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1.
使用Advanced Microwave Scanning Radiometer for EOS(AMSR-E)的海洋产品数据海表温度、风速,大气水蒸气、云液态水,通过遗传算法建立其与近海面气温和比湿之间的经验关系,进行近海面气温和比湿的实时反演.反演结果与The Tropical Ocean-Atmosphere(TAO)和The National Data Buoy Center(NDBC)的浮标实测资料进行比较,实时近海面气温和比湿的均方根误差分别为1.18℃和1.36 g/kg.分析结果表明,利用遗传算法采用AMSR-E海洋产品数据可以较好地反演近海面气温和比湿.  相似文献   

2.
基于多元线性回归方法,利用2013-01-06的AMSR2辐射计亮温数据和红外-微波融合SST数据产品,开展了近海面气温反演算法研究,并用TAO,RAMA和PIRATA等浮标实测数据对近海面气温的反演结果进行检验。近海面气温反演结果误差情况:均方根误差为0.66℃,偏差为0.02℃,相关系数R为0.91,该误差结果表明所建立近海面气温反演算法较好的反映在60°S~60°N纬度范围内的近海面气温分布情况;同时为进一步确定不同纬度近海面气温反演的误差分布,将近海面气温反演结果与ECMWF再分析数据进行了对比分析,结果表明,从赤道起算,纬度每升高或降低1°,反演均方根误差约增大0.1℃。  相似文献   

3.
介绍了一种将大气效应考虑在内、利用Landsat TM、ETM+热红外数据进行近海岸海表水温反演的单窗算法.在该算法中,将地表气温、相对湿度等常规气象资料作为初始参数,根据对流层中大气温度随高度呈线性降低、水汽随高度呈指数衰减的规律,建立了估算平均大气温度及水汽含量的通用模式.通过与实测数据及MODIS Terra海表水温产品比较发现,该算法能够提高运用TM/ETM+TIR单波段数据进行近岸海表水温(SST)反演的精度:一方面,反演所得结果更接近于海表实际水温;另一方面,它在一定程度上剔除大气中的水汽对SST反演的影响,进而提高海表水温的温度对比度.该提出的大气校正算法只需地表大气温度及相对湿度资料,该算法也无需进行大气模式的界定.  相似文献   

4.
15年测高资料反演南海北部潮汐结果的分析   总被引:1,自引:0,他引:1       下载免费PDF全文
在调和分析的基础上,结合差比关系的运用,利用T/P和Jason-1卫星测高数据进行了南海北部潮汐状况的反演、分析。其中沿轨数据和交点数据的海面异常(SLA)样本标准差(STD)值计算表明,对于15年资料而言,潮汐分析结果已基本一致。对3年轨道改变后的T/P资料分析发现,运用差比分析的办法能使其分析精度有20%左右的提高,达到与15年资料相近的分析效果。最后文章将近岸的反演结果与实测值作了对比,得出在大多数地区(除水动力复杂区域外),沿轨数据的反演水位与实测值的误差均值小于19cm,STD值小于14cm。  相似文献   

5.
基于人工神经网络方法,利用海面水温、海面风速以及海面气压反演南海近海面气温,采用的基础数据集是国际综合海洋-大气数据集(International Comprehensive Ocean-Atmosphere Data Set,2.4 Release,ICOADS2.4)1981—2008年的观测资料,其中1981—2000年的观测资料用来建立模型,2001—2008年的观测资料用来进行模型检验。采用的人工神经网络方法是引入动量因子并采用批处理梯度下降法的BP(Back propagation)算法。试验结果表明,基于人工神经网络建立的近海面气温反演方法明显优于多元线性回归方法,尤其是在春季和冬季,海面水温、海面风速以及海面气压与近海面气温之间存在较强的非线性关系,人工神经网络的优势更加明显。总体而言,人工神经网络在各月的反演效果较均衡,均方根误差介于1.5—1.8℃之间,平均绝对误差为1.1—1.3℃。  相似文献   

