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1. Holocene eolian sediment and organic matter from terraces and hillslopes around Healy, central Alaska

   https://doi.org/10.18739/A2X921M1C  

   Walker, Caitlin; Kaufman, Darrell; McKay, Nicholas; Schuur, Edward (January 2024, NSF Arctic Data Center)

   Three natural exposures near Healy, Alaska (Dry Creek, Panguingue Creek, and Healy Spur) and transects of shallow cores from three hillslopes near Eight Mile Lake were analyzed for particle-size distribution, loss-on-ignition for organic matter content, and radiocarbon dating. This study is part of a Master’s thesis research project by Walker at Northern Arizona University (https://www.proquest.com/openview/80b94829f88d5c8e0d0d678581079273/1?pq-origsite=gscholar&cbl=18750&diss=y). It builds on work of Marshall et al. (2023; doi: 10.1029/2022JG007290) who reported data from additional sediment cores taken along one of the hillslopes in this study, namely Hillslope A (https://arcticdata.io/catalog/view/doi:10.18739/A2F76683D). The motivation was to compare datasets of eolian material between different depositional settings, as well as identify trends in eolian thickness and particle size across the Healy landscape to reconstruct Holocene eolian deposition and identify the factors influencing depositon. 

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2. A Spatially Detailed and Economically Complete Blue Water Footprint of the United States

   https://doi.org/10.5194/hess-2017-650  

   Rushforth, Richard R.; Ruddell, Benjamin L. (January 2017, Hydrology and Earth System Sciences Discussions)

   This paper quantifies and maps a spatially detailed and economically complete blue water footprint for the United States, utilizing the National Water Economy Database version 1.1 (NWED). NWED utilizes multiple mesoscale federal data resources from the United States Geological Survey (USGS), the United States Department of Agriculture (USDA), the U.S. Energy Information Administration (EIA), the U.S. Department of Transportation (USDOT), the U.S. Department of Energy (USDOE), and the U.S. Bureau of Labor Statistics (BLS) to quantify water use, economic trade, and commodity flows to construct this water footprint. Results corroborate previous studies in both the magnitude of the U.S. water footprint (F) and in the observed pattern of virtual water flows. The median water footprint (F_CUMed) of the U.S. is 181 966 Mm³ (F_Withdrawal: 400 844 Mm³; F_CUMax: 222 144 Mm³; F_CUMin: 61 117 Mm³) and the median per capita water footprint (F'_CUMed) of the U.S. is 589 m³ capita^−1 (F'_Withdrawal: 1298 m³ capita^−1; F'_CUMax: 720 m³ capita^−1; F'_CUMin: 198 m³ capita^−1). The U.S. hydro-economic network is centered on cities and is dominated by the local and regional scales. Approximately (58 %) of U.S. water consumption is for the direct and indirect use by cities. Further, the water footprint of agriculture and livestock is 93 % of the total U.S. water footprint, and is dominated by irrigated agriculture in the Western U.S. The water footprint of the industrial, domestic, and power economic sectors is centered on population centers, while the water footprint of the mining sector is highly dependent on the location of mineral resources. Owing to uncertainty in consumptive use coefficients alone, the mesoscale blue water footprint uncertainty ranges from 63 % to over 99 % depending on location. Harmonized region-specific, economic sector-specific consumption coefficients are necessary to reduce water footprint uncertainties and to better understand the human economy's water use impact on the hydrosphere. 

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3. Physical and optical characteristics of heavily melted “rotten” Arctic sea ice

   https://doi.org/10.5194/tc-13-775-2019  

   Frantz, Carie M.; Light, Bonnie; Farley, Samuel M.; Carpenter, Shelly; Lieblappen, Ross; Courville, Zoe; Orellana, Mónica V.; Junge, Karen (January 2019, The Cryosphere)

   Abstract. Field investigations of the properties of heavily melted “rotten” Arcticsea ice were carried out on shorefast and drifting ice off the coast ofUtqiaġvik (formerly Barrow), Alaska, during the melt season. While noformal criteria exist to qualify when ice becomes rotten, the objectiveof this study was to sample melting ice at the point at which its structural andoptical properties are sufficiently advanced beyond the peak of the summerseason. Baseline data on the physical (temperature, salinity, density,microstructure) and optical (light scattering) properties of shorefast icewere recorded in May and June 2015. In July of both 2015 and 2017, smallboats were used to access drifting rotten ice within ∼32 km of Utqiaġvik. Measurements showed that pore space increased as icetemperature increased (−8 to 0 ^∘C), ice salinitydecreased (10 to 0 ppt), and bulk density decreased (0.9 to0.6 g cm⁻³). Changes in pore space were characterized with thin-sectionmicrophotography and X-ray micro-computed tomography in the laboratory. Theseanalyses yielded changes in average brine inclusion number density (whichdecreased from 32 to 0.01 mm⁻³), mean pore size (whichincreased from 80 µm to 3 mm), and total porosity (increased from0 % to > 45 %) and structural anisotropy (variable, withvalues of generally less than 0.7). Additionally, light-scattering coefficientsof the ice increased from approximately 0.06 to > 0.35 cm⁻¹ as the ice melt progressed. Together, these findings indicate thatthe properties of Arctic sea ice at the end of melt season are significantlydistinct from those of often-studied summertime ice. If such rotten ice wereto become more prevalent in a warmer Arctic with longer melt seasons, thiscould have implications for the exchange of fluid and heat at the oceansurface. 

