New and Existing Opportunities for Measuring Boundary Layer Moisture for Convection Initiation Studies (Invited Presentation)

One of the necessary ingredients for improved understanding and forecasting of convection initiation is sufficient boundary layer moisture. Several well-established and new techniques to measure water vapor profiles and spatial moisture variability will be described. These include radar refractivity retrievals which provide real-time low-level moisture maps within ~40 km from weather radars, S-band/Ka-band attenuation-based moisture retrievals which provide water vapor profiles when cloud echoes are present and continuous water vapor profiles obtained from active micropulse water vapor DIAL (Differential Absorption Lidar) and passive AERI (Atmospheric Emitted Radiance Interferometer) systems. Additionally operational ground-based GPS (Global Positioning System) receivers provide continuous integrated water vapor data. The combination of multiple GPS receivers may provide 3D moisture retrievals via the tomographic retrieval technique. Strengths and limitations of these different observing techniques and their potential impact on studying and forecasting convection initiation will be described. The combination of these various water vapor measurement techniques in creating a 3D field may be possible through data assimilation methods.