More Like this

1. Common Era sea-level budgets along the U.S. Atlantic coast

   https://doi.org/10.1038/s41467-021-22079-2  

   Walker, Jennifer S.; Kopp, Robert E.; Shaw, Timothy A.; Cahill, Niamh; Khan, Nicole S.; Barber, Donald C.; Ashe, Erica L.; Brain, Matthew J.; Clear, Jennifer L.; Corbett, D. Reide; et al (December 2021, Nature Communications)

   null (Ed.)

   Abstract Sea-level budgets account for the contributions of processes driving sea-level change, but are predominantly focused on global-mean sea level and limited to the 20th and 21st centuries. Here we estimate site-specific sea-level budgets along the U.S. Atlantic coast during the Common Era (0–2000 CE) by separating relative sea-level (RSL) records into process-related signals on different spatial scales. Regional-scale, temporally linear processes driven by glacial isostatic adjustment dominate RSL change and exhibit a spatial gradient, with fastest rates of rise in southern New Jersey (1.6 ± 0.02 mm yr −1 ). Regional and local, temporally non-linear processes, such as ocean/atmosphere dynamics and groundwater withdrawal, contributed between −0.3 and 0.4 mm yr −1 over centennial timescales. The most significant change in the budgets is the increasing influence of the common global signal due to ice melt and thermal expansion since 1800 CE, which became a dominant contributor to RSL with a 20th century rate of 1.3 ± 0.1 mm yr −1 . 

   more » « less
2. Timing of emergence of modern rates of sea-level rise by 1863

   https://doi.org/10.1038/s41467-022-28564-6  

   Walker, Jennifer S.; Kopp, Robert E.; Little, Christopher M.; Horton, Benjamin P. (February 2022, Nature Communications)

   Abstract Sea-level rise is a significant indicator of broader climate changes, and the time of emergence concept can be used to identify when modern rates of sea-level rise emerged above background variability. Yet a range of estimates of the timing persists both globally and regionally. Here, we use a global database of proxy sea-level records of the Common Era (0–2000 CE) and show that globally, it is very likely that rates of sea-level rise emerged above pre-industrial rates by 1863 CE (P= 0.9; range of 1825 [P= 0.66] to 1873 CE [P= 0.95]), which is similar in timing to evidence for early ocean warming and glacier melt. The time of emergence in the North Atlantic reveals a distinct spatial pattern, appearing earliest in the mid-Atlantic region (1872–1894 CE) and later in Canada and Europe (1930–1964 CE). Regional and local sea-level changes occurring over different time periods drive the spatial pattern in emergence, suggesting regional processes underlie centennial-timescale sea-level variability over the Common Era. 

   more » « less
3. Regional Occupancy Is Negatively Related to Richness Across Time and Space

   https://doi.org/10.1111/geb.70009  

   Shipley, B_R; Saupe, E_E (February 2025, Global Ecology and Biogeography)

   ABSTRACT AimBiological diversity is shaped by processes occurring at different spatial and temporal scales. However, the direct influence of the spatial and temporal scale on patterns of occupancy is still understudied. Today, occupancy is often negatively correlated with species richness, but it is unknown whether this relationship is scale dependent and consistent through time. Here, we use datasets of contemporary and paleontological communities to explore the occupancy‐richness relationship across space and time, examining how scale influences this relationship. LocationVarying spatial extents with global coverage. TimeVaries from 7 mya to 2021 CE. Taxaforaminifera, mammals, birds, fish, and plants. MethodsWe gathered datasets spanning different spatial, temporal, and taxonomic extents. We binned each dataset into distinct time periods and spatially subsampled them into regional pools of varying sizes. We calculated regional occupancy and richness for each pool, measuring the strength of the relationship between the two. Using linear mixed models, we related the occupancy‐richness relationship to the size of the regional pools, overall species richness, and climatic changes through time. ResultsWe observed nearly ubiquitous negative occupancy‐richness relationships across taxa, spatial scale, and time. The size of the regional pools and time bins had no consistent effects on the strength of the relationship, but the strength of the negative relationship varied substantially among taxa, with foraminifera and North American pollen showing weaker relationships than mammals and birds. Changes in this relationship through time were not driven by climatic perturbations but by the species richness observed across all regional pools. ConclusionsPatterns of regional richness and occupancy are consistently negatively related and independent of spatial and temporal scale and of direct climatic changes. However, differences in the ecology of species (e.g., dispersal ability) and changes in biodiversity and community composition through time may cause fluctuations in the strength of the occupancy‐richness relationship. 

   more » « less
4. Spatial and temporal variation of ecosystem properties at macroscales

   https://doi.org/10.1111/ele.13346  

   Soranno, Patricia A.; Wagner, Tyler; Collins, Sarah M.; Lapierre, Jean‐Francois; Lottig, Noah R.; Oliver, Samantha K.; Knops, ed., Johannes (July 2019, Ecology Letters)

   Abstract Although spatial and temporal variation in ecological properties has been well‐studied, crucial knowledge gaps remain for studies conducted at macroscales and for ecosystem properties related to material and energy. We test four propositions of spatial and temporal variation in ecosystem properties within a macroscale (1000 km's) extent. We fit Bayesian hierarchical models to thousands of observations from over two decades to quantify four components of variation – spatial (local and regional) and temporal (local and coherent); and to model their drivers. We found strong support for three propositions: (1) spatial variation at local and regional scales are large and roughly equal, (2) annual temporal variation is mostly local rather than coherent, and, (3) spatial variation exceeds temporal variation. Our findings imply that predicting ecosystem responses to environmental changes at macroscales requires consideration of the dominant spatial signals at both local and regional scales that may overwhelm temporal signals. 

   more » « less
5. The Historical Development of Large‐Scale Paleoclimate Field Reconstructions Over the Common Era

   https://doi.org/10.1029/2022RG000782  

   Smerdon, Jason E.; Cook, Edward R.; Steiger, Nathan J. (October 2023, Reviews of Geophysics)

   Abstract Climate field reconstructions (CFRs) combine modern observational data with paleoclimatic proxies to estimate climate variables over spatiotemporal grids during time periods when widespread observations of climatic conditions do not exist. The Common Era (CE) has been a period over which many seasonally‐ and annually‐resolved CFRs have been produced on regional to global scales. CFRs over the CE were first produced in the 1970s using dendroclimatic records and linear regression‐based approaches. Since that time, many new CFRs have been produced using a wide range of proxy data sets and reconstruction techniques. We assess the early history of research on CFRs for the CE, which provides context for our review of advances in CFR research over the last two decades. We review efforts to derive gridded hydroclimatic CFRs over continental regions using networks of tree‐ring proxies. We subsequently explore work to produce hemispheric‐ and global‐scale CFRs of surface temperature using multi‐proxy data sets, before specifically reviewing recently‐developed data assimilation techniques and how they have been used to produce simultaneous reconstructions of multiple climatic fields globally. We then review efforts to develop standardized and digitized databases of proxy networks for use in CFR research, before concluding with some thoughts on important next steps for CFR development. 

   more » « less