scholarly journals Atmospheric Blocking Signatures in Total Ozone and Ozone Miniholes

2010 ◽  
Vol 23 (14) ◽  
pp. 3967-3983 ◽  
Author(s):  
David Barriopedro ◽  
Manuel Antón ◽  
José Agustín García
Keyword(s):  
Total Ozone ◽  
Polar Vortex ◽  
Atmospheric Blocking ◽  
Weather Forecasts ◽  
The Pacific ◽  
Working Together ◽  
The Relationship ◽  
European Sector ◽  
Ozone Column

Abstract This paper analyzes the statistical relationship between the total ozone column (TOC) and atmospheric blocking using 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data for the 1978–98 period, with special emphasis on winter and the European and eastern Pacific sectors. Regional blocking occurrence is accompanied by a decrease of TOC within the anticyclonic circulation region and a distinctive ozone increase upstream and downstream (upstream and south) in the Pacific (European) sector. Blocking significantly enhances the likelihood of low TOC extremes, especially over the Scandinavian and the Alaska Peninsulas, where more than 50% of winter blocks lead to TOC values in the lowest tail of the distribution. The relationship between ozone miniholes and blocking is confined to the high latitudes of both basins and is strong in Europe, where about half of the ozone miniholes occur simultaneously with blocking. Blocking-related ozone miniholes (blocking ozone miniholes) are also among the most intense and persistent. Although blocking activity does not drive the interannual variability of regional ozone miniholes, blocking ozone miniholes account for up to two-thirds of the total observed trend of ozone miniholes in Europe. The polar vortex is proposed as a feasible candidate for explaining the enhanced coupling of blocking and ozone miniholes in Europe and its long-term modulation. Blocking ozone miniholes are consistent with an almost purely dynamic origin caused by horizontal transport of ozone-poor air and vertical motions working together at different levels to reduce ozone content. Although the contribution of the former is dominant, accounting for two-thirds of ozone reduction in the 330–850-K column, the effect of the latter becomes a distinctive feature of blocking ozone miniholes.

scholarly journals Geophysical validation and long-term consistency between GOME-2/MetOp-A total ozone column and measurements from the sensors GOME/ERS-2, SCIAMACHY/ENVISAT and OMI/Aura

2012 ◽  
Vol 5 (9) ◽  
pp. 2169-2181 ◽  
Author(s):  
M. E. Koukouli ◽  
D. S. Balis ◽  
D. Loyola ◽  
P. Valks ◽  
W. Zimmer ◽  
...  
Keyword(s):  
Total Ozone ◽  
Satellite Monitoring ◽  
Total Ozone Column ◽  
Satellite Sensors ◽  
Data Processor ◽  
Ozone Monitoring ◽  
Scanning Imaging ◽  
Ozone Column ◽  
Seasonal Dependence

Abstract. The main aim of the paper is to assess the consistency of five years of Global Ozone Monitoring Experiment-2/Metop-A [GOME-2] total ozone columns and the long-term total ozone satellite monitoring database already in existence through an extensive inter-comparison and validation exercise using as reference Brewer and Dobson ground-based measurements. The behaviour of the GOME-2 measurements is being weighed against that of GOME (1995–2011), Ozone Monitoring Experiment [OMI] (since 2004) and the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY [SCIAMACHY] (since 2002) total ozone column products. Over the background truth of the ground-based measurements, the total ozone columns are inter-evaluated using a suite of established validation techniques; the GOME-2 time series follow the same patterns as those observed by the other satellite sensors. In particular, on average, GOME-2 data underestimate GOME data by about 0.80%, and underestimate SCIAMACHY data by 0.37% with no seasonal dependence of the differences between GOME-2, GOME and SCIAMACHY. The latter is expected since the three datasets are based on similar DOAS algorithms. This underestimation of GOME-2 is within the uncertainty of the reference data used in the comparisons. Compared to the OMI sensor, on average GOME-2 data underestimate OMI_DOAS (collection 3) data by 1.28%, without any significant seasonal dependence of the differences between them. The lack of seasonality might be expected since both the GOME data processor [GDP] 4.4 and OMI_DOAS are DOAS-type algorithms and both consider the variability of the stratospheric temperatures in their retrievals. Compared to the OMI_TOMS (collection 3) data, no bias was found. We hence conclude that the GOME-2 total ozone columns are well suitable to continue the long-term global total ozone record with the accuracy needed for climate monitoring studies.

