A Possible Aeronomy of Extrasolar Terrestrial Planets

Terrestrial planetary systems may exist around nearby stars as the Earth-sized counterparts to the many giant planets already discovered within the solar neighborhood. In this chapter we first discuss the numerous techniques which have been suggested to search for extrasolar terrestrial planets. We then focus on the expected results from that technique in which an orbiting telescope or interferometer is used to obtain a visible or infrared spectrum of a planet, without contamination from the parent star. We show examples of such spectra for selected cases: the present Earth, the Neoproterozoic (snowball) Earth, a methane-rich Earth, and the present Mars and Venus. We conclude by discussing the implications of such spectra for the detection of life on an extrasolar terrestrial planet.Comment: This will appear in the upcoming AGU Monograph 130 "Atmospheres in the Solar System: Comparative Aeronomy". It will be on page 36

Does Scientific Uncertainty in News Articles Affect Readers' Trust and Decision-Making?

Even though a main goal of science is to reduce the uncertainty in scientific results by applying ever-improving research methods, epistemic uncertainty is an integral part of science. As such, while uncertainty might be communicated in news articles about climate science, climate skeptics have also exploited this uncertainty to cast doubt on science itself. We performed two studies to assess whether scientific uncertainty affects laypeople’s assessments of issue uncertainty, the credibility of the information, their trust in scientists and climate science, and impacts their decision-making. In addition, we addressed how these effects are influenced by further information on relevant scientific processes, because knowing that uncertainty goes along with scientific research could ease laypeople’s interpretations of uncertainty around evidence and may even protect against negative impacts of such uncertainty on trust. Unexpectedly, in study 1, after participants read both a text about research methods and a news article that included scientific uncertainty, they had lower trust in the scientists’ assertions than when they read the uncertain news article alone (but this did not impact trust in climate science or decision-making). In study 2, we tested whether these results occurred due to participants overestimating the scientific uncertainty at hand. Hence, we varied the framing of uncertainty in the text on scientific processes. We found that exaggerating the scientific uncertainty produced by scientific processes (vs. framing the uncertainty as something to be expected) did not negatively affect participants’ trust ratings. However, the degree to which participants preferred effortful reasoning on problems (intellective epistemic style) correlated with ratings of trust in scientists and climate science and with their decision-making. In sum, there was only little evidence that the introduction of uncertainty in news articles would affect participants’ ratings of trust and their decision-making, but their preferred style of reasoning did

Spectral Evolution of an Earth-Like Planet

We have developed a characterization of the geological evolution of the Earths atmosphere and surface in order to model the observable spectra of an Earth-like planet through its geological history. These calculations are designed to guide the interpretation of an observed spectrum of such a planet by future instruments that will characterize exoplanets. Our models focus on spectral features that either imply habitability or are required for habitability. These features are generated by H2O, CO2, CH4, O2, O3, N2O, and vegetation-like surface albedos. We chose six geological epochs to characterize. These epochs exhibit a wide range in abundance for these molecules, ranging from a CO2 rich early atmosphere, to a CO2/CH4-rich atmosphere around 2 billion years ago to a present-day atmosphere. We analyzed the spectra to quantify the strength of each important spectral feature in both the visible and thermal infrared spectral regions, and the resolutions required to unambiguously observe the features for each epoch. We find a wide range of spectral resolutions required for observing the different features. For example, H2O and O3 can be observed with relatively low resolution, while O2 and N2O require higher resolution. We also find that the inclusion of clouds in our models significantly affects both the strengths and resolutions required to observe all spectral features.Comment: 34 pages, 24 fig, pdf, ApJ, TB

Overview of NASA's Carbon Monitoring System Flux-Pilot Project

NASA's space-based observations of physical, chemical and biological parameters in the Earth System along with state-of-the-art modeling capabilities provide unique capabilities for analyses of the carbon cycle. The Carbon Monitoring System is developing an exploratory framework for detecting carbon in the environment and its changes, with a view towards contributing to national and international monitoring activities. The Flux-Pilot Project aims to provide a unified view of land-atmosphere and ocean-atmosphere carbon exchange, using observation-constrained models. Central to the project is the application of NASA's satellite observations (especially MODIS), the ACOS retrievals of the JAXA-GOSAT observations, and the "MERRA" meteorological reanalysis produced with GEOS-S. With a primary objective of estimating uncertainty in computed fluxes, two land- and two ocean-systems are run for 2009-2010 and compared with existing flux estimates. An transport model is used to evaluate simulated CO2 concentrations with in-situ and space-based observations, in order to assess the realism of the fluxes and how uncertainties in fluxes propagate into atmospheric concentrations that can be more readily evaluated. Finally, the atmospheric partial CO2 columns observed from space are inverted to give new estimates of surface fluxes, which are evaluated using the bottom-up estimates and independent datasets. The focus of this presentation will be on the science goals and current achievements of the pilot project, with emphasis on how policy-relevant questions help focus the scientific direction. Examples include the issue of what spatio-temporal resolution of fluxes can be detected from polar-orbiting satellites and whether it is possible to use space-based observations to separate contributions to atmospheric concentrations of (say) fossil-fuel and biological activit

