The increasingly dominant role of climate change on length of day variations.

The melting of ice sheets and global glaciers results in sea-level rise, a pole-to-equator mass transport increasing Earth's oblateness and resulting in an increase in the length of day (LOD). Here, we use observations and reconstructions of mass variations at the Earth's surface since 1900 to show that the climate-induced LOD trend hovered between 0.3 and 1.0 ms/cy in the 20th century, but has accelerated to 1.33 [Formula: see text] 0.03 ms/cy since 2000. We further show that surface mass transport fully explains the accelerating trend in the Earth oblateness observed in the past three decades. We derive an independent measure of the decreasing LOD trend induced by Glacial Isostatic Adjustment (GIA) of [Formula: see text]0.80 [Formula: see text] 0.10 ms/cy, which provides a constraint for the mantle viscosity. The sum of this GIA rate and lunar tidal friction fully explains the secular LOD trend that is inferred from the eclipse record in the past three millennia prior to the onset of contemporary climate change. Projections of future climate warming under high emission scenarios suggest that the climate-induced LOD rate may reach 2.62 [Formula: see text] 0.79 ms/cy by 2100, overtaking lunar tidal friction as the single most important contributor to the long-term LOD variations.

The causes of sea-level rise since 1900.

The rate of global-mean sea-level rise since 1900 has varied over time, but the contributing factors are still poorly understood1. Previous assessments found that the summed contributions of ice-mass loss, terrestrial water storage and thermal expansion of the ocean could not be reconciled with observed changes in global-mean sea level, implying that changes in sea level or some contributions to those changes were poorly constrained2,3. Recent improvements to observational data, our understanding of the main contributing processes to sea-level change and methods for estimating the individual contributions, mean another attempt at reconciliation is warranted. Here we present a probabilistic framework to reconstruct sea level since 1900 using independent observations and their inherent uncertainties. The sum of the contributions to sea-level change from thermal expansion of the ocean, ice-mass loss and changes in terrestrial water storage is consistent with the trends and multidecadal variability in observed sea level on both global and basin scales, which we reconstruct from tide-gauge records. Ice-mass loss-predominantly from glaciers-has caused twice as much sea-level rise since 1900 as has thermal expansion. Mass loss from glaciers and the Greenland Ice Sheet explains the high rates of global sea-level rise during the 1940s, while a sharp increase in water impoundment by artificial reservoirs is the main cause of the lower-than-average rates during the 1970s. The acceleration in sea-level rise since the 1970s is caused by the combination of thermal expansion of the ocean and increased ice-mass loss from Greenland. Our results reconcile the magnitude of observed global-mean sea-level rise since 1900 with estimates based on the underlying processes, implying that no additional processes are required to explain the observed changes in sea level since 1900.

Understanding of Contemporary Regional Sea-Level Change and the Implications for the Future.

Global sea level provides an important indicator of the state of the warming climate, but changes in regional sea level are most relevant for coastal communities around the world. With improvements to the sea-level observing system, the knowledge of regional sea-level change has advanced dramatically in recent years. Satellite measurements coupled with in situ observations have allowed for comprehensive study and improved understanding of the diverse set of drivers that lead to variations in sea level in space and time. Despite the advances, gaps in the understanding of contemporary sea-level change remain and inhibit the ability to predict how the relevant processes may lead to future change. These gaps arise in part due to the complexity of the linkages between the drivers of sea-level change. Here we review the individual processes which lead to sea-level change and then describe how they combine and vary regionally. The intent of the paper is to provide an overview of the current state of understanding of the processes that cause regional sea-level change and to identify and discuss limitations and uncertainty in our understanding of these processes. Areas where the lack of understanding or gaps in knowledge inhibit the ability to provide the needed information for comprehensive planning efforts are of particular focus. Finally, a goal of this paper is to highlight the role of the expanded sea-level observation network-particularly as related to satellite observations-in the improved scientific understanding of the contributors to regional sea-level change.

Role of Social Support on Mental Health Among Resettled Bhutanese Refugees in Ohio.

More than 80% of Bhutanese refugees have resettled in the United States. Social support can lead to better resilience against poor mental health outcomes among this population. This study assessed the role of social support on mental health among the resettled Bhutanese adults in Central Ohio. This study used data collected by the Ohio Department of Mental Health and Addiction Services on 200 Bhutanese adults in Columbus. Social support was measured using a 12-item perceived social support scale. The 25-item Hopkins Symptoms Checklist was used to quantify depression and anxiety experienced in the past month. One-in-three participants reported mental health problems. Compared to participants with high social support, those with medium (OR 5.28, 95% CI 2.09-13.37) and low social support (OR 10.94, 95% CI 2.53-47.33) had more than 5- and 10-fold increased odds of mental health problems respectively. Future studies could further explore the role of social support on mental health during relocation, resettlement, and acculturation processes.

Demographic and Psychosocial Factors Associated with Suicidal Ideation among Resettled Bhutanese Refugees.

