Possible change in Korean streamflow seasonality based on multi‐model climate projections     

I. W. Jung  D. H. Bae  B. J. Lee 《水文研究》2013,27(7):1033-1045

Seasonality in hydrology is closely related to regional water management and planning. There is a strong consensus that global warming will likely increase streamflow seasonality in snow‐dominated regions due to decreasing snowfall and earlier snowmelt, resulting in wetter winters and drier summers. However, impacts to seasonality remain unclear in rain‐dominated regions with extreme seasonality in streamflow, including South Korea. This study investigated potential changes in seasonal streamflow due to climate change and associated uncertainties based on multi‐model projections. Seasonal flow changes were projected using the combination of 13 atmosphere–ocean general circulation model simulations and three semi‐distributed hydrologic models under three different future greenhouse gas emission scenarios for two future periods (2020s and 2080s). Our results show that streamflow seasonality is likely to be aggravated due to increases in wet season flow (July through September) and decreases in dry season flow (October through March). In South Korea, dry season flow supports water supply and ecosystem services, and wet season flow is related to flood risk. Therefore, these potential changes in streamflow seasonality could bring water management challenges to the Korean water resources system, especially decreases in water availability and increases in flood risk. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Determination of Trace Elements in Geological Reference Materials G‐3, GSP‐2 and SGD‐1a by Low‐Dilution Glass Bead Digestion and ICP‐MS     

Chan‐Soo Park  Hyung Seon Shin  Haeyoung Oh  Jong Hwa Moon  Hana Cho  Chang‐sik Cheong 《Geostandards and Geoanalytical Research》2013,37(3):361-368

We present a revised alkali fusion method for the determination of trace elements in geological samples. Our procedure is based on simple acid digestion of powdered low‐dilution (flux : sample ≈ 2 : 1) glass beads where large sample dilution demanded by high total dissolved solids, a main drawback of conventional alkali fusion, could be circumvented. Three geological reference materials (G‐3 granite, GSP‐2 granodiorite and SGD‐1a gabbro) decomposed by this technique and routine tabletop acid digestion were analysed for thirty trace elements using a quadrupole ICP‐MS. Results by conventional acid digestion distinctly showed poor recoveries of Zr, Hf and rare earth elements due to incomplete dissolution of resistant minerals. On the other hand, results obtained by our method were in reasonable agreement with reference data for most analytes, indicating that refractory minerals were efficiently dissolved and volatile loss was insignificant.  相似文献   

Evaluation of GPS orbit prediction strategies for the IGS Ultra-rapid products   总被引：2，自引：1，他引：1  

Kevin K. Choi  Jim Ray  Jake Griffiths  Tae-Suk Bae 《GPS Solutions》2013,17(3):403-412

The International GNSS Service (IGS) provides Ultra-rapid GPS & GLONASS orbits every 6 h. Each product is composed of 24 h of observed orbits with predicted orbits for the next 24 h. We have studied how the orbit prediction performance varies as a function of the arc length of the fitted observed orbits and the parameterization strategy used to estimate the empirical solar radiation pressure (SRP) effects. To focus on the dynamical aspects of the problem, nearly ideal conditions have been adopted by using IGS Rapid orbits and known earth rotation parameters (ERPs) as observations. Performance was gauged by comparison with Rapid orbits as truth by examining WRMS and median orbit differences over the first 6-h and the full 24-h prediction intervals, as well as the stability of the Helmert frame alignment parameters. Two versions of the extended SRP orbit model developed by the Centre for Orbit Determination in Europe (CODE) were tested. Adjusting all nine SRPs (offsets plus once-per-revolution sines and cosines in each satellite-centered frame direction) for each satellite shows smaller mean sub-daily, scale, and origin translation differences. On the other hand, eliminating the four once-per-revolution SRP parameters in the sun-ward and the solar panel axis directions yields orbit predictions that are much more rotationally stable. We found that observed arc lengths of 40–45 h produce the most stable and accurate predictions during 2010. A combined strategy of rotationally aligning the 9 SRP results to the 5 SRP frame should give optimal predictions with about 13 mm mean WRMS residuals over the first 6 h and 50 mm over 24 h. Actual Ultra-rapid performance will be degraded due to the unavoidable rotational errors from ERP predictions.  相似文献   

Multi-proxy evidence for late Holocene anthropogenic environmental changes at Bongpo marsh on the east coast of Korea     

Jungjae Park  Keun Bae Yu  Hyoun Soo Lim  Young Ho Shin 《Quaternary Research》2012,78(2):209-216