Temporal and Spatial Variability and Trend Investigation of Total Ozone Column over Iraq Employing Remote Sensing Data: 1979-2012

2015 ◽  
Vol 53 ◽  
pp. 1-18
Author(s):  
Ali M. Al-Salihi ◽  
Zehraa M. Hassan
Keyword(s):  
Remote Sensing ◽  
Spatial Variability ◽  
Total Ozone ◽  
Positive Trend ◽  
Climate Change Research ◽  
Total Ozone Column ◽  
Temporal And Spatial Variability ◽  
Temporal And Spatial ◽  
Ozone Column

The objective of this paper is to analyze the temporal and spatial variability of the total ozone column (TOC) distributions and trends over Iraq, during the last 30 years (1979–2012) using remote sensing-derived TOC data. Due to shortage of ground-based TOC measurements. TOC data derived from the Total Ozone Mapping Spectrometer (TOMS) for the period 1979–2004 and Ozone Monitoring Instrument (OMI) for the period 2005–2012 with spatial resolution (1o×1o) were used in present study. The spatial, long-term, monthly variations of TOC over Iraq were analysed. For the spatial variability, the latitudinal variability has a large range between (45 to 55) DU in winter and spring whereas during summer and autumn months ranged between (6 to 10) DU. Also represents an annual cycle with maximum in March and minimum in October. In contrast, the longitudinal variability is not significant. The long-term variability represented a notable decline for the period 1979–2012. The ozone negative trend was observed significantly during 1979–2004, for all months with trend ranged between (− 0.3 to 2) DU/year whereas the ozone positive trend was appear clearly during 2005–2007, for all months (0.1 to 2.3) DU/year ,except February and September which presented negative trends. The results can provide comprehensive descriptions of the TOC variations in Iraq and benefit climate change research in this region.

scholarly journals Extended and refined multi sensor reanalysis of total ozone for the period 1970–2012

2015 ◽  
Vol 8 (3) ◽  
pp. 3283-3319 ◽  
Author(s):  
R. J. van der A ◽  
M. A. F. Allaart ◽  
H. J. Eskes
Keyword(s):  
Data Assimilation ◽  
Total Ozone ◽  
Transport Model ◽  
Forecast Error ◽  
Satellite Observations ◽  
Weather Forecasts ◽  
Stratospheric Temperature ◽  
The Individual ◽  
Data Assimilation Technique ◽  
Ozone Column

Abstract. The ozone multi-sensor reanalysis (MSR) is a multi-decadal ozone column data record constructed using all available ozone column satellite datasets, surface Brewer and Dobson observations and a data assimilation technique with detailed error modelling. The result is a high-resolution time series of 6 hourly global ozone column fields and forecast error fields that may be used for ozone trend analyses as well as detailed case studies. The ozone MSR is produced in two steps. First, the latest reprocessed versions of all available ozone column satellite datasets are collected, and are corrected for biases as function of solar zenith angle, viewing angle, time (trend), and stratospheric temperature using Brewer/Dobson ground measurements from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC; http://www.woudc.org/). Subsequently the debiased satellite observations are assimilated within the ozone chemistry and data assimilation model TMDAM driven by meteorological analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF). The MSR2 (MSR version 2) reanalysis upgrade described in this paper consists of an ozone record for the 43 year period 1970–2012. The chemistry-transport model and data assimilation system have been adapted to improve the resolution, error modelling and processing speed. BUV satellite observations have been included for the period 1970–1977. The total record is extended with 13 years compared to the first version of the ozone multi sensor reanalysis, the MSR1. The latest total ozone retrievals of 15 satellite instruments are used: BUV-Nimbus4, TOMS-Nimbus7, TOMS-EP, SBUV-7, -9, -11, -14, -16, -17, -18, -19, GOME, SCIAMACHY, OMI and GOME-2. The resolution of the model runs, assimilation and output is increased from 2° x 3° to 1° x 1°. The analysis is driven by three-hourly meteorology from the ERA-interim reanalysis of ECMWF starting from 1979, and ERA-40 before that date. The chemistry parameterization has been updated. The performance of the MSR2 analysis is studied with the help of observation-minus-forecast (OmF) departures from the data assimilation, by comparisons with the individual station observations and with ozone sondes. The OmF statistics show that the mean bias of the MSR2 analyses is less than 1% with respect to debiased satellite observations after 1979.

