Statistical downscaling for daily precipitation in Korea using combined PRISM,RCM, and quantile mapping: Part 1, methodology and evaluation in historical simulation

In this study, we present the Parameter-elevation Relationships on Independent Slopes Model (PRISM)-based Dynamic downscaling Error correction (PRIDE) model, which is suitable for complex topographies, such as the Korean peninsula. The PRIDE model is constructed by combining the PRISM module, the Regional Climate Model (RCM) anomaly, and quantile mapping (QM) to produce high-resolution (1 km) grid data at a daily time scale. The results show that the systematic bias of the RCM was significantly reduced by simply substituting the climatological observational seasonal cycle at a daily timescale for each grid point obtained from the PRISM. QM was then applied to correct additional systematic bias by constructing the transfer functions under the cumulative density function framework between the model and observation using six types of transfer functions. K-fold cross-validation of the PRIDE model shows that the number of modeled precipitation days is approximately 90~121% of the number of observed precipitation days for the five daily precipitation classes, indicating that the PRIDE model reasonably estimates the observational frequency of daily precipitation under a quantile framework. The relative Mean Absolute Error (MAE) is also discussed in the framework of the intensity of daily precipitation.     

A Photometric Study of EB-type eclipsing binary GO CYG

Two colour (B and V) photoelectric observations of EB-type eclipsing binary GO Cyg were carried out for 15 nights during October and December 1996. Three new times of minimum lights have been derived. With these and previously published times of minimum lights, a continuous period increase of dP/dt = 1.51 × 10^-7 d yr^-1 was estimated from the quadratic light element. B and V light curves have been analyzed by the method of the Wilson and Devinney Differential Correction. GO Cyg is confirmed to belong to the group of near contact systems based on light curve analysis and its absolute dimensions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Two species of the genusoncaea (copepoda, poecilostomatoida, oncaeidae) from the east sea, Korea

Abstract   Oncaea venusta Philippi, 1843 has been known as having some different size groups, but recent genetic study for cyt b and ITS 1 (Elverset al. 2006) suggests that these size groups can be considered as different species. Of these size groups, the largestO. venusta Philippi and the smallestO. venella Farran, 1929 were first described in Korean waters. The latter is easily distinguishable from the former in the following characteristics in addition to its small size: (1) length to width ratio of genital double somite of two genders smaller, and (2) female second pediger bearing inconspicuous dorso-posterior swelling.Oncaea venusta andO. venella co-occur in Korean waters during spring to fall, but their occurrence patterns seasonally differ: the former shows higher density in fall while the latter does in summer.     

Spatial analysis of future East Asian seasonal temperature using two regional climate model simulations

CORDEX-East Asia, a branch of the coordinated regional climate downscaling experiment (CORDEX) initiative, provides high-resolution climate simulations for the domain covering East Asia. This study analyzes temperature data from regional climate models (RCMs) participating in the CORDEX - East Asia region, accounting for the spatial dependence structure of the data. In particular, we assess similarities and dissimilarities of the outputs from two RCMs, HadGEM3-RA and RegCM4, over the region and over time. A Bayesian functional analysis of variance (ANOVA) approach is used to simultaneously model the temperature patterns from the two RCMs for the current and future climate. We exploit nonstationary spatial models to handle the spatial dependence structure of the temperature variable, which depends heavily on latitude and altitude. For a seasonal comparison, we examine changes in the winter temperature in addition to the summer temperature data. We find that the temperature increase projected by RegCM4 tends to be smaller than the projection of HadGEM3-RA for summers, and that the future warming projected by HadGEM3-RA tends to be weaker for winters. Also, the results show that there will be a warming of 1-3°C over the region in 45 years. More specifically, the warming pattern clearly depends on the latitude, with greater temperature increases in higher latitude areas, which implies that warming may be more severe in the northern part of the domain.     

