• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.2
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• pp.51-61
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• 2010

Surface particulate organic carbon (POC) concentration was measured in the Northeastern Gulf of Mexico on 9 cruises from November 1997 to August 2000 to investigate the seasonal and spatial variability related to synchronous remote sensing data (Sea-viewing Wide Field-of-view Sensor (SeaWiFS), sea surface temperature (SST), sea surface height anomaly (SSHA), and sea surface wind (SSW)) and recorded river discharge data. Surface POC concentrations have higher values (>100 $mg/m^3$) on the inner shelf and near the Mississippi Delta, and decrease across the shelf and slope. The inter-annual variations of surface POC concentrations are relatively higher during 1997 and 1998 (El Nino) than during 1999 and 2000 (La Nina) in the study area. This phenomenon is directly related to the output of Mississippi River and other major rivers, which associated with global climate change such as ENSO events. Although highest river runoff into the northern Gulf of Mexico Coast occurs in early spring and lowest flow in late summer and fall, wide-range POC plumes are observed during the summer cruises and lower concentrations and narrow dispersion of POC during the spring and fall cruises. During the summer seasons, the river discharge remarkably decreases compared to the spring, but increasing temperature causes strong stratification of the water column and increasing buoyancy in near-surface waters. Low-density plumes containing higher POC concentrations extend out over the shelf and slope with spatial patterns and controlled by the Loop Current and eddies, which dominate offshore circulation. Although river discharge is normal or abnormal during the spring and fall seasons, increasing wind stress and decreasing temperature cause vertical mixing, with higher surface POC concentrations confined to the inner shelf.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.170-177
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• 2007

In this study, the long-term predictability of El Nino and La Nina events of Pusan National University Coupled General Circulation Model(PNU/CME CGCM) developed from a Research and Development Grant funded by Korea Meteorology Administration(KMA) was examined in terms of the correlation coefficients of the sea surface temperature between the model and observation and skill scores at the tropical Pacific. For the purpose, long-term global climate was hindcasted using PNU/CME CGCM for 12 months starting from April, July, October and January(APR RUN, JUL RUN, OCT RUN and JAN RUN, respectively) of each and every years between 1979 and 2004. Each 12-month hindcast consisted of 5 ensemble members. Relatively high correlation was maintained throughout the 12-month lead hindcasts at the equatorial Pacific for the four RUNs starting at different months. It is found that the predictability of our CGCM in forecasting equatorial SST anomalies is more pronounced within 6-month of lead time, in particular. For the assessment of model capability in predicting El Nino and La Nina, various skill scores such as Hit rates and False Alarm rate are calculated. According to the results, PNU/CME CGCM has a good predictability in forecasting warm and cold events, in spite of relatively poor capability in predicting normal state of equatorial Pacific. The predictability of our CGCM was also compared with those of other CGCMs participating DEMETER project. The comparative analysis also illustrated that our CGCM has reasonable long-term predictability comparable to the DEMETER participating CGCMs. As a conclusion, PNU/CME CGCM can predict El Nino and La Nina events at least 12 months ahead in terms of NIino 3.4 SST anomaly, showing much better predictability within 6-month of leading time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.407-428
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• 1991