6.
利用1974~1982年黄、东海海洋水文气象标准断面实测资料对近海面空气湿度的分布、变化进行了分析。讨论了冬、夏季海、气温与湿度的关系,并对冬、夏季近海面空气湿度进行了估算。结果表明,夏季,空气湿度为气温的函数;冬季,除了考虑空气本身平流的水汽外,还必须考虑海洋向大气的水汽输送。  相似文献   

7.
利用济南和威海成山头1951—2006年的冬季气温的观测资料,用MHF(墨西哥帽函数)小波分析了两地冬季气温的多时间尺度变化特征并对两地出现的极端气候进行了一定分析。结果表明近60a来,济南冬季年平均气温(0.82℃)比威海成山头冬季年平均气温(0.53℃)高,济南和威海成山头两地冬季气温倾向率分别为0.431℃/10a和0.359℃/10a;两地在较大时间尺度上,突变点位置比较接近,在较小时间尺度上,演变略有差异,济南冬季气温变化比威海成山头略快;在振动周期上,济南的冬季平均气温变化以5,18a左右周期振动较强,威海成山头的冬季平均气温变化则以4,18a左右为较强周期振动;在未来一段时间内,两地冬季气温将保持偏高状态,但都有转低的趋势;出现极端气候时有明显的群发性和阶段性,成山头出现极端气候时情况更加恶劣。  相似文献   

8.
利用山东省1991—2021年122个国家级气象观测站的逐日气温、降水量、相对湿度、风速等资料,分析山东省内气候利弊条件,并采用人体舒适度指数(IBC)计算分析全省人体舒适度的时空分布特征。结果表明:(1)半岛、鲁南东部地区适宜气温日数和适宜降水日数占比多于山东中西部地区;中西部地区适宜风速日数占比多于东部地区;半岛及鲁南东部地区很少出现高温天气,半岛东端易出现大风天气;沿海地区、鲁南地区的适宜湿度日数占比较其他地区偏多。(2)全省历年平均人体舒适度指数均属于偏凉等级,大部地区人体舒适日数呈增多趋势。月均IBC多较为舒适,无寒冷等级(1级),也无偏热以上等级(7~10级),多数人舒适日数(4~6级)月际变化呈“M”形分布,5、6、9月舒适日最多,冬季、初春、秋末冷不舒适日数多,仅夏季出现较少的热不舒适日数。(3)山东各地均有6~7个月的舒适期,半岛、鲁南东部地区为最舒适,主要体现在青岛、烟台、威海地区气候最舒适期(5级)长达4个月,内陆城市仅有3个月。(4)全省各地人体舒适日数与同期平均气温、平均相对湿度、平均风速密切相关,夏季气温偏低、风速偏大、湿度适中时人体舒适度较好,其他季节大致反之。  相似文献   

9.
根据我国沿海近10多年来潮位观测数据进行年均过程的统计,同时与有关气象资料和文献进行了联系比照分析,研究结果表明,20世纪90年代以来我国沿海海面持续波动上升,其年均值70年代中期至80年代中期比较平均偏高1.2-6.4cm,有些海区个别年份偏高值达7.0-8.0cm,如南海1999年偏高8.5cm,这10多年来我国沿海台风风暴潮发生的平均次数与前期比较虽略有减少(由年均8.0次减少为年均6.9次),但强度增大,其中47个站疹观测到破历史记录的高水位,三个站次出现1000a一遇的高水位,灾害损失巨大,地学中的“海面变化”,自器测时代以来是由各地验潮站水位测量的年均值取得的,显然,这是一种相对变化,它只是消除各地地质运动(如新构造运动,地基升降等)影响因子后才具有广泛的水动型时空对比意义,本文根据实测水位数据统计所得的成果,进而与同时空的气象资料相比照,分析认为,近10我年来我国沿海平面与1975-1986年期间比较有普遍较大幅度的升高现象,除个别站位需考虑陆动型因素影响外,这与同时期发生在我国沿海的风暴增水过程的增强不无关系,因为风暴增水过程含括在各年水夹无益 (邓地学意义上的海面变化)的统计中。  相似文献   

