East Asian monsoon variation and climate changes in Jeju Island, Korea, during the latest Pleistocene to early Holocene

A 4.96-m-long sediment core from the Hanon paleo-maar in Jeju Island, Korea was studied to investigate the paleoclimatic change and East Asian monsoon variations during the latest Pleistocene to early Holocene (23,000-9000 cal yr BP). High-resolution TOC content, magnetic susceptibility, and major element composition data indicate that Jeju Island experienced the coldest climate around 18,000 cal yr BP, which corresponds to the last glacial maximum (LGM). Further, these multi-proxy data show an abrupt shift in climatic regime from cold and arid to warm and humid conditions at around 14,000 cal yr BP, which represents the commencement of the last major deglaciation. After the last major deglaciation, the TOC content decreased from 13,300 to 12,000 cal yr BP and from 11,500 to 9800 cal yr BP, thereby reflecting the weakening of the summer monsoon. The LGM in Jeju Island occurred later in comparison with the Chinese Loess Plateau. Such a disparity in climatic change events between central China and Jeju Island appears to be caused by the asynchrony between the coldest temperature event and the minimum precipitation event in central China and by the buffering effect of the Pacific Ocean.     

An Atlantic influence on Amazon rainfall

Rainfall variability over the Amazon basin has often been linked to variations in Pacific sea surface temperature (SST), and in particular, to the El Niño/Southern Oscillation (ENSO). However, only a fraction of Amazon rainfall variability can be explained by ENSO. Building upon the recent work of Zeng (Environ Res Lett 3:014002, 2008), here we provide further evidence for an influence on Amazon rainfall from the tropical Atlantic Ocean. The strength of the North Atlantic influence is found to be comparable to the better-known Pacific ENSO connection. The tropical South Atlantic Ocean also shows some influence during the wet-to-dry season transition period. The Atlantic influence is through changes in the north-south divergent circulation and the movement of the ITCZ following warm SST. Therefore, it is strongest in the southern part of the Amazon basin during the Amazon’s dry season (July–October). In contrast, the ENSO related teleconnection is through anomalous east-west Walker circulation with largely concentrated in the eastern (lower) Amazon. This ENSO connection is seasonally locked to boreal winter. A complication due to the influence of ENSO on Atlantic SST causes an apparent North Atlantic SST lag of Amazon rainfall. Removing ENSO from North Atlantic SST via linear regression resolves this causality problem in that the residual Atlantic variability correlates well and is in phase with the Amazon rainfall. A strong Atlantic influence during boreal summer and autumn is particularly significant in terms of the impact on the hydro-ecosystem which is most vulnerable during the dry season, as highlighted by the severe 2005 Amazon drought. Such findings have implications for both seasonal-interannual climate prediction and understanding the longer-term changes of the Amazon rainforest.     

The effect of aerosol representation on cloud microphysical properties in Northeast Asia

This study performed a three-dimensional regional-scale simulation of aerosol and cloud fields using a meso-scale non-hydrostatic model with a bin-based cloud microphysics. The representation of aerosols in the model has been improved to account for more realistic multi-modal size distribution and multiple chemical compositions. Two case studies for shallow stratocumulus over Northeast Asia in March 2005 were conducted with different aerosol conditions to evaluate model performance. Improved condensation nuclei (CN) and cloud condensation nuclei (CCN) are attributable to the newly constructed aerosol size distribution. The simulated results of cloud microphysical properties (cloud droplet effective radius, liquid water path, and optical thickness) with improved CN/CCN number are close to the retrievals from satellite-based observation. The effects of aerosol on the microphysical properties of shallow stratocumulus are investigated by model simulation, in terms of columnar aerosol number concentration. Enhanced aerosol number concentration results in increased liquid water path in humid case, but invariant liquid water path in dry case primarily due to precipitation occurrence. The changes of cloud microphysical properties are more predominant for small aerosol burden than for large aerosol burden with the retarded changes in cloud mass and size due to inactive condensation and collision-coalescence processes. Quantitative evaluation of sensitivity factor between aerosol and cloud microphysical properties indicates a strong aerosol-cloud interaction in Northeast Asian region.     