The eastern coastal area having variability of climate is located within Taebaek mountain range and the east coast of Korea. It is therefore ease to cause the wind damages in paddy field during rice growing season. The wind damages to rice plant in this area were mainly caused by the Fohn wind (dry and hot wind) blowing over the Taebaek mountain range and the cold humid wind from the coast. The dry wind cause such as the white head, broken leaves, cut-leaves, dried leaves, shattering of grain, glume discolouration and lodging, On the other hand the cold humid wind derived from Ootsuku air mass in summer cause such symptom as the poor rice growth, degeneration of rachis brenches and poor ripening. To minimize the wind damages and utilize as a preparatory data for wind injury of rice in future, several experiments such as the selection of wind resistant variety to wind damage, determination of optimum transplanting date, improvement of fertilizer application methods, improvement of soils and effect of wind break net were carried out for 8 years from 1982 to 1989 in the eastern coastal area. The results obtained are summarized as follows. 1. According to available statisical data from Korean meteorological services (1954-1989) it is apperent that cold humid winds frequently cause damage to rice fields from August 10th to September 10th, it is therefore advisable to plan rice cultivation in such a way that the heading date should not be later than August 10th. 2. During the rice production season, two winds cause severe damage to the rice fields in eastern coastal area of Korea. One is the Fohn winds blowing over the Taebaek mountain range and the other is the cold humid wind form the coast. The frequency of occurrence of each wind was 25%. 3. To avoid damage caused by typhoon winds three different varieties of rice were planted at various areas. 4. In the eastern coastal area of Korea, the optimum ripening temperature for rice was about 22.2$^{\circ}C$ and the optimum heading date wad August 10th. The optimum transplanting time for the earily maturity variety was June 10th., medium maturity variety was May 20th and that of late maturity was May 10th by means of growing days degree (GDD) from transplanting date to heading date. 5.38% of this coastal area is sandy loamy soil while 28% is high humus soil. These soil types are very poor for rice cultivation. In this coastal area, the water table is high, the drainage is poor and the water temperature is low. The low water temperature makes it difficult for urea to dissolve, as a result rice growth was delayed, and the rice plant became sterile. But over application of urea resulted in blast disease in rice plants. It is therefore advise that Ammonium sulphate is used in this area instead of urea. 6. The low temperature of the soil inhibits activities of microorganism for phosphorus utilization so the rice plant could not easily absorb the phosphorus in the soil. Therefore phosphorus should be applied in splits from transplanting to panicle initiation rather than based application. 7. Wind damage was severe in the sandy loamy soil as compared to clay soils. With the application of silicate. compost and soil from mointain area. the sand loamy soil was improved for rice grain colour and ripening. 8. The use of wind break nets created a mocro-climate such as increased air. soil and water temperature as well as the reduction of wind velocity by 30%. This hastened rice growth, reduced white head and glume discolouration. improved rice quality and increased yield. 9. Two meter high wind break net was used around the rice experimental fields and the top of it. The material was polyethylene sheets. The optimum spacing was 0.5Cm x 0.5Cm. and that of setting up the wind break net was before panicle initiation. With this set up, the field was avoided off th cold humid wind and the Fohn. The yield in the treatment was 20% higher than the control. 10. After typhoon, paddy field was irrigated deeply and water was sprayed to reduce white head, glume discolouration, so rice yield was increased because of increasing ripening ratio and 1, 000 grain weight.

• Journal of Korean Society of Forest Science
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• v.53 no.1
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• pp.37-43
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• 1981

This study was aimed at expanding the tea plant culture in Korea to further north, and the leaf-form and the cold resistance of the tea plants selected form 7 districts(around Korea) were investigated. 1. The length of tea leaf is 5.1cm to 8.4cm, the width of the leaf is 2.3cm to 3.6cm, but the area of tea leaf in Mt. Mudung is $26.88cm^2$ and that is the widest of all. 2. The tooth number of the tea leaf in 43 to 73 but the number of Mt. Borim is remarkably number of all. The tooth number is increased or decreased in proportion to the leaf width and to the leaf length. 3. The lateral vein number is generally 13 to 19. The vein number of Mt. Borim is especially number of all. That is also increased or decreased in proportion to the leaf width and to the leaf length. 4. In general, the number of leaf formation index is 2 to 3, and ablong. 5. In general, those which come upper lands are remarkably small in length and width of the tea leaf and those which come from level lands are large. 6. All kinds of tea plant which is growing in Korea, area, are the same as those imported from China : Thea sinensis Linne var. Bohea. 7. I supposed that the external form of tea plant has a little changed by geography or climate for many a long day, since the tea plant had been transplanted in Mt. Samsin. 8. In the treatment of low temperature and duration of vernalization of their plants, those selected from Mt. Mudung and Mt. Hwaun were the coldest resistance, those from Mt. Samsin and Mt. Borim were medium and those from Mt. Joge and Nursery were cold sensitive. 9. The critical temperature of the tea plant from Mt. Mudung, Mt, Hwaum, Mt, Samsin and Mt. Borim was about $-10^{\circ}C$, and that from Mt. Joga and Nursery was about $-5^{\circ}C$. The critical temperature of frost injury of all tea plants in this experiments was $-15^{\circ}C$. 10. In spite of increasing the vernalization time, the critical temperature was not effected, but the treatments over critical temperature were increased their frost injuries. Based on these results, the coldest resistance, Mt. Mudung tea plant, was considered expanding their culture to further north improvement yields of the tea plants in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.217-223
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• 2010