Prospects of using Bayesian model averaging for the calibration of one-month forecasts of surface air temperature over South Korea

In this study, we investigated the prospect of calibrating probabilistic forecasts of surface air temperature (SAT) over South Korea by using Bayesian model averaging (BMA). We used 63 months of simulation results from four regional climate models (RCMs) with two boundary conditions (NCEP-DOE and ERA-interim) over the CORDEX East Asia. Rank histograms and residual quantile-quantile (R-Q-Q) plots showed that the simulation skills of the RCMs differ according to season and geographic location, but the RCMs show a systematic cold bias irrespective of season and geographic location. As a result, the BMA weights are clearly dependent on geographic location, season, and correlations among the models. The one-month equal weighted ensemble (EWE) outputs for the 59 stations over South Korea were calibrated using the BMA method for 48 monthly time periods based on BMA weights obtained from the previous 15 months of training data. The predictive density function was calibrated using BMA and the individual forecasts were weighted according to their performance. The raw ensemble forecasts were assessed using the flatness of the rank histogram and the R-Q-Q plot. The results showed that BMA improves the calibration of the EWE and the other weighted ensemble forecasts irrespective of season, simulation skill of the RCM, and geographic location. In addition, deterministic-style BMA forecasts usually perform better than the deterministic forecast of the single best member.     

Taxonomy and zoogeography of euchaetid copepods (Calanoida,Clausocalanoidea) from Korean waters,with notes on their female genital structure

Euchaetid copepods (Calanoida, Clausocalanoidea) were collected from the southeastern region of Korea and the East/Japan Sea from June 2007 to August 2008. Seven species were found and redescribed in this study: five species from the genus Euchaeta (E. concinna, E. indica, E. longicornis, E. plana and E. rimana) and two species from the genus Paraeuchaeta (P. elongata and P. russelli). Using scanning electron microscopy, we observed detailed taxonomic features with special references to their genital structure. The euchaetid copepods show speciesspecific characteristics on their genital structures, in particular on the shapes of genital operculum and genital flange. Their zoogeographies were also discussed. They can be regarded as an indicator species of the Tsushima Warm Current and East Sea Intermediate Water.     

Reproductive pattern of the epifaunal amphipodPontogeneia rostrata (Crustacea) on dolsando sandy shore in Korea

Reproductive patterns of an epifaunal amphipod,Pontogeneia rostrata, were studied on Dolsando sandy shore in Korea. The life history pattern was iteroparous, with recruitment mainly occurring from winter to spring. The sex ratio was male-biased, especially during breeding periods. The mean body length of females was significantly larger than that of males. Brood size and egg volume were positively related to the body length of ovigerous females. There was no significant difference in brood size between successive breeding periods, but egg volumes were significantly higher in early winter (December) than in late spring breeding (May and June), increasing the probability of survival to hatching. These traits contribute to more reproductive potential in early winter than in late spring breeding. The mean brood size of epifaunalP. rostrata was larger but the mean egg volume smaller than that of infaunal amphipods in this sampling area. We suggest that reproductive effort for epifaunal species may be proportionally greater than for infaunal species in risky environments.     

Zircon chemistry and new laser ablation U–Pb ages for uraniferous granitoids in SW Cameroon

The Ekomedion two-mica granite,southwestern Cameroon,has potential for uranium and molybdenum mineralization.Here,we present LA-ICP-MS U-Pb ages,Lu-Hf isotope characteristics,trace element concentrations and Ti-geothermometry of zircon from this granite hosting U-Mo mineralization in pegmatitic pods.The majority of zircon are CL-dark though some CL-bright cores were also identified.U-Pb zircon age data range from 121±3 to743±11 Ma with only 5 of 34 ages being near concordant.The concordant mean age of 603±12 Ma is similar to ages of granitic intrusions along the Central African Shear Zone in Cameroon.Apparent ages with mean of261±6 Ma reveal open system behavior with respect to Pb and/or U.Zircon e Hfi values range from-20.3 to-0.3.This implies that U-Mo was remobilized during partial melting of the surrounding gneiss.Zircon Th/U>0.1 as well as an increasing Hf with decreasing Th/U indicates that fractional crystallization was the main factor that controlled U-Mo mineralization in pegmatitic pods.Y and Y/Ho ratios cluster from 29 to 33 close to the chondritic ratio of 28 and indicate fractionation of Y and Ho with low F contents during the earliest stages of crystallization.Late stage accumulation of F-rich magmatic-hydrothermal fluids impacted U-Mo mineralization as a ligand.Zircon contains a prominent negative Eu anomaly pointing to a fractionating system rich in plagioclase.Calculated Ti-in-zircon temperatures span 672℃to1232℃with the temperatures at the high end reflecting interference from mineral inclusions in the zircon grains while the lower temperature values are linked to crystallization.