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1.
Viktor Gouretski Franco Reseghetti 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(6):812-833
The World Ocean Database 2005 as of May 2009 is used to estimate temperature and sample depth biases of expendable (XBT) and mechanical (MBT) bathythermographs by comparing bathythermograph temperature profiles with more accurate bottle and conductivity/temperature/depth (CTD) data. It is shown that the application of depth corrections estimated earlier from side-by-side XBT/CTD inter-comparisons, without accounting for a pure thermal bias, leads to even larger disagreement with the CTD and bottle reference temperatures. Our calculations give evidence for a depth-variable XBT fall-rate correction with the manufacturer-derived depth being underestimated in the upper 200 m and overestimated below this depth. These results are in agreement with side-by-side inter-comparisons and direct fall-rate estimates. Correcting XBT sample depths by a multiplicative factor which is constant with depth does not allow an effective elimination of the total temperature bias throughout the whole water column. The analysis further suggests a dependence of the fall rate on the water temperature which was reported earlier in the literature. Comparison among different correction schemes implies a significant impact of systematic biases on the estimates of the global ocean heat content anomaly. 相似文献
2.
海洋温度的变化会显著影响水下声传播、生物活动、气象和洋流等现象，温深是反映海洋变化运动规律的基本参数。投弃式温深剖面仪（Expendable Bathythermograph，XBT）、温盐深测量仪（Conductivity Temperature Depth，CTD）、全球海洋实时观测网（Array for Real-time Geostrophic Oceanography，Argo）等是目前进行海水温深测量的主要仪器。其中XBT因其现场测量简便、效率高、硬件成本低等特点，正在被大规模使用。本文主要介绍有关海洋温度测量的背景及演化历史，分析对比了国内外相关仪器设备的发展现状，总结了国产化产品还存在的差距和不足，另外对传感器、结构设计、数据通讯传输、数据后处理、可靠性研究等关键技术和研究热点进行了详细介绍，最后对未来无人平台的技术发展路线给出了思路和见解，开展投弃式温深剖面仪的相关技术研究和产品研制对实现国产化有积极的推动意义。 相似文献
3.
The fall-rate of the T-5 expendable bathythermograph (XBT) produced by Tsurumi Seiki (TSK) Co., Ltd and that by Sippican Inc.,
are intercompared by a series of contemporaneous and colocated measurements with conductivity-temperature-depth (CTD) profilers.
It is confirmed that the fall-rates of the two manufacturers' T-5 differ by about 5 percent, despite the fact that they had
been believed to be identical for many years. The cause of the difference is discussed on the basis of a detailed cross-examination
of the two T-5 models. It is found for the first time that the two models are different in several respects. The manufacturer's
fall-rate equation is only applicable to the Sippican T-5, for which Boyd and Linzell's (1993) equation seems to be slightly
more accurate. Kizu et al.'s (2005) equation gives a clearly less biased depth than the manufacturers' equation for the TSK T-5. It is also found that
the fall-rates of both T-5 models are dependent on water temperature, perhaps because of viscosity. The temperature-dependency
of the fall-rate of the TSK T-5 is larger than that of the Sippican T-5. 相似文献
4.
The accuracy of the manufacturer’s fall-rate equation for the T-5 Model of expendable bathythermograph (XBT) has been investigated based on about 300 collocated pairs of XBT-CTD (Conductivity-Temperature-Depth profiler) measurements in various climatological regions. We found that the equation systematically overestimates depth by about 5% for the T-5 produced by Tsurumi Seiki, Co. Ltd. (TSK), but almost no bias is associated with the T-5 produced by Sippican, Inc., in USA. The cause of this difference is not clear, because the two manufacturers’ T-5 probes are reported to have identical shape and weight in water. We propose a new fall-rate equation for the TSK T-5: z(t) = 6.54071t - 0.0018691t
2, where z(t) is depth in meters at time, t, in seconds. 相似文献
5.
A non-destructive temperature calibration system for expendable bathythermographs (XBT) is described. A transfer standard technique has been used to estimate XBT thermistor probe-to-probe temperature variability. One-point calibration results suggest that a standard deviation of 0.025°C is typical at 10°C. Additional calibration data from nine XBT thermistors suggest that probe-to-probe temperature variability is largest at 0°C (ca. 0.03°C) and decreases uniformly to a minimum at 30°C (ca. 0.01°C). 相似文献
6.
Comparison experiment between XBT of T-7 probe and CTD was conducted at 15 stations in the sea area centered on 29°N, 135°E in December 1985. There were systematic errors in XBT temperature profiles in comparison with CTD temperature profiles. The main cause of errors was attributed to an error in the free-fall speed of the XBT probes which was provided by the XBT maker. A previous equation for depth correction proposed by Heinmilleret al. (1983) could not give effective correction for our data. A new equation between the probe depth and the elapsed time from landing of the probe on the water was obtained by the method of adjusting temperature gradients of XBT profiles to those of CTD profiles. This equation agreed with the theoretical result given by Seaver and Kuleshov (1982) much better than that of Heinmilleret al. (1983). Systematic errors due to a scatter of values of the reference resistance and variation of B-constant of thermistors used in XBT also seemed to exist. After an adjustment using the temperature difference between XBT and CTD in the mixed layer with depths of about 100 m, the standard deviation of temperature difference between XBT and CTD from the surface to the depth of 750 m was 0.14°C. 相似文献
7.