This study was conducted to reclassify Dongsong series based on the second edition of Soil Taxonomy and to discuss the formation of Dongsong series distributed on the lava plain at Cheolweon in Korea. Morphological properties of typifying pedon of Dongsong series were investigated, and physico-chemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Dongsong series has brown (7.5YR 4/2) silty clay loam Ap horizon (0-16 cm), brown (7.5YR 4/2) silty clay loam BA horizon (16-22 cm), brown (7.5YR 4/2) silty clay Bt1 horizon (22-50 cm), reddish brown (5YR 5/4) silty clay Bt2 horizon (50-92 cm), and brown (7.5YR 4/3) silty clay loam Bt3 horizon (92-120 cm). It occurs on lava plain derived from baslt materials. The typifying pedon has higher bulk density than 0.90 Mg $m^{-3}$. That can not be classified as Andisol. But it has an argillic horizon from a depth of 22 to more than 120 cm, and a base saturation (sum of cations) of less than 35% at 125 cm below the upper boundary of the argillic horizon. It can be classified as Ultisol, not as Andisol or Alfisol. It has aquic conditions for some time in normal years in one or more horizons within 50 cm of the mineral soil surface, redoximorphic features between a depth of 25 cm, and a depth of 40 cm from the mineral soil surface, and redox concentrations, and 50%or more redox depletions with chroma of 2 or less in the matrix within the upper 12.5 cm of the argillic horizon. Therefore it can be classified as Aquult. It has episaturation, and keys out as Epiaquult. It has 50% or more chroma of 3 or more in one or more horizons between a depth of 25 cm from the mineral soil surface, and a depth of 75 cm. It can be classified as Aeric Aquult. Dongsong series have 35%or more clay at the particle-size control section, and have mesic soil temperature regime. Therefore they can be classified as fine, mesic family of Aeric Epiaquults, not as fine, mesic family of Typic Epiaqualfs. The Quarternary volcanic activities occurred in Jeju Island, Ulrung Island, Baekryeong Island, Cheolweon area, and Mt. Paekdu et al. in the Korean Penninsula. Most of them belong to the central eruption type, but Cheolweon area may be of the fissure eruption type. Dongsong series occur on Cheolweon lava plains derived from basaltic materials. Most soils distributed in Jeju Island, and derived from mainly pyroclastics are developed as Andisols. But Dongsong series distributed in Cheolweon lava plains which have a relatively dry climate and derived from basaltic materials are developed as Ultisols.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.357-373
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• 1975

