Enhanced Year Round Observations at the Korean Jang Bogo Station, Terra Nova Bay

Abstract

Enhanced year-round observations on atmospheric process from the surface to upper atmosphere is ongoing at Terra Nova Bay, Antarctica based on the Korean Jang Bogo station (74°37.4' S, 164°13.7'E). All instruments for meteorology and atmospheric physics were installed over 2014 to 2015 and operated successfully. They are automated synoptic observation system, autosonde, ozonesonde, radiometers, gas analyzer and turbulent flux system. Radiosonde is usually launched once a day (00 UTC) over February to November. Ozonsonde observation is made relatively frequently before, during and after the ozone hole but, once a month except that period. Based on preliminary results over the last three years, annul mean of net radiation at the surface in Jang Bogo station was approximately 27 Wm-2 and 23 Wm-2 in 2015 and 2016, respectively, indicating that the surface gained energy resulting from surface radiation balance on yearly basis. While UV-B radiation at the surface showed significant variation corresponding to the occurrence of ozone hole from late August to early November in 2015, there was no lasting and pronounced change in its magnitude in 2016. Air temperature ranged from ？34.6 to 7.6 oC with annual averaged value of ？15.8 oC in 2015 and ？15.9 oC in 2016. Overall, wind speed was not strong at Jang Bogo Station, but very strong wind has occurred intermittently with the gust of 41.2 ms-1 on May, 2016. Monthly averaged wind speed at 10 m high was in the rage of 2.7 to 6.4 ms-1. Annual averaged wind speed were 4.3 ms-1 in 2015 and 3.9 ms-1 in 2016, respectively. Wind from west was the dominant except for from northeast in summer season. The strongest wind blew from northwest. Visibility in 2016 was good year round. On average, November and December were the best for the visibility. Atmospheric stability near the surface showed similar behaviors for the three years except for on October in 2015 when the surface was covered with snow, possibly by low temperature on September, making stable atmosphere boundary layer condition to extend one month longer than in the other two years. Daily averaged carbon dioxide concentration ranged from 396.4 ppm (February) to 399.6 ppm (November) in 2015 and 398.5 ppm (January) to 402.7 ppm (October) with annual mean of 401.0 ppm in 2016. In the meanwhile, daily averaged methane concentration was in the range of 1,769 ppm (late February) to 1,805 ppb (October) in 2015 and 1,788 ppb (March) to 1,812 ppb (October) with annual mean of 1,796 ppb in 2016. Background concentration of black carbon at the station was around 10 ng/m3. The sea near the station was completely frozen around March 20 in 2014, on February 28 in 2015 and on March 1 in 2016. The recorded minimum monthly mean temperature over the last two years occurred at a altitude of ~ 20 km on August with a value of ？85.8 oC. Decrease and increase in the temperature at the level of minimum monthly mean temperature occurred one month early in 2016, compared to those in 2015. Maximum monthly mean wind speed was ~93 ms-1 at a altitude of ~ 28 km on September in 2016. For both years, there was pronounced differences in wind speed above 10 km, especially above 20 km where wind speed over 60 ms-1 occurred on September and October in 2016. On December of 2015, Rn measurement started. It has been analyzed for various applications such as a variety of transport processes, boundary layer processes, source identification of aerosol and gases. This work was funded by two Korea Polar Research Institute projects (PE17010)