10.
基于美国国家冰雪数据中心 (NSIDC) 海冰资料、美国国家环境预报中心 (NCEP) 再分析格点数据和黄渤海近岸13个气象站点逐日气温数据,通过相关分析和合成分析,研究了 2007-2018 年黄渤海海冰范围的变化特征,探讨了近 12 年黄渤海海冰范围对近岸陆地气温、大气环流和局地天气过程的响应。结果表明: (1) 黄渤海海冰范围年际振荡明显,近 12 年呈现先增加后减小的趋势,与同期黄渤海近岸气温呈显著负相关关系;每年 1 月下旬至 2 月下旬是一年中海冰范围最大的时期。(2) 海冰范围偏大与偏小年份东亚地区 500 hPa 大气环流形势呈现出近乎相反的分布。 (3) 东亚阻塞形势的建立是黄渤海海冰范围爆发性增大的一个前兆信号,它带来的大风降温天气是造成黄渤海海冰范围爆发性增大的重要原因.  相似文献   

11.
东南太平洋茎柔鱼(Dosidicus gigas)是短生命周期大洋性经济鱼类,其资源量受环境因素变化的影响较大。根据我国鱿钓船队2013~2017年在东南太平洋的生产统计数据,结合海洋环境数据包括海表面温度(SST)、海表面盐度(SSS)、叶绿素a浓度(chl a),运用BP神经网络(back propagation network)模型来标准化单位捕捞努力量渔获量(catch per unit effort, CPUE,也称名义CPUE)。以均方误差(mean square errors, MSE)和平均相对变动值(average relative variances, ARV)为最优模型判断依据,比较隐含层节点3-10的神经网络模型,发现6-9-1结构为最优模型。用Garson算法解释模型结果,发现各输入层因子对东南太平洋茎柔鱼资源丰度影响重要度排序为chl a、SST、经度(Lon)、SSS、纬度(Lat)、月份(Month)。并作名义CPUE和标准化CPUE资源丰度对比分布图,结果显示CPUE与标准化CPUE总体分布状况基本一致,但局部区域存在明显差异, 80°~85°W及10°~20°S海域适宜鱿钓生产,表明BP神经网络模型可以适用于东南太平洋茎柔鱼的CPUE标准化,从而为鱿钓渔业生产提供一定参考依据。  相似文献   

12.
Nineteen surface sediment samples, collected onboard ORV Sagar Kanya during the 199C and 200th (the pilot expedition to Southern Ocean) cruises along a north-south transect between 1.92° S to 55.01° S latitude and 67.88° E and 44.89° E longitude, were studied for total planktonic foraminiferal assemblage, relative abundance and the oxygen isotopic values of the indicator planktic species Globigerina bulloides. These profiles were compared with the latitudinal variations in the average salinity and nutrient (phosphate) contents of the top 100 meters water column. The initial results have traced the signatures of salinity linked variations of different water masses in the study region. The influence of Australian Mediterranean Water (AAMW) has been noticed in the present dataset.  相似文献   

13.
Long time-series of sea surface temperature (SST) and pseudo wind stress (τ) in six areas in the South-East Atlantic are analysed as possible inputs into fisheries models. The areas encompass oceanic and coastal regimes. A clear seasonal signal is evident in all areas, with an amplitude in SST of 3–4°C in the upwelling areas and 5°C farther offshore and on the Agulhas Bank. Warming lags in the north and offshore by 1–2 months. Monthly variability is highest in the upwelling areas. An increasing trend in SST is suggested in all areas, the post-World War II era being about 1,0°C warmer than earlier periods. Some coherence occurs between areas at times, although at other times the anomalies are distinctly out of phase. There is a suggestion of an upward trend in the equatorward wind stress in some offshore areas after 1964, with a sharp change in 1975. Benguela Niños are evident in the environmental record and have a periodicity of around 10 years.  相似文献   

