Reply on RC2

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> 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 (&delta;¹⁸O) that tracks the combined change in sea surface temperature (SST) and the oxygen isotopic composition of seawater (&delta;¹⁸O_sw), a measure of hydrologic variability. Increasingly, coral &delta;¹⁸O 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 &delta;¹⁸O_sw 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 &delta;¹⁸O records from the Common Era. The database contains 54 paired Sr / Ca-&delta;¹⁸O records and 125 unpaired Sr / Ca or &delta;¹⁸O 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 &ndash; and application in paleo-data assimilation projects.The CoralHydro2k database will be available on the NOAA National Center for Environmental Information&rsquo;s Paleoclimate data service with serializations in MATLAB, R, Python, and LiPD.