2,601 research outputs found
Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity
Monitoring of earth's atmosphere was conducted for several years utilizing the ITOS series of low-altitude, polar-orbiting weather satellites. A space environment monitoring package was included in these satellites to perform measurements of a portion of earth's charged particle environment. The charged particle observations proposed for the low-altitude weather satellite TIROS N, are described which will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Such observations may be of use in future studies of the relationships between geomagnetic activity and atmospheric weather pattern developments. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance of distinguishing between solar and geomagnetic activity as possible causative sources. Such differentiation is necessary because of the widely different spatial and time scales involved in the atmospheric energy input resulting from these various sources of activity
Misplaced expectations from climate disclosure initiatives
The financial sectorâs response to pressures around climate change has emphasized the role of disclosure, notably through the recommendations of the Financial Stability Boardâs Task Force on Climate-related Financial Disclosures. This Perspective examines two dimensions of the expectations behind transparency and disclosure initiatives: the belief that disinvestment is driven by disclosure; and that investment âswitchesâ from high- to low-carbon assets. We warn about the risk of disappointment from inflated expectations about what transparency can really deliver and suggest some areas that research and public policy should examine to mobilize the required capital to meet climate goals
The shape and pace of change in the electricity transition: sectoral dynamics and indicators of progress
Change is not linear. Time and again, industries, policymakers, and commentators
in markets, technologies, and societies. This report outlines the potential dynamics of the transition to net-zero emissions; explains the general principles, characteristics, and common drivers of growth of emerging technologies; and explores progress against metrics of transition in electricity generation.
Given that rapid technological progress and diffusion of zero-carbon technologies are critical to reduce emissions at the pace and scale required, this report looks at the deployment levels and rates of change needed to achieve global climate goals, assuming the widely observed âS-curveâ and pace of change.
The electricity sector has to lead the global transition required to avoid dangerous climate change. Meeting the goal of limiting warming to 1.5°C, as set out in the Paris Agreement, requires global power sector 1 Namely: âHolding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C.â (UN, 2015).
CO2 emissions to reach net zero before 2050, with most studies showing that solar and wind are likely to become dominant sources of zero-carbon power. Many assessments of deployment levels to date are very pessimistic, extrapolating linear growth and looking at the absolute contribution from renewable energy sources, which, though growing, is still limited. This report probes deeper and anchors its analysis in the more commonly observed nonlinear dynamics of technological transition, comparing the trends since 2010 with the pace of transition required.
The results may surprise, and bring clarity to where progress is being made and where and how it needs to be pushed faster. A rapid transition is underway and appears now unstoppable, though its pace and depth will depend on policy. But inconsistency with dynamic indicators for fossil fuel-based generation points to a high risk of stranded fossil fuel generation assets irrespective of future policy decisions
Climate finance and disclosure for institutional investors: why transparency is not enough
The finance sectorâs response to pressures around climate change has emphasized disclosure, notably through the recommendations of the Financial Stability Boardâs Task Force on Climate-related Financial Disclosures (TCFD). The implicit assumptionâthat if risks are fully revealed, finance will respond rationally and in ways aligned with the public interestâis rooted in the âefficient market hypothesisâ (EMH) applied to the finance sector and its perception of climate policy. For low carbon investment, particular hopes have been placed on the role of institutional investors, given the apparent matching of their assets and liabilities with the long timescales of climate change. We both explain theoretical frameworks (grounded in the âthree domainsâ, namely satisficing, optimizing, and transforming) and use empirical evidence (from a survey of institutional investors), to show that the EMH is unsupported by either theory or evidence: it follows that transparency alone will be an inadequate response. To some extent, transparency can address behavioural biases (first domain characteristics), and improving pricing and market efficiency (second domain); however, the strategic (third domain) limitations of EMH are more serious. We argue that whilst transparency can help, on its own it is a very long way from an adequate response to the challenges of âaligning institutional climate financeâ
Ellipticity Conditions for the Lax Operator of the KP Equations
The Lax pseudo-differential operator plays a key role in studying the general
set of KP equations, although it is normally treated in a formal way, without
worrying about a complete characterization of its mathematical properties. The
aim of the present paper is therefore to investigate the ellipticity condition.
For this purpose, after a careful evaluation of the kernel with the associated
symbol, the majorization ensuring ellipticity is studied in detail. This leads
to non-trivial restrictions on the admissible set of potentials in the Lax
operator. When their time evolution is also considered, the ellipticity
conditions turn out to involve derivatives of the logarithm of the
tau-function.Comment: 21 pages, plain Te
The hybrid spectral problem and Robin boundary conditions
The hybrid spectral problem where the field satisfies Dirichlet conditions
(D) on part of the boundary of the relevant domain and Neumann (N) on the
remainder is discussed in simple terms. A conjecture for the C_1 coefficient is
presented and the conformal determinant on a 2-disc, where the D and N regions
are semi-circles, is derived. Comments on higher coefficients are made.
A hemisphere hybrid problem is introduced that involves Robin boundary
conditions and leads to logarithmic terms in the heat--kernel expansion which
are evaluated explicitly.Comment: 24 pages. Typos and a few factors corrected. Minor comments added.
Substantial Robin additions. Substantial revisio
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