14.
Pigment indices were used to investigate the distribution and composition of phytoplankton in the northern Benguela during the austral spring of 2000, with sampling being conducted on five transect lines between 19°S and 25°S and at other inshore stations on the shelf. Total chlorophyll a concentrations (TChla) at the surface ranged from 18.4mg m?3 at shallow inshore stations to 0.58mg m?3 at offshore localities in deeper water. Phytoplankton communities in the inshore environment were characterised by elevated biomass levels and the dominance of diatoms (high FucDP indices). These diatom populations were associated with cool, higher density, nutrient-rich waters near the coast. Phytoplankton biomass declined with increasing distance offshore and the communities changed to a mixed population where small flagellates were generally dominant (high FlagDP indices). These flagellate communities were associated with warmer, lower density waters. Whereas dinoflagellates (PerDP Index) and prokaryotes (ZeaDP Index) were observed throughout the region, their contribution to the communities was of secondary importance.  相似文献   

15.
Producing high-quality match-ups coupling the Japanese geostationary satellite, Himawari-6 (H6), and buoy SST observations, we have developed the new SST retrieval method. Kawamura et al. (2010) developed the previous version of SST product called MTSAT SST, which left several scientific/technical questions. For solving them, 6,711 algorithm tuning match-ups with precise navigation and 240,476 validation match-ups are generated for covering all seasons and wide ocean coverage. For discriminating the previous MTSAT SST, we call the new version of SST H6 SST. It is found that the SZA dependences of MTSAT SST algorithm are different from area to area of SZA > 40–50° N/S. The regionally different SZA dependences are treated by dividing the H6 disk coverage into five areas by the latitude lines of 40° N/S first and the longitude lines of 100° K and 180° K. Using the algorithm tuning match-ups, Nonlinear SST (NLSST) equations are derived for all of the five areas. Though the sun zenith angle dependency correction term is also examined, there is no significant regional difference. Therefore, this term is used in the H6 SST algorithm again. The new H6 SST equation is formed by the areal NLSST and the sun zenith angle dependency term for each area. The statistical evaluation of H6 SST using the validation match-ups show the small negative biases and the RMS errors of about 0.74° K for each area. For the full H6 disk, the bias is −0.1° K and the RMS error 0.74° K. The histogram of H6 SST minus the in situ SST for each area has a similar Gaussian shape with small negative skewness, and the monthly validation of H6 SST for each area is consistent with those for the whole period and the histograms  相似文献   

16.
Cao  Hui-qing  Bai  Xu  Ma  Xian-dong  Yin  Qun  Yang  Xiang-yu 《中国海洋工程》2022,36(5):767-780

Offshore wind energy resources are operational in cold regions, while offshore wind turbines will face the threat of icing. Therefore, it is necessary to study icing of offshore wind turbines under different icing conditions. In this study, icing sensitivity of offshore wind turbine blades are performed using a combination of FLUENT and FENSAP-ICE software, and the effects of liquid water content (LWC), medium volume diameter (MVD), wind speed and air temperature on blade icing shape are analyzed by two types of ice, namely rime ice and glaze ice. The results show that the increase of LWC and MVD will increase the amount of ice that forms on the blade surface for either glaze ice or rime ice, and an increase of MVD will expand the adhesion surface between ice and blade. Before reaching the rated wind speed of 11.4 m/s, it does not directly affect the icing shape. However, after reaching the rated wind speed, the attack angle of the incoming flow decreases obviously, and the amount of ice increases markedly. When the ambient air temperature meets the icing conditions of glaze ice (i.e., −5°C to 0°C), the lower the temperature, the more glaze ice freezes, whereas air temperature has no impact on the icing of rime ice. Compared with onshore wind turbines, offshore wind turbines might face extreme meteorological conditions, and the wind speed has no impact on the amount of ice that forms on the blade surface for most wind speeds