国家海洋技术中心根据科研需求研发了抛弃式温度剖面仪(XBT)等一系列抛弃式产品.针对2014年8月份在西太平洋海域投放的XBT和XCTD所获取的温度数据进行对比分析,单剖面结果显示两者相关系数达到了0.95,在温跃层处出现温度差,断面标准差分析结果为200 m以上温跃层处较大而200m以下标准差较小,最大和最小标准差值分别为0.39和0.08.温度断面分析结果显示两者在同样的位置出现等值线的凹凸现象,对大洋水团特殊物理海洋现象描述基本一致.分析温跃层处两者温度存在偏差的原因有3个:不同传感器的不同响应时间引起的误差、深度测量公式的误差以及传感器本身的测量误差影响.国产XBT的数据质量较好,总体上性能能满足对环境复杂海域的快速走航观测,数据质量准确度和可靠性都较好. 相似文献
8.
本文基于常用的统计方法,通过与WOA09观测的海洋溶解氧浓度数据进行比较,定量地评估了9个CMIP5地球系统模式在历史排放试验中海洋溶解氧气候态特征的模拟能力。在海表,由于地球系统模式均能很好地模拟海表温度（SST）,模式模拟的海表溶解氧浓度分布与观测一致,模拟结果无论是全球平均浓度偏差还是均方根误差均接近0,空间相关系数与标准偏差接近1。在海洋中层以及深层这些重要水团所在的区域,各模式的模拟能力则差异较大,尤其在溶解氧低值区（OMZs）所在的500m到1000m,各模式均出现全球平均偏差、均方根误差的极大值以及空间相关系数的极小值。在海洋内部,模式偏差的原因比较复杂。经向翻转环流和颗粒有机碳通量均对模式的偏差有贡献。分析结果表明物理场偏差对溶解氧偏差的贡献较大。一些重要水团,比如北大西洋深水,南极底层水以及北太平洋中层水在极大程度上影响了溶解氧在这些海区的分布。需要指出的是,虽然在海洋内部各模式模拟的溶解氧浓度偏差较大,但是多模式平均结果却能表现出与观测较好的一致性。 相似文献
9.
New CTD-XBT (T-7 probe) comparison data are analyzed, which provide additional evidence of XBT depth error and support previous results (Hanawa and Yoritaka, 1987; Hanawa and Yoshikawa, 1991). The depth difference between the corrected and uncorrected data is about 26 m at 750 m. In the present study, new data processing procedures by which the depth errors are automatically detected, are developed and adopted. In the new method, first, temperature gradients (TG) of XBT and CTD profiles are calculated. Then, 20 m segment of the XBT-TG profile which should fit to the CTD-TG profile of 20 m segment to be referred to is searched in the XBT-TG profile. Actually, this is achieved by shifting the XBT-TG profile of 20 m segment so as to minimize the area surrounded by both TG profiles. The shifted depth of XBT-TG profile for CTD-TG profile can be regarded as the XBT depth error. This processing is repeated at intervals of 5 m from 10 m to 790 m of CTD-TG profile. The relationship between the scatter of the quadratic depth-time equation coefficients and the depth error is also discussed. It is shown that when the two coefficients have a certain relationship, the depth differences between the plural depth-time equations are small, even if the two coefficients of those equations have apparently very different values.This paper was presented and discussed in the Ad Hoc Meeting of the IGOSS Task Team on Quality Control for Automated System, held in Marion, Massachusetts,U.S.A. in June 3–6, 1991. 相似文献
10.
利用热带太平洋TAO浮标阵列评估全球高分辨率浪-潮-流耦合模式同化结果 总被引：3，自引：0，他引：3
In order to evaluate the assimilation results from a global high resolution ocean model, the buoy observations from tropical atmosphere ocean(TAO) during August 2014 to July 2015 are employed. The horizontal resolution of wave-tide-circulation coupled ocean model developed by The First Institute of Oceanography(FIOCOM model) is 0.1°×0.1°, and ensemble adjustment Kalman filter is used to assimilate the sea surface temperature(SST), sea level anomaly(SLA) and Argo temperature/salinity profiles. The simulation results with and without data assimilation are examined. First, the overall statistic errors of model results are analyzed. The scatter diagrams of model simulations versus observations and corresponding error probability density distribution show that the errors of all the observed variables, including the temperature, isotherm depth of 20°C(D20), salinity and two horizontal component of velocity are reduced to some extent with a maximum improvement of 54% after assimilation. Second, time-averaged variables are used to investigate the horizontal and vertical structures of the model results. Owing to the data assimilation, the biases of the time-averaged distribution are reduced more than70% for the temperature and D20 especially in the eastern Pacific. The obvious improvement of D20 which represents the upper mixed layer depth indicates that the structure of the temperature after the data assimilation becomes more close to the reality and the vertical structure of the upper ocean becomes more reasonable. At last,the physical processes of time series are compared with observations. The time evolution processes of all variables after the data assimilation are more consistent with the observations. The temperature bias and RMSE of D20 are reduced by 76% and 56% respectively with the data assimilation. More events during this period are also reproduced after the data assimilation. Under the condition of strong 2014/2016 El Ni?o, the Equatorial Undercurrent(EUC) from the TAO is gradually increased during August to November in 2014, and followed by a decreasing process. Since the improvement of the structure in the upper ocean, these events of the EUC can be clearly found in the assimilation results. In conclusion, the data assimilation in this global high resolution model has successfully reduced the model biases and improved the structures of the upper ocean, and the physical processes in reality can be well produced. 相似文献