New insights into the crustal structure of the North German Basin from reprocessing of seismic reflection data using the Common Reflection Surface stack

The influence of deep crustal processes on basin formation and evolution and its relation to current morphology is not well understood yet. A key feature to unravel these issues is a detailed seismic image of the crust. A part of the data recorded by the hydrocarbon industry in the late 1970s and 1980s in the North German Basin were released to the public recently. The seismic reflection data were recorded down to 15 s two-way travel time. The mean Common Midpoint fold of about 20 is relatively low compared to contemporary seismic acquisitions. The processing of the 1980s focussed on the sedimentary structures to explore the hydrocarbon potential of this area. We applied the Common Reflection Surface stack technique to the data sets, which is well suited for low-fold data. The reprocessing was focussed on the imaging of the subsedimentary crustal range. The reprocessed images show enhanced reflections, especially in the mid and lower crustal part. Also, the image of the salt structures in the graben area was improved. Furthermore, the reprocessed images indicate an almost flat Moho topography in the area of the Glückstadt Graben and an additional lower crustal structure, which can be correlated with a high-density body found in recent gravity modeling studies.     

On Geomentality

Geomentality is an established and lasting frame (state) of mind regarding the environment. It is necessarily translated into a geographical behavioral pattern and is reflected in a pattern of cultural landscape. An individual or a group of people can hold a geomentality about a particular environment. What an architect's plan is to a building, a geomentality is to a pattern of cultural landscape. Geomentality is ultimately responsible for the development of a cultural landscape pattern. Determining a geomentality is therefore the key in explaining a pattern of cultural landscape more profoundly than is possible by some conventional methods.     

The Korean Folk Custom Forbidding The Establishment of Water Wells

For over a thousand years many settlements in Korea forbid the digging of water‐wells. This custom can be explained using geomancy, which personifies local landscapes or names them after animate or inanimate objects. In ‘sailing boat’ landscapes the digging of water‐wells was prohibited because this was viewed as analogous to making a hole in the bottom of a boat, which would thus bring misfortune to local residents. Based on this geomantic reasoning, people considered the custom of forbidding well digging to be an integral part of the art of geomancy, with its origin in a geomantic belief system. My earlier research sustained this explanation but this paper, which is based on two recent instances of field work, rejects the established view on the custom. The aim of this paper is to critically re‐examine this established view and suggests a new idea that the folk custom of prohibiting well digging in Korea was not originally derived from geomancy, but was conceived from a non‐geomantic indigenous Korean idea and have become linked to geomancy through the enforcement process of practicing the custom in traditional Korean society.     

Tsunami research in Korea

The tsunamis that have occurred in many places around the world over the past decades have taken a heavy toll on human lives and property. The eastern coast of the Korean Peninsula is not safe from tsunamis and has sustained tsunami damage in the past. The aim of this study is to review the past, present, and future of some aspects of tsunami research in Korea. A composite numerical model comprising propagation and inundation models is described. The paper also covers tsunami mitigation efforts in Korea, and a tsunami hazard map is developed and introduced.     

Genomic cloning and expression of vitellogenin gene from the self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae)

We cloned the vitellogenin gene from the self-fertilizing fish Rivulus marmoratus, and sequenced 12,326 bp. The number of exons of R. marmoratus and rainbow trout vitellogenin genes were different, and also the splicing junctions are different throughout most of the exons and introns but the amino acid similarity of R. marmoratus vitellogenin gene to other species was rather high. In promoter region of R. marmoratus vitellogenin gene, there were several E2 binding sites and the estrogen response element (ERE). We discuss here the gene structure and expression of R. marmoratus vitellogenin gene.     

Internal generation of waves on an arc in a rectangular grid system

This paper presents a technique to generate waves at oblique angles in finite difference numerical models in a rectangular grid system by using internal generation technique [Lee, C., Suh, K.D., 1998. Internal generation of waves for time-dependent mild-slope equations. Coast. Eng. 34, 35–57.] along an arc-shaped line source. Tests were made for four different types of wave generation layouts. Quantitative experiments were conducted under the following conditions: the propagation of waves on a flat bottom, the refraction and shoaling of waves on a planar slope, and the diffraction of waves to a semi-infinite breakwater. Numerical experiments were conducted using the extended mild-slope equations of Suh et al. [Suh, K.D., Lee, C., Park, W.S., 1997. Time-dependent equations for wave propagation on rapidly varying topography. Coast. Eng. 32, 91–117.]. The fourth layout type consisting of two parallel lines connected to a semicircle showed the best solutions, especially for a small grid size. This technique is useful for the numerical simulation of irregular waves with broad-banded directional spectrum using conventional spectral wave models for the reasonable estimation of bottom friction and wave-breaking.