  相似文献   

17.
Studies of offshore wave climate based on satellite altimeter significant wave height(SWH) have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China's coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square(RMS) of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum(0.97) and the RMS difference was the minimum(0.28 m) in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang(Yangtze River) Estuary. The RMS difference was the maximum(0.32 m) in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China's offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China's offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6–2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas: the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%–6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands(9–12 m), and the northeast of the South China Sea and the East China Sea had the second largest wave heights(7–11 m). For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province(7–8 m), whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea(4–6 m). An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%.  相似文献   

18.
We report, from remote sensing and in situ observations, a new type of permanent structure in the eastern subtropical Atlantic Ocean, that we call the “Canary Eddy Corridor”. The phenomenon, is a zonal long-lived (>3 months) mesoscale eddy corridor, whose source is the flow perturbation of the Canary Current and the Trade Winds at the Canary Islands. The latitudinal range of the corridor spans 22°N–29°N and extends from the Canaries to at least 32ºW, near the mid-Atlantic. This is the main region of long-lived westward-propagating eddies in the subtropical northeast Atlantic. From a age-distribution study we observe that at least 10% of mesoscale eddies in this region are long-lived, with a dominance of anticyclones over cyclones. Another four westward-propagating eddy corridors were also detected: two small corridors north and south of the Azores Front; a small zonal corridor located near 31ºN, south of the island of Madeira; and a small corridor located near the Cape Blanc giant filament. The existence of these corridors may change, at least for the northeastern subtropical Atlantic, the general idea that mesoscale eddies are disorganized, ubiquitous structures in the ocean. The Canary Eddy Corridor constitutes a direct zonal pathway that conveys water mass- and biogeochemical properties offshore from the Canary Island/Northwest Africa upwelling system, and may be seen as a recurrent offshore pump of organic matter and carbon to the oligotrophic ocean interior. Estimates of volume and mass transport indicate that Canary Eddy Corridor westward transport is more than one-fourth of the southward transport of the Canary Current. The westward transport of kinetic energy by the eddies of the Canary Corridor is as important as the southward transport by the Canary Current. The total primary production related to the Corridor may be as high as the total primary production of the northwest Africa upwelling system for the same latitude range.  相似文献   

19.
The Humboldt Current System (HCS) is dominated by two pelagic species; Peruvian anchovy or anchoveta (Engraulis ringens) and sardine (Sardinops sagax). Using data from 43 acoustic surveys conducted from 1983 through 2005 by the Peruvian Marine Institute (IMARPE), we examined the distribution of these two species relative to water masses. We tested the hypothesis that anchovy was found more frequently in upwelled cold coastal water (CCW) and mixed waters (MCW) than in other water types and that sardine was more associated with more offshore oceanic surface subtropical water (SSW). Surface temperature, salinity, latitude, season and distance to the coast data were used to define water masses. Results using generalized additive models (GAM), modelling sardine and anchovy presence–absence as a function of year, water body, bottom depth and latitude, showed that anchovy were primarily found in CCW and MCS, while sardine were more ubiquitous relative to water masses with some predilection for SSW. These results were supported by various indexes of anchovy and sardine distribution versus water mass as well as temporal and location variables.  相似文献   

20.
The annual distribution and dispersal of early‐stage phyllosoma of the Japanese spiny lobster Panulirus japonicus were examined in the East China Sea and the Sea of Japan off western Japan. Early‐stage larvae were sampled mainly in summer and relatively near the coast off western Kyusyu Island. Few larvae were found in the other three seasons in the East China Sea and the Sea of Japan. This finding suggests that P. japonicus larvae are retained in coastal areas for a few months after hatching until stage V and are transported offshore until autumn, before they grow to stage VI. Examination of archival drifter data off western Kyusyu Island during the spawning season of P. japonicus supported the relatively rapid dispersal of the larvae from the East China Sea near Japan to the Pacific Ocean or the Sea of Japan. Larval transport from the East China Sea to the Pacific Ocean, which is considered to be a main distribution area of middle‐ and late‐stage larvae, would occur in the south at approximately 32–33°N in the East China Sea near western Kyusyu Island.  相似文献   

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