This study was conducted to evaluate the winter active polycross progenies of 10 genotypes selected at the hot and dry climate of the Southern Oregon in their performance in the progeny test comparing with a high yielding variety, 'Fawn', and a winter active variety, 'TFM', as the control varieties at Daejon, Korea. Various plant and leaf characteristics, especially which related to photosynthesis, and forage production during the first summer after their establishment, were examined. The important conclusions of this study are summarized as follows: 1. The winter active genotypes and variety had less leaf fresh weight and dry weight per leaf than variety 'Fawn'. Variations among polycross progenies of genotypes for these characteristics were great. 2. The winter active genotypes and variety had less leaf area per leaf than variety 'Fawn'. Leaf area among polycross progenies of genotypes deviated greatly and poly cross progenies of 'genotype-16' had the same average leaf area as 'Fawn'. 3. Differences of specific leaf weight (S. L. W.) in the winter active genotypes and variety were not significant. Probably the genetic diversity for S. L. W were not big and were narrowed down already in this genetic population. It was suggested that the photosynthate production within the population might not be different and there might be differences in the photosynthate production-translocation balance. Further study for the diurnal change in S. L. W. within the population might be useful. 4. The winter active variety and genotypes had less leaf width than 'Fawn' does. Leaf width among polycross progenies of genotypes deviated significantly. 5. Differences among controls and polycross progeny group in the initial plant height were significant and variety 'Fawn' was taller than the winter active genotypes and variety. But the differences were not significant in the regrowth of plant height after the first forage harvest. On the contrary. the differences among polycross progenies of genotypes were not significant in the initial plant but the differences in their polycross progeny performance became obvious and great in the regrowth ability which is an improtent agronomic characteristics for forage crops produced in the pasture and for hay and silage. 6. Plant width of the winter active genotypes and variety was lesser than 'Fawn' variety. 7. Differences of tiller number became evident and variety 'Fawn' had higher tiller number than the winter active genotypes and variety after the first forage cutting. There, deviations among polycross progenies of genotypes were great for this characteristic. It was obvious that the genetic differences became more evident in the second measurement after the first cutting of forage probably because this characteristic were stimulated by defoliation in the cartain genotypes and variety. 8. The winter active genotypes and variety on the initial growth. the regrowth ability andtotal yield had lesser forage yield than variety 'Fawn'. Deviation of forage yield among polycross progenies of genotypes were great and gave basis for selection according to their polycross progeny performance improving the forage yield of these winter active tall fescue population during summer. 9. It was concluded that the winter active variety and genotypes in this study was poorer than variety 'Fawn' for the most of leaf and plant characteristics including forage yield. For these measurements, the variations among polycross progenies of genotypes were great. and plant breeding might able to improve further this winter active tall fescue through the polycross progeny testing method for the higher forage production during summer in Korea. 10. The result of the associations among various characteristics under study were quite agreeable with the results of the analysis of variance and woul be useful in the selection of desirable genotypes for the development of a new variety.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.341-356
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• 1975

This study was carried out to evaluate three winter active synthetic varieties in a succeeding generations of improvement and polycross progenies of seven genotypes selected at the cool and wet climate of the Western Oregon, in their performance of the polycross progeny test comparing with a control variety, high yielding 'Fawn', at Daejon, Korea. Various plant and leaf characteristics, especially related to photosynthesis, and forage production during the first summer after the establishment were examined. The important conclusions of this study are summarized as follows: 1. The differences of leaf fresh weight among groups and control exhibit genetic differences. The a verage of leaf fresh weight of polycross progeny group was the heaviest and those of winter active synthetic varieties in the succeeding generations of improvement was heavier than variety 'fawn'. Within polycross progeny group the genotypes exhibit genetic differences for leaf dry weight. 2. The leaf area exhibited genetic differences among groups and control. The average of winter active synthetic varieties in a succeeding generation was larger than variety 'Fawn'. Those oi the polycross progeny group was the largest among groups and control. 3. Differences of specific leaf weight(S. L. W.) among and within varieties, genotypes and control were not significant. Further investigation in this respect is necessary through the study of the diurnal change in S. L. W. 4. Differences of leaf width among groups and control exhibited genetic differences. The average leaf width of winter active varieties was larger than those of 'Fawn' variety. And those of polycross progenies of genotypes was the largest. 5. Plant height of 'fawn' variety in the first measurement was higher than those of winter active tall fescue varieties and genotypes. The deviation in plant height among polyeross progenies of seven genotypes gave a great deviation. The regrowth ability of plant height was not different suggesting that this characteristics was about the same among and within groups and control. 6. Plant width, spreading ability, improved through the succeeding generations of the improvement of the winter active synthetic varieties for the first measurement. Differences of plant width at the second measurement among genotypes within polycross progeny group were big enough to show the genetic difference. 7. Tiller number of the winter active synthetic varieties and the average of genotypes in polycross progeny was more than those of the control 'Fawn' in the first measurement. On the second measurement, the differences of tiller number appeared among three synthetic varieties indicating improvement, and there were genetic differences among seven genotypes in polycross progeny test. 8. Forage yield on the first cutting showed a considerble improvement of forage yield in the more advanced generation of synthetic varieties and genetic differences among seven genotypes in the polycross progeny test. The average of polycross progeny group was higher than those of the control or three winter active varieties. It was suggested that we could make a further improvement for the forage yield. 9. The regrowth ability of these winter active varieties and genotypes was about the same capacity at least on the measurement of the regrowth in forage yield and plant height during summer. 10. On the whole, the averages of the polycross progeny group was in the highest value and those of synthetic varieties were higher than the control variety, 'Fawn', for the most characteristics except S. L. W. and the plant height on the first measurement even though the differences were not always significant. And there were genetic differences among seven gentypes in their performance of the polycross progeny. 11. Although it was not always sgnificant, the most advanced winter active variety, '1002', had in the highest value for all plant characteristics and forage yield measurements than the other two varieties, '1001'. 12. The results of the association study among various characteristics were quite agreeable and would be useful in the selection of desirable genotypes for the development of a better variety.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.20-30
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• 1979

