• Title/Summary/Keyword: Marine weather forecast

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Comparison of Marine Insolation Estimating Methods in the Adriatic Sea

  • Byun, Do-Seong;Pinardi, Nadia
    • Ocean Science Journal
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    • v.42 no.4
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    • pp.211-222
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    • 2007
  • We compare insolation results calculated from two well-known empirical formulas (Socket and Beaudry's SB73 formula and the original Smithsonian (SMS) formula) and a radiative transfer model using input data predicted from meteorological weather-forecast models, and review the accuracy of each method. Comparison of annual mean daily irradiance values for clear-sky conditions between the two formulas shows that, relative to the SMS, the SB73 underestimates spring values by 9 W $m^{-2}$ in the northern Adriatic Sea, although overall there is a good agreement between the annual results calculated with the two formulas. We also elucidate the effect on SMS of changing the 'Sun-Earth distance factor (f)', a parameter which is commonly assumed to be constant in the oceanographic context. Results show that the mean daily solar radiation for clear-sky conditions in the northern Adriatic Sea can be reduced as much as 12 W $m^{-2}$ during summer due to a decrease in the f value. Lastly, surface irradiance values calculated from a simple radiative transfer model (GM02) for clear-sky conditions are compared to those from SB73 and SMS. Comparison with iu situ data in the northern Adriatic Sea shows that the GM02 estimate gives more realistic surface irradiance values than SMS, particularly during summer. Additionally, irradiance values calculated by GM02 using the buoy meteorological fields and ECMWF (The European Centre for Medium Range Weather Forecasts) meteorological data show the suitability of the ECMWF data usage. Through tests of GM02 sensitivity to key regional meteorological factors, we explore the main factors contributing significantly to a reduction in summertime solar irradiance in the Adriatic Sea.

Development of a RIA-based Dynamic Mashup Service for Ocean Environment (RIA 기반 해양 환경 동적 매쉬업 서비스 개발)

  • Ceong, Hee-Taek;Kim, Hae-Jin;Kim, Hae-Ran
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.10
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    • pp.2292-2298
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    • 2010
  • A mashup is a web page or application that uses and combines information, contents or Open APIs available on the web to create a new service. The mashup developed by the need not combination of simple information can contribute to new added-values with practicality and convenience. Thus, in this paper, we want to develop a RIA-based dynamic mashup service for the users considering weather forecast and marine information importantly. We design and implement the system that it can register a number of information about a domain dynamically through registration process based on the map and present a mark of domain location on the map and the information including internal environment, external environment and weather of related to the domain within a webpage. Implemented service need not require a tedious process visiting other web sites every time to confirm the relevant information because we can see simultaneously related information with a map within a page.

The Cause of Abnormal Tidal Residuals Along the Coast of the Yellow Sea in November 2013 (황해연안의 2013년 11월 이상조위편차 발생 원인)

  • Kim, Ho-Kyun;Kim, Young Taeg;Lee, Dong Hwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.4
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    • pp.344-353
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    • 2016
  • The cause of abnormal tidal residuals was examined by analyzing sea levels, sea surface atmospheric pressures, winds at ten tide stations, and current, measured at the coast of the Yellow Sea from the night of November $24^{th}$ to the morning of the $25^{th}$ in 2013, along with weather chart. Additionally, the cross-correlations among the measured data were also examined. The 'abnormal tidal residuals' mentioned in this study refer to differences between maximum and minium tidal residuals. The largest abnormal tidal residual was identified to be a difference of 176 cm occurring over 4 hours and 1 minute at YeongJongDo (YJD) with a maximum tidal residual of 111 cm and minimum of -65 cm. The smallest abnormal tidal residual was 68 cm at MoSeulPo (MSP) during 8 hours 52 minutes. The cause of these abnormal tidal residuals was not a meteo-tsunami generated by an atmospheric pressure jump but wind generated by the pressure patterns. The flow speed due to these abnormal tidal residuals as measured at ten tide stations was not negligible, representing 16 ~ 41 % of the annual average ebb current speed. From the cross correlation among the tidal residuals, winds, and tidal residual currents, we learned the northern flow, due to southerly winds, raised the sea level at Incheon when a low pressure center located on the left side of the Korean Peninsula. After passing the Korean Peninsula, a southern flow due to northerly winds decreased the sea level.

