## 3 Results  
Figure 2 shows the frequency distribution of the seasonal occurrence of clouds with a cloud fraction exceeding 80% during the time period specified by our study. The seasonal samples of data for each grid are average 2618 (winter), 2697 (spring), 2730 (summer), and 2687 (fall), respectively. The occurrence frequency of clouds around the Korean Peninsula in winter was approximately 49% on sea and 31% on land. The occurrence frequency of clouds was approximately 6% higher during  
this season than others due to the development of cumulus column clouds in the warm and humid atmosphere caused by warm current. This excluded the downwind regions on the Korean Peninsula located in the westerly wind zone (East Coast, South Coast, and Jeju Island) [23; 52]. The occurrence frequency of clouds on land was approximately 8% higher than in other regions due to the development of orographic clouds near the Taebaek and Sobaek Mountains (Figure 2a), which are located at an altitude of 500 m to 1000 m and sometimes higher [8]. Jeju Island is surrounded by the sea, and the occurrence frequency of clouds is therefore approximately 28%. This is about 17% higher than other land areas due to the inflow of clouds generated at sea [53]. There was no substantial difference between land and sea cloud occurrence frequency in all seasons except winter. Summer exhibited the highest occurrence frequency of clouds at approximately 47%, with frequencies of at least 60% around the Taebaek and Sobaek Mountains. Overall, winter exhibited cloud fractions exceeding 80% with a high occurrence frequency, and the difference in frequency between land and sea was found to be large. Therefore, the frequency distribution of clouds differs according to the season, land, sea, and topographical characteristics around the Korean Peninsula [54]. However, not all distributed clouds have the characteristics necessary for precipitation enhancement. Figure 2: Frequency distribution by season (**a–d**) of clouds with COMS cloud fraction exceeding 80% (the solid red line indicates the Taebaek and Sobaek Mountains). Figure 3 shows the distribution of CTT, CTH, and occurrence frequency of seedable clouds (both water and ice cloud phases) generated around the Korean Peninsula. As shown in Figure 2, the occurrence frequency of seedable clouds was high in regions with a high frequency of cloud occurrence. Approximately 42% of the occurrence frequency of clouds corresponded to seedable clouds; the average occurrence in seasons other than winter was approximately 17%. Winter had the highest occurrence frequency of seedable clouds at approximately 13% on land and 21% on sea (overall average of 18%). Seedable clouds on land had an average CTH of approximately 2.73 km, which was 0.30 km higher than average sea CTH. The distribution of CTT varied with the latitude, and was approximately 2 K lower on land, at an average of \(-\)10.30 \({}^{\circ}\)C. The average occurrence frequency of seedable clouds around the Korean Peninsula in the spring and fall was approximately 8%. However, the frequency distribution of these clouds was 10% to 15% around the Taebaek/Sobaek Mountains and Jeju Island, respectively. The summer season exhibited the lowest occurrence frequency of seedable clouds at approximately 6% and also showed a low frequency on land at an average of 8%. The average CTH in summer was 2.61 km, which is similar to other seasons. However, the CTT in summer was the highest of all seasons at 9.79 \({}^{\circ}\)C. Table 1 shows the occurrence frequency and characteristics of seedable clouds according to season and cloud type. Figure 3: Frequency distribution of seedable clouds (both water cloud phase and ice cloud phase (**a**–**d**) and cloud characteristics (CTH: (**e**–**h**)), (CTT: (**i**–**l**)) by season around the Korean Peninsula. Table 1 shows the characteristics of seedable clouds, including land and sea regions within a radius of 150 km from the Korean Peninsula.