Strictly One-Dimensional Electron System in Au Chains on Ge(001) Revealed By Photoelectron K-Space Mapping

Atomic nanowires formed by Au on Ge(001) are scrutinized for the band topology of the conduction electron system by k-resolved photoemission. Two metallic electron pockets are observed. Their Fermi surface sheets form straight lines without undulations perpendicular to the chains within experimental uncertainty. The electrons hence emerge as strictly confined to one dimension. Moreover, the system is stable against a Peierls distortion down to 10 K, lending itself for studies of the spectral function. Indications for unusually low spectral weight at the chemical potential are discussed.Comment: 4 pages, 4 figures - revised version with added Fig. 2e) and additional reference

Aerosols and Water Ice in Jupiter's Stratosphere from UV-NIR Ground-based Observations

Jupiter's atmosphere has been sounded in transmission from the UV to the IR, as if it were a transiting exoplanet, by observing Ganymede while passing through Jupiter's shadow. The spectra show strong extinction due to the presence of aerosols and haze in Jupiter's atmosphere and strong absorption features of methane. Here, we report a new detailed analysis of these observations, with special emphasis on the retrievals of the vertical distribution of the aerosols and their sizes, and the properties and distribution of the stratospheric water ice. Our analysis suggests the presence of aerosols near the equator in the altitude range of 100 hPa up to at least 0.01 hPa, with a layer of small particles (mean radius of 0.1 μm) in the upper part (above 0.1 hPa), an intermediate layer of aerosols with a radius of 0.3 μm, extending between ∼10 and 0.01 hPa, and a layer with larger sizes of ∼0.6 μm at approximately 100-1 hPa. The corresponding loads for each layer are ∼2 × 10 g cm, ∼3.4 × 10 g cm, and ∼1.5 × 10 g cm, respectively, with a total load of ∼2.0 × 10 g cm. The lower and middle layers agree well with previous measurements; but the finer particles of 0.1 μm above 0.01 hPa have not been reported before. The spectra also show two broad features near 1.5 and 2.0 μm, which we attribute to a layer of very small (∼10 nm) HO crystalline ice in Jupiter's lower stratosphere (∼0.5 hPa). While these spectral signatures seem to be unequivocally attributable to crystalline water ice, they require a large amount of water ice to explain the strong absorption features.© 2018. The American Astronomical Society. All rights reserved.We are very grateful to Rafael Escribano, Victor Herrero, Anni Maattanen, Beatriz Mate, Agustin Sanchez-Lavega, and Miguel Angel Satorre for very valuable discussions on the water ice topic. The IAA team was supported by the Spanish MICINN under projects ESP2014-54362-P, ESP2017-87143-R, and EC FEDER funds. This work is also partly financed by the Spanish Ministry of Economics and Competitiveness through grant ESP2013-48391-C4-2-R. M.G.C. is also supported by the MINECO under its >Ramon y Cajal> subprogram

Design and description of the MUSICA IASI full retrieval product

IASI (Infrared Atmospheric Sounding Interferometer) is the core instrument of the currently three Metop (Meteorological operational) satellites of EUMETSAT (European Organization for the Exploitation of Meteorological Satellites). The MUSICA IASI processing has been developed in the framework of the European Research Council project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water). The processor performs an optimal estimation of the vertical distributions of water vapour (H$_{2}$O), the ratio between two water vapour isotopologues (the HDO/H$_{2}$O ratio), nitrous oxide (N$_{2}$O), methane (CH$_{4}$), and nitric acid (HNO$_{3}$) and works with IASI radiances measured under cloud-free conditions in the spectral window between 1190 and 1400 cm$^{-1}$. The retrieval of the trace gas profiles is performed on a logarithmic scale, which allows the constraint and the analytic treatment of ln [HDO]−ln [H$_{2}$O] as a proxy for the HDO/H$_{2}$O ratio. Currently, the MUSICA IASI processing has been applied to all IASI measurements available between October 2014 and June 2021 and about two billion individual retrievals have been performed

Vertical profile of peroxyacetyl nitrate (PAN) from MIPAS-STR measurements over Brazil in February 2005 and its contribution to tropical UT NOy partitioning

We report on the retrieval of PAN (CH₃C(O)OONO₂) in the upper tropical troposphere from limb measurements by the remote-sensor MIPAS-STR on board the Russian high altitude research aircraft M55-Geophysica. The measurements were performed close to Araçatuba, Brazil, on 17 February 2005. The retrieval was made in the spectral range 775–820 cm^&minus;1 where PAN exhibits its strongest feature but also more than 10 species interfere. Especially trace gases such as CH₃CCl₃, CFC-113, CFC-11, and CFC-22, emitting also in spectrally broad not-resolved branches, make the processing of PAN prone to errors. Therefore, the selection of appropriate spectral windows, the separate retrieval of several interfering species and the careful handling of the water vapour profile are part of the study presented. <br><br> The retrieved profile of PAN has a maximum of about 0.14 ppbv at 10 km altitude, slightly larger than the lowest reported values (&lt;0.1 ppbv) and much lower than the highest reported in the literature (0.65 ppbv). Besides the NO_y constituents measured by MIPAS-STR (HNO₃, ClONO₂, HO₂NO₂, PAN), the in situ instruments aboard the Geophysica provide simultaneous measurements of NO, NO₂, and the sum NO_y. Comparing the sum of in-situ and remotely derived NO+NO₂+HNO₃+ClONO₂+HO₂NO₂+PAN with total NO_y a deficit of 30–40% (0.2–0.3 ppbv) in the troposphere remains unexplained whereas the values fit well in the stratosphere

