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Arctic cyclones are key drivers of sea ice and ocean variability. During the 2019–2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, joint observations of the coupled air‐ice‐ocean system were collected at multiple spatial scales. Here, we present observations of a strong mid‐winter cyclone that impacted the MOSAiC site as it drifted in the central Arctic pack ice. The sea ice dynamical response showed spatial structure at the scale of the evolving and translating cyclonic wind field. Internal ice stress and ocean stress play significant roles, resulting in timing offsets between the atmospheric forcing and the ice response and post‐cyclone inertial ringing in the ice and ocean. Ice motion in response to the wind field then forces the upper ocean currents through frictional drag. The strongest impacts to the sea ice and ocean from the passing cyclone occur as a result of the surface impacts of a strong atmospheric low‐level jet (LLJ) behind the trailing cold front and changing wind directions between the warm‐sector LLJ and post cold‐frontal LLJ. Impacts of the cyclone are prolonged through the coupled ice‐ocean inertial response. Local impacts of the approximately 120 km wide LLJ occur over a 12 hr period or less and at scales of a kilometer to a few tens of kilometers, meaning that these impacts occur at combined smaller spatial scales and faster time scales than most satellite observations and coupled Earth system models can resolve. Plain Language Summary: Arctic winter cyclones are an important part of the Arctic climate system. Yet, due to sparse observations, processes of the coupled sea ice‐ocean response to cyclones are not fully understood. During the 2019–2020 Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, observations of the atmosphere, sea ice, and ocean were collected at a range of spatial scales. Here, we describe the atmospheric structure and coupled ice‐ocean response to a strong winter cyclone using data from surface weather stations, weather balloons, radar, and a weather model. We then describe the sea ice motion using a large set of global positioning system buoys and ice radar images. Finally, we examine the upper ocean currents and structure using ocean buoy data. The most important part of the storm structure for the sea ice is the development of an atmospheric low‐level jet (LLJ), a narrow region of fast‐moving air that eventually circles around the storm. The sudden change in ice drift speed at the time that the LLJ passes overhead enhances motion of the ice and ocean. Periodic currents in the ocean initiated by the sudden wind change of the LLJ continue for days following the passage of the storm, prolonging its effects. Key Points: A strong cyclone crossed the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) in midwinter 2020Detailed, multi‐platform observations enable characterization of coupled air‐ice‐ocean interactions during the passage of the cycloneThe development of a low‐level atmospheric jet is a key factor in the spatially and temporally varying sea ice‐ocean response to the storm [ABSTRACT FROM AUTHOR]

In nature, organisms are exposed to variable environmental conditions that impact their performance and fitness. Despite the ubiquity of environmental variability, substantial knowledge gaps in our understanding of organismal responses to nonconstant thermal regimes remain. In the present study, using zebrafish (Danio rerio) as a model organism, we applied geometric morphometric methods to examine how challenging but ecologically realistic diel thermal fluctuations experienced during different life stages influence adult body shape, size, and condition. Zebrafish were exposed to either thermal fluctuations (22–32°C) or a static optimal temperature (27°C) sharing the same thermal mean during an early period spanning embryonic and larval ontogeny (days 0–30), a later period spanning juvenile and adult ontogeny (days 31–210), or a combination of both. We found that body shape, size, and condition were affected by thermal variability, but these plasticity‐mediated changes were dependent on the timing of ontogenetic exposure. Notably, after experiencing fluctuating temperatures during early ontogeny, females displayed a deeper abdomen while males displayed an elongated caudal peduncle region. Moreover, males displayed beneficial acclimation of body condition under lifelong fluctuating temperature exposure, whereas females did not. The present study, using ecologically realistic thermal regimes, provides insight into the timing of environmental experiences that generate phenotypic variation in zebrafish. [ABSTRACT FROM AUTHOR]

