Seeking New Insights: A Design Thinking Approach to Persuasive Technology Aimed at Supporting Clients of a Weight Management Program

The application of persuasive technology has been shown to be effective in a weight management context. However, it has been observed that the impact is not as significant as predicted. The aim of this project was to investigate whether a Design Thinking approach could generate new insights that could be used to drive the development of an innovative application to help people on their weight management journey. Findings show that although no radically new user needs were identified, the needs that users did express most pertinently are not effectively met by currently available technology. Further, we examined the Design Thinking approach itself and sought to identify criteria for the design of successful insight gathering activities, through end-user engagement. We summarize these at the end of this paper

Quantifying subtropical North Pacific gyre mixed layer primary productivity from Seaglider observations of diel oxygen cycles

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 42 (2015): 4032–4039, doi:10.1002/2015GL063065.Using autonomous underwater gliders, we quantified diurnal periodicity in dissolved oxygen, chlorophyll, and temperature in the subtropical North Pacific near the Hawaii Ocean Time-series (HOT) Station ALOHA during summer 2012. Oxygen optodes provided sufficient stability and precision to quantify diel cycles of average amplitude of 0.6 µmol kg−1. A theoretical diel curve was fit to daily observations to infer an average mixed layer gross primary productivity (GPP) of 1.8 mmol O2 m−3 d−1. Cumulative net community production (NCP) over 110 days was 500 mmol O2 m−2 for the mixed layer, which averaged 57 m in depth. Both GPP and NCP estimates indicated a significant period of below-average productivity at Station ALOHA in 2012, an observation confirmed by 14C productivity incubations and O2/Ar ratios. Given our success in an oligotrophic gyre where biological signals are small, our diel GPP approach holds promise for remote characterization of productivity across the spectrum of marine environments.The authors acknowledge support from the National Science Foundation (NSF) through an NSF Science and Technology Center, the Center for Microbial Oceanography Research and Education (C-MORE; NSF EF-0424599). D.N. also was supported by NSF (OCE-1129644) and an Independent Study Award from the Woods Hole Oceanographic Institution (WHOI). D.M.K. was also supported by the Gordon and Betty Moore Foundation. WHOI Summer Student Fellow Cole Stites-Clayton, Stanford University, contributed to early stages of Seaglider data analysis and was supported by an NSF REU grant to WHOI (OCE-1156952)

Cross-Basin Comparison of Phosphorus Stress and Nitrogen Fixation in Trichodesmium

We investigated the phosphorus (P) status and N2 fixation rates of Trichodesmium populations from the North Pacific, western South Pacific, and western North Atlantic. Colonies of Trichodesmium were collected and analyzed for endogenous alkaline phosphatase (AP) activity using enzyme-labeled fluorescence ( ELF) and for nitrogenase activity using acetylene reduction. AP hydrolyzes dissolved inorganic phosphate (DIP) from dissolved organic phosphorus and is active in Trichodesmium colonies experiencing P stress. Across multiple stations in the subtropical North and South Pacific, there was low to moderate ELF labeling in Trichodesmium, although labeling was present in other taxa. In contrast, Trichodesmium ELF labeling in the North Atlantic ranged from low to high. Low ELF labeling corresponded with high DIP concentrations while high ELF labeling occurred only at North Atlantic stations with DIP concentrations \u3c = 40 nmol L-1, indicating that Trichodesmium was not experiencing dramatic P stress in the Pacific Ocean while P stress was evident in the western North Atlantic. However, nitrogenase activity was significantly higher in the P-stressed western North Atlantic than in the Pacific Ocean (0.40-1.30 compared to 0.01-0.46 nmol C2H4 h-1 colony-1. These data underscore the differential basin-level importance of P availability to Trichodesmium and suggest that factors other than P are constraining their N2 fixation rates in the Pacific

