from radiosondes, a radar wind profiler, a doppler lidar (DL), the X-band scanning radar’s doppler capabilities, and distributed meteorological stations to characterize the spatiotemporal structure blowing snow and of snowpack and blown-snow sublimation.

Aerosol Regimes and Radiation

SAIL will establish aerosol regimes, the processes controlling the life cycle of aerosols in those regimes, and quantify the impacts of aerosols in those regimes on the atmospheric and surface radiative budget by combining the suite of measurements from the Mobile Aerosol Observing System with radiometric observations.

Aerosol-Precipitation Interactions

SAIL will quantify the sensitivity of cloud phase and precipitation to cloud condensation nuclei (CCN) and ice-nucleating particle (INP) concentrations by co-analyzing X-band scanning precipitation radar data with a suite of measurements from the Mobile Aerosol Observing System and INP observations.

Surface Energy Balance

SAIL will quantify the seasonally-varying surface energy balance, the land-surface and atmospheric factors controlling it, and the spatial variability in those factors by using a suite of radiometric and cloud observations, and observations of turbulent fluxes of momentum, sensible, and latent heat to explore the dominant factors controlling these fluxes.