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Ocean Science Journal - A minimum 19 year tidal prediction dataset covering nodal (satellite) modulation effects is required to determine the Lowest Astronomical Tide (LAT) and Highest Astronomical... 相似文献
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This study investigated the spatial distributions and long-term trends of the annual highest and lowest temperatures (summer peak temperature, SPT; winter peak temperature, WPT) and their timings (summer peak day, SPD; winter peak day, WPD) in South Korea and analyzed their relationship with the general circulation patterns. The two peaks were determined by selecting the highest and the lowest points after extracting temperature variations longer than the seasonal scale (91 days) in the time series of daily mean temperatures. For the long-term trend, we examined data for 100 years (1909–2008) for five stations and data for 35 years (1974–2008) for 61 stations. The SPD in South Korea is August 4 on average. It is earliest (July 31) in the central inland region, the central hilly sections, and the southern inland region and latest (August 10) in the southern coastal region and on Jeju Island (Seogwipo). The WPD in South Korea is January 16 on average. It is earliest (January 13) in the central inland region and southern inland region and latest (January 24) on Jeju Island (Jeju) and in Ulleungdo. The SPT and WPT are highest on Jeju Island (Seogwipo; 27.3 and 6.4 °C, respectively) and lowest in the central hilly sections (Daegwallyeong; 20.2 and ?7.9 °C, respectively). The interannual variations in the WPD and WPT are greater than those in SPD and SPT. A significant increasing trend in the WPT was observed for all of the analyzed stations only for the second half of the 100-year period (1959–2008). In the case of the 35-year period, the SPD did not show any clear changes at all stations, but the WPD tended to occur earlier at three stations in the east coastal area. The WPT showed an increasing trend at 55 stations for 35 years, but the SPT showed an increasing trend only in Seogwipo (0.041 °C/year) and even showed a decreasing trend in Mungyeong (?0.049 °C/year). General circulation patterns were indexed and their correlations with the seasonal peaks were investigated. No correlations were found with the SPD. However, the WPD showed a significant positive correlation with the day of the highest Siberian High Intensity (SHI) and the day of the lowest Arctic Oscillation Index (AOI). Furthermore, the SPT showed negative correlations with the intensities of the Okhotsk High and North Pacific High, whereas the WPT showed a negative correlation with SHI and a positive correlation with AOI and with the intensity of the northerly wind that flows into the Korean Peninsula. 相似文献
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A solution for the correct interpolation of data across regions with abrupt changes in tidal phase-lag 总被引：1，自引：0，他引：1
This paper provides an explanation of an automated solution for correctly interpolating phase-lags across abrupt boundaries. Although an automated solution to this problem has existed for several years, this is not commonly known and so many researchers continue to perform corrections manually. Interpolation errors commonly occur when tidal propagation surfaces are generated for regimes with amphidromic points. General correction methods are manual, clunky and prone to operator error. The problem can be solved by applying a simple method to scalarize the phase-lag vectors pre-interpolation. This approach successfully and automatically generates correct tidal phase-lag interpolation values and may be applied to any surface mapping software used to interpolate phase-lags. 相似文献
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Suryun Ham Song-You Hong Yign Noh Soon-Il An Young-Hwa Byun Hyun-Suk Kang Johan Lee Won-Tae Kwon 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(4):457-463
This paper investigates the effects of river discharge on simulated climatology from 1979 to 1988 using the Hadley Centre Global Environmental Model version 2. Two experiments are performed with and without the inclusion of Total Runoff Integrating Pathways. The results show that the inclusion of flow routing can lead to the decrease of salinity over the coastal region due to freshwater. This reduction results in a shallower mixed layer depth, which in turn leads to the weakening of trade winds and a decrease in vertical mixing in the ocean. The enhanced sensible and latent heat fluxes over warmed SST improve the simulated precipitation and thermodynamic circulation. As a result, the experiment with flow routing is capable of improving the large-scale climate feature with an increase in precipitation over the eastern tropical equatorial Pacific region. 相似文献
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A land data assimilation system using the MODIS-derived land data and its application to numerical weather prediction in East Asia 总被引：1，自引：0，他引：1
Yoon-Jin Lim Kun-Young Byun Tae-Young Lee Hyojung Kwon Jinkyu Hong Joon Kim 《Asia-Pacific Journal of Atmospheric Sciences》2012,48(1):83-95
Land Data Assimilation Systems have been developed to generate the surface initial conditions such as soil moisture and temperature for better prediction of weather and climate. We have constructed Korea Land Data Assimilation System (KLDAS) based on an uncoupled land surface modeling framework that integrates high-resolution in-situ observation, satellite data, land surface information from the WRF Preprocessing System (WPS) and the MODIS land products over the East Asia. To present better surface conditions, the KLDAS is driven by atmospheric forcing data from the in-situ rainfall gauges and satellite. In this study, we 1) briefly introduce the KLDAS, 2) evaluate the meteorological states near the surface and the surface fluxes reproduced by the KLDAS against the in-situ observation, and then 3) examine the performance of the mesoscale model initialized by the KLDAS. We have generated a 5-year, 10 km, hourly atmospheric forcing dataset for use in KLDAS operating across East Asia. The KLDAS has effectively reproduced the observed patterns of soil moisture, soil temperature, and surface fluxes. Further scrutiny reveals that the numerical simulations incorporating the KLDAS outputs show better agreement in both the simulated near-surface conditions and rainfall distribution over the Korean Peninsula, compared to those without the KLDAS. 相似文献
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We present CCD surface photometry for four globular clusters: NGC 2298, NGC 6402, NGC 6934 and NGC 7089. Our photometry was aimed at the central 3 arcmin region in each cluster. We show that the surface brightness distributions of these clusters are well described by the isothermal King (1966) models. Our color analysis shows that NGC 7089 exhibits a remarkable color gradient in which the central region is bluer than the outer parts by the amplitude inB-V 0.1 mag/. Color gradients have also been detected in the central regions of NGC 6402 and NGC 6934, although the variation does not extend to outer part. No gradient has been detected in NGC 2298. Similar color gradients have been previsouly observed exclusively in highly concentrated systems classified as post core collapse clusters. 相似文献
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This study provides a practical guide to the use of classical tidal prediction algorithms in coastal numerical forecasting models such as tide and tide-storm-surge models. Understanding tidal prediction parameter formulas and their limitations is key to successfully modifying and upgrading tidal prediction modules in order to increase the accuracy of perpetual interannual simulations and, in particular, storm-surge modeling studies for tide-dominated coastal environments. The algorithms for the fundamental prediction parameters, the five astronomical variables, used in tidal prediction are collated and tested. Comparisons between their estimation using different parameterizations shows that these methods yield essentially the same results for the period 1900–2099, revealing all are applicable for tidal forecasting simulation. Through experiments using a numerical model and a harmonic prediction program, the effects of nodal modulation correction and its update period on prediction accuracy and sensitivity are examined and discussed using a case study of the tidally-dominated coastal regime off the west coast of Korea. Results indicate that this correction needs updating within <30 days for accurate perpetual interannual tidal and mean sea-level predictions, and storm-surge model predictions requiring centimeter accuracy, for tidally-dominated coastal regimes. Otherwise, unacceptable systematic errors occur. 相似文献