Volcano impacts on climate and biogeochemistry in a coupled carbon–climate model

Volcanic eruptions induce a dynamical response in the climate system characterized by short-term global reductions in both surface temperature and precipitation, as well as a response in biogeochemistry. The available observations of these responses to volcanic eruptions, such as to Pinatubo, provide a valuable method to compare against model simulations. Here, the Community Climate System Model Version 3 (CCSM3) reproduces the physical climate response to volcanic eruptions in a realistic way, as compared to direct observations from the 1991 eruption of Mount Pinatubo. The model's biogeochemical response to eruptions is smaller in magnitude than observed, but because of the lack of observations, it is not clear why or where the modeled carbon response is not strong enough. Comparison to other models suggests that this model response is much weaker over tropical land; however, the precipitation response in other models is not accurate, suggesting that other models could be getting the right response for the wrong reason. The underestimated carbon response in the model compared to observations could also be due to the ash and lava input of biogeochemically important species to the ocean, which are not included in the simulation. A statistically significant reduction in the simulated carbon dioxide growth rate is seen at the 90% level in the average of 12 large eruptions over the period 1870–2000, and the net uptake of carbon is primarily concentrated in the tropics, with large spatial variability. In addition, a method for computing the volcanic response in model output without using a control ensemble is tested against a traditional methodology using two separate ensembles of runs; the method is found to produce similar results in the global average. These results suggest that not only is simulating volcanoes a good test of coupled carbon–climate models, but also that this test can be performed without a control simulation in cases where it is not practical to run separate ensembles with and without volcanic eruptions.NASA Astrobiology Institute (NNGO6G127G)National Science Foundation (U.S.) (Grant 1049033)National Science Foundation (U.S.) (Grant 1021614

Assessing the skill of a high-resolution marine biophysical model using geostatistical analysis of mesoscale ocean chlorophyll variability from field observations and remote sensing

© The Author(s), 2021. This article is distributed under the terms of the Creaive Commons Attribution License. The definitive version was published in Eveleth, R., Glover, D. M., Long, M. C., Lima, I. D., Chase, A. P., & Doney, S. C. . Assessing the skill of a high-resolution marine biophysical model using geostatistical analysis of mesoscale ocean chlorophyll variability from field observations and remote sensing. Frontiers in Marine Science, 8, (2021): 612764, https://doi.org/10.3389/fmars.2021.612764.High-resolution ocean biophysical models are now routinely being conducted at basin and global-scale, opening opportunities to deepen our understanding of the mechanistic coupling of physical and biological processes at the mesoscale. Prior to using these models to test scientific questions, we need to assess their skill. While progress has been made in validating the mean field, little work has been done to evaluate skill of the simulated mesoscale variability. Here we use geostatistical 2-D variograms to quantify the magnitude and spatial scale of chlorophyll a patchiness in a 1/10th-degree eddy-resolving coupled Community Earth System Model simulation. We compare results from satellite remote sensing and ship underway observations in the North Atlantic Ocean, where there is a large seasonal phytoplankton bloom. The coefficients of variation, i.e., the arithmetic standard deviation divided by the mean, from the two observational data sets are approximately invariant across a large range of mean chlorophyll a values from oligotrophic and winter to subpolar bloom conditions. This relationship between the chlorophyll a mesoscale variability and the mean field appears to reflect an emergent property of marine biophysics, and the high-resolution simulation does poorly in capturing this skill metric, with the model underestimating observed variability under low chlorophyll a conditions such as in the subtropics.This work was supported in part by the National Aeronautics and Space Administration (NASA) as part of the North Atlantic Aerosol and Marine Ecosystems Study (NAAMES; NASA grant 80NSSC18K0018). The CESM project is supported by the National Science Foundation and the Office of Science (BER) of the United States Department of Energy. Computing resources were provided by the Climate Simulation Laboratory at NCAR’s Computational and Information Systems Laboratory (CISL), sponsored by the National Science Foundation and other agencies. This research was enabled by CISL compute and storage resources

