• Title/Summary/Keyword: sea temperature

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Short-term Variation of Sea Surface Temperature Caused by Typhoon Nabi in the Eastern Sea of Korean Peninsula Derived from Satellite Data (위성영상에서 관측한 태풍 Nabi 통과시의 한반도 동부해역 수온의 단기변동)

  • Kim, Sang-Woo;Yamada, Keiko;Jang, Lee-Hyun;Hong, Chul-Hoon;Go, Woo-Jin;Suh, Young-Sang;Lee, Chu;Lee, Gyu-Hyong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.2
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    • pp.102-107
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    • 2007
  • A remarkable sea surface cooling (SSC) event was observed in the eastern sea of Korean peninsula based on new generation sea surface temperature (NGSST) satellite images in September 2005, when typhoon Nabi passed over the East Sea. The degree of SSC ranged from $1^{\circ}C\;to\;4^{\circ}C$, and its maximum was observed in the southeastern sea area. Daily variations in sea surface temperature at a longitudinal line $(35^{\circ}-41^{\circ}N,\;132^{\circ}E)$, derived from satellite data for September 1-13, 2005, showed that the SSC lasted about 3 days after the typhoon passed in the south of $39^{\circ}N$, whereas it was unclear in the north of$39^{\circ}N$. Water temperature measured by a mooring buoy suggested that the SSC was caused mainly by a vertical mixing of the water column driven by the typhoon, rather than by coastal upwelling.

Temperature Variabilities at Upper Layer in the Korean Marine Waters Related to Climate Regime Shifts in the North Pacific (한국주변해역 상층부의 수온 변동과 북태평양 기후체제와의 관계)

  • Rahman, SM M.;Lee, Chung Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.1
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    • pp.145-151
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    • 2016
  • Temperature variability at the upper layer related to climate regime shifts in the Korean waters was illustrated using water temperature, climate index. Three major climate regime shifts (CRS) in 1976, 1988 and 1998 in north Pacific region had an significant influence on the major marine ecosystems structure pattern. Three marginal seas around Korean peninsula; East Sea, East China Sea and Yellow Sea also got important impact from this kind of decadal shift. We used 10m sea water temperatures in four regions of Korean waters since 1950 to detect major fluctuation patterns both seasonally and also decadal shift. 1988 CRS was occurred in all of the study areas in most seasons however, 1998 CRS was only detected in the Yellow Sea and in the southern part of the East Sea. 1976 CRS was detected in all of the study area mainly in winter. After 1998 CRS, the water temperature in the southern part of the East Sea, East China Sea and Yellow Sea were going into decreased pattern; however, in the northern part of the East Sea, it was further shifted to increasing pattern which was started from 1988 CRS period.

Sea Ice Extents and global warming in Okhotsk Sea and surrounding Ocean - sea ice concentration using airborne microwave radiometer -

  • Nishio, Fumihiko
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.76-82
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    • 1998
  • Increase of greenhouse gas due to $CO_2$ and CH$_4$ gases would cause the global warming in the atmosphere. According to the global circulation model, it is pointed out in the Okhotsk Sea that the large increase of atmospheric temperature might be occurredin this region by global warming due to the doubling of greenhouse effectgases. Therefore, it is very important to monitor the sea ice extents in the Okhotsk Sea. To improve the sea ice extents and concentration with more highly accuracy, the field experiments have begun to comparewith Airborne Microwave Radiometer (AMR) and video images installed on the aircraft (Beach-200). The sea ice concentration is generally proportional to the brightness temperature and accurate retrieval of sea ice concentration from the brightness temperature is important because of the sensitivity of multi-channel data with the amount of open water in the sea ice pack. During the field experiments of airborned AMR the multi-frequency data suggest that the sea ice concentration is slightly dependending on the sea ice types since the brightness temperature is different between the thin and small piece of sea ice floes, and a large ice flow with different surface signatures. On the basis of classification of two sea ice types, it is cleary distinguished between the thin ice and the large ice floe in the scatter plot of 36.5 and 89.0GHz, but it does not become to make clear of the scatter plot of 18.7 and 36.5GHz Two algorithms that have been used for deriving sea ice concentrations from airbomed multi-channel data are compared. One is the NASA Team Algorithm and the other is the Bootstrap Algorithm. Intrercomparison on both algorithms with the airborned data and sea ice concentration derived from video images bas shown that the Bootstrap Algorithm is more consistent with the binary maps of video images.

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Fishing Characteristics of Pacific Herring Clupea pallasii and Relationship between Its Catch and Sea Temperature during the Past 50 Years in Korean Waters (50년간 우리나라 청어(Clupea pallasii)의 어획 특성 및 어획량과 수온과의 관계)

  • Yoo, Joon-Taek;Kim, Jung Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.2
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    • pp.208-217
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    • 2021
  • This study described the fishing characteristics of Pacific herring Clupea pallasii and examined the relationship between its catch and sea temperature in Korean waters from 1970 to 2019. Although the herring catch in Korean waters stayed below 1,000 tons per year from the mid-1970s to mid-1980s, the catch in the winters in the East Sea of Korea started to increase markedly after 1987-1988, when the sea surface temperature (SST) seemed to shift to a warmer regime. Since the mid-2000s, overall, herring was caught throughout the year in the East Sea and eastern South Sea of Korea, and its catch significantly increased by around 30,000 tons per year. The main fishing grounds of herring in the poor fishing years until the mid-1980s were possibly formed in the western offshore of Korea, and subsequently the fishing grounds were distributed in the eastern coast of Korea. While the standardized catch per unit effort (CPUE) for two main fisheries of herring catch was significantly correlated with the herring catch since the 2000s, there was a gradual decline since the 2010s. The herring catch in the East Sea had significant positive correlations with SSTs, but that in the West Sea had a significant negative correlation.

