A strategy for the measurement of CO2 distribution in the stratosphere

Abstract. In this study we introduce a new strategy for the measurement of CO2 distribution in the stratosphere. The proposed experiment is based on an orbiting limb sounder that measures the atmospheric emission within both the thermal infrared (TIR) and far-infrared (FIR) regions. The idea is to exploit the contribution of the pure rotational transitions of molecular oxygen in the FIR to determine the atmospheric fields of temperature and pressure that are necessary to retrieve the distribution of CO2 from its rovibrational transitions in the TIR. The instrument envisaged to test the new strategy is a Fourier transform spectrometer with two output ports hosting a FIR detector devoted to measuring the O2 transitions and a TIR detector devoted to measure the CO2 transitions. Instrumental and observational parameters of the proposed experiment have been defined by exploiting the heritage of both previous studies and operational limb sounders. The performance of the experiment has been assessed with two-dimensional (2-D) retrievals on simulated observations along a full orbit. For this purpose, optimal spectral intervals have been defined using a validated selection algorithm. Both precision and spatial resolution of the obtained CO2 distributions have been taken into account in the results–evaluation process. We show that the O2 spectral features significantly contribute to the performance of CO2 retrievals and that the proposed experiment can determine 2-D distributions of the CO2 volume mixing ratio with precisions of the order of 1 ppmv in the 10–50 km altitude range. The error budget, estimated for the test case of an ideal instrument and neglecting the spectroscopic errors, indicates that, in the 10–50 km altitude range, the total error of the CO2 fields is set by the random component. This is also the case at higher altitudes, provided the retrieval system is able to model the non-local thermal equilibrium conditions of the atmosphere. The best performance is obtained at altitudes between 20 and 50 km, where the vertical resolution ranges from 3 to 5 km, and the horizontal resolution is of the order of 300–350 km depending on latitude

Trabalho e intolerância religiosa: um estudo sobre a Problemática do preconceito contra praticantes de religiões de matriz africana no ambiente organizacional

The present article has as objective to analyze the influences and consequences of religious intolerance in the interpersonal behavior inside organizations. The study integrates African descent religions believers, that are part of African descent religions meetinghouse in the Médio Paraíba region. It has been deployed bibliographic and descriptive researches in field, with data collection spawned from focus groups using semi structured questions. Thirty participants were interviewed and divided into three groups of ten people each, with ages from 18 to 70 years old, with gender, ethnic and sexual orientation diversity. By the data analysis it has been brought to a conclusion that the religious intolerance is latent and emergent in the institutional ambit, being a great intensifier in interpersonal conflict and psychic suffering of the worker, in need of attention and new organizational strategies development. The conclusion also showed the necessity of growth of psychology professionals integration to contribute in solutions and confrontation of this problematic.Este artículo tiene por objeto analizar las influencias y consecuencias de la intolerancia religiosa en el comportamiento interpersonal dentro de las organizaciones. El estudio integra practicantes de religiones africanas, pertenecientes a centros de religión de origen africano en la región de Media Paraíba. La investigación bibliográfica y la investigación descriptiva se aplicaron en el campo, con la recopilación de datos de un grupo de focal utilizando preguntas semiestructuradas. Se entrevistó a treinta participantes, divididos en tres grupos de diez personas cada uno, con una edad mínima de 18 años y una edad máxima de 70, con diversidad de género, etnia y orientación sexual. Desde el análisis de datos se concluyó que la intolerancia religiosa es algo latente y emergente en el ámbito institucional, como también un gran potenciador de conflictos interpersonales y sufrimientos psíquicos del colaborador, que carece de atención y desarrollo de nuevas estrategias organizativas, así como una mayor integración de los profesionales de la psicología para contribuir a la solución y enfrentando este problema.O presente artigo tem como objetivo analisar as influências e consequências da intolerância religiosa no comportamento interpessoal dentro das organizações. O estudo integra professantes de religiões africana, pertencentes de centros de religião de matriz africana na região do Médio Paraíba. Foi aplicada pesquisa bibliográfica e pesquisa descritiva em campo, com coletas de dados a partir de grupo focal utilizando perguntas semiestruturadas. Foram entrevistados 30 participantes divididos em três grupos de dez pessoas cada, com idade mínima de 18 e máxima de 70 anos, com diversidade de gênero, etnia e orientação sexual. A partir da análise de dados chegou-se à conclusão que a intolerância religiosa é algo latente e emergente no âmbito institucional, sendo grande potencializador de conflitos interpessoais e sofrimento psíquico do colaborador, carecendo de atenção e desenvolvimento de novas estratégias organizacionais, assim como maior integração de profissionais da psicologia para contribuir na solução e enfrentamento dessa problemática

Phosgene in the UTLS: seasonal and latitudinal variations from MIPAS observations

