To elucidate optimum environmental condition for artificial cultivation of Grifola frondosa, light condition and CO2 concentration have been examined. First, the effects of light quality(blue, green, white) and light intensity(200, 500, 800, 1200 lux) on primordia formation, fruit body yield and morphological properties of Grifola frondosa in bag culture method were tested. Among different color fluorescents, white light(400∼620 nm) had a high mushroom yield(242 g) and a shorter cultivation period(52 days) In particular, morphological properties of G. frondosa using blue light(400∼560 nm) was obtained a wide and deep colored pileus. We also investigated that the appropriate light intensity for production of G. frondosa. The experimental results indicated that 500 lux light was the most effective on mushroom production, whereas, primordia formation was effective at 200 lux. In summary, we propose that the optimal light condition for the bag culture of G. frondosa is white source of fluorescent light and 500lux of light intensity. Second, G. frondosa were cultivated at four CO2 level, 500, 800, 1000, and 1500 ppm after spawning. Comparison in production of fruit body in G. frondosa better result were obtained at lower CO2 levels below 800 ppm. The higher ratio of primordia formation, faster time of primordia initiation and days to harvest(57 days), higher yields and quality of fruit body at lower CO2 levels below 800 ppm than higher that over 1000 ppm, whereas shape of fruit body at higher CO2 levels over 1000 ppm were showed abnormal and lower quality.

This study was carried out to obtain basic data on physiological characteristics for an artificial cultivation of Grifola frondosa. Ten strains of G. frondosa were collected from Korea, China and Japan and those were isolated and tested. PDA medium was selected for the favorable culture medium. The optimal conditions for the mycelial growth of G. frondosa were 25℃ and pH 4∼5 respectively. The carbon and nitrogen sources for the optimum mycelial growth were fructose and peptone, respectively. Highest mycelial growth was observed when the C/N ratio was 10∼20. Significant differences among lines were found for production yield and crop cycle time. KME44009 had a short spawn run time, high yield, good color and quality compare with other strains. To find out the suitable medium composition of G. frondosa, physicochemical conditions were investigated. The T2 formulation (55:25:8:12 mixing ratio of oak sawdust, oak chip, wheat bran and soybean cake) showed the shortest time to complete the crop cycle and the highest yields(weight of fresh mushrooms harvested at maturity). Among the physicochemical factors, pH, crude oil and total nitrogen may affect mushroom yield. Therefore, development of suitable medium would benefit from increased production efficiency of G. frondosa mushrooms and be commercial potential.

This study was carried out to obtain basic data on physiological characteristics for an artificial cultivation of Grifola frondosa. Ten strains of G. frondosa were collected from Korea, China and Japan and those were isolated and tested. PDA medium was selected for the favorable culture medium. The optimal conditions for the mycelial growth of G. frondosa were 25℃ and pH 4～5 respectively. The carbon and nitrogen sources for the optimum mycelial growth were fructose and peptone, respectively. Highest mycelial growth was observed when the C/N ratio was 10～20. Significant differences among lines were found for production yield and crop cycle time. KME44009 had a short spawn run time, high yield, good color and quality compare with other strains. To find out the suitable medium composition of G. frondosa, physicochemical conditions were investigated. The T2 formulation(55:25:8:12 mixing ratio of oak sawdust, oak chip, wheat bran and soybean cake) showed the shortest time to complete the crop cycle and the highest yields(weight of fresh mushrooms harvested at maturity). Among the physicochemical factors, pH, crude oil and total nitrogen may affect mushroom yield. Therefore, development of suitable medium would benefit from increased production efficiency of G. frondosa mushrooms and be commercial potential.

톱밥:비트펄프:면실박(50:30:20) 배지의 면실박 대체배지로서 아주까리박, 유채박을 사용한 경우 C/N율은 대조와 유사하였고, 야자박, 코코넛박을 이용한 배지에서는 대조보다 높은 C/N율을 나타났다. 아주까리박, 유채박 사용시 배양일수는 2∼5일, 초발이소요일수는 2일 지연 되었고 수량 또한 대조보다 20g이상 낮게 나타났으며 야자박, 코코넛박 사용시 배양일수는 3일 지연되었으나 수량은 관행재배 128g/병과 비슷하게 나타났다. 경제성 분석결과, 미송톱밥:비트펄프:면실박(50:30:20)의 관행재배에서 면실박 대체배지로 야자박, 코코넛박을 이용시 1000병규모로 연간 8.2회 재배 경우 소득이 각각 2,864천원, 2,733천원으로 관행재배의 2,849천원 대비 101%, 96%의 소득지수를 보였다.

