Abstract EI Nino–Southern Oscillation (ENSO) is a complex ocean-atmosphere interaction phenomenon occurring in nature that has a profound impact on global atmospheric circulation. As ENSO is a coupled ocean-atmosphere phenomenon, in addition to the commonly used sea surface temperature (SST), water vapor in the atmosphere can be used to monitor the evolution of ENSO and to investigate its consequences (e.g., droughts and flooding). The Global Navigation Satellite System (GNSS), in addition to its applications for positioning, timing, and navigation, is another established atmospheric observing system used to remotely sense precipitable water vapor (PWV) in the atmosphere. The accuracy of the GNSS-derived PWV measurements was assessed from 12 stations based on observations made at co-located radiosonde stations as a reference. The results show that mean values of the root-mean-square error (RMSE) and biases of 6-hourly GNSS-derived PWV derived from all 12 stations are valued at 1.48 mm and −0.30 mm, respectively. Regarding monthly means, mean values of the RMSE and biases of the GNSS-derived PWV are valued at 0.66 mm and −0.23 mm, respectively. The variability in PWV estimated from 56 GNSS stations positioned close to the sea indicates that it is significantly affected by ENSO events. Generally, a 1-K increase in SST will lead to an 11% increase in PWV across all of the stations. A case study conducted at the TOW2 station in Australia shows that the non-linear trend of the PWV depicts the evolution of two severe flood events and one severe drought event occurring in this region. Comparative results derived from TOW2 and from another 24 stations show a good agreement between PWV and total precipitation. These results suggest that GNSS-derived PWV together with other climatic variables (e.g., SST) can be used as an indication of the evolution of ENSO events and as a possible indicator of drought and flood occurrence.

中文翻译：

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GNSS衍生的可降水水汽与海面温度的相关性及其对厄尔尼诺-南方涛动的响应

摘要 EI Nino-Southern Oscillation (ENSO) 是自然界中发生的一种复杂的海洋-大气相互作用现象，对全球大气环流具有深远的影响。由于 ENSO 是一种海洋-大气耦合现象，除了常用的海面温度 (SST) 外，大气中的水蒸气还可用于监测 ENSO 的演变并调查其后果（例如干旱和洪水）。全球导航卫星系统 (GNSS) 除了定位、授时和导航应用外，还是另一个成熟的大气观测系统，用于遥感大气中的可降水水汽 (PWV)。GNSS 衍生的 PWV 测量值的准确性是根据在同一地点的无线电探空仪站进行的观测作为参考从 12 个站进行评估的。结果表明，来自所有 12 个站点的 6 小时 GNSS 衍生 PWV 的均方根误差 (RMSE) 和偏差的平均值分别为 1.48 毫米和 -0.30 毫米。关于月均值，均方根误差的平均值和 GNSS 衍生的 PWV 偏差的值分别为 0.66 毫米和 -0.23 毫米。从靠近大海的 56 个 GNSS 站估计的 PWV 变化表明它受到 ENSO 事件的显着影响。通常，SST 增加 1-K 将导致所有站点的 PWV 增加 11%。在澳大利亚 TOW2 站进行的案例研究表明，PWV 的非线性趋势描述了该地区发生的两次严重洪水事件和一次严重干旱事件的演变。TOW2 和另外 24 个站点的比较结果表明 PWV 与总降水量之间具有良好的一致性。这些结果表明，GNSS 衍生的 PWV 与其他气候变量（例如 SST）一起可用作 ENSO 事件演变的指示以及干旱和洪水发生的可能指标。