Atmospheric Biomarkers and their Evolution over Geological Timescales

The search for life on extrasolar planets is based on the assumption that one can screen extrasolar planets for habitability spectroscopically. The first space born instruments able to detect as well as characterize extrasolar planets, Darwin and terrestrial planet finder (TPF-I and TPF-C) are scheduled to launch before the end of the next decade. The composition of the planetary surface, atmosphere, and its temperature-pressure profile influence a detectable spectroscopic signal considerably. For future space-based missions it will be crucial to know this influence to interpret the observed signals and detect signatures of life in remotely observed atmospheres. We give an overview of biomarkers in the visible and IR range, corresponding to the TPF-C and TPF-I/DARWIN concepts, respectively. We also give an overview of the evolution of biomarkers over time and its implication for the search for life on extrasolar Earth-like planets. We show that atmospheric features on Earth can provide clues of biological activities for at least 2 billion years.Comment: for high resolution images see http://cfa-www.harvard.edu/~lkaltenegge

Reflexives Schreiben als Seminarkonzept in den Lehramtsstudiengängen

Schreiben hat positive Effekte auf die Auseinandersetzung mit und Aneignung von Lerninhalten (ein Überblick bei TYNJÄLÄ, MASON & LONKA, 2001; BANGERT-DROWNS, HURLEY & WILKONSON, 2004). In der Hochschullehre bietet das Lernen durch Schreiben einen vielversprechenden Ansatz, um den Wissens- und Erkenntnisgewinn von Studierenden in einem selbstregulierten Rahmen zu unterstützen (siehe z. B. NÜCKLES, HÜBNER & RENKL, 2009) und damit einen Weg der Forderung nach mehr Selbstregulation und Eigenverantwortung der Studierenden im Lernprozess (GERHOLZ, 2012) nachzukommen. In diesem Beitrag wird ein Seminarkonzept vorgestellt, das die Tätigkeit des Schreibens als Instrument zur Reflexion und Erkenntnisgenerierung integriert. Ziel ist es, die Fähigkeit zur systematischen, theoriegeleiteten Reflexion der eigenen Lehr- und Lernvorstellungen von Lehramtsstudierenden im Master of Education (weiter) zu entwickeln. Kooperative Schreibaufgaben, die Teil eines Portfolios sind, sollen dies bewirken. 23.01.2013 | Elisabeth Paus & Regina Jucks (Münster

NASA's Carbon Monitoring System Flux-Pilot Project: A Multi-Component Analysis System for Carbon-Cycle Research and Monitoring

The importance of greenhouse gas increases for climate motivates NASA s observing strategy for CO2 from space, including the forthcoming Orbiting Carbon Observatory (OCO-2) mission. Carbon cycle monitoring, including attribution of atmospheric concentrations to regional emissions and uptake, requires a robust modeling and analysis infrastructure to optimally extract information from the observations. NASA's Carbon-Monitoring System Flux-Pilot Project (FPP) is a prototype for such analysis, combining a set of unique tools to facilitate analysis of atmospheric CO2 along with fluxes between the atmosphere and the terrestrial biosphere or ocean. NASA's analysis system is unique, in that it combines information and expertise from the land, oceanic, and atmospheric branches of the carbon cycle and includes some estimates of uncertainty. Numerous existing space-based missions provide information of relevance to the carbon cycle. This study describes the components of the FPP framework, assessing the realism of computed fluxes, thus providing the basis for research and monitoring applications. Fluxes are computed using data-constrained terrestrial biosphere models and physical ocean models, driven by atmospheric observations and assimilating ocean-color information. Use of two estimates provides a measure of uncertainty in the fluxes. Along with inventories of other emissions, these data-derived fluxes are used in transport models to assess their consistency with atmospheric CO2 observations. Closure is achieved by using a four-dimensional data assimilation (inverse) approach that adjusts the terrestrial biosphere fluxes to make them consistent with the atmospheric CO2 observations. Results will be shown, illustrating the year-to-year variations in land biospheric and oceanic fluxes computed in the FPP. The signals of these surface-flux variations on atmospheric CO2 will be isolated using forward modeling tools, which also incorporate estimates of transport error. The results will be discussed in the context of interannual variability of observed atmospheric CO2 distributions

Direkt erfragt: die Messung von Lehrorientierungen per Fragebogen mit offenem Antwortformat

Der Text beschreibt die Messung von Lehrorientierungen durch ein offenes Antwortformat. Lehrende (n = 71) und Studierende (n = 276) der Universität Münster führten den Satzanfang "Für gute Lehre ist es aus meiner Sicht wichtig, dass ..." fort. Die in den Ausführungen genannten Aspekte wurden inhaltsanalytisch (MAYRING, 2010) entlang des Modells zu Konzeptionen des Lehrens von KEMBER (1997) ausgewertet. Die Ergebnisse zeigen, dass Studierende noch stärker als Lehrende eine Lehrendenorientierung aufweisen. Zudem zeigten sich in der Gruppe der Studierenden Fächerunterschiede. In der Diskussion gehen wir auf die Anwendbarkeit der offenen Befragung zu Lehrauffassungen ein und beziehen die Ergebnisse auf – mit anderen Verfahren ermittelte – bisherige Befunde. 21.06.2013 | Lena Päuler & Regina Jucks (Münster

Phase Determination from Mostly One-sided Interferograms

We show how to detect and correct for non-linear phase shifts in a mainly one-sided interferogram of an emission-line source. We simultaneously detect and correct for an out-of-phase emission background from the spectrometer. The method requires two auxiliary spectra, one of a strong continuum source, and one of an emission-line source with little or no continuum