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Expedition 379T of the D/V JOIDES Resolution was the first in the new NSF funded JR100 program, intended to provide the US paleoceanographic community a new way for recovering long sediment records (up to 100 meters below seafloor) outside of the IODP program. As such, it bridges between the conventional coring capability on UNOLS ships and the deep sea drilling program. The primary objective of the expedition was to investigate links between oceanographic changes at the northern margin of the Antarctic Circumpolar Current and climate variability on the South American continent over the past few glacial-interglacial cycles, with a special emphasis on obtaining high-resolution records of the Eemian interval and the last two glacial terminations. Given very high sedimentation rates along the Chilean margins, the new cores will enable reconstruction of surface and intermediate water variability at centennial-to-millennial resolution, which will extend available records from previous coring expeditions (ODP Expedition 202), thus permitting comparison of Southern Hemisphere records of the Holocene and last interglacial (LIG- Eemian), terminations I and II, and the MIS 5e-5d glacial inception. Eight sites were cored during Expedition 379T, recovering a total of 2232 m of sediment cores in 670–3055 m water depth with an average recovery of 101.8% during 14.62 days of on-site operations. The eight sites extend over a wide latitudinal distance (46-36°S) covering the modern transition from the Antarctic subpolar to the subtropical zones as well as spanning water depths intersecting the Antarctic Intermediate Water (AAIW), Pacific Deep Water (PDW) and Circumpolar deep water (CPDW) water masses. Six of the sites are located on the Chilean margins at intermediate water depths (670-1534 mbsl) and the other two sites are situated in deep water off the shelf (2032 and 3055 mbsl). Three holes were APC cored in all but one site allowing for compositing complete splices for paleoceanographic reconstructions. Shipboard analyses of the sediment cores included determining properties including magnetic susceptibility (MS), gamma ray attenuation (GRA), natural gamma radiation (NGR), visual description and imaging, paleomagnetic measurements, and micropaleontology (foraminifers, nannofossil and diatoms). Low-resolution (1 per core) interstitial water samples were collected for shipboard elemental analysis at each site. In addition, high-resolution interstitial water samples (1 per section) were collected at each site for further shore-based isotopic and elemental investigations totaling 472 IW samples.

Codebase and data files for this study. Github repo: https://github.com/sdtaylor/phenology_dataset_study Manuscript preprint: https://doi.org/10.1101/335802 Abstract: Large-scale observational data from citizen science efforts are becoming increasingly common in ecology, and researchers often choose between these and data from intensive local-scale studies for their analyses. This choice has potential trade-offs related to spatial scale, observer variance, and inter-annual variability. Here we explored this issue with phenology by comparing models built using data from the large-scale, citizen science National Phenology Network (NPN) effort with models built using data from more intensive studies at Long Term Ecological Research (LTER) sites. We built process based phenology models for species common to each dataset. From these models we compared parameter estimates, estimates of phenological events, and out-of-sample errors between models derived from both NPN and LTER data. We found that model parameter estimates for the same species were most similar between the two datasets when using simple models, but parameter estimates varied widely as model complexity increased. Despite this, estimates for the date of phenological events and out-of-sample errors were similar, regardless of the model chosen. Predictions for NPN data had the lowest error when using models built from the NPN data, while LTER predictions were best made using LTER-derived models, confirming that models perform best when applied at the same scale they were built. Accordingly, the choice of dataset depends on the research question. Inferences about species-specific phenological requirements are best made with LTER data, and if NPN or similar data are all that is available, then analyses should be limited to simple models. Large-scale predictive modeling is best done with the larger-scale NPN data, which has high spatial representation and a large regional species pool. LTER datasets, on the other hand, have high site fidelity and thus characterize inter-annual variability extremely well. Future research aimed at forecasting phenology events for particular species over larger scales should develop models which integrate the strengths of both datasets. &nbsp

Expedition 379T of the D/V JOIDES Resolution was the first in the new NSF funded JR100 program, intended to provide the US paleoceanographic community a new way for recovering long sediment records (up to 100 meters below seafloor) outside of the IODP program.As such, it bridges between the conventional coring capability on UNOLS ships and the deep sea drilling program.The primary objective of the expedition was to investigate links between oceanographic changes at the northern margin of the Antarctic Circumpolar Current and climate variability on the South American continent over the past few glacial-interglacial cycles, with a special emphasis on obtaining high-resolution records of the Eemian interval and the last two glacial terminations. Given very high sedimentation rates along the Chilean margins, the new cores will enable reconstruction of surface and intermediate water variability at centennial-to-millennial resolution, which will extend available records from previous coring expeditions (ODP Expedition 202), thus permitting comparison of Southern Hemisphere records of the Holocene and last interglacial (LIG- Eemian), terminations I and II, and the MIS 5e-5d glacial inception. Eight sites were cored during Expedition 379T, recovering a total of 2232 m of sediment cores in 670–3055 m water depth with an average recovery of 101.8% during 14.62 days of on-site operations.The eight sites extend over a wide latitudinal distance (46-36°S) covering the modern transition from the Antarctic subpolar to the subtropical zones as well as spanning water depths intersecting the Antarctic Intermediate Water (AAIW), Pacific Deep Water (PDW) and Circumpolar deep water (CPDW) water masses.Six of the sites are located on the Chilean margins at intermediate water depths (670-1534 mbsl) and the other two sites are situated in deep water off the shelf (2032 and 3055 mbsl).Three holes were APC cored in all but one site allowing for compositing complete splices for paleoceanographic reconstructions. Shipboard analyses of the sediment cores included determining properties including magnetic susceptibility (MS), gamma ray attenuation (GRA), natural gamma radiation (NGR), visual description and imaging, paleomagnetic measurements, and micropaleontology (foraminifers, nannofossil and diatoms).Low-resolution (1 per core) interstitial water samples were collected for shipboard elemental analysis at each site.In addition, high-resolution interstitial water samples (1 per section) were collected at each site for further shore-based isotopic and elemental investigations totaling 472 IW samples. &nbsp