Relation between total ozone and sub-tropical jet stream

This article investigates the relationship between total ozone and subtropical jet stream (STJ). Total ozone data have been obtained from the total ozone mapping spectrometer (TOMS) instrument on the Nimbus - 7 satellite and have been examined in conjunction with meteorological data in the region 90°- 160°E, 20° -50°N, i.e., the entrance region of the East Asian STJ from October 1982 to September 1983. The STJ marks the boundary between the high tropical tropopause (ca. 1000 hPa) and lower subtropical tropopause (ca. 200 hPa). In winter it has been found that the total ozone contours are almost parallel to the wind direction, and the horizontal gradient in total ozone increases as the wind speed strengthens. The STJ normally marks a steep gradient in total ozone but in spring anomalous patterns are seen sometimes with very small gradients across the jet. A particular study has been conducted of these events, which are associated with a layer of relatively low but still stratospheric potential vorticity (PV) at around 150 hPa (380K) on the poleward side of the jet. This appears to be consistent with a transfer of air from troposphere to stratosphere above the jet core in March and April.

Study of Variability of Atmospheric Ozone over Jumla in Half Period of 24 Solar Cycle

This paper reports the variation of total ozone column (TOC) over Jumla (Lat.:-29.28° N, Long.:-82.16° E and Alt.:- 2300 m above sea level) from 2008 to 2014 derived from Total Ozone Mapping Spectrometer (TOMS) satellite observations. The monthly, seasonal, annual variations of TOC, solar insolation and clearness index have been analyzed. The result exemplifies that during the whole study period, the maximum value of monthly average TOC is 289.21 DU ± 10.75 DU in April, while the minimum value is 257.23 DU ± 11.25 DU in December. The results also show that TOC is highly seasonal dependent with larger TOC in spring 273.68 DU ± 14.92 DU and lower in the winter season (260.68 DU ± 15.25 DU). The average annual value of TOC exhibits slightly variable with a maximum in 2010 (277.52 DU ± 40.64 DU) and minimum in 2008 (267.19 DU ± 11.11 DU). The average values of solar insolation and clearness index for whole study the period are 5.10 86 kWh/m2/day ± 0.86 kWh/m2/day and 0.59 ± 0.12 respectively. The average value of TOC during the whole study period is 271.84 DU ± 14.19 DU, which indicates a good amount of stratospheric ozone content over Jumla.

Calculating the Height and the Position of Volcanic Cloud SO2 With a Lagrangian Trajectory Tool

<p>We have developed a new trajectory tool to reconstruct the altitude and the position of SO<sub>2</sub> in a volcanic plume. Starting with 2D map of satellite observed SO<sub>2</sub>, known volcano location, and reanalysis wind fields from the NASA Goddard Earth Observing System (GEOS) model, the Goddard trajectory tool allows us to estimate the altitude and concentration of SO<sub>2</sub> in the volcanic plume at time of observation. We used this tool for the June 21, 2019 Mt. Raikoke eruption and the June 15, 1991 Mt. Pinatubo event. We used SO<sub>2</sub> data from the Ozone Mapping and Profiler Suite/Nadir Mapper (OMPS/NM) onboard the NASA-NOAA Suomi satellite and obtained a distribution of SO<sub>2</sub> altitudes between 1 and 19 kilometers in different parts of the Raikoke SO<sub>2</sub> clouds, with the highest SO<sub>2</sub> concentration between 11 and 16 km, in good agreement with data from independent SO<sub>2</sub> layer height retrievals from the Ozone Monitoring Instrument (OMI) aboard the NASA Aura spacecraft; the Tropospheric Monitoring Instrument (TROPOMI) onboard the European Copernicus Sentinel 5 precursor satellite and Infrared Atmospheric Sounding Interferometer (IASI) on the European Space Agency's (ESA) MetOp series of a polar orbiting satellites. We then applied this method to the Pinatubo eruption using SO<sub>2</sub> column measurements from the NASA Total Ozone Mapping Spectrometer (TOMS) and using wind fields from the National Centers for Environmental Prediction Reanalysis version 2. We found that the southern part of the Pinatubo plume is located in the troposphere, and the northern part is in the stratosphere.</p>

Impacto do ENOS na Variabilidade da Coluna Total de Ozônio Sobre a Região Nordeste do Brasil - Parte 2: La Niña Canônico e Modoki