Estuaries represent the primary linkage between the terrestrial and marine carbon cycles, and estuarine processing of riverine and coastal carbon plays a disproportionately large role in the global carbon cycle relative to the small areal extent of the estuarine environments. However, knowledge of the rate of organic carbon deposition and burial in estuarine sediments is lacking at regional scales. Data on surficial total organic carbon, linear sedimentation, and bulk density of estuarine sediments were compiled and categorized via a cluster analysis in order to estimate carbon deposition within the contiguous United States (CONUS). The cluster analysis broadly grouped estuaries by geography, but exceptions to geographic clustering highlighted differences within regions. A transfer function from deposition to burial based on linear sedimentation rate was used to estimate burial efficiency, and thus the rate of carbon burial within each cluster. We estimate organic carbon deposition rates within CONUS estuarine sediments to be 161 [121–217, 95% confidence] g C/m2/yr with a burial efficiency estimated at 38 [34–42, 95% confidence] %, which yields a long‐term burial rate of 64 [44–97, 95% confidence] g C/m2/yr. Spatially integrated organic deposition and burial rates are 11.3 [8.5–15.2, 95% confidence] and 4.5 [3.1–6.8, 95% confidence] Tg C/yr, respectively. Our findings allow a more thorough understanding of coastal carbon cycling, which is critical for both management purposes as well as for the assessment of the role of estuaries in past and future climate change. Plain Language Summary: Estuaries are diverse ecosystems located at the coastal mouth of rivers or within embayments, where terrestrial and marine environments meet. Estuaries tend to be highly productive and provide many critical ecosystem services for their communities. Carbon‐based material delivered primarily by rivers or produced by aquatic organisms is deposited within the sediments of estuaries. Organisms in sediments consume some of the deposited material and respire it principally as carbon dioxide. However, a portion is buried within deeper sediments and is removed from the contemporary carbon cycle. The rate of material deposited and ultimately buried can influence the function of the estuary as well as its relation to communities and the adjacent coastal ecosystems. On longer time scales (many thousands of years), this removal can also influence the global carbon cycle. We grouped estuaries based on their physical and chemical characteristics and estimated sediment deposition and burial rates for the contiguous United States, where we found that approximately 40% of deposited material was buried within sediments. Key Points: Sedimentation processes in estuaries within the contiguous United States are estimated to deposit 11.3 [8.5–15.2, 95% confidence] Tg of carbon per yearRemineralization liberates a significant portion of deposited carbon, yielding centennial‐scale burial of 4.5 [3.1–6.8, 95% confidence] Tg carbon per yearEstuaries of the contiguous United States are classified into six clusters based on geospatial and biogeochemical characteristics using k‐means analysis [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) absorption and fluorescence properties were investigated for seawater samples collected from the polar mixed layer (0–30 m) of the Canada Basin in 2010–2012. Sea ice concentration as well as fractions of meteoric and sea ice meltwater (fMW and fSIM) calculated from oxygen isotope ratio (δ18O) were applied to assess the importance of discrete freshwater inputs to the distribution of DOM. Parallel factor analysis identified four humic‐like (C1‐2 and C4‐C5) and one protein‐like (C3) fluorescent components in 380 excitation‐emission matrix spectra. Surprisingly, despite different sea ice cover and biological regimes, DOM composition was largely homogeneous spanning these annual surveys. A strong and reoccurring coastal influence on DOM absorption and humic‐like DOM was observed each year and was particularly pronounced during the summer 2011 survey. Enrichment of DOM humic signal (C1, C2, and C4) in brine‐rich (fSIM < 0) waters relative to sea ice melt‐dominated waters (fSIM > 0; p < 0.05) was found during 2011 and 2012 in the offshore region (>76°N) where coastal influences were minimal (fMW < 0.1). Similar fSIM < 0 were found for 2011 and 2012, either when considering the Canada Basin as a whole or the offshore region (>76°N) exclusively, which could imply that brine formation influenced humic signals in polar mixed layer seawater. Findings herein highlight that future projected changes in freshwater sources and brine production in the Canada Basin will likely implicate the distribution and composition of DOM. Plain Language Summary: In this paper we showed that despite different sea ice cover in summer‐early fall, the average levels and composition of colored dissolved organic matter remained relatively unchanged in surface waters in the Canada Basin in 2010–2012. Only the northwest region experiencing strong brine rejection showed elevated humic signals. We also suggest to use the 140°W line as reference for dissolved organic matter monitoring in the Canada Basin in future studies. Key Points: The absorption and fluorescing characteristics of DOM were relatively homogenous in the Canada Basin in summer/early fall 2010–2012The humic‐like components were more abundant in the brine‐rich mixed layerThe 140°W line is proposed for monitoring DOM compositional changes in the Canada Basin [ABSTRACT FROM AUTHOR]