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a Fourier transform spectrometer that measured mid-infrared atmospheric limb emission spectra from July 2002 to April 2012 on board the polar-orbiting satellite ENVISAT. We have used MIPAS data to study the latitudinal variations of phosgene (COCl2 or carbonyl chloride) and, for the first time, its seasonal variation in the upper troposphere/lower stratosphere region (UTLS). Retrievals of phosgene were made using the 830–860 cm−1 region, corresponding to the ν5 bands of COCl2. Unfortunately, in that region, the ν4 band of CFC-11, which is much stronger than COCl2 ν5, hides the phosgene emission. In order to evaluate seasonality and latitudinal distribution of phosgene we have analysed all the measurements made by MIPAS on days 18 and 20 of each month of 2008 with the optimized retrieval model (ORM) recently upgraded with the multi-target retrieval technique and with the optimal estimation functionality to apply external constraints to the state vector. Average seasonal profiles of phosgene show an evident latitudinal variability with the largest values observed in the tropical regions (maximum  ≈  35 parts per trillion by volume (pptv) at about 300 hPa). In the midlatitude and polar regions, the volume mixing ratio (VMR) values do not exceed 30 pptv and the vertical distributions are less peaked. Our analysis highlights that COCl2 seasonal variability is fairly low, apart from the polar regions

Differences in ozone retrieval in MIPAS channels A and AB: a spectroscopic issue

Discrepancies in ozone retrievals in MIPAS channels A (685–970cm−1) and AB (1020–1170cm−1) have been a long-standing problem in MIPAS data analysis, amounting to an interchannel bias (AB–A) of up to 8% between ozone volume mixing ratios in the altitude range 30–40km. We discuss various candidate explanations, among them forward model and retrieval algorithm errors, interchannel calibration inconsistencies and spectroscopic data inconsistencies. We show that forward-modelling errors as well as errors in the retrieval algorithm can be ruled out as an explanation because the bias can be reproduced with an entirely independent retrieval algorithm (GEOFIT), relying on a different forward radiative transfer model. Instrumental and calibration issues can also be refuted as an explanation because ozone retrievals based on balloon-borne measurements with a different instrument (MIPAS-B) and an independent level-1 data processing scheme produce a rather similar interchannel bias. Thus, spectroscopic inconsistencies in the MIPAS database used for ozone retrieval are practically the only reason left. To further investigate this issue, we performed retrievals using additional spectroscopic databases. Various versions of the HITRAN database generally produced rather similar channel AB–A differences. Use of a different database, namely GEISA-2015, led to similar results in channel AB, but to even higher ozone volume mixing ratios for channel A retrievals, i.e. to a reversal of the bias. We show that the differences in MIPAS channel A retrievals result from about 13% lower air-broadening coefficients of the strongest lines in the GEISA-2015 database. Since the errors in line intensity of the major lines used in MIPAS channels A and AB are reported to be considerably lower than the observed bias, we posit that a major part of the channel AB–A differences can be attributed to inconsistent air-broadening coefficients as well. To corroborate this assumption we show some clearly inconsistent air-broadening coefficients in the HITRAN-2008 database. The interchannel bias in retrieved ozone amounts can be reduced by increasing the air-broadening coefficients of the lines in MIPAS channel AB in the HITRAN-2008 database by 6%–8%

Phosgene distribution derived from MIPAS ESA v8 data: intercomparisons and trends

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) measured the middle-infrared limb emission spectrum of the atmosphere from 2002 to 2012 on board ENVISAT, a polar-orbiting satellite. Recently, the European Space Agency (ESA) completed the final reprocessing of MIPAS measurements, using version 8 of the level 1 and level 2 processors, which include more accurate models, processing strategies, and auxiliary data. The list of retrieved gases has been extended, and it now includes a number of new species with weak emission features in the MIPAS spectral range. The new retrieved trace species include carbonyl chloride (COCl2), also called phosgene. Due to its toxicity, its use has been reduced over the years; however, it is still used by chemical industries for several applications. Besides its direct injection in the troposphere, stratospheric phosgene is mainly produced from the photolysis of CCl4, a molecule present in the atmosphere because of human activity. Since phosgene has a long stratospheric lifetime, it must be carefully monitored as it is involved in the ozone destruction cycles, especially over the winter polar regions. In this paper we exploit the ESA MIPAS version 8 data in order to discuss the phosgene distribution, variability, and trends in the middle and lower stratosphere and in the upper troposphere. The zonal averages show that phosgene volume mixing ratio is larger in the stratosphere, with a peak of 40 pptv (parts per trillion by volume) between 50 and 30 hPa at equatorial latitudes, while at middle and polar latitudes it varies from 10 to 25 pptv. A moderate seasonal variability is observed in polar regions, mostly between 80 and 50 hPa. The comparison of MIPAS–ENVISAT COCl2 v8 profiles with the ones retrieved from MIPAS balloon and ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) measurements highlights a negative bias of about 2 pptv, mainly in polar and mid-latitude regions. Part of this bias is attributed to the fact that the ESA level 2 v8 processor uses an updated spectroscopic database. For the trend computation, a fixed pressure grid is used to interpolate the phosgene profiles, and, for each pressure level, VMR (volume mixing ratio) monthly averages are computed in pre-defined 10∘ wide latitude bins. Then, for each latitudinal bin and pressure level, a regression model has been fitted to the resulting time series in order to derive the atmospheric trends. We find that the phosgene trends are different in the two hemispheres. The analysis shows that the stratosphere of the Northern Hemisphere is characterized by a negative trend of about −7 pptv per decade, while in the Southern Hemisphere phosgene mixing ratios increase with a rate of the order of +4 pptv per decade. This behavior resembles the stratospheric trend of CCl4, which is the main stratospheric source of COCl2. In the upper troposphere a positive trend is found in both hemispheres.</p