Asynchronous warming and δ18O evolution of deep Atlantic water masses during the last deglaciation.

The large-scale reorganization of deep ocean circulation in the Atlantic involving changes in North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) played a critical role in regulating hemispheric and global climate during the last deglaciation. However, changes in the relative contributions of NADW and AABW and their properties are poorly constrained by marine records, including δ18O of benthic foraminiferal calcite (δ18Oc). Here, we use an isotope-enabled ocean general circulation model with realistic geometry and forcing conditions to simulate the deglacial water mass and δ18O evolution. Model results suggest that, in response to North Atlantic freshwater forcing during the early phase of the last deglaciation, NADW nearly collapses, while AABW mildly weakens. Rather than reflecting changes in NADW or AABW properties caused by freshwater input as suggested previously, the observed phasing difference of deep δ18Oc likely reflects early warming of the deep northern North Atlantic by ∼1.4 °C, while deep Southern Ocean temperature remains largely unchanged. We propose a thermodynamic mechanism to explain the early warming in the North Atlantic, featuring a strong middepth warming and enhanced downward heat flux via vertical mixing. Our results emphasize that the way that ocean circulation affects heat, a dynamic tracer, is considerably different from how it affects passive tracers, like δ18O, and call for caution when inferring water mass changes from δ18Oc records while assuming uniform changes in deep temperatures.

A mixed methods evaluation of family-driven care implementation in juvenile justice agencies in Georgia.

BACKGROUND: Improving family engagement in juvenile justice (JJ) system behavioral health services is a high priority for JJ systems, reform organizations, and family advocacy groups across the United States. Family-driven care (FDC) is a family engagement framework used by youth-serving systems to elevate family voice and decision-making power at all levels of the organization. Key domains of a family-driven system of care include: 1) identifying and involving families in all processes, 2) informing families with accurate, understandable, and transparent information, 3) collaborating with families to make decisions and plan treatments, 4) responding to family diversity and inclusion, 5) partnering with families to make organizational decisions and policy changes, 6) providing opportunities for family peer support, 7) providing logistical support to help families overcome barriers to participation, and 8) addressing family health and functioning. FDC enhances family participation, empowerment, and decision-making power in youth services; ultimately, improving youth and family behavioral health outcomes, enhancing family-child connectedness, and reducing youth recidivism in the JJ setting. METHODS: We evaluated staff-perceived adoption of the eight domains of FDC across detention and community services agencies in the state of Georgia. We collected mixed methods data involving surveys and in-depth qualitative interviews with JJ system administrators, staff, and practitioners between November 2021- July 2022. In total, 140 individuals from 61 unique JJ agencies participated in surveys; and 16 JJ key informants participated in qualitative interviews. RESULTS: FDC domains with the highest perceived adoption across agencies included identifying and involving families, informing families, collaborative decision-making and treatment planning, and family diversity and inclusion. Other domains that had mixed or lower perceived adoption included involving families in organizational feedback and policy making, family peer support, logistical support, and family health and functioning. Adoption of FDC domains differed across staff and organizational characteristics. CONCLUSIONS: Findings from this mixed methods assessment will inform strategic planning for the scale-up of FDC strategies across JJ agencies in the state, and serve as a template for assessing strengths and weaknesses in the application of family engagement practices in systems nationally.

Enhanced simulated early 21st century Arctic sea ice loss due to CMIP6 biomass burning emissions.

The mechanisms underlying decadal variability in Arctic sea ice remain actively debated. Here, we show that variability in boreal biomass burning (BB) emissions strongly influences simulated Arctic sea ice on multidecadal time scales. In particular, we find that a strong acceleration in sea ice decline in the early 21st century in the Community Earth System Model version 2 (CESM2) is related to increased variability in prescribed BB emissions in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) through summertime aerosol-cloud interactions. Furthermore, we find that more than half of the reported improvement in sea ice sensitivity to CO2 emissions and global warming from CMIP5 to CMIP6 can be attributed to the increased BB variability, at least in the CESM. These results highlight a new kind of uncertainty that needs to be considered when incorporating new observational data into model forcing while also raising questions about the role of BB emissions on the observed Arctic sea ice loss.