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4. Carbon Flux Explorer optical assessment of C, N and P fluxes

   https://doi.org/10.5194/bg-16-1249-2019  

   Bourne, Hannah L.; Bishop, James K.; Wood, Todd J.; Loew, Timothy J.; Liu, Yizhuang (January 2019, Biogeosciences)

   Abstract. The magnitude and controls of particulate carbon exported from surface watersand its remineralization at depth are poorly constrained. The Carbon FluxExplorer (CFE), a Lagrangian float-deployed imaging sediment trap, has beendesigned to optically measure the hourly variations of particle flux tokilometer depths for months to seasons while relaying data in near-real timeto shore via satellite without attending ships. The main optical proxy forparticle load recorded by the CFE, volume attenuance (VA; units ofmATN cm²), while rigorously defined and highly precise, has not beenrobustly calibrated in terms of particulate organic carbon (POC), nitrogen(PN) and phosphorus (PP). In this study, a novel 3-D-printed particle samplerusing cutting edge additive manufacturing was developed and integrated withthe CFE. Two such modified floats (CFE-Cals) were deployed a total of15 times for 18–24 h periods to gain calibration imagery and samples atdepths near 150 m in four contrasting productivity environments during theJune 2017 California Current Ecosystem Long-Term Ecological Research (LTER)process study. Regression slopes for VA : POC and VA : PN (unitsmATN cm²: mmol; R², n, p value in parentheses) were1.01×10⁴ (0.86, 12, < 0.001) and 1.01×10⁵(0.86, 15, < 0.001), respectively, and were not sensitive toparticle size classes or the contrasting environments encountered. PP was notwell correlated with VA, reflecting the high lability of P relative to C andN. The volume attenuance flux (VAF) to POC flux calibration is compared toprevious estimates. 

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5. Luquillo LTER signature Monthly and Daily dataset

   https://doi.org/10.6073/pasta/15caa75d4e779eeb3a05e38c2c7d342e  

   Leon, Miguel C (October 2024, Environmental Data Initiative)

   This dataset contains population, meteorological, phenological, and chemical data collected from tropical montane stream and forest ecosystems. This synthesis product merges 11 distinct datasets into a single comprehensive resource, facilitating easier comparison and study of diverse ecological data. Try our data explorer [here.](https://luqshiny.lter.network/sigds/) It provides a multi-faceted dataset essential to enhance biodiversity monitoring, ecosystem management, and global change research. Data spans from 1975 to 2024, with some gaps and missing data points. Particularly at the beginning of the time span measurements started with temperature and rainfall before other dataset collections began with the inception of the LUQ LTER in the late 1980s. For phenology 17 species were selected for inclusion, listed below. 11 dominant species as described in Uriarte et al. 2009 (DOI 10.1890/08-0707.1). As well as in decline species PALRIP- Palicourea riparia and CISVER - Cissus verticillata. Species that show a strong response to hurricanes PHYRIV - Phytolacca rivinoides- an understory herb and IPOTL -Ipomoea tiliacea- Morning glory vine. And a species thriving understory shrub SMIDOM - Smilax domingensis. - **From Uriarte et al. 2009 these 11 species represent 75% of the stems >=10 cm dbh in the LFDP plot: ** - **ALCLAT** - Alchornea latifolia - **CASARB** - Casearia arborea - **CECSCH** - Cecropia schreberiana - **DACEXC** - Dacryodes excelsa - **GUAGUI** - Guarea guidonia - **INGLAU** - Inga laurina - **MANBID** - Manilkara bidentata - **PREMON** - Prestoea montana - **SCHMOR** - Schefflera morototoni - **SLOBER** - Sloanea berteriana - **TABHET** - Tabebuia heterophylla - **PALRIP** - Palicourea riparia - For more details on methods and variables see each individual dataset: - Canopy Trimming Experiment (CTE) Litterfall: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=162](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=162) - Litterfall in tabonuco (subtropical wet) forest in the Luquillo Experimental Forest, Puerto Rico (MRCE Litterfall data): [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=111](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=111) - Rainfall at El Verde Field Station, Rio Grande, Puerto Rico since 1975: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=14](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=14) - Maximum temperature at El Verde Field Station, Rio Grande, Puerto Rico since October 1992: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=16](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=16) - Minimum temperature at El Verde Field Station, Rio Grande, Puerto Rico since 1975: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=17](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=17) - Chemistry of stream water from the Luquillo Mountains, Quebrada Sonadora and Quebrada Prieta: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=20](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=20) - Shrimp populations in Quebrada Prieta (Pools 0, 8, 9, 15) (El Verde): [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=54](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=54) - Meteorological data from El Verde Field Station: NADP Tower: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=127](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=127) - Chemistry of rainfall and throughfall from El Verde and Bisley: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=174](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=174) - Phenologies of the Tabonuco Forest trees and shrubs: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=88](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=88) - Prieta streams - Discharge and water level: [https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=182](https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-luq&identifier=182) We would like to acknowledge the contributions of all those who have worked in the Luquillo LTER over the course of its 36 year and counting history. The LUQ LTER thanks you for your contribution. Code for generating this signature dataset are available on github here: [https://github.com/miguelcleon/LUQ-LTER-signature-dataset](https://github.com/miguelcleon/LUQ-LTER-signature-dataset) Support for this work was provided by grants BSR-8811902, DEB-9411973, DEB-9705814 , DEB-0080538, DEB-0218039 , DEB-0620910 , DEB-1239764, DEB-1546686, and DEB-1831952 from the National Science Foundation to the University of Puerto Rico as part of the Luquillo Long-Term Ecological Research Program. Additional support was provided by the USDA Forest Service International Institute of Tropical Forestry and the University of Puerto Rico. 

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