| dc.description.abstract | In situ measurements from Controlled Meteorological (CMET) balloons are used to study Arctic air mass transformation in marine cold air outbreaks (mCAOs) over the Nordic Seas. 6 CMET balloons were launched from Ny- ̊Alesund on 24 March-5 April 2022 in association with the ISLAS 2022 field campaign. In the aftermath, the data from the CMET balloons were quality controlled, and calculations of height and wind data were carried out due to extensive GPS outages encountered by the balloons. Subsequently, the data from CMET flight 2 and flight 4 are analyzed using comparisons with radiosondes, a dropsonde and AROME-Arctic forecasts with different lead times. The results revealed good agreement between the CMET and AROME-Arctic forecasts. The largest difference was found for potential temperature and wind speed. Increased forecast accuracy with decreasing lead time was present for both flights, with the smallest accuracy change in flight 4 for humidity. Moreover, two simulations with the Lagrangian particle dispersion model FLEXPART- AROME are analyzed in order to verify one of the CMET flights. Two different forecast initializations and release locations were used, and the weighted mean trajectories at three different altitudes surrounding the CMET balloon were investigated. A decreasing absolute horizontal transport deviation (AHTD) with height was found, and further analysis revealed that vertical wind shears were located at the locations of increased trajectory errors. This study displays a quantification of the performance of CMET balloons in a challenging Arctic environment, and the study shows that it is possible to retrieve useful information on mCAOs from CMET balloons. | |
