631 research outputs found
Using IASI to simulate the total spectrum of outgoing long-wave radiances
A new method of deriving high-resolution top-of-atmosphere spectral radiances
in 10 181 bands, over the whole outgoing long-wave spectrum of the Earth, is
presented. Correlations between different channels measured by the Infrared
Atmospheric Sounding Interfermeter (IASI) on the MetOp-A (Meteorological Operation) satellite and
unobserved wavenumbers are used to estimate far infrared (FIR) radiances at
0.5 cm−1 intervals between 25.25 and 644.75 cm−1 (the FIR),
and additionally between 2760 and 3000 cm−1 (the NIR – near infrared). Radiances simulated by the
line-by-line radiative transfer model (LBLRTM) are used to construct the
prediction model. The spectrum is validated by comparing the Integrated Nadir
Long-wave Radiance (INLR) product spanning the whole 25.25–3000 cm−1
range with the corresponding broadband measurements from the Clouds and the Earth's Radiant Energy System (CERES) instrument on the Terra and Aqua
satellites at points of simultaneous nadir overpass. There is a mean difference of 0.3 W m−2 sr−1 (0.5% relative difference).
This is well within the uncertainties associated with the measurements made
by either instrument. However, there is a noticeable contrast when the bias
is separated into night-time and daytime scenes with the latter being
significantly larger, possibly due to errors in the CERES Ed3 Spectral Response Functions (SRF) correction
method. In the absence of an operational spaceborne instrument that isolates
the FIR, this product provides a useful proxy for such
measurements
within the limits of the regression model it is based on, which is shown to
have very low root mean squared errors. The new high-resolution spectrum is
presented for global mean clear and all skies where the FIR is shown
to contribute 44 and 47% to the total INLR, respectively. In terms of the
spectral cloud effect (Cloud Integrated Nadir Long-wave Radiance – CINLR), the FIR contributes 19% and in some
subtropical instances appears to be negative; results that would go
unobserved with a traditional broadband analysis
Reproduction of Twentieth Century Intradecadal to Multidecadal Surface Temperature Variability in Radiatively Forced Coupled Climate Models
[1] Coupled Model Intercomparison Project 3 simulations that included time-varying radiative forcings were ranked according to their ability to consistently reproduce twentieth century intradecadal to multidecadal (IMD) surface temperature variability at the 5° by 5° spatial scale. IMD variability was identified using the running Mann-Whitney Z method. Model rankings were given context by comparing the IMD variability in preindustrial control runs to observations and by contrasting the IMD variability among the ensemble members within each model. These experiments confirmed that the inclusion of time-varying external forcings brought simulations into closer agreement with observations. Additionally, they illustrated that the magnitude of unforced variability differed between models. This led to a supplementary metric that assessed model ability to reproduce observations while accounting for each model\u27s own degree of unforced variability. These two metrics revealed that discernable differences in skill exist between models and that none of the models reproduced observations at their theoretical optimum level. Overall, these results demonstrate a methodology for assessing coupled models relative to each other within a multimodel framework
Challenges of achieving good environmental status in the Northeast Atlantic
The sustainable exploitation of marine ecosystem services is dependent on achieving and maintaining an adequate ecosystem state to prevent undue deterioration. Within the European Union, the Marine Strategy Framework Directive (MSFD) requires member states to achieve Good Environmental Status (GEnS), specified in terms of 11 descriptors. We analyzed the complexity of social-ecological factors to identify common critical issues that are likely to influence the achievement of GEnS in the Northeast Atlantic (NEA) more broadly, using three case studies. A conceptual model developed using a soft systems approach highlights the complexity of social and ecological phenomena that influence, and are likely to continue to influence, the state of ecosystems in the NEA. The development of the conceptual model raised four issues that complicate the implementation of the MSFD, the majority of which arose in the Pressures and State sections of the model: variability in the system, cumulative effects, ecosystem resilience, and conflicting policy targets. The achievement of GEnS targets for the marine environment requires the recognition and negotiation of trade-offs across a broad policy landscape involving a wide variety of stakeholders in the public and private sectors. Furthermore, potential cumulative effects may introduce uncertainty, particularly in selecting appropriate management measures. There also are endogenous pressures that society cannot control. This uncertainty is even more obvious when variability within the system, e.g., climate change, is accounted for. Also, questions related to the resilience of the affected ecosystem to specific pressures must be raised, despite a lack of current knowledge. Achieving good management and reaching GEnS require multidisciplinary assessments. The soft systems approach provides one mechanism for bringing multidisciplinary information together to look at the problems in a different light
The Japanese model in retrospective : industrial strategies, corporate Japan and the 'hollowing out' of Japanese industry
This article provides a retrospective look at the Japanese model of industrial development. This model combined an institutional approach to production based around the Japanese Firm (Aoki's, J-mode) and strategic state intervention in industry by the Japanese Ministry of International Trade and Industry (MITI). For a long period, the alignment of state and corporate interests appeared to match the wider public interest as the Japanese economy prospered. However, since the early 1990s, the global ambitions of the corporate sector have contributed to a significant 'hollowing out' of Japan's industrial base. As the world today looks for a new direction in economic management, we suggest the Japanese model provides policy-makers with a salutary lesson in tying the wider public interest with those of the corporate sector
The blind monks and the elephant : contrasting narratives of financial crisis
Three persuasive narratives of the US subprime crisis are explored with reference both to theory and to emergency acts of public policy undertaken. First the role of pecuniary externalities that amplify any shocks to the quality of risk-assets held by Investment Banks and others. Second is adverse selection in marketing these assets; and third the role of financial panic in making investment-banking disaster-prone. How relevant these differing perspectives proved is attested by the nature of state support and by subsequent findings in courts of law.
As Chair of the US Federal Reserve, Janet Yellen argued that vulnerabilities within the US financial system in the mid-2000s were “numerous and familiar from past financial panics”. That the varied threats to stability featuring in these narratives should be complements and not substitutes is of more than technical interest: it helps to explain why the US financial system was so exposed to radical failure
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