High latitude warming and permafrost thaw will expose vast stores of deep soil organic carbon (SOC) to decomposition. Thaw also changes water movement causing either wetter or drier soil. The fate of deep SOC under different thaw and moisture conditions is unclear. We measured weekly growing‐season δ13C of ecosystem respiration (Recoδ13C) across thaw and moisture conditions (Shallow‐Dry; Deep‐Dry; Deep‐Wet) in a soil warming manipulation. Deep SOC loss was inferred from known δ13C signatures of plant shoot, root, surface soil, and deep soil respiration. In addition, a 2‐year‐old vegetation removal treatment (No Veg) was used to isolate surface and deep SOC decomposition contributions to Reco. In No Veg, seasonal Recoδ13C indicated that deep SOC loss increased as the soil column thawed, while in vegetated areas, root contributions appeared to dominate Reco. The Recoδ13C differences between Shallow‐Dry and Deep‐Dry were significant but surprisingly small. This most likely suggests that, under dry conditions, soil warming stimulates root and surface SOC respiration with a negative 13C signature that opposes the more positive 13C signal from increased deep SOC respiration. In Deep‐Wet conditions, Recoδ13C suggests reduced deep SOC loss but could also reflect altered diffusion or methane (CH4) dynamics. Together, these results demonstrate that frequent Recoδ13C measurements can detect deep SOC loss and that plants confound the signal. In future studies, soil profile δ13C measurements, vegetation removal across thaw gradients, and isotopic effects of CH4 dynamics could further deconvolute deep SOC loss via surface Reco. Plain Language Summary: Carbon (C) stored in permafrost soil is like a global savings account that keeps C out of the atmosphere. Arctic warming makes permafrost soil C vulnerable to microbial decomposition, and C released to the atmosphere would accelerate global warming. In this study we used 13C isotopes, which function like molecular fingerprints, to detect permafrost soil C decomposition from a soil warming experiment that doubled the thawed soil volume and changed soil moisture conditions. We found that permafrost soil C decomposition was best detected when vegetation was removed. Deeper thaw depth had only a small effect on isotopic signatures possibly because the signal from higher permafrost soil C decomposition was overwhelmed by a simultaneous increase in surface soil decomposition and respiration from plants. In wet areas, the isotopic signal changed which could imply reduced permafrost soil C decomposition. In wet areas, methane cycling might also change the isotope signature. We conclude that seasonal 13C sampling could be useful for detecting permafrost soil C decomposition if combined with measurements that can isolate contributions from surface soil, roots, and methane cycling. Developing methods that make it easier to assess permafrost soil C decomposition is critical for estimating the balance of our global C savings account. Key Points: Vegetation removal shows deep soil C loss does increase with thaw, and plant contributions to Reco dilute delta13C signals from deep soilSeasonal Reco delta13C suggests warming and permafrost thaw may stimulate deep soil respiration and also surface soil and plant respirationWet conditions may reduce deep soil C loss, with possible effects of altered diffusion dynamics and increased methane cycling on delta13C [ABSTRACT FROM AUTHOR]

Background Early risk factors for poor child outcomes are well established, and some group parenting programmes have demonstrated good outcomes for children under 3 years of age. This randomized controlled trial evaluated the effectiveness of the Incredible Years® Toddler Parenting Programme with parents of 1-year-old and 2-year-old children recruited by staff in disadvantaged Flying Start areas across Wales. Methods Eighty-nine families with a child aged between 12 and 36 months at baseline participated in a pragmatic community-based trial of the programme in eight Flying Start areas. Outcomes were measured at baseline, 6 months and 12 months using measures of parental mental health, competence, child behaviour, child development, home environment and blinded-observation of parent-child interactions. Results Significant intervention group improvements were found in parental mental well-being and observed praise at 6 months. Significant improvements for the intervention group at 12 months included child development, home environment and parental depression. Conclusion The study provides preliminary evidence for programme attendance. [ABSTRACT FROM AUTHOR]