We present a multi-proxy record (pollen, microscopic charcoal, magnetic susceptibility, carbon-isotopic composition, total organic carbon [TOC], carbon/nitrogen [C/N] ratios, and particle size) of the late Holocene environmental change and human activities from Bongpo marsh on the east coast of Korea. Mutual interaction between the environment and humans during the late Holocene has not been properly investigated in Korea due to the lack of undisturbed samples with high sedimentation rates. In this study, the history of human responses to late Holocene environmental changes is clearly reconstructed using a multi-proxy paleoenvironmental approach that has not previously been applied in Korea. The evidence from Bongpo marsh indicates that 1) Bongpo marsh began to develop ca. 650 BC as a coastal lagoon was rapidly filled with organic matter, 2) agricultural disturbance around the study site remained slight until ca. AD 600, 3) full-scale intensive agriculture prevailed and the area of deforestation increased between ca. AD 600 and ca. AD 1870, and 4) the land use changed from lowland rice agriculture to upland cultivation when agricultural productivity declined after AD 1870, probably due to severe deforestation and the consequent heavy influx of clastic sediment on rice fields, as described in various historical documents.  相似文献   

Promises and Perils of Decentralized Forest Governance: The Case of Indonesia's Forest Management Units in Reducing Emission from Deforestation and Forest Degradation (REDD+)     

Jae Soo Bae  Lawrence Fisher  Moira Moeliono  Jessica DeShazo 《社会与自然资源》2014,27(12):1346-1354

Indonesia's forest management unit (Kesatuan Pengelolaan Hutan or KPH) system can be a promising mechanism for balancing international and national interests for global carbon mitigation initiatives with local interests in project implementation. We discuss the potential role of the KPH system in implementing REDD+ (Reducing Emission from Deforestation and Forest Degradation) projects and improving decentralized forest governance. Substantial financial gains from international initiatives like REDD+ and others can provide appropriate motivation for the central government to ensure successful decentralization of forest management. Development and implementation of REDD+ activities can also support the KPHs in performing their basic functions: conducting forest inventory, developing and implementing forest management plans, and strengthening communication and coordination with local communities. However, engaging indigenous peoples and local communities, which is a legal mandate for the system, will require building some measure of democratic process that can hold the KPHs accountable to local people.  相似文献   

Inversion Schemes for Surface Wave Attenuation and Q in the Crust and the Mantle     

Wook Bae Lee  Sean C. Solomon 《Geophysical Journal International》1975,43(1):47-71

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Long-term and real-time monitoring system of the East/Japan sea     

Kuh Kim  Yun Bae Kim  Jong Jin Park  SungHyun Nam  Kyung-Ae Park  Kyung-Il Chang 《Ocean Science Journal》2005,40(1):25-44

Long-term, continuous, and real-time ocean monitoring has been undertaken in order to evaluate various oceanographic phenomena and processes in the East/Japan Sea. Recent technical advances combined with our concerted efforts have allowed us to establish a real-time monitoring system and to accumulate considerable knowledge on what has been taking place in water properties, current systems, and circulation in the East Sea. We have obtained information on volume transport across the Korea Strait through cable voltage measurements and continuous temperature and salinity profile data from ARGO floats placed throughout entire East Sea since 1997. These ARGO float data have been utilized to estimate deep current, inertial kinetic energy, and changes in water mass, especially in the northern East Sea. We have also developed the East Sea Real-time Ocean Buoy (ESROB) in coastal regions and made continual improvements till it has evolved into the most up-to-date and effective monitoring system as a result of remarkable technical progress in data communication systems. Atmospheric and oceanic measurements by ESROB have contributed to the recognition of coastal wind variability, current fluctuations, and internal waves near and off the eastern coast of Korea. Long-term current meter moorings have been in operation since 1996 between Ulleungdo and Dokdo to monitor the interbasin deep water exchanges between the Japanese and Ulleung Basins. In addition, remotely sensed satellite data could facilitate the investigation of atmospheric and oceanic surface conditions such as sea surface temperature (SST), sea surface height, near-surface winds, oceanic color, surface roughness, and so on. These satellite data revealed surface frontal structures with a fairly good spatial resolution, seasonal cycle of SST, atmospheric wind forcing, geostrophic current anomalies, and biogeochemical processes associated with physical forcing and processes. Since the East Sea has been recognized as a natural laboratory for global oceanic changes and a clue to abrupt climate change, we aim at constructing a 4-D continuous real-time monitoring system, over a decade at least, using the most advanced techniques to understand a variety of oceanic processes in the East Sea.  相似文献   

Biostratigraphy and Paleoenvironment in Cheju Sedimentary Basin, Determined by Materials from Exploration Wells Geobuk-1 and Okdom-1     

