On 8 November 2013, Typhoon Haiyan impacted the Philippines with estimated winds of approximately 314 km h-1 and an associated 5–7-m-high storm surge that struck Tacloban City and the surrounding coast of the shallow, funnel-shaped San Pedro Bay. Typhoon Haiyan killed more than 6,000 people, superseding Tropical Storm Thelma of November 1991 as the deadliest typhoon in the Philippines. Globally, it was the deadliest tropical cyclone since Nargis hit Myanmar in 2008. Here, we use field measurements, eyewitness accounts, and video recordings to corroborate numerical simulations and to characterize the extremely high velocity flooding caused by the Typhoon Haiyan storm surge in both San Pedro Bay and on the more open Pacific Ocean coast. We then compare the surge heights from Typhoon Haiyan with historical records of an unnamed typhoon that took a similar path of destruction in October 1897 (Ty 1897) but which was less intense, smaller, and moved more slowly. The Haiyan surge was about twice the height of the 1897 event in San Pedro Bay, but the two storm surges had similar heights on the open Pacific coast. Until stronger prehistoric events are explored, these two storm surges serve as worst-case scenarios for this region. This study highlights that rare but disastrous events should be carefully evaluated in the context of enhancing community-based disaster risk awareness, planning, and response.

Reconstructions of key climate parameters prior to anthropogenic influences serve to constrain decadal to multicentury natural climate variability. In the western Pacific region, relatively few reconstructions exist north of the Western Pacific Warm Pool (WPWP), a region critical to global climate. In this study, we collected a coral core from Houbihu, southern Taiwan, and generated a 225-year reconstruction of annual and wintertime sea surface temperature, dry season sea surface salinity, and wet season rainfall records derived from paired Porites Sr/Ca and δ 18 O profiles extending back to the end of the Little Ice Age (1850 CE). Multidecadal sea surface temperature trends generally track regional surface temperature reconstructions, indicating the dominant influence of solar and volcanic radiative forcings. Reconstructed dry season sea surface salinity reflects an advection signal linked to the East Asian Winter Monsoon and the Pacific Decadal Oscillation, both influencing variations in the Kuroshio Intrusion across the Luzon Strait. Reconstructed wet season rainfall, on the other hand, reveals influence of the Pacific Decadal Oscillation on the decadal variability of local and regional rainfall patterns. Relative to the late 1900s, our climate reconstructions document cooler and drier (high salinity and low rainfall) conditions during the end of the Little Ice Age, supporting other lines of evidence of a retracted WPWP region during this period. In the late 20th to early 21st century, our climate reconstructions record warming and freshening (low salinity and high rainfall) trends, highlighting the potential impact of anthropogenic forcing in the extension of the WPWP.

The Luzon Strait (LS) hosts the largest transport of water between the Western Pacific Ocean

The Indo‐Pacific coral Diploastrea heliopora reveals regional multidecadal‐ to centennial‐ scale climate variability using coral carbonate δ18O (δ18Oc) as a combined proxy for sea surface temperature (SST) and sea surface salinity (SSS). However, to assess the coral's full potential in resolving climatic events, an independent SST proxy would be more advantageous. We examined both Sr/Ca and δ18O of Diploastrea against an adjacent Porites lobata core collected from northeast Luzon, Philippines. Winter Sr/Ca data from Diploastrea show a significant correlation to SST (r = −0.41, p < 0.05, (root‐mean‐square of the residual) RMSR = 0.81°C) and provide a proxy with similar sensitivity as Porites (r = −0.57, p < 0.05, RMSR = 0.62°C). An interspecies SST record is shown to be robust and used for a reconstruction of the Pacific Decadal Oscillation during boreal winter (r = −0.70, p = 0.02). While we were unable to generate a robust Diploastrea δ18O‐SSS calibration at interannual timescale, the freshening trend toward the present, commonly observed in the region, is qualitatively captured in Diploastrea δ18O. Comparison with Porites δ18O and instrumental SSS records shows that the magnitude of freshening is consistent between coral species. Wet and dry season Porites δ18O provide support for the relative influence of El Niño–Southern Oscillation events and local precipitation to SSS variability at our site. The multiproxy, multispecies approach of this study further strengthens the evidence for Diploastrea as an alternate climate archive in the Indo‐Pacific region and seals its potential in helping resolve less understood global‐scale climate phenomena.