We investigated soil organic carbon (SOC) characteristics in three forests along a north-south transect in Sweden where these forest types cover about 69% of the landscape. There was variation in 14C ages, and the median ages ranged from about 25 to > 2500 cal BP in SOC. Although total SOC and nitrogen (N) contents decreased, stable carbon isotope and humification indices increased with depth. These progressive changes with depth and age were related to degradation. The δ13C values and specific biomarkers indicated that organic carbon was primarily from C3 plants. Biomarkers were effective in distinguishing OC input from specific sources (i.e. angiosperms, gymnosperms and grasses). A sharp decrease in biomarkers with depth indicated degradation of OC in the upper soil horizon, and limited contribution in the subsoil towards the stabilization of SOC. The sharp decrease in carbon stocks and 14C age in the soil OC pool with increasing soil depth, and quite large values for the percentage of modern carbon, suggested a decrease in SOC pools. Overall, these results showed that carbon sequestration in high latitude forests was small, and their role as potential carbon sinks needs to be reassessed. Highlights We studied soil organic carbon (SOC) characteristics in Swedish boreal and temperate forests., The decline of SOC with depth contributes little to carbon sequestration in deeper soil horizons., Soil degradation causes a decline in total carbon, nitrogen, alkanes and lignin with depth and age., The role of these forests as carbon sinks needs to be reassessed because of degradation of SOC. [ABSTRACT FROM AUTHOR]

Background Parental language is associated with children's later language development. Parenting programmes, based on social learning theory, enhance a range of parenting behaviours, yet there is limited evidence for their effect on parental language. Aim To assess the benefits of a behavioural-based parenting programme, which features components of language and communication, to enhance parental language. Method Parents of toddlers, aged 12 to 36 months, were recruited from eight Flying Start early intervention centres across Wales. Participants were randomised 2:1 either to a parenting programme ( n = 60) or to a wait-list control group ( n = 29). Researchers were blind to participant allocation throughout the trial. Fifteen-minute video-recorded observations of parents and children interacting during free-play, both at a pre-intervention and at 6-month follow-up, provided the data for the study. Five observed measures of parental language were assessed; quantity and variety, encouraging, critical, child-led and parent led interactions. Intervention The Incredible Years Parent- Toddler Programme ( IYPTP) is a 12-week group-based behavioural intervention that teaches effective relationship and behavioural management skills including social, emotional and persistence coaching to enable parents to better support their children's development. Results Of 89 dyads that completed pre-intervention assessments 81 (54 intervention and 27 control) met the criteria for the current study. Intention to treat analysis indicated that child-led language interactions significantly benefited from the intervention [regression coefficient ( B) = −1.44, 95% confidence intervals ( CI) = −2.59 to −0.29, P = 0.015, effect size ( ES) = 0.47] and a positive trend for encouraging language in favour of the intervention sample was evident. Per-protocol sample analysis replicated these findings with encouraging language reaching statistical significance ( B = 1.07, 95% CI = 0.11 to 2.03, P = 0.03, ES = 0.52). No further benefits were evident. Conclusions The IYPTP has limited evidence as an effective programme for enhancing some aspects of parental language. [ABSTRACT FROM AUTHOR]

Natural environmental change has produced countless opportunities for species to disperse into and persist in habitats where they previously did not exist. Introduction and stocking programmes have facilitated similar sorts of colonization opportunities across considerably greater geographical scales and often in much shorter periods of time. Even though the mechanism of colonization differs, the result can be the same: evolutionary change in the colonizing population in response to novel selection pressures. As a consequence, some human-mediated fish transfers have unintentionally yielded novel research opportunities to study how phenotypes and genes interact with their environment and affect ecological and evolutionary change. The primary purpose here is to explore how work, directly or indirectly involved with human-mediated transfers, has unintentionally yielded novel research and research opportunities in fish ecology and evolution. Insights have produced new knowledge or altered previously held perceptions on topics such as local adaptation, rate of evolutionary change, phenotypic plasticity, alternative reproductive strategies, population structure and colonization probability. Well-documented stocking programmes, especially in terms of history, numbers and original population sources, can provide highly fertile ground for generating further insights on the ecology and evolution of fishes and of the factors likely to influence the success of conservation-based, restoration programmes. [ABSTRACT FROM AUTHOR]