ABSTRACT

For 30+ years, submarine cable voltage measurements have been a critical measurement system used to produce a highly valuable time series of daily Florida Current volume transport at 27°N in the Florida Straits. However, the high cost associated with replacing the measurement system, should the existing telecommunications cable break, represents a significant vulnerability to the continuation of this important transport time series. Six years of data from tide gauges near the ends of the cable at 27°N have been used to test the potential of a paired tide gauge system to replace the cable in the event of a future problem. Validations against the daily cable observations, and against snapshot transport estimates from ship sections, suggest that the tide gauges do represent a viable replacement, however, the accuracy of the transports determined from the tide gauges is lower than for the cable observations (2.7 Sv vs. 1.7 Sv, respectively). The tide gauges capture roughly 55% of the total variance observed by the cable. The correlation between the cable data and the tide gauge differences is fairly constant (r ≈ 0.75) after low-pass filtering the data at periods from 3 to 365 days, illustrating a lack of coherence sensitivity to those time scales.

摘要

30 多年来，海底电缆电压测量一直是一个关键的测量系统，用于生成佛罗里达海峡 27°N 每日佛罗里达洋流体积传输的高价值时间序列。然而，如果现有电信电缆断裂，与更换测量系统相关的高成本代表了继续这一重要传输时间序列的重大脆弱性。来自 27°N 电缆末端附近潮汐计的六年数据已被用于测试成对潮汐计系统在未来出现问题时更换电缆的潜力。对每日电缆观测和船舶部分的快照运输估计的验证表明，潮汐计确实代表了一种可行的替代品，然而，由潮汐测量仪确定的传输精度低于电缆观测值（分别为 2.7 Sv 和 1.7 Sv）。潮汐测量仪捕获了电缆观察到的总方差的大约 55%。在对 3 到 365 天周期的数据进行低通滤波后，电缆数据和潮汐测量仪差异之间的相关性相当稳定（r ≈ 0.75），说明对这些时间尺度缺乏相干敏感性。