Evaluation and Assimilation of Low-Level Moisture from the MPD during the

The MicroPulse DIAL (MPD) is a new type of differential absorption lidar that can monitor the moisture in the lower troposphere under clear-sky conditions continuously with high temporal and vertical spatial resolutions. Three MPDs were deployed during the "PRE"-CIP2021 experiment in Colorado in the 2021 summer and the PRECIP2022 campaign in Taiwan in the 2022 summer. Verifications during the "PRE"-CIP2021 experiment suggest that the real-time forecasts with the assimilation of all-sky infrared radiances match the MPD observations reasonably good, although notable descrepencies exist, since all-sky infrared radiances are unable to observe moisture near the surface. The assimilation of the MPD observations lead to improved match between the data assimilation analyses and the observations -- as well as during the subsequent forecasts, although the improvements after assimilating MPD observations only last for a limited time during the forecasts. On the other hand, rainfall forecasts are only slightly improved, likely due to the fact that the majority of the rainfall systems during "PRE"-CIP experiment are localized thunderstorms; while low-level moisture conditions are important for the formation and development of thunderstorms, many other factors also contributed to their forecasts. However, MPD is proved to be a reliable, stable, and relatively economical instrument that can provide critical, high-resolution lower-tropospheric moisture observations that compliments the current observing system.