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1976 following after the seletion of 1974 and 1975, twenty trees from each of three natural populations of the species were selected and seeds were collected, and the locations and conditions of populations are presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our fifth report of this series. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period(1931~1960) measured from the nearest meteorological station to each population are shown in fig. 2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Samchuk area (Pop. 9) were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index (i.e.: length to diameter ratio) are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be not significant in population and to be highly significant in family differences within population. 3. The morohological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed weight, seed length, seed thickness but not among the populations in the other observed traits. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the correlation between cone length and seed wing length, between seed wing width and seed width were significantly positive in population 8 and 9 but in population 7. The positive correlations between seed length and seed width were calculated in all populations studied 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 seedling height of these progenies. But the differences in 1-1 seedling height and root collar diameter are shown only among familes within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. As shown in table 15, statistical differences are considered to be significant among the populations in stomata row on both sides of the needle but not in serration density. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.33-45
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• 1978

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1975 following after the selection of 1974, twenty trees from each of three natural populations of the species were selected and their open-pollinated seeds were collected, and the locations and conditions of the populations ate presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our second report of this series, in which Myong-Ju and Ul-Jin populations were regarded to be superior phenotypically to suweon population. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period (1931~1960) measured from the nearest meteorological stations to each population are shown in fig.2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Suweon area, population 6, were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index, i.e., length to diameter ratio are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be highly significant in population differences and family differences within population. 3. The morphological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed-wing length, seed-wing index, seed weight, seed-length and seed index but not among the populations in the other observed traits. The values of correlation coefficient between the characters of cone and seed are given in table 10 and the positive significant correlations can be observed in the most parts of the compared traits. 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 and 1-1 seedling height of these progenies. But the differences in root collar diameter are shown only among families within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. The number of stomata row on both sides of needle and the serration density were measured in the seedlings from each of the families of the three populations. As shown in table 15, statistical differences are considered to be significant among the populations and among the families within population in serration density but not among the populations in stomata row on both sides of the needle. The results differ from those of the third report of this series. Even if one of the reason seems to be the diversity of selected populations, it could not be confirmed definitely. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Atmosphere
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• v.33 no.2
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• pp.275-295
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• 2023

In Korea, there are four institutions related to atmospheric science: the university's atmospheric science-related department, the Korea Meteorological Administration (KMA), the ROK Air Force Weather Group, and the Meteorological Industry Association. These four institutions have developed while maintaining a deep cooperative relationship with the Korea Meteorological Society (KMS) for the past 60 years. At the university, 6,986 bachelors, 1,595 masters, and 505 doctors, who are experts in meteorology and climate, have been accredited by 2022 at 7 universities related to atmospheric science. The KMA is carrying out national meteorological tasks to protect people's lives and property and foster the meteorological industry. The ROK Air Force Weather Group is in charge of military meteorological work, and is building an artificial intelligence and space weather support system through cooperation with universities, the KMA, and the KMS. Although the Meteorological Industry Association has a short history, its members, sales, and the number of employees are steadily increasing. The KMS greatly contributed to raising the national meteorological service to the level of advanced countries by supporting the development of universities, the KMA, the Air Force Meteorological Agency, and the Meteorological Industry Association.