Yun Hyesu  Yi Sangheon  Kim Jae-Ho  Yi Songsuk  Kim Gi-Hyoun  Park Dong Bae 《中国地质大学学报(英文版)》2000,11(2)

A micropaleontological analysis was made using materi-als from exploration wells Geobuk-1 (Td:2 72 2 .5m) andOkdom-1 (Td:2 90 3 .7m) for the purpose of biostratigraphicand paleoenvironmental interpretation of the Cheju sedimenta-ry basin.Two wells yield relatively abundant microfossilssuch as dinoflagellates,calcareous nannofossils,pollen andspores.The biostratigraphic and paleoenvironmental settingsanalyzed by microfossil assemblages seem to be closely relatedto the framework of the local t…  相似文献   

Changes in ecosystem components induced by climate variability off the eastern coast of the Korean Peninsula during 1960–1990     

Sukyung Kang  Suam Kim  Sang-Won Bae 《Progress in Oceanography》2000,47(2-4)

To understand the variations of ecosystem components in response to changing environment, especially relating to a shift in the climate regime during mid 1970s, we analyzed the physical and biological time-series data collected from the eastern part of the Korean Peninsula during 1960–1990. The Northeast Pacific Pressure Index (NEPPI) in winter seasons showed a negative correlation (r=−0.384, p<0.05) with SOI in summer. The standardized chronologies of tree ring-width showed high correlations with precipitation of Ulleung Island and Kangrung city (r=0.408, p<0.05; r=0.410, p<0.05) and seawater temperatures (r=0.407, p<0.05). Sharp increases in tree growth appeared in 1969, 1973, 1979, 1983, and 1987. Among these years, all except 1979 seem to have a close connection with the El Niño which had persisted more than five seasons. Air temperatures in spring at Ulleung Island and Kangrung area appeared comparatively higher during the intense Aleutian low period after 1976. The Mixed Layer Depth (MLD) was shallower (18.2 m) and less variable during 1961–1975 compared to that (26.1 m) of 1976–1990. The shallower MLD in spring during the earlier period resulted in the higher chl a concentration than in the later years. Consequently, estimated zooplankton biomass in spring tended to decrease from the 1960s to the late 1980s in accordance with the phytoplankton decreases. In the East Sea, composition changes in fish species as well as fish catches were observed. Catches of pollock, sardine, and saury had good correlations with annual NEPPI.  相似文献   

Late Quaternary glacial history of Khentey Mountains,Central Mongolia     

Purevmaa Khandsuren  Yeong Bae Seong  Jeong Sik Oh  Hyun Hee Rhee  Khadbaatar Sandag  Byung Yong Yu 《Boreas: An International Journal of Quaternary Research》2019,48(3):779-799

Mongolian glaciers have been the subject of relatively little research, resulting in less geochronological constraint than other parts of Central Asia. The Khentey Mountains (latitude 47–51°N, longitude 105–112°E) are a typical landlocked mountain range exhibiting clear geomorphic evidence of late Quaternary glaciation. Yet, compared to western parts of Mongolia such as the Mongolian Altay, Gobi Altay, Khangay, and Khovsgol, glacial history of the Khentey Mountains is poorly understood. To address this, and permit comparison of the Khentey glacier–climate record with other alpine regions in Mongolia, we performed geomorphological mapping and cosmogenic ¹⁰Be surface‐exposure dating in two glaciated regions of the Khentey Mountains: Yestii and Khagiin Khar. Specifically, we measured ¹⁰Be in 34 samples collected from five moraine sequences, which, together with morphostratigraphy, correspond to four main glacial stages: (i) The M_y1 terminal moraine sequence for Yestii (21.0±4.9 ka) and the M_k1 moraine for Khagiin Khar (19.6±2.6 ka), both of which represent the Last Glacial Maximum; (ii) the Lateglacial M_k2 moraine, dated to 16.0±3.5 ka; (iii) the M_k3 moraine, dated to either 17.6±7.0 ka (Lateglacial) or 12.1±1.1 ka (Younger Dryas); and (iv) the currently undated M_k4 moraine (~2200 m a.s.l.), to which we assign a Holocene age. Our results suggest that the timing of maximum glacier extent in Mongolia was regionally variable. In the Khentey Mountains, maximum glaciation occurred during Marine Isotope Stage (MIS) 2, whereas the maximum occurred during MIS 3 in Khangay and Khovsgol and during MIS 4 in the Altay. The MIS 2 glacial maximum in the Khentey Mountains coincided with the global sea level minimum during the Last Glacial Maximum, and was followed by at least three glacial re‐advances during the Lateglacial to possibly the Holocene.  相似文献