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Descriptions are provided of the automated aerosol-type classification and mass concentration calculation algorithm for real-time data processing and aerosol products in Korea Aerosol Lidar Observation Network (KALION, http://www.kalion.kr). The KALION algorithm provides aerosolcloud classification and three aerosol types (clean continental, dust, and polluted continental/urban -1 19 -

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This study investigates long-term trends and characteristics of aerosol light scattering coefficient at Seoul and Baengnyeongdo in order to understand aerosol optical and radiative properties around Korea. The analysis period is limited to one year of 2011. First, the aerosol scattering coefficients (σ sp ) of both sites show strong linear dependence on the PM 2.5 mass concentrations with significant correlations between both. Further, correlations and sensitivity between σ sp and PM 2.5 increase with relative humidity, implying both relationships are strongly dependent upon moisture amounts in the atmosphere. This study applied 3-step careful quality control procedures to the analysis of σ sp for the insurance of data confidence.For the relationship analysis of extinction coefficients (σ ext ) to visibility and aerosol optical depth, σ sp observed at 3 p.m. have been used with help of aerosol absorption coefficients (σ ap ) in order to remove its dependence upon relative humidity, and also those of rainy period have been excluded. As expected, σ ext estimated are inversely proportional to visibility observation by eye. Finally, aerosol extinction coefficients have been vertically integrated with an assumption of nearly well-mixed within an e-folding height to determine aerosol optical depth, and compared with those retrieved from sunphotometer. The results show a reasonable agreement in spite of an inherent difference of each definition. We expect these findings would help to eventually understand aerosol radiative forcing and its effect on the regional climate change around Korea.

In this study, we used an intensive observation dataset of a mobile observation vehicle (MOVE) to investigate the characteristics of thermal environments and diurnal variations of road surface temperature (RST) and air temperature, particularly at the urban street level, during the 2019 Building Block 3-dimensional urban Meteorological Experiment (BBMEX) campaign in Seoul. For the purpose of comparing characteristics of RST and air temperature with different surrounding thermal environments, we divided the road into four sections (S1: Open Section, S2: High-Rise Buildings, S3: Low-Rise Buildings, S4: Street Trees). This study demonstrates that the greater sky view factors (SVFs) are generally coincident with the greater RSTs, with a significance at the 5% level. The diurnal variations indicated that the time lag between observed maximum air temperature and RST has about one hour, which is attributable to an increase air temperatures above artificial pavement through heat convection with some latency. The diurnal temperature ranges (DTRs) of RST in S2 and S4 were relatively smaller than those of S1 and S3, with differences ranging from 2.9 °C to 4.5 °C. The current results will assist planners and decision makers in determining policy priorities with regard to urban street design and planning.

In this study, based on the daily maximum wind speed and maximum instantaneous wind speed data recorded at 61 observation points operated by the Korea Meteorological Administration from 1993 to 2018, the self-organizing map clustering method was used to classify regions with similar characteristics of strong wind and gust wind occurrence and intensity. Characteristics of these regions were analyzed by averaging 30 variables related to wind for each cluster. As a result, 13 homogeneous regions of strong wind and gust wind in Korea were identified, which were clearly divided into regions of high and low strong wind frequency of occurrences. In most regions, the average daily maximum wind speed and maximum instantaneous wind speed were high in spring and winter. However, the average daily maximum wind speed and maximum instantaneous wind speed exceeding the criteria of strong wind (14 m s −1 ) and gust wind (20 m s −1 ) in this study were high in summer and autumn. Among the four clusters with high occurrence of strong wind and gust wind, one was classified as a specific region with high occurrence in summer and autumn. This results are likely to be beneficial to support regional customized special weather reports and disaster prevention.

: Planetary Boundary Layer Height (PBLH) is a major input parameter for weather forecasting and atmosphere diffusion models. In order to estimate the sub-grid scale variability of PBLH, we need to monitor PBLH data with high spatio-temporal resolution. Accordingly, we introduce a LIdar observation VEhicle (LIVE), and analyze PBLH derived from the lidar loaded in LIVE. PBLH estimated from LIVE shows high correlations with those estimated from both WRF model (R 2 = 0.68) and radiosonde (R 2 = 0.72). However, PBLH from lidar tend to be overestimated in comparison with those from both WRF and radiosonde because lidar appears to detect height of Residual Layer (RL) as PBLH which is overall below near the overlap height (< 300 m). PBLH from lidar with 10 min time resolution shows typical diurnal variation since it grows up after sunrise and reaches the maximum after 2 hours of sun culmination. The average growth rate of PBLH during the analysis period (2014/06/26 ~ 30) is 1.79 (-2.9 5.7) m min -1 . In addition, the lidar signal measured from moving LIVE shows that there is very low noise in comparison with that from the stationary observation. The PBLH from LIVE is 1065 m, similar to the value (1150 m) derived from the radiosonde launched at Sokcho. This study suggests that LIVE can observe continuous and reliable PBLH with high resolution in both stationary and mobile systems.