21 Layer troposphere-stratosphere climate model

The global climate model is extended through the stratosphere by increasing the vertical resolution and raising the rigid model top to the 0.01 mb (75 km) level. The inclusion of a realistic stratosphere is necessary for the investigation of the climate effects of stratospheric perturbations, such as changes of ozone, aerosols or solar ultraviolet irradiance, as well as for studying the effect on the stratosphere of tropospheric climate changes. The observed temperature and wind patterns throughout the troposphere and stratosphere are simulated. In addition to the excess planetary wave amplitude in the upper stratosphere, other model deficiences include the Northern Hemisphere lower stratospheric temperatures being 5 to 10 C too cold in winter at high latitudes and the temperature at 50 to 60 km altitude near the equator are too cold. Methods of correcting these deficiencies are discussed

Spectral radiometry and tropospheric aerosols: Report of panel

The term aerosols, as used here, refers to the haze, smoke, and dust that appear in the troposphere. The term does not refer to the hydrometeors in cumulus and stratus clouds but does include the sulfuric acid-water droplets which are assumed to predominate in the stratospheric aerosol layer. The aerosol properties that were measured from satellites and those which can be made in the near term (up to 1992) will be reviewed. The capabilities that will exist in the years 1992 to 2000, with implementation of EOS, are then discussed. Finally, a few words will be said concerning the potential for aerosol measurements for the decade after 2000

Numerical experiments on short-term meteorological effects on solar variability

A set of numerical experiments was conducted to test the short-range sensitivity of a large atmospheric general circulation model to changes in solar constant and ozone amount. On the basis of the results of 12-day sets of integrations with very large variations in these parameters, it is concluded that realistic variations would produce insignificant meteorological effects. Any causal relationships between solar variability and weather, for time scales of two weeks or less, rely upon changes in parameters other than solar constant or ozone amounts, or upon mechanisms not yet incorporated in the model

Theory and observations: Model simulations of the period 1955-1985

The main objective of the theoretical studies presented here is to apply models of stratospheric chemistry and transport in order to understand the processes that control stratospheric ozone and that are responsible for the observed variations. The model calculations are intended to simulate the observed behavior of atmospheric ozone over the past three decades (1955-1985), for which there exists a substantial record of both ground-based and, more recently, satellite measurements. Ozone concentrations in the atmosphere vary on different time scales and for several different causes. The models described here were designed to simulate the effect on ozone of changes in the concentration of such trace gases as CFC, CH4, N2O, and CO2. Changes from year to year in ultraviolet radiation associated with the solar cycle are also included in the models. A third source of variability explicitly considered is the sporadic introduction of large amounts of NO sub x into the stratosphere during atmospheric nuclear tests

Predictive use of the Maximum Entropy Production principle for Past and Present Climates

In this paper, we show how the MEP hypothesis may be used to build simple climate models without representing explicitly the energy transport by the atmosphere. The purpose is twofold. First, we assess the performance of the MEP hypothesis by comparing a simple model with minimal input data to a complex, state-of-the-art General Circulation Model. Next, we show how to improve the realism of MEP climate models by including climate feedbacks, focusing on the case of the water-vapour feedback. We also discuss the dependence of the entropy production rate and predicted surface temperature on the resolution of the model

The GROUSE project II: Detection of the Ks-band secondary eclipse of exoplanet HAT-P-1b

Context: Only recently it has become possible to measure the thermal emission from hot-Jupiters at near-Infrared wavelengths using ground-based telescopes, by secondary eclipse observations. This allows the planet flux to be probed around the peak of its spectral energy distribution, which is vital for the understanding of its energy budget. Aims: The aim of the reported work is to measure the eclipse depth of the planet HAT-P-1b at 2.2micron. This planet is an interesting case, since the amount of stellar irradiation it receives falls in between that of the two best studied systems (HD209458 and HD189733), and it has been suggested to have a weak thermal inversion layer. Methods: We have used the LIRIS instrument on the William Herschel Telescope (WHT) to observe the secondary eclipse of HATP-1b in the Ks-band, as part of our Ground-based secondary eclipse (GROUSE) project. The observations were done in staring mode, while significantly defocusing the telescope to avoid saturation on the K=8.4 star. With an average cadence of 2.5 seconds, we collected 6520 frames during one night. Results: The eclipse is detected at the 4sigma level, the measured depth being 0.109+/-0.025%. The uncertainties are dominated by residual systematic effects, as estimated from different reduction/analysis procedures. The measured depth corresponds to a brightness temperature of 2136+150-170K. This brightness temperature is significantly higher than those derived from longer wavelengths, making it difficult to fit all available data points with a plausible atmospheric model. However, it may be that we underestimate the true uncertainties of our measurements, since it is notoriously difficult to assign precise statistical significance to a result when systematic effects are important.Comment: 7 pages, 10 figures, Accepted for publication in A&

