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We present tropospheric water vapor profiles measured with a Raman lidar during three field campaigns held in Finland. Co-located radio soundings are available throughout the period for the calibration of the lidar signals. We investigate the possibility of calibrating the lidar water vapor profiles in the absence of co-existing on-site soundings using water vapor profiles from the combined Advanced InfraRed Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU) satellite product; the Aire Limitée Adaptation dynamique Développement INternational and High Resolution Limited Area Model (ALADIN/HIRLAM) numerical weather prediction (NWP) system, and the nearest radio sounding station located 100 km away from the lidar site (only for the permanent location of the lidar). The uncertainties of the calibration factor derived from the soundings, the satellite and the model data are< 2:8, 7.4 and 3.9%, respectively. We also include water vapor mixing ratio intercomparisons between the radio soundings and the various instruments/model for the period of the campaigns. A good agreement is observed for all comparisons with relative errors that do not exceed 50% up to 8 km altitude in most cases. A 4- year seasonal analysis of vertical water vapor is also presented for the Kuopio site in Finland. During winter months, the air in Kuopio is dry (1:15±0:40 gkg-1); during summer it is wet (5:54±1:02 gkg-1); and at other times, the air is in an intermediate state. These are averaged values over the lowest 2 km in the atmosphere. Above that height a quick decrease in water vapor mixing ratios is observed, except during summer months where favorable atmospheric conditions enable higher mixing ratio values at higher altitudes. Lastly, the seasonal change in disagreement between the lidar and the model has been studied. The analysis showed that, on average, the model underestimates water vapor mixing ratios at high altitudes during spring and summer. [ABSTRACT FROM AUTHOR]

OASIS is a multidisciplinary project aiming at a comprehensive quantification of the role of atmospheric aerosols in efficient precipitation enhancement efforts in the United Arab Emirates (UAE). The projects specific scientific objectives are to: 1) undertake a comprehensive 1-year field campaign (Feb 2018 – Feb 2019) in the UAE employing a multitude of in-situ and lidar instruments to quantify the characteristics and the vertical profile of current background aerosol population as well as the key meteorological drivers of cloud formation in the study region, 2) identify optimal seeding strategies (in terms of e.g., time, location, amount of seeding) by using mesoscale meteorological simulations together with cloud-resolving model simulations with a highly advanced aerosol microphysics description, 3) quantify the characteristics of theoretically optimal ice nucleation seed aerosol by employing a suite of molecular-level simulation methods in order to support future experimental work aiming to develop more efficient ice nuclei, and 4) utilize novel statistical approaches to identify the major sources of uncertainty in prediction of rain enhancement success.This presentation summarizes the main results from the first two project years after the completion of the field campaign and a substantial fraction of the mesoscale, cloud-scale and molecular scale modelling work. Our findings highlight the close connection between the aerosol concentrations and the boundary layer dynamics in the UAE atmosphere, illuminate the optimal seeding strategies in both winter stratocumulus and summer convective cloud cases, and point to surface defects as potential sites for efficient ice nucleation. [ABSTRACT FROM AUTHOR]