This study aims to identify socio-demographic and psychosocial characteristics associated with the suicidal ideation among resettled Bhutanese refugees in the United States. Structured interviews were conducted with 200 resettled Bhutanese refugees in Columbus, Ohio. Multivariable logistic regression analysis was conducted to identify variables associated with suicidal ideation. Most participants were male (59.0%), married (77.9%), 55% reported no formal education, 12% were of Dalit ("lower") caste, and 6.2% reported suicidal ideation. Multivariable logistic regression analysis included four variables that were significant at p < 0.05 in bivariate analyses: caste, post-settlement difficulties, mental health diagnosis, and social support. Higher odds of suicidal ideation were linked to mental health diagnosis [adjusted odds ratio (AOR): 8.7], low social support (AOR: 23.6), and post-settlement difficulties (AOR: 1.4). In the multivariable model, untouchable caste had elevated odds of suicidal ideation but statistically not significant. Culturally competent mental health services are needed to support individuals at risk for suicidal ideation.

The Ohio Cross-Cultural Tobacco Control Alliance: understanding and eliminating tobacco-related disparities through the integration of science, practice, and policy.

OBJECTIVES: We examined the development of a process designed to eliminate tobacco-related disparities in the state of Ohio and described how a cross-cultural work group used a multicomponent community planning process to develop capacity to address such disparities. METHODS: The community development model was used as a guide in the planning process. We employed a case study, focus groups, and telephone interviews to assess the process and collect data on tobacco use and awareness. We also employed the appreciative inquiry framework to create the organizational design for the Ohio Cross-Cultural Tobacco Control Alliance (CCTCA), which was formed from the cross-cultural work group and charged with addressing tobacco-related disparities in the state. RESULTS: Data on tobacco use and awareness were collected from 13 underserved populations. At the end of the planning process, the CCTCA was initiated along with structural capacity to serve as a new program incubator highlighting tobacco use and awareness levels in these populations. CONCLUSIONS: The CCTCA appeared to be an effective way to begin mobilizing agencies serving underserved populations by providing an operational structure to address tobacco-related disparities. The alliance also successfully implemented culturally competent community-based programs and policies to help eliminate disparities.

Tracking the weight of Hurricane Harvey's stormwater using GPS data.

On 26 August 2017, Hurricane Harvey struck the Gulf Coast as a category four cyclone depositing ~95 km3 of water, making it the wettest cyclone in U.S. HISTORY: Water left in Harvey's wake should cause elastic loading and subsidence of Earth's crust, and uplift as it drains into the ocean and evaporates. To track daily changes of transient water storage, we use Global Positioning System (GPS) measurements, finding a clear migration of subsidence (up to 21 mm) and horizontal motion (up to 4 mm) across the Gulf Coast, followed by gradual uplift over a 5-week period. Inversion of these data shows that a third of Harvey's total stormwater was captured on land (25.7 ± 3.0 km3), indicating that the rest drained rapidly into the ocean at a rate of 8.2 km3/day, with the remaining stored water gradually lost over the following 5 weeks at ~1 km3/day, primarily by evapotranspiration. These results indicate that GPS networks can remotely track the spatial extent and daily evolution of terrestrial water storage following transient, extreme precipitation events, with implications for improving operational flood forecasts and understanding the response of drainage systems to large influxes of water.

Should coastal planners have concern over where land ice is melting?

There is a general consensus among Earth scientists that melting of land ice greatly contributes to sea-level rise (SLR) and that future warming will exacerbate the risks posed to human civilization. As land ice is lost to the oceans, both the Earth's gravitational and rotational potentials are perturbed, resulting in strong spatial patterns in SLR, termed sea-level fingerprints. We lack robust forecasting models for future ice changes, which diminishes our ability to use these fingerprints to accurately predict local sea-level (LSL) changes. We exploit an advanced mathematical property of adjoint systems and determine the exact gradient of sea-level fingerprints with respect to local variations in the ice thickness of all of the world's ice drainage systems. By exhaustively mapping these fingerprint gradients, we form a new diagnosis tool, henceforth referred to as gradient fingerprint mapping (GFM), that readily allows for improved assessments of future coastal inundation or emergence. We demonstrate that for Antarctica and Greenland, changes in the predictions of inundation at major port cities depend on the location of the drainage system. For example, in London, GFM shows LSL that is significantly affected by changes on the western part of the Greenland Ice Sheet (GrIS), whereas in New York, LSL change predictions are greatly sensitive to changes in the northeastern portions of the GrIS. We apply GFM to 293 major port cities to allow coastal planners to readily calculate LSL change as more reliable predictions of cryospheric mass changes become available.

Climate-driven polar motion: 2003-2015.

Earth's spin axis has been wandering along the Greenwich meridian since about 2000, representing a 75° eastward shift from its long-term drift direction. The past 115 years have seen unequivocal evidence for a quasi-decadal periodicity, and these motions persist throughout the recent record of pole position, in spite of the new drift direction. We analyze space geodetic and satellite gravimetric data for the period 2003-2015 to show that all of the main features of polar motion are explained by global-scale continent-ocean mass transport. The changes in terrestrial water storage (TWS) and global cryosphere together explain nearly the entire amplitude (83 ± 23%) and mean directional shift (within 5.9° ± 7.6°) of the observed motion. We also find that the TWS variability fully explains the decadal-like changes in polar motion observed during the study period, thus offering a clue to resolving the long-standing quest for determining the origins of decadal oscillations. This newly discovered link between polar motion and global-scale TWS variability has broad implications for the study of past and future climate.