Consilient Discrepancy: Porosity and Atmosphere in Cinema and Architecture

Cinema constitutes a way of looking at the world, at a world – its aspect, its appearance; but it also presents how that world looks, its prospect – by the prospective glance it throws back toward us. The “look” of a film – its mood, ambiance or atmosphere – eclipses formal and aesthetics registers. It is fundamentally world-forming, and therefore both cosmogonic and ethical: cosmogonic because it produces a world in the midst of, and as, the temporality that devolves through its passage; and ethical because the world it brings about is an inhabited world, a conjugation of people and place that constructs particular ways of being-there-together. The premise here is that atmosphere, ambiance and mood have never been vague categories for cinema and need not be for architecture: rather, that they are in fact producible through deliberate organizational strategies – kinematic and narrative in film, tectonic and material in architecture – according to what might be called “consilient discrepancy” – the coexistence of disseveral systems in unaligned multiplicity that, while never fusing, resonate to produce emergent conditions. Cinema offers architecture an accessible and instructive instance of such consilient discrepancy, because, in it, atmosphere is more fully captured and the conditions that create it more evidently analyzable. To that extent, cinema provides architecture with comparative grounds for engaging with atmosphere through a properly tectonic practice that can potentially enrich the design and experience of architecture. Consilient discrepancy is evident across multiple registers in film. It can function at the level of narrative, space and time and thus puts into question verisimilitude, causality, situational and durational veracity. An example of this is the constitutive disjunctions of Jean-Luc Godard’s jump cut montage where sampled film sequences, film and photographic stills, texts and citations, ambient sound, spoken word and music, build into complex assemblages of sense (Histoire(s) du Cinema, 1998). It is evident in Nicholas Roeg’s multiple, simultaneous temporalities where past and future events interpenetrate and mutually condition the narrative present (Bad Timing, 1980). Similarly, we can find it in Michelangelo Antonioni’s sequence shots that traverse multiple timeframes across the same space – a technique that enables past and present to communicate and amplify the affective, foundational value of the unseen and off-frame (The Passenger, 1975). Another example would be David Lynch’s labyrinthine existential settings, constituted of interminable slippages between indeterminable and infinitely potentialized spaces of dreams, imagination, memory and reality (Mulholland Drive, 2001). Likewise, we could cite Michael Hanake’s persistent displacement of causality and verisimilitude through ambiguous narrative viewpoints (Caché, 2005), and Roy Andersson’s radically liminal settings and characters whose lives constitute larval pre- and/or posthuman states of existence (A Pigeon Sat on a Branch Reflecting on Existence, 2014). This paper will foreground two foundational characteristics of atmosphere in cinema, as evident in the works just cited, and explore their applicability to architecture. The first characteristic is the consilient discrepancy outlined here by way of introduction, and the second, related characteristic, is a spatiality of porosity and occlusion. The provisional aim of comparing cinema and architecture according to this tectonic logic is to go beyond typical ways of understanding cinema’s formal engagement with architecture. For this purpose, a detailed analysis of Béla Tarr’s film Werckmeister Harmonies (2000) will serve as a case study for how the medium of cinema generates atmosphere, ambiance and mood through visual language. This will be followed by a similarly detailed consideration of concomitant qualities created in two recent works by the architects Flores Prats, the Mills Museum and Casal Balaguer. Functioning as exemplars of how cinematic qualities can be made manifest in architecture, these precedents will further substantiate the cinematic–architectonic proposition ventured in this paper

Radiative Transfer for Exoplanet Atmospheres

Remote sensing of the atmospheres of distant worlds motivates a firm understanding of radiative transfer. In this review, we provide a pedagogical cookbook that describes the principal ingredients needed to perform a radiative transfer calculation and predict the spectrum of an exoplanet atmosphere, including solving the radiative transfer equation, calculating opacities (and chemistry), iterating for radiative equilibrium (or not), and adapting the output of the calculations to the astronomical observations. A review of the state of the art is performed, focusing on selected milestone papers. Outstanding issues, including the need to understand aerosols or clouds and elucidating the assumptions and caveats behind inversion methods, are discussed. A checklist is provided to assist referees/reviewers in their scrutiny of works involving radiative transfer. A table summarizing the methodology employed by past studies is provided.Comment: 7 pages, no figures, 1 table. Filled in missing information in references, main text unchange

Radiative forcing in the 21st century due to ozone changes in the troposphere and the lower stratosphere

Radiative forcing due to changes in ozone is expected for the 21st century. An assessment on changes in the tropospheric oxidative state through a model intercomparison ("OxComp'') was conducted for the IPCC Third Assessment Report (IPCC-TAR). OxComp estimated tropospheric changes in ozone and other oxidants during the 21st century based on the "SRES'' A2p emission scenario. In this study we analyze the results of 11 chemical transport models (CTMs) that participated in OxComp and use them as input for detailed radiative forcing calculations. We also address future ozone recovery in the lower stratosphere and its impact on radiative forcing by applying two models that calculate both tropospheric and stratospheric changes. The results of OxComp suggest an increase in global-mean tropospheric ozone between 11.4 and 20.5 DU for the 21st century, representing the model uncertainty range for the A2p scenario. As the A2p scenario constitutes the worst case proposed in IPCC-TAR we consider these results as an upper estimate. The radiative transfer model yields a positive radiative forcing ranging from 0.40 to 0.78 W m(-2) on a global and annual average. The lower stratosphere contributes an additional 7.5-9.3 DU to the calculated increase in the ozone column, increasing radiative forcing by 0.15-0.17 W m(-2). The modeled radiative forcing depends on the height distribution and geographical pattern of predicted ozone changes and shows a distinct seasonal variation. Despite the large variations between the 11 participating models, the calculated range for normalized radiative forcing is within 25%, indicating the ability to scale radiative forcing to global-mean ozone column change