Coral reconstruction often serves as a major proxy of high-resolution sea surface temperature (SST) variability beyond the instrumental era. However, coral reconstructions are sparse and are usually studied for interannual variability, with few studies on the monthly features. In this study, we reconstruct the monthly SST spatial field by applying the paleoclimate data assimilation method to the coral records of the latest CoralHydro2k data set for the instrument period of 1880–2000. A comparison with observed SST variability shows that our assimilated tropical SST variability performs reasonably well for the seasonal cycle and monthly ENSO characteristics, notably the phase-locking and onset timing, and more realistic spatial fields relative to the model simulations. This study suggests the feasibility of applying paleoclimate data assimilation to reconstruct the monthly SST in the historical period.

珊瑚重建通常是仪器时代之后高分辨率海面温度 （SST） 变化的主要代表。然而，珊瑚重建很少，通常研究年际变化，对每月特征的研究很少。在这项研究中，我们通过将古气候数据同化方法应用于 1880-2000 年仪器期间最新 CoralHydro2k 数据集的珊瑚记录，重建了每月的 SST 空间场。与观测到的 SST 变化的比较表明，我们同化的热带 SST 变化在季节周期和每月 ENSO 特征方面表现得相当好，特别是锁相和开始时间，以及相对于模式模拟的更真实的空间场。本研究提出了应用古气候数据同化重建历史时期每月 SST 的可行性。