Decision making for net zero policy design and climate action:Considerations for improving translation at the research-policy interface: A UK Carbon Dioxide Removal Case Study

The impacts of climate change on society and the natural environment are being experienced now, with extreme weather events increasing in frequency and severity across the globe. To keep the Paris Agreement's ambition of limiting warming to 1.5ºC above pre-industrial levels there is now also a need to establish and scale a new sector to remove CO2 at Giga-tonne scale for over a century. Despite this mounting evidence and warnings, current climate policy in the UK and globally falls far short of achieving the required reductions in CO2 emissions or establishment of a new removal sector needed to stave off the risks posed by climate change. Some of the science on climate risk is abundant and well evidenced, but the policy response is lacking in effectiveness. Other evidence to design policy, such as Carbon Dioxide Removal (CDR), is fraught with deep uncertainty. Why are the plethora of scientific evidence, assessments and decision support tools available to decision and policymakers not always translating into effective climate-net zero policy action? How can emergent evidence be brought in introduced to shape new sectors such as CDR? What are the capacity gaps? Through a combination of literature review, interviews and UK policy workshops over 17 months these are some of the questions that this contribution sought insight. We set out three recommendations for policymakers and other stakeholders, including academic researchers and third sector organisations, to address the identified gaps associated with translating climate risk and net zero decision support into effective climate policy: Enhance collaboration between decision-makers, policymakers, analysts, researchers, and other stakeholders to co-develop and co-design operational climate risk assessments and policies, relevant to context. Identify the research and capacity gaps around climate risk decision-making under uncertainty, and work with stakeholders across the decision value chain to ensure those gaps are addressed. Co-create effective translation mechanisms to embed decision-support tools into policy better, employing a participatory approach to ensure inclusion of diverse values and viewpoints. It is fundamental that there is improvement in our understanding about how we can make good decisions and operationalise them, rather than simply focus on further research on the climate risk and net zero problem

Decision making for net zero policy design and climate action:Considerations for improving translation at the research-policy interface: A UK Carbon Dioxide Removal Case Study

The impacts of climate change on society and the natural environment are being experienced now, with extreme weather events increasing in frequency and severity across the globe. To keep the Paris Agreement's ambition of limiting warming to 1.5ºC above pre-industrial levels there is now also a need to establish and scale a new sector to remove CO2 at Giga-tonne scale for over a century. Despite this mounting evidence and warnings, current climate policy in the UK and globally falls far short of achieving the required reductions in CO2 emissions or establishment of a new removal sector needed to stave off the risks posed by climate change. Some of the science on climate risk is abundant and well evidenced, but the policy response is lacking in effectiveness. Other evidence to design policy, such as Carbon Dioxide Removal (CDR), is fraught with deep uncertainty. Why are the plethora of scientific evidence, assessments and decision support tools available to decision and policymakers not always translating into effective climate-net zero policy action? How can emergent evidence be brought in introduced to shape new sectors such as CDR? What are the capacity gaps? Through a combination of literature review, interviews and UK policy workshops over 17 months these are some of the questions that this contribution sought insight. We set out three recommendations for policymakers and other stakeholders, including academic researchers and third sector organisations, to address the identified gaps associated with translating climate risk and net zero decision support into effective climate policy: Enhance collaboration between decision-makers, policymakers, analysts, researchers, and other stakeholders to co-develop and co-design operational climate risk assessments and policies, relevant to context. Identify the research and capacity gaps around climate risk decision-making under uncertainty, and work with stakeholders across the decision value chain to ensure those gaps are addressed. Co-create effective translation mechanisms to embed decision-support tools into policy better, employing a participatory approach to ensure inclusion of diverse values and viewpoints. It is fundamental that there is improvement in our understanding about how we can make good decisions and operationalise them, rather than simply focus on further research on the climate risk and net zero problem

A short diastereoselective total synthesis of (±)-vibralactone

A total synthesis of the (±)-vibralactone has been achieved in 11 steps and 16% overall yield from malonic acid. Key steps include a highly diastereoselective allylation of an α-formyl ester containing an all carbon α-quaternary center, a Pd-catalyzed deallylative β-lactonization, and an aldehyde-selective Wacker oxidation of a terminal alkene

Design, Development, and In-flight Testing of a Pointer/tracker for In-flight Experiments to Measure Aero-optical Effects over a Scaled Turret

We address the design, development, and testing of a pointer/tracker as a probe beam for the purpose of making high-speed, aero-optical measurements of the flow over a scaled beam director turret. The tracker uses retro-reflection of the probe beam off of a Reflexite annulus surrounding the turret. The constraints of the design required a near-total-commercial off the shelf system that could be quickly installed and removed in a rented aircraft. Baseline measurements of environmental vibrations are used to predict pointing performance; mitigation of line-of-sight jitter on the probe beam is achieved through passive isolation and the design of relay optics. Accommodation of ambient light is made with the use of wavelength filters and track algorithms. Postanalysis of measured data is compared to design estimates

A Candidate Substellar Companion to HR 7329

We present the discovery of a candidate substellar companion from a survey of nearby, young stars with the NICMOS coronagraph on the Hubble Space Telescope. The H ~ 12 mag object was discovered approximately 4" from the young A0V star HR 7329. Using follow-up spectroscopy from STIS, we derive a spectral type between M7V and M8V with an effective temperature of ~ 2600 K. We estimate that the probability of a chance alignment with a foreground dwarf star of this nature is ~ 10^(-8) and therefore suggest the object (HR 7329B) is physically associated with HR 7329 with a projected separation of 200 AU. Current brown dwarf cooling models indicate a mass of less than 50 Jupiter masses for HR 7329B based on age estimates of < 30 Myr for HR7329A.Comment: 8 pages LATEX, 5 ps figures, accepted for Ap