scholarly journals NDACC UV-visible total ozone measurements: improved retrieval and comparison with correlative satellite and ground-based observations

2010 ◽  
Vol 10 (8) ◽  
pp. 20405-20460
Author(s):  
F. Hendrick ◽  
J.-P. Pommereau ◽  
F. Goutail ◽  
R. D. Evans ◽  
D. Ionov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Total Ozone ◽  
Complete Removal ◽  
Temperature Correction ◽  
Atmospheric Composition ◽  
Vertical Column ◽  
Stratospheric Temperature ◽  
Uv Visible ◽  
Ozone Column

Abstract. Accurate long-term monitoring of total ozone is one of the most important requirements for identifying possible natural or anthropogenic changes in the composition of the stratosphere. For this purpose, the NDACC (Network for the Detection of Atmospheric Composition Change) UV-visible Working Group has made recommendations for improving and homogenizing the retrieval of total ozone columns from twilight zenith-sky visible spectrometers. These instruments, deployed all over the world in about 35 stations, allow measurements of total ozone twice daily with little sensitivity to stratospheric temperature and cloud cover. The NDACC recommendations address both the DOAS retrieval parameters and the calculation of air mass factors (AMF) needed for the conversion of O3 slant column densities into vertical column amounts. The most important improvement is the use of O3 AMF look-up tables calculated using the TOMS V8 O3 profile climatology, that allows accounting for the dependence of the O3 AMF on the seasonal and latitudinal variations of the O3 vertical distribution. To investigate their impact on the retrieved ozone columns, the recommendations have been applied to measurements from the NDACC/SAOZ (Système d'Analyse par Observation Zénithale) network. The revised SAOZ ozone data from eight stations covering all latitude regions have been compared to TOMS, GOME-GDP4, SCIAMACHY-TOSOMI, OMI-TOMS, and OMI-DOAS satellite overpass observations, as well as to those of collocated Dobson and Brewer instruments. A significant improvement is obtained after applying the new O3 AMFs, although systematic seasonal differences between SAOZ and all other instruments remain. These are shown to mainly originate from i) the temperature dependence of the ozone absorption cross sections in the UV being not or improperly corrected by some retrieval algorithms, and ii) the longitudinal differences in tropospheric ozone column being ignored by zonal climatologies. For those measurements sensitive to stratospheric temperature like TOMS, OMI-TOMS, Dobson and Brewer, the application of a temperature correction results in the almost complete removal of the seasonal difference with SAOZ, improving significantly the consistency between all ground-based and satellite total ozone observations.

