• Journal of the Korean earth science society
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• v.43 no.3
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• pp.367-385
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• 2022

This study evaluates the temperature and precipitation results in East Asia simulated from the Hadley Centre Global Environmental Model version 3 regional climate model (HadGEM3-RA) developed by the UK Met Office. The HadGEM3-RA is conducted in the Coordinated Regional climate Downscaling Experiment-East Asia (CORDEX-EA) Phase II domain for 15 year (2000-2014). The spatial distribution of rainbands produced from the HadGEM3-RA by the summer monsoon is in good agreement with the Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation of water resources (APRODITE) data over the East Asia. But, precipitation amount is overestimated in Southeast Asia and underestimated over the Korean Peninsula. In particular, the simulated summer rainfall and APRODITE data show the least correlation coefficient and the maximum value of root mean square error in South Korea. Prediction of temperature in Southeast Asia shows underestimation with a maximum error during winter season, while it appears the largest underestimation in South Korea during spring season. In order to evaluate local predictability, the time series of temperature and precipitation compared to the ASOS data of the Seoul Meteorological Station is similar to the spatial average verification results in which the summer precipitation and winter temperature underestimate. Especially, the underestimation of the rainfall increases when the amounts of precipitation increase in summer. The winter temperature tends to underestimate at low temperature, while it overestimates at high temperature. The results of the extreme climate index comparison show that heat wave is overestimated and heavy rainfall is underestimated. The HadGEM3-RA simulated with a horizontal resolution of 25 km shows limitations in the prediction of mesoscale convective system and topographic precipitation. This study indicates that improvement of initial data, horizontal resolution, and physical process are necessary to improve predictability of regional climate model.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.210-221
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• 2008

The mesoscale environmental surveys were conducted between $5^{\circ}N\;and\;17^{\circ}N$ mainly along the $131.5^{\circ}W$ meridian from 1997 to 2002 to investigate controlling factors of carbon and nitrogen contents in bottom sediments. Sediments of the study area showed zonal distribution pattern depending on latitudinal position and can be classified into four types; calcareous ooze($5{\sim}6^{\circ}N$), siliceous sediments($8{\sim}12^{\circ}N$), pelagic red clay($16{\sim}17^{\circ}N$), and mixed sediments($7^{\circ}N$). Inorganic carbon(IC) contents varied depending on water depth and carbonate compensation depth(CCD). Carbonate materials were well preserved in the low latitude region, where water depths are shallower than CCD. In contrast, the higher latitude region dominated by siliceous sediment and pelagic red clays has low productivity in water column as well as the water depths deeper than CCD. Thus, most of carbonate materials were dissolved, which resulted in IC contents of less than 0.05% in the sediments. Organic carbon(OC) and total nitrogen contents(TN) in siliceous sediments were higher than in pelagic red clay sediments simply because of higher primary productivity in the siliceous sediment dominated area. The contents of OC and TN were lower in the calcareous ooze than in the siliceous sediments. It is attributed to the high input of calcareous material to the bottom due to relatively shallow water depth of the area, which diluted organic matter contents in the sediment. Overall results indicated that water depth relative to CCD, primary production in water column, and sedimentation rate largely controls the large-scale distribution of carbon and nitrogen contents in the study area.