Seasonal and interannual variations of HCN amounts in the upper troposphere and lower stratosphere observed by MIPAS

We present a HCN climatology of the years 2002-2012, derived from FTIR limb emission spectra measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the ENVISAT satellite, with the main focus on biomass burning signatures in the upper troposphere and lower stratosphere. HCN is an almost unambiguous tracer of biomass burning with a tropospheric lifetime of 5-6 months and a stratospheric lifetime of about 2 years. The MIPAS climatology is in good agreement with the HCN distribution obtained by the spaceborne ACE-FTS experiment and with airborne in situ measurements performed during the INTEX-B campaign. The HCN amounts observed by MIPAS in the southern tropical and subtropical upper troposphere have an annual cycle peaking in October-November, i.e. 1-2 months after the maximum of southern hemispheric fire emissions. The probable reason for the time shift is the delayed onset of deep convection towards austral summer. Because of overlap of varying biomass burning emissions from South America and southern Africa with sporadically strong contributions from Indonesia, the size and strength of the southern hemispheric plume have considerable interannual variations, with monthly mean maxima at, for example, 14 km between 400 and more than 700 pptv. Within 1-2 months after appearance of the plume, a considerable portion of the enhanced HCN is transported southward to as far as Antarctic latitudes. The fundamental period of HCN variability in the northern upper troposphere is also an annual cycle with varying amplitude, which in the tropics peaks in May after and during the biomass burning seasons in northern tropical Africa and southern Asia, and in the subtropics peaks in July due to trapping of pollutants in the Asian monsoon anticyclone (AMA). However, caused by extensive biomass burning in Indonesia and by northward transport of part of the southern hemispheric plume, northern HCN maxima also occur around October/November in several years, which leads to semi-annual cycles. There is also a temporal shift between enhanced HCN in northern low and mid- to high latitudes, indicating northward transport of pollutants. Due to additional biomass burning at mid- and high latitudes, this meridional transport pattern is not as clear as in the Southern Hemisphere. Upper tropospheric HCN volume mixing ratios (VMRs) above the tropical oceans decrease to below 200 pptv, presumably caused by ocean uptake, especially during boreal winter and spring. The tropical stratospheric tape recorder signal with an apparently biennial period, which was detected in MLS and ACE-FTS data from mid-2004 to mid-2007, is corroborated by MIPAS HCN data. The tape recorder signal in the whole MIPAS data set exhibits periodicities of 2 and 4 years, which are generated by interannual variations in biomass burning. The positive anomalies of the years 2003, 2007 and 2011 are caused by succession of strongly enhanced HCN from southern hemispheric and Indonesian biomass burning in boreal autumn and of elevated HCN from northern tropical Africa and the AMA in subsequent spring and summer. The anomaly of 2005 seems to be due to springtime emissions from tropical Africa followed by release from the summertime AMA. The vertical transport time of the anomalies is 1 month or less between 14 and 17 km in the upper troposphere and 8-11 months between 17 and 25 km in the lower stratosphere

Jugend im sozialistischen Großbetrieb (Großerhebung): Bd. 1: Hauptergebnisse, Probleme, Folgerungen

Der vorliegende Bericht enthält die Ergebnisse der ersten Großerhebung, die das Zentralinstitut für Jugendforschung Leipzig über die Entwicklung junger Arbeiter in einem Betrieb der chemischen Industrie in der Stadt Schwedt durchgeführt hat. Ziel der Untersuchung war die Analyse der Rolle und Bedingungen sozialistischer Arbeitskollektive für die Persönlichkeitsentwicklung junger Facharbeiter der chemischen Industrie "unter besonderer Berücksichtigung der Tätigkeit der Leiter bei der Gestaltung des entwickelten gesellschaftlichen Systems des Sozialismus und der Durchsetzung der wissenschaftlich-technischen Revolution". Es wurden 405 junge Facharbeiter im Alter von 18 bis 26 Jahren und 169 Facharbeiter über 26 Jahre befragt. In der Untersuchung wurde die Einstellung junger Arbeiter zu den Bedingungen erfaßt, die sich aus der Errichtung des "gesellschaftlichen Systems des Sozialismus und der Durchführung der wissenschaftlich-technischen Revolution" ergeben, und es wurde überprüft, inwieweit sich diese Bedingungen des Produktions- und Reproduktionsprozesses auf die Einstellung und Verhaltensweisen der jungen Arbeiter auswirken. Dazu diente die Ermittlung der Stellung der jungen Arbeiter "in den Arbeitskollektiven und deren erzieherischer und persönlichkeitsbildender Einfluß" auf die Jugendlichen. Die Befragung hat ergeben, daß die Mehrheit der jungen Arbeiter politisch-ideologisch dem Marxismus-Leninismus und ihrem Staat verbunden ist. Die Befragten sind von der positiven Entwicklung der DDR-Volkswirtschaft überzeugt. Ihre Einstellung zur Arbeit wird als positiv erachtet, sowie ihre Einstellung zur FDJ. Bei der Gruppe der 21- bis 24jährigen zeigt sich, daß diese in vielen Einstellungs- und Verhaltensbereichen weniger positiv als die jüngeren Jugendlichen bzw. die über 26 Jahre alten Arbeitnehmer urteilen. (psz

Corrigendum to "Seasonal and interannual variations of HCN amounts in the upper troposphere and lower stratosphere observed by MIPAS" published in Atmos. Chem. Phys., 15, 563-582, 2015

No abstract available