Variations of Sea Level and Sea Surface Temperature in Korean Seas by Topex/Poseidon and NOAA

  • Yoon, Hong-Joo;Kang, Heung-Soon;Lee, Bong-Sic;Jeong, Young-Deok
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.880-883
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    • 2006
  • Altimeter(Topex/Poseidon) and AVHRR(NOAA) data were used to study the variations and correlations of Sea Level(SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea(Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

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Study on Thin Sea Ice Thickness using Passive Microwave Brightness Temperature

  • Naoki, Kazuhiro;Ukita, Jinro;Nishio, Fumihiko
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.1015-1018
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    • 2006
  • The use of passive microwave data for estimating sea-ice thickness is limited by strong dependence of emissivity on near-surface brine. However, this particular characteristic becomes a basis for an algorithm to estimate thickness of thin sea-ice if a thickness-salinity-emissivity relationship is established. This study aims at developing an algorithm to estimate sea ice thickness on the basis of this relationship. In order to establish a thickness-salinity-emissivity relationship, we have conducted multi-platform synchronous observations in the Sea of Okhotsk. We note a positive relationship between thickness and brightness temperature. From observations, we also establish an empirical relationship between salinity and emissivity, thus between thickness and brightness temperature. The derived relationship is qualitatively similar to the one based on Hoekstra and Cappillino's formulation. Our results suggest that for thin sea-ice in the winter period there is potential to develop an algorithm to estimate sea-ice thickness.

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Variations of Sea Level and Sea Surface Temperature in Korean Seas by Topex/Poseidon and NOAA

  • Yoon, Hong-Joo;Kang, Heung-Soon;Cho, Han-Keun
    • Korean Journal of Remote Sensing
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    • v.23 no.1
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    • pp.59-63
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    • 2007
  • Altimeter (Topex/Poseidon) and AVHRR (NOAA) data were used to study the variations and correlations of Sea Level (SL) and Sea Surface Temperature (SST) in the North East Asian Seas from November 1993 to May 1998. This region is influenced simultaneously to continental and oceanic climate as the border of the East Sea (Japan Sea). SL and SST have increased gradually every year because the global warming, and presented usually a strong annual variations in Kuroshio extension region with the influence of bottom topography.

The Impacts of Seawater Surface Temperature Rising on Sea Mustard Yields of Goheung and Wando Coast in Korea (고흥·완도 해수표층온도 상승이 미역 단수에 미치는 영향)

  • Cho, Jae-Hwan;Suh, Jeong-Min;Lee, Nam-Su;Ha, Hyun-Jung
    • Journal of Environmental Science International
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    • v.27 no.3
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    • pp.147-154
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    • 2018
  • The purpose of this article is analyzing the impacts of seawater surface temperature rise on sea mustard yields of Goheung and Wando coast in Korea, with employing a panel data regression model. Our results show that there has been a negative impacts on sea mustard yields as seawater surface temperature continuously has been rising. Especially if the upward trend in seawater surface temperature since 2005 will be maintained in future, sea mustard yield is expected to decrease by 2.6% per year.

Pacific Equatorial Sea Surface Temperature Variation During the 2015 El Niño Period Observed by Advanced Very-High-Resolution Radiometer of NOAA Satellites

  • Lee, Seongsuk;Yi, Yu
    • Journal of Astronomy and Space Sciences
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    • v.35 no.2
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    • pp.105-109
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    • 2018
  • El $Ni{\tilde{n}}o$ is the largest fluctuation in the climate system, and it can lead to effects influencing humans all over the world. An El $Ni{\tilde{n}}o$ occurs when sea surface temperatures in the central and eastern tropical Pacific Ocean become substantially higher than average. We investigated the change in sea surface temperature in the Pacific Ocean during the El $Ni{\tilde{n}}o$ period of 2015 and 2016 using the advanced very-high-resolution radiometer (AVHRR) of NOAA Satellites. We calculated anomalies of the Pacific equatorial sea surface temperature for the normal period of 1981-2010 to identify the variation of the 2015 El $Ni{\tilde{n}}o$ and warm water area. Generally, the warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America during an El $Ni{\tilde{n}}o$ period. However, we identified an additional warm water region in the $Ni{\tilde{n}}o$ 1+2 and Peru coastal area. This indicates that there are other factors that increase the sea surface temperature. In the future, we will study the heat coming from the bottom of the sea to understand the origin of the heat transport of the Pacific Ocean.

Prediction of Vertical Sea Water Temperature Profile in the East Sea Based on Machine Learning and XBT Data

  • Kim, Young-Joo;Lee, Soo-Jin;Kim, Young-Won
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.11
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    • pp.47-55
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    • 2022
  • Recently, researches on the prediction of sea water temperature using artificial intelligence models has been actively conducted in Korea. However, most researches in the sea around the Korean peninsula mainly focus on predicting sea surface temperatures. Unlike previous researches, this research predicted the vertical sea water temperature profile of the East Sea, which is very important in submarine operations and anti-submarine warfare, using XBT(eXpendable Bathythermograph) data and machine learning models(RandomForest, XGBoost, LightGBM). The model was trained using XBT data measured from sea surface to depth of 200m in a specific area of the East Sea, and the prediction accuracy was evaluated through MAE(Mean Absolute Error) and vertical sea water temperature profile graphs.