The auroral observation has been started at Jang Bogo Station (JBS), Antarctica by using a visible All-sky camera (v-ASC) in 2018 to routinely monitor the aurora in association with the simultaneous observations of the ionosphere, thermosphere and magnetosphere at the station. In this article, the auroral observations are introduced with the analysis procedure to recognize the aurora from the v-ASC image data and to compute the auroral occurrences and the initial results on their spatial and temporal distributions are presented. The auroral occurrences are mostly confined to the northern horizon in the evening sector and extend to the zenith from the northwest to cover almost the entire sky disk over JBS at around 08 MLT (magnetic local time; 03 LT) and then retract to the northeast in the morning sector. At near the magnetic local noon, the occurrences are horizontally distributed in the northern sky disk, which shows the auroral occurrences in the cusp region. The results of the auroral occurrences indicate that JBS is located most of the time in the polar cap near the poleward boundary of the auroral oval in the nightside and approaches closer to the oval in the morning sector. At around 08 MLT (03 LT), JBS is located within the auroral oval and then moves away from it, finally being located in the cusp region at the magnetic local noon, which indicates that the location of JBS turns out to be ideal to investigate the variabilities of the poleward boundary of the auroral oval from long-term observations of the auroral occurrences. The future plan for the ground auroral observations near JBS is presented.

Korea Polar Research Institute (KOPRI) installed an ionospheric sounding radar system called Vertical Incidence Pulsed Ionospheric Radar (VIPIR) at Jang Bogo Station (JBS) in 2015 in order to routinely monitor the state of the ionosphere in the auroral oval and polar cap regions. Since 2017, after two-year test operation, it has been continuously operated to produce various ionospheric parameters. In this article, we will introduce the characteristics of the JBS-VIPIR observations and possible applications of the data for the study on the polar ionosphere. The JBS-VIPIR utilizes a log periodic transmit antenna that transmits 0.5–25 MHz radio waves, and a receiving array of 8 dipole antennas. It is operated in the Dynasonde B-mode pulse scheme and utilizes the 3-D inversion program, called NeXtYZ, for the data acquisition and processing, instead of the conventional 1-D inversion procedure as used in the most of digisonde observations. The JBS-VIPIR outputs include the height profiles of the electron density, ionospheric tilts, and ion drifts with a 2-minute temporal resolution in the bottomside ionosphere. With these observations, possible research applications will be briefly described in combination with other observations for the aurora, the neutral atmosphere and the magnetosphere simultaneously conducted at JBS.

We analyze the observations of temperature and ozone measured by the Microwave Limb Sounder (MLS) during the period of 2005–2016, to investigate the vertical structures of temperature and ozone in the stratosphere and mesosphere during stratospheric sudden warming (SSW). We compute the height profiles of the correlation coefficients between 55 height levels of MLS temperature anomalies and compare them with the results of Whole Atmosphere Community Climate Model simulations for three major SSWs. We also construct the temperature and ozone anomalies for the events to investigate the changes in the temperature and ozone distributions with height. There seems to always be a relatively weak but broad negative correlation between the temperature anomaly at 10 hPa and temperature anomalies over the entire mesosphere during the period before SSW events. However, this pattern gets stronger in the lower mesosphere but becomes a positive correlation in the upper mesosphere and lower thermosphere after the onset of SSW. We also found that the temperatures from the simulations show a similar trend to the observational results but with smaller variations and the transition height from negative to positive correlation in the mesosphere is much lower in the simulation than in the actual observations.

Jang Bogo Station (JBS), the second Korean Antarctic research station, was established in Terra Nova Bay, Antarctica (74.62°S 164.22°E) in February 2014 in order to expand the Korea Polar Research Institute (KOPRI) research capabilities. One of the main research areas at JBS is space environmental research. The goal of the research is to better understand the general characteristics of the polar region ionosphere and thermosphere and their responses to solar wind and the magnetosphere. Ground-based observations at JBS for upper atmospheric wind and temperature measurements using the Fabry-Perot Interferometer (FPI) began in March 2014. Ionospheric radar (VIPIR) measurements have been collected since 2015 to monitor the state of the polar ionosphere for electron density height profiles, horizontal density gradients, and ion drifts. To investigate the magnetosphere and geomagnetic field variations, a search-coil magnetometer and vector magnetometer were installed in 2017 and 2018, respectively. Since JBS is positioned in an ideal location for auroral observations, we installed an auroral all-sky imager with a color sensor in January 2018 to study substorms as well as auroras. In addition to these observations, we are also operating a proton auroral imager, airglow imager, global positioning system total electron content (GPS TEC)/scintillation monitor, and neutron monitor in collaboration with other institutes. In this article, we briefly introduce the observational activities performed at JBS and the preliminary results of these observations.