Characteristics of Tropical Cyclones in 2010 (2010년 태풍 특징)

  • Lim, Myeong Soon;Moon, Il-Ju;Cha, Yu-Mi;Chang, Ki-Ho;Kang, Ki-Ryong;Byun, Kun Young;Shin, Do-Shick;Kim, Ji Young
    • Atmosphere
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    • v.24 no.3
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    • pp.283-301
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    • 2014
  • In 2010, only 14 tropical cyclones (TCs) were generated over the western North Pacific (WNP), which was the smallest since 1951. This study summarizes characteristics of TCs generated in 2010 over the WNP and investigates the causes of the record-breaking TC genesis. A long-term variation of TC activity in the WNP and verification of official track forecast in 2010 are also examined. Monthly tropical sea surface temperature (SST) anomaly data reveal that El Ni$\tilde{n}$o/Southern Oscillation (ENSO) event in 2010 was shifted from El Ni$\tilde{n}$o to La Ni$\tilde{n}$a in June and the La Ni$\tilde{n}$a event was strong and continued to the end of the year. We found that these tropical environments leaded to unfavorable conditions for TC formation at main TC development area prior to May and at tropics east of $140^{\circ}E$ during summer mostly due to low SST, weak convection, and strong vertical wind shear in those areas. The similar ENSO event (in shifting time and La Ni$\tilde{n}$a intensity) also occurred in 1998, which was the second smallest TC genesis year (16 TCs) since 1951. The common point of the two years suggests that the ENSO episode shifting from El Ni$\tilde{n}$o to strong La Ni$\tilde{n}$a in summer leads to extremely low TC genesis during La Ni$\tilde{n}$a although more samples are needed for confidence. In 2010, three TCs, DIANMU (1004), KOMPASU (1007) and MALOU (1009), influenced the Korean Peninsula (KP) in spite of low total TC genesis. These TCs were all generated at high latitude above $20^{\circ}N$ and arrived over the KP in short time. Among them, KOMPASU (1007) brought the most serious damage to the KP due to strong wind. For 14 TCs in 2010, mean official track forecast error of the Korea Meteorological Administration (KMA) for 48 hours was 215 km, which was the highest among other foreign agencies although the errors are generally decreasing for last 10 years, suggesting that more efforts are needed to improve the forecast skill.

Data Assimilation Effect of Mobile Rawinsonde Observation using Unified Model Observing System Experiment during the Summer Intensive Observation Period in 2013 (2013년 여름철 집중관측동안 통합모델 관측시스템실험을 이용한 이동형 레윈존데 관측의 자료동화 효과)

  • Lim, Yun-Kyu;Song, Sang-Keun;Han, Sang-Ok
    • Journal of the Korean earth science society
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    • v.35 no.4
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    • pp.215-224
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    • 2014
  • Data assimilation effect of mobile rawinsonde observation was evaluated using Unified Model (UM) with a Three-Dimensional Variational (3DVAR) data assimilation system during the intensive observation program of 2013 summer season (rainy season: 20 June-7 July 2013, heavy rain period: 8 July-30 July 2013). The analysis was performed by two sets of simulation experiments: (1) ConTroL experiment (CTL) with observation data provided by Korea Meteorological Administration (KMA) and (2) Observing System Experiment (OSE) including both KMA and mobile rawinsonde observation data. In the model verification during the rainy season, there were no distinctive differences for 500 hPa geopotential height, 850 hPa air temperature, and 300 hPa wind speed between CTL and OSE simulation due to data limitation (0000 and 1200 UTC only) at stationary rawinsonde stations. In contrast, precipitation verification using the hourly accumulated precipitation data of Automatic Synoptic Observation System (ASOS) showed that Equivalent Threat Score (ETS) of the OSE was improved by about 2% compared with that of the CTL. For cases having a positive effect of the OSE simulation, ETS of the OSE showed a significantly higher improvement (up to 41%) than that of the CTL. This estimation thus suggests that the use of mobile rawinsonde observation data using UM 3DVAR could be reasonable enough to assess the improvement of prediction accuracy.