Resumo Este estudo apresenta a segunda etapa da avaliação espaço-temporal das tendências a longo prazo nos valores da Coluna Total de Ozônio (CTO) sobre o Nordeste Brasileiro (NEB) durante a atuação do modo de variabilidade atmosférica El Niño - Oscilação Sul (ENOS), com foco na fase La Niña (modalidades Canônica e Modoki). O objetivo é analisar a variação anual e os efeitos desse fenômeno na região de estudo no período entre 1997 e 2018. Os dados utilizados são provenientes de sensoriamento remoto, gerados pelos sensores Total Ozone Mapping Spectrometer (TOMS) e Ozone Monitoring Instrument (OMI), disponibilizados pela National Aeronautics and Space Administration (NASA), e analisados através de médias, valores de anomalias e diagramas hovmoller. Foi constatado que eventos La Niña provocam, predominantemente, aumento na concentração de ozônio sobre o NEB. Nos períodos de atuação desse modo de variabilidade a desaceleração da Circulação Brewer-Dobson (CBD) é causada pela intensificação dos ventos alísios gerando acúmulo de ozônio na região tropical. Entre as duas modalidades, fenômenos Modoki apresentam esse efeito mais intensificado. O maior (+6,5) e menor (-3,0) valor médio mensal de anomalia obtidos ocorreram durante sua atuação, registrados na região norte do NEB em julho e setembro, respectivamente.

Impacto do ENOS na Variabilidade da Coluna Total de Ozônio Sobre a Região Nordeste do Brasil - Parte 1: El Niño Canônico e Modoki

Resumo O objetivo deste trabalho é analisar a variação anual e os efeitos do modo de variabilidade atmosférica El Niño (Canônico e Modoki) na Coluna Total de Ozônio (CTO) sobre o Nordeste Brasileiro (NEB) entre 1997 e 2018 utilizando dados dos sensores Total Ozone Mapping Spectrometer (TOMS) e Ozone Monitoring Instrument (OMI). Foi constatada uma variação mensal média em toda área estudada com comportamento típico de domínio do ciclo anual na variabilidade sazonal, apresenta valor mínimo no mês de maio e máximo em outubro. Observou-se uma tendência de decaimento na série dos valores médios durante o período analisado. Análises de agrupamento revelaram que diferentes regiões da NEB possuem comportamentos e valores médios de CTO diferenciados. Análise de ondeletas expôs ciclos de doze meses de duração atuando na CTO em toda área estudada, ciclos de seis meses, demonstrando que o ciclo semianual domina a variabilidade sazonal em menores latitudes, e ciclos de dois-três anos, representando a importante atuação da Oscilação Quase Bienal (OQB). As médias das anomalias mostram que eventos El Niño afetam a CTO causando, predominantemente, diminuição de seus valores. Esses eventos em modalidade Modoki tem maior potencial em afetar a CTO que os Canônicos com anomalias negativas de maior intensidade.

Monitoramento de Longo Prazo e Climatologia de Campos Estratosféricos quando da Ocorrência dos Eventos de Influência do Buraco de Ozônio Antártico sobre o Sul do Brasil

Resumo O monitoramento de longo prazo dos eventos de Influência do Buraco de Ozônio Antártico sobre o Sul do Brasil foi realizado no período de 35 anos entre 1979 e 2013 e calculada a climatologia e anomalias dos campos estratosféricos quando de sua ocorrência. Para isso, foram analisados os dados da coluna total de ozônio (CTO) obtidos através de Espectrofotômetros Brewer, instalados no Observatório Espacial do Sul - OES/CRS/INPE - MCTIC (29,4 °S; 53,8 °O; 488,7 m) e pelos instrumentos de satélite Total Ozone Mapping Spectrometer (TOMS) e Ozone Monitoring Instrument (OMI), além de parâmetros da reanálise II do NCEP/DOE (National Centers for Environmental Prediction/ Departament of Energy) e trajetórias retroativas do modelo HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory). A metodologia empregada mostrou-se eficaz na identificação de 62 eventos com uma redução média de -9,35 ± 2,93% no conteúdo de ozônio. Além disso, foi realizada a identificação do padrão de circulação estratosférica através de campos médios e anomalias da vorticidade potencial, vento e temperatura para os dias de ocorrência do fenômeno, sendo observado um padrão de deslocamento de onda, embebida dentro de uma ampla região de circulação ciclônica, com ventos predominantemente de sul é advectado em direção ao Sul do Brasil.

