Thermodynamic Characteristics of Snowfall Clouds using Dropsonde Data During ICE-POP 2018

The aircraft observation campaign was performed to investigate thermodynamic conditions of snowfall cloud over the East Sea of Korean peninsula from 2 February to 16 March 2018. During this period, four snowfall events occurred in the Yeongdong region and three cases were analyzed using dropsonde data. Snowfall cases were associated with the passage of southern low-pressure (maritime warm air mass) and expansion of northern high-pressure (continental polar air mass). Case 1 and Case 2a were related to low-pressure systems, and Case 2b and Case 3 were connected with high-pressure systems, respectively. And their thermodynamic properties and horizontal distribution of snowfall cloud were differed according to the influence of the synoptic condition. In Case 1 and Case 2a, atmospheric layers between sea surface and 350 hPa contained moisture more than 15 mm of TPW with multiple inversion layers detected by dropsonde data, while the vertical atmosphere of Case 2b and Case 3 were dry as TPW 5 mm or less with a single inversion inversion layer around 750 similar to 850 hPa. However, the vertical distributions of equivalent potential temperature (theta(e)) were similar as moist-adiabatically neutral condition regardless of the case. But, their values below 900 hPa were about 10 K higher in Case 1 and Case 2a (285 similar to 290 K) than in Case 2b and Case 3 (275 similar to 280 K). The difference in these values is related to the characteristics of the incoming air mass and the location of the snowfall cloud.