The Pacific Decadal Oscillation (PDO) is a complex aggregate of different atmospheric and oceanographic forcings spanning the extratropical and tropical Pacific. The PDO has widespread climatic and societal impacts, thus understanding the processes contributing to PDO variability is critical. Distinguishing PDO‐related variability is particularly challenging in the tropical Pacific due to the dominance of the El Niño–Southern Oscillation and influence of anthropogenic warming signals. Century‐long western Pacific records of subannual sea surface temperature (SST) and sea surface salinity (SSS), derived from coral Sr/Ca and δ18O profiles, respectively, allow for evaluating different climatic sensitivities and identifying PDO‐related variability in the region. The summer Sr/Ca‐SST record provides evidence of a significant SST increase, likely tied to greenhouse gas emissions. Anthropogenic warming is masked in the winter Sr/Ca‐SST record by interannual to multidecadal scale changes driven by the East‐Asian Winter Monsoon and the PDO. Decadal climate variability during winter is strongly correlated to the PDO, in agreement with other PDO records in the region. The PDO also exerts influence on the SSS difference between the dry and wet season coral δ18O (δ18Oc)‐SSS records through water advection. The PDO and El Niño–Southern Oscillation constructively combine to enhance/reduce advection of saline Kuroshio waters at our site. Overall, we are able to demonstrate that climate records from a tropical reef environment significantly capture PDO variability and related changes over the period of a century. This implies that the tropical western Pacific is a key site in understanding multifrequency climate variability, including its impact on tropical climate at longer timescales.

Cloud and convective processes vary at scales significantly smaller than a general circulation model (GCM) grid box, requiring them to be parameterized on simulated grid-scale variables (Boucher et al., 2013). Because such parameterizations employ different assumptions (Lopez, 2007), representation of cloud and convective effects in climate models inherently hold large uncertainties. Cloud and convective parameterizations, aside from aerosol schemes and aerosol-cloud interactions (Meehl et al., 2020), are considered the leading source of inter-model spread in equilibrium climate sensitivity (ECS) estimates (

Abstract. The response of the hydrological cycle to anthropogenic climate change, especially across the tropical oceans, remains poorly understood due to the scarcity of long instrumental temperature and hydrological records. Massive shallow-water corals are ideally suited to reconstructing past oceanic variability as they are widely distributed across the tropics, rapidly deposit calcium carbonate skeletons that continuously record ambient environmental conditions, and can be sampled at monthly to annual resolution. Most coral-based reconstructions utilize stable oxygen isotope composition (δ18O) that tracks the combined change in sea surface temperature (SST) and the oxygen isotopic composition of seawater (δ18Osw), a measure of hydrologic variability. Increasingly, coral δ18O time series are paired with time series of strontium-to-calcium ratios (Sr / Ca), a proxy for SST, from the same coral to quantify temperature and δ18Osw variability through time. To increase the utility of such reconstructions, we present the CoralHydro2k database: a compilation of published, peer-reviewed coral Sr / Ca and δ18O records from the Common Era. The database contains 54 paired Sr / Ca-δ18O records and 125 unpaired Sr / Ca or δ18O records, with 88 % of these records providing data coverage from 1800 CE to present. A quality-controlled set of metadata with standardized vocabulary and units accompanies each record, informing the use of the database. The CoralHydro2k database tracks large-scale temperature and hydrological variability. As such, it is well-suited for investigations of past climate variability, comparisons with climate model simulations including isotope-enabled models – and application in paleo-data assimilation projects.The CoralHydro2k database will be available on the NOAA National Center for Environmental Information’s Paleoclimate data service with serializations in MATLAB, R, Python, and LiPD.

Abstract. The response of the hydrological cycle to anthropogenic climate change, especially across the tropical oceans, remains poorly understood due to the scarcity of long instrumental temperature and hydrological records. Massive shallow-water corals are ideally suited to reconstructing past oceanic variability as they are widely distributed across the tropics, rapidly deposit calcium carbonate skeletons that continuously record ambient environmental conditions, and can be sampled at monthly to annual resolution. Climate reconstructions based on corals primarily use the stable oxygen isotope composition (δ18O), which acts as a proxy for sea surface temperature (SST), and the oxygen isotope composition of seawater (δ18Osw), a measure of hydrological variability. Increasingly, coral δ18O time series are paired with time series of strontium-to-calcium ratios (Sr/Ca), a proxy for SST, from the same coral to quantify temperature and δ18Osw variability through time. To increase the utility of such reconstructions, we present the CoralHydro2k database, a compilation of published, peer-reviewed coral Sr/Ca and δ18O records from the Common Era (CE). The database contains 54 paired Sr/Ca–δ18O records and 125 unpaired Sr/Ca or δ18O records, with 88 % of these records providing data coverage from 1800 CE to the present. A quality-controlled set of metadata with standardized vocabulary and units accompanies each record, informing the use of the database. The CoralHydro2k database tracks large-scale temperature and hydrological variability. As such, it is well-suited for investigations of past climate variability, comparisons with climate model simulations including isotope-enabled models, and application in paleodata-assimilation projects. The CoralHydro2k database is available in Linked Paleo Data (LiPD) format with serializations in MATLAB, R, and Python and can be downloaded from the NOAA National Center for Environmental Information's Paleoclimate Data Archive at https://doi.org/10.25921/yp94-v135 (Walter et al., 2022).