Profile information on CO from SCIAMACHY observations using cloud slicing and comparison with model simulations

We apply a cloud slicing technique (CST), originally developed for Total Ozone Mapping Spectrometer (TOMS) ozone observations, to CO vertical column densities retrieved from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). CST makes use of the shielding effect of clouds and combines trace gas column measurements of cloudy pixels with different cloud heights to retrieve fractional columns aloft. Here we determine seasonal mean tropospheric CO profiles at a vertical resolution of about 1 km, which is much finer than what can be obtained from thermal infrared (IR) instruments. However, since both the atmospheric CO profiles and the effective cloud heights depend systematically on meteorology, and in addition part of the retrieved signal originates from the clear part of the satellite ground pixel, the profiles retrieved from the CST have to be interpreted with care. We compare the seasonal mean SCIAMACHY CO profiles with the output from two atmospheric models sampled in the same way as the satellite observations. We find in general good agreement of the spatial patterns, but systematic differences in the absolute values are observed in both hemispheres (more strongly in the Northern Hemisphere), indicating that the source strengths in the emission inventories are probably underestimated.

Assessment of the Latitudinal Behavior of Total Column Ozone at Nine Discrete 1º-Wide Latitude Bands, from TOMS and OMI Data

Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument OMI Version 8 data, from November 1978 to February 2013, have been used to retrieve the shape and amplitude of the daily mean of the total column ozone (TCO) and their associated dispersion over eleven selected 1°-wide latitude bands. Their inter-annual variation at 44.5° S, 23.5° S, 23.5° N, 44.5° N and 59.5° N shows a quasi-regular periodic behavior. However, Polar Regions exhibit abrupt changes, whereas at the Equator a complex perturbation of periodicity is highlighted, which could be associated to the effect of the quasi-biennial oscillation (QBO). The discrete 1°-wide latitude bands show a stabilization of TCO levels from the late nineties, but they do not display a generalized recovery. Indeed, at the Equator, between 1997 and 2013, a 1.4% per decade decrease in the total column ozone is exhibited, which may be significant given that during the 1987-1994 period the decrease was only of 0.5%. Additionally, the discrete bands reveal the appearance of a perturbation of the inter-annual ozone variations at 59.5° S, in contrast to regular behavior in the Northern Hemisphere and at other latitudes. The perturbation apparently begins in the 1980-1984 time series and is clear and systematic after 1998.

Validation of the Suomi NPP Ozone Mapping and Profiler Suite total column ozone using Brewer and Dobson spectrophotometers

This study mainly focuses on the validation of total column (TC) ozone data derived from the Ozone Mapping and Profiler Suite (OMPS) on board the NASA's Suomi National Polar-orbiting Partnership satellite (NPP). OMPS is an advanced suite of three hyperspectral instruments that maps global ozone on a daily basis and extends the more than 30 yr total ozone and ozone profile records. The algorithm used to derive OMPS TC ozone is adapted from the heritage of Total Ozone Mapping Spectrometer (TOMS) Version 7 algorithm but with a number of enhancements. Validation is primarily performed through comparisons with an ensemble of 74 global distributed Brewer and Dobson spectrophotometers measurements. Linear regression performs fair agreement between OMPS TC ozone and ground-based TC ozone measurements with root mean square error (RMSE) around of 3% (10 DU). Comparison shows that OMPS TC ozone estimates 0.21% higher than Brewer measurements average, with station-to-station standard deviation of 3.14%. As comparing with Dobson measurements, OMPS TC ozone averages 0.86% higher than the station average with standard deviation of 3.05%. The relative differences between OMPS and ground TC ozone were analysed varying with latitude and time as well as viewing geometry respectively. Comparisons show relative differences within 2% over most of latitude and viewing conditions. Only comparing with Brewer measurements did it show an OMPS TC ozone dependent error, large negative bias was observed as OMPS TC ozone below 220 DU and positive bias shown above 460 DU.

CO profiles from SCIAMACHY observations using cloud slicing and comparison with model simulations

We apply a cloud slicing technique (CST), originally developed for Total Ozone Mapping Spectrometer (TOMS) ozone observations, to CO vertical column densities retrieved from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY). CST makes use of the shielding effect of clouds and combines trace gas column measurements of cloudy pixels with different cloud heights to retrieve fractional columns aloft. Here we determine seasonal mean tropospheric CO profiles at a vertical resolution of 1 km, which is much finer than what can be obtained from thermal IR instruments. However, since both the atmospheric CO profiles and the effective cloud heights depend systematically on meteorology, the profiles retrieved from the CST have to be interpreted with care. We compare the seasonal mean SCIAMACHY CO profiles with the output from two atmospheric models sampled in the same way as the satellite observations. We find systematic differences both in the absolute values and vertical and horizontal gradients. The results indicate that vertical (re)distributions of emissions and their strengths are not well represented in the models. It seems likely that deep convective transport is underestimated.