An Infrared Coronagraphic Survey for Substellar Companions

We have used the F160W filter (1.4-1.8 um) and the coronagraph on the Near-InfraRed Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope (HST) to survey 45 single stars with a median age of 0.15 Gyr, an average distance of 30 pc, and an average H-magnitude of 7 mag. For the median age we were capable of detecting a 30 M_Jup companion at separations between 15 and 200 AU. A 5 M_Jup object could have been detected at 30 AU around 36% of our primaries. For several of our targets that were less than 30 Myr old, the lower mass limit was as low as a Jupiter mass, well into the high mass planet region. Results of the entire survey include the proper motion verification of five low-mass stellar companions, two brown dwarfs (HR7329B and TWA5B) and one possible brown dwarf binary (Gl 577B/C).Comment: 11 figures, accepted by A

Confirming the Primarily Smooth Structure of the Vega Debris Disk at Millimeter Wavelengths

Clumpy structure in the debris disk around Vega has been previously reported at millimeter wavelengths and attributed to concentrations of dust grains trapped in resonances with an unseen planet. However, recent imaging at similar wavelengths with higher sensitivity has disputed the observed structure. We present three new millimeter wavelength observations that help to resolve the puzzling and contradictory observations. We have observed the Vega system with the Submillimeter Array (SMA) at a wavelength of 880 μm and an angular resolution of 5"; with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at a wavelength of 1.3 mm and an angular resolution of 5"; and with the Green Bank Telescope (GBT) at a wavelength of 3.3 mm and angular resolution of 10". Despite high sensitivity and short baselines, we do not detect the Vega debris disk in either of the interferometric data sets (SMA and CARMA), which should be sensitive at high significance to clumpy structure based on previously reported observations. We obtain a marginal (3σ) detection of disk emission in the GBT data; the spatial distribution of the emission is not well constrained.We analyze the observations in the context of several different models, demonstrating that the observations are consistent with a smooth, broad, axisymmetric disk with inner radius 20–100 AU and width ≾50 AU. The interferometric data require that at least half of the 860 μm emission detected by previous single-dish observations with the James Clerk Maxwell Telescope be distributed axisymmetrically, ruling out strong contributions from flux concentrations on spatial scales of ≾100 AU. These observations support recent results from the Plateau de Bure Interferometer indicating that previous detections of clumpy structure in the Vega debris disk were spurious

A model for permeability evolution during volcanic welding

Volcanic ash and pyroclasts can weld when deposited hot by pyroclastic density currents, in near-vent fall deposits, or in fractures in volcano interiors. Welding progressively decreases the permeability of the particle packs, influencing a range of magmatic and volcanic processes, including magma outgassing, which is an important control on eruption dynamics. Consequently, there is a need for a quantitative model for permeability evolution during welding of ash and pyroclasts under the range of conditions encountered in nature. Here we present in situ experiments in which hydrous, crystal-free, glassy pyroclasts are imaged via x-ray tomography during welding at high temperature. For each 3D dataset acquired, we determine the porosity, Darcian gas permeability, specific surface area, and pore connectivity. We find that all of these quantities decrease as a critical percolation threshold is approached. We develop a constitutive mathematical model for the evolution of permeability in welding volcanic systems based on percolation theory, and validate the model against our experimental data. Importantly, our model accounts for polydispersivity of the grainsize in the particle pack, the pressures acting on the pack, and changes in particle viscosity arising from degassing of dissolved H2O during welding. Our model is theoretically grounded and has no fitting parameters, hence it should be valid across all magma compositions. The model can be used to predict whether a cooling pyroclast pack will have sufficient time to weld and to degas, the scenarios under which a final deposit will retain a permeable network, the timescales over which sealing occurs, and whether a welded deposit will have disequilibrium or equilibrium H2O content. A user-friendly implementation of the model is provided

Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars

We present low-resolution ultraviolet spectra of 14 low redshift (z<0.8) quasars observed with HST/STIS as part of a Snap project to understand the relationship between quasar outflows and luminosity. By design, all observations cover the CIV emission line. Nine of the quasars are from the Hamburg-ESO catalog, three are from the Palomar-Green catalog, and one is from the Parkes catalog. The sample contains a few interesting quasars including two broad absorption line (BAL) quasars (HE0143-3535, HE0436-2614), one quasar with a mini-BAL (HE1105-0746), and one quasar with associated narrow absorption (HE0409-5004). These BAL quasars are among the brightest known (though not the most luminous) since they lie at z<0.8. We compare the properties of these BAL quasars to the z1.4 Large Bright Quasar samples. By design, our objects sample luminosities in between these two surveys, and our four absorbed objects are consistent with the v ~ L^0.62 relation derived by Laor & Brandt (2002). Another quasar, HE0441-2826, contains extremely weak emission lines and our spectrum is consistent with a simple power-law continuum. The quasar is radio-loud, but has a steep spectral index and a lobe-dominated morphology, which argues against it being a blazar. The unusual spectrum of this quasar resembles the spectra of the quasars PG1407+265, SDSSJ1136+0242, and PKS1004+13 for which several possible explanations have been entertained.Comment: Uses aastex.cls, 21 pages in preprint mode, including 6 figures and 2 tables; accepted for publication in The Astronomical Journal (projected vol 133