As a part of collaborative efforts to understand ionospheric irregularities, the Korea ionospheric scintillation sites (KISS) network has been built based on global positioning system (GPS) receivers with sampling rates higher than 1 Hz. We produce the rate of TEC index (ROTI) to represent GPS TEC fluctuations related to ionospheric irregularities. In the KISS network, two ground-based GPS sites at Kiruna (marker: KIRN; geographic: 67.9° N, 21.4° E; geomagnetic: 65.2° N) and Chuuk (marker: CHUK; geographic: 7.5° N, 151.9° E; geomagnetic: 0.4° N) were selected to evaluate the ROTI value for ionospheric irregularities during the occurrence of the 2015 St. Patrick’s Day storm. The KIRN ROTI values in the aurora region appear to be generally much higher than the CHUK ROTI values in the EIA region. The CHUK ROTI values increased to ~0.5 TECU/min around UT=13:00 (LT=23:00) on March 16 in the quiet geomagnetic condition. On March 17, 2015, CHUK ROTI values more than 1.0 TECU/min were measured between UT=9:00 and 12:00 (LT=19:00 and 22:00) during the first main phase of the St. Patrick’s Day storm. This may be due to ionospheric irregularities by increased pre-reversal enhancement (PRE) after sunset during the geomagnetic storm. Post-midnight, the CHUK ROTI showed two peaks of ~0.5 TECU/min and ~0.3 TECU/min near UT=15:00 (LT=01:00) and UT=18:00 (LT=04:00) at the second main phase. The KIRN site showed significant peaks of ROTI around geomagnetic latitude=63.3° N and MLT=15:40 on the same day. These can be explained by enhanced ionospheric irregularities in the auroral oval at the maximum of AE index

In December 2015, we have installed neutron monitors at the Jang Bogo station in Antarctica. The Jang Bogo station is the second science station which is located at the coast (74° 37.4´S, 164° 13.7´E) of Terra Nova Bay in Northern Victoria Land of Antarctica. A neutron monitor is an instrument to detect neutrons from secondary cosmic rays collided by the atmosphere. The installation of neutron monitor at Jang Bogo station is a part of transferred mission for neutron monitor at McMurdo station of USA. Among 18 tubes of 18-NM64 neutron monitor, we have completed relocation of 6 tubes and the rest will be transferred in December 2017. Currently, comparison of data from the neutron monitors of both two stations is under way and there is a good agreement between the data. The neutron monitors at Jang Bogo station will be quite useful to study the space weather when the installation is completed.

Since the operation of the King Sejong Station (KSS) started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI) and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI) was installed to observe the temperature in the mesosphere and lower thermosphere (MLT) region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere.

The purpose of this study was to develop the best mushroom cultivation conditions and the combination of mushroom culture media in order for mushroom producers and consumers. To reach this target, we first investigated the genetic relationship and developed suitable conditions of mycelial growth in Hypsizygus marmoreus strains. One superior strain of H. marmoreus was selected from 124 strains using bag culture. One hundred and twenty four strains were genetically classified into four main groups using two Universal Rice primers, URP2R and URP17R. The studies on the effects of different temperature (17, 21, 25, 29, 33℃) showed that 25℃ is the best temperature for mycelial growth for almost all strains while at 33℃ most of mycelium stop growth. Finally, ten strains were selected according to the groups identified by their temperature requirements. The length of mycelial growth in PDA, MCM, GPYM, MEA and MYP were longer than those in Czapek Dox. The selected ten strains of H. marmoreus showed heavier dry weight of mycelia at pH 3.0∼7.0 than any other pH. Although it was not show distinct requirement of carbon and nitrogen sources for vegetative growth according to strains, mainly the mycelial growth of the ten selected strains were observed at media including xylan and yeast extract, peptone, tryptone, respectively. Moreover, higher C/N ratio was observed in higher dry weight of mycelia.