Randomly Charged Polymers, Random Walks, and Their Extremal Properties

Motivated by an investigation of ground state properties of randomly charged polymers, we discuss the size distribution of the largest Q-segments (segments with total charge Q) in such N-mers. Upon mapping the charge sequence to one--dimensional random walks (RWs), this corresponds to finding the probability for the largest segment with total displacement Q in an N-step RW to have length L. Using analytical, exact enumeration, and Monte Carlo methods, we reveal the complex structure of the probability distribution in the large N limit. In particular, the size of the longest neutral segment has a distribution with a square-root singularity at l=L/N=1, an essential singularity at l=0, and a discontinuous derivative at l=1/2. The behavior near l=1 is related to a another interesting RW problem which we call the "staircase problem". We also discuss the generalized problem for d-dimensional RWs.Comment: 33 pages, 19 Postscript figures, RevTe

Climate-induced interannual variability of marine primary and export production in three global coupled climate carbon cycle models

© 2008 Author(s). This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 5 (2008): 597-614, doi:10.5194/bg-5-597-2008Fully coupled climate carbon cycle models are sophisticated tools that are used to predict future climate change and its impact on the land and ocean carbon cycles. These models should be able to adequately represent natural variability, requiring model validation by observations. The present study focuses on the ocean carbon cycle component, in particular the spatial and temporal variability in net primary productivity (PP) and export production (EP) of particulate organic carbon (POC). Results from three coupled climate carbon cycle models (IPSL, MPIM, NCAR) are compared with observation-based estimates derived from satellite measurements of ocean colour and results from inverse modelling (data assimilation). Satellite observations of ocean colour have shown that temporal variability of PP on the global scale is largely dominated by the permanently stratified, low-latitude ocean (Behrenfeld et al., 2006) with stronger stratification (higher sea surface temperature; SST) being associated with negative PP anomalies. Results from all three coupled models confirm the role of the low-latitude, permanently stratified ocean for anomalies in globally integrated PP, but only one model (IPSL) also reproduces the inverse relationship between stratification (SST) and PP. An adequate representation of iron and macronutrient co-limitation of phytoplankton growth in the tropical ocean has shown to be the crucial mechanism determining the capability of the models to reproduce observed interactions between climate and PP.This work was supported by the EU grants 511106-2 (FP6 RTD project EUR-OCEANS) and GOCE-511176 (FP6 RTP project CARBOOCEAN) by the European Commission. TLF and FJ also acknowledge support from the Swiss National Science Foundations. SCD and MJB received support from NASA NNG06G127G

The global carbon budget 1959-2011

Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002–2011), EFF was 8.3 ± 0.4 PgC yr−1, ELUC 1.0 ± 0.5 PgC yr−1, GATM 4.3 ± 0.1PgC yr−1, SOCEAN 2.5 ± 0.5 PgC yr−1, and SLAND 2.6 ± 0.8 PgC yr−1. For year 2011 alone, EFF was 9.5 ± 0.5 PgC yr−1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 ± 0.5 PgC yr−1, approximately constant throughout the decade; GATM was 3.6 ± 0.2 PgC yr−1, SOCEAN was 2.7 ± 0.5 PgC yr−1, and SLAND was 4.1 ± 0.9 PgC yr−1. GATM was low in 2011 compared to the 2002–2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 ± 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9–3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future

Projected 21st century decrease in marine productivity : a multi-model analysis

© Authors, 2010. This work is distributed under the Creative Commons Attribution 3.0 License. The definitive version was published in Biogeosciences 7 (2010): 979-1005, doi: 10.5194/bg-7-979-2010Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.This work was funded by the European Union projects CARBOOCEAN (511176-2) and EUROCEANS (511106-2) and is a contribution to the “European Project on Ocean Acidification” (EPOCA) which received funding from the European Community’s Seventh Framework Programme (FP7/2007–2013) under grant agreement no. 211384. Additional support was received from the Swiss National Science Foundation. SCD acknowledges support from the NASA Ocean Biology and Biogeochemistry Program (NNX07AL80G). LB aknowledges support from the EU Project MEECE (Marine Ecosystem Evolution in a Changing Environnement, grant agreement 212085)