The NSF NCAR Earth Observing Laboratory (EOL) has supported over 600 national and international field campaigns which represent half a century of field-based observational science. Our mission is to provide responsive, high quality data services to researchers in field campaigns including pre-field phase planning, real-time decision-making tools, and long-term data curation to support the complete project life cycle. Such support includes (1) serving as the online hub for field campaign operations with access to r…

Abstract Cold fog forms via various thermodynamic, dynamic, and microphysical processes when the air temperature is less than 0°C. It occurs frequently during the cold season in the western United States yet is challenging to detect using standard observations and is very difficult to predict. The Cold Fog Amongst Complex Terrain (CFACT) project was conceived to investigate the life cycle of cold fog in mountain valleys. The overarching goals of the CFACT project are to 1) investigate the life cycle of cold-fog ev…

Abstract The ozonesonde observations in Hanoi, Vietnam, over 14 years since 2004, have confirmed an enhancement in lower tropospheric ozone concentration at about 3 km altitude in the spring season. We investigated the evolution of the ozone enhancement from analysis of meteorological data, backward trajectories, and model sensitivity experiments. In spring, air masses over Hanoi exhibit strong height dependence. At 3 km, the high‐ozone air masses originate from the land area to the west of Hanoi, while low‐ozone …

The ozonesonde observations in Hanoi, Vietnam, over 14 years since 2004, have confirmed an enhancement in lower tropospheric ozone concentration at about 3 km altitude in the spring season. We investigated the evolution of the ozone enhancement from analysis of meteorological data, backward trajectories, and model sensitivity experiments. In spring, air masses over Hanoi exhibit strong height dependence. At 3 km, the high-ozone air masses originate from the land area to the west of Hanoi, while low-ozone air masse…

Abstract Understanding lowermost stratosphere (LMS) ozone variability is an important topic in the trends and climate assessment communities because of feedbacks among changing temperature, dynamics, and ozone. LMS evaluations are usually based on satellite observations. Free tropospheric (FT) ozone assessments typically rely on profiles from commercial aircraft. Ozonesonde measurements constitute an independent data set encompassing both LMS and FT. We used Southern Hemisphere Additional Ozonesondes (SHADOZ) data…