Early economic encounters in the Pacific or, proto-globalization in Tonga

2010 ◽  
Vol 166 (2-3) ◽  
pp. 293-314
Author(s):  
Paul Van der Grijp
Keyword(s):  
Nation State ◽  
Local Autonomy ◽  
Time And Space ◽  
Social Scientists ◽  
Capitalist Economy ◽  
Global Capital ◽  
The Pacific ◽  
Economy Globalization ◽  
The Relationship

This article aims to demonstrate the degree and nature of local autonomy in long term processes of globalization in Tonga. Tonga is exceptional in that it has never been officially colonized and in the continuity of its political (paramount chiefly) system. Also, but this is less exceptional, it has never had a pure modernistic, capitalist economy. Globalization is a specific, contemporary configuration in the relationship between capital and the nation-state or, in the words of William Greider (1997), it is like ‘a runaway horse without a rider’. Global capital is characterized by strategies of predatory mobility. However, the global and the national are not necessarily exclusive but are interacting and overlapping. Social scientists work with the nation-state as a container which would represent a unit in time and space, a ‘unified spatiotemporality’ according to the sociologist Saskia Sassen (2000). She adds that much history failed to confirm the latter hypothesis. The author may add from his part that anthropologists, although alike ‘social scientists’, rather work with the notions of culture and society which, in the case of more recent Tongan history, overlap with that of the nation-state. Although the notion of globalization is a rather recent invention with an exclusive contemporary application, we may discern the roots of its practice already in the early trading contacts between Europeans and Tongans.

scholarly journals GUV long-term measurements of total ozone column and effective cloud transmittance at three Norwegian sites

2021 ◽  
Vol 21 (10) ◽  
pp. 7881-7899
Author(s):  
Tove M. Svendby ◽  
Bjørn Johnsen ◽  
Arve Kylling ◽  
Arne Dahlback ◽  
Germar H. Bernhard ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Total Ozone ◽  
Monitoring Network ◽  
High Time Resolution ◽  
Data Sets ◽  
Total Ozone Column ◽  
Ice Melt ◽  
Arctic Ice ◽  
Ozone Column

Abstract. Measurements of total ozone column and effective cloud transmittance have been performed since 1995 at the three Norwegian sites Oslo/Kjeller, Andøya/Tromsø, and in Ny-Ålesund (Svalbard). These sites are a subset of nine stations included in the Norwegian UV monitoring network, which uses ground-based ultraviolet (GUV) multi-filter instruments and is operated by the Norwegian Radiation and Nuclear Safety Authority (DSA) and the Norwegian Institute for Air Research (NILU). The network includes unique data sets of high-time-resolution measurements that can be used for a broad range of atmospheric and biological exposure studies. Comparison of the 25-year records of GUV (global sky) total ozone measurements with Brewer direct sun (DS) measurements shows that the GUV instruments provide valuable supplements to the more standardized ground-based instruments. The GUV instruments can fill in missing data and extend the measuring season at sites with reduced staff and/or characterized by harsh environmental conditions, such as Ny-Ålesund. Also, a harmonized GUV can easily be moved to more remote/unmanned locations and provide independent total ozone column data sets. The GUV instrument in Ny-Ålesund captured well the exceptionally large Arctic ozone depletion in March/April 2020, whereas the GUV instrument in Oslo recorded a mini ozone hole in December 2019 with total ozone values below 200 DU. For all the three Norwegian stations there is a slight increase in total ozone from 1995 until today. Measurements of GUV effective cloud transmittance in Ny-Ålesund indicate that there has been a significant change in albedo during the past 25 years, most likely resulting from increased temperatures and Arctic ice melt in the area surrounding Svalbard.

scholarly journals Record low ozone values over the Arctic in boreal spring 2020

2021 ◽  
Vol 21 (2) ◽  
pp. 617-633
Author(s):  
Martin Dameris ◽  
Diego G. Loyola ◽  
Matthias Nützel ◽  
Melanie Coldewey-Egbers ◽  
Christophe Lerot ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Total Ozone ◽  
Stratospheric Ozone ◽  
Polar Vortex ◽  
Ozone Hole ◽  
The Arctic ◽  
Atmospheric Conditions ◽  
Total Ozone Column ◽  
The Antarctic ◽  
Ozone Column

Abstract. Ozone data derived from the Tropospheric Monitoring Instrument (TROPOMI) sensor on board the Sentinel-5 Precursor satellite show exceptionally low total ozone columns in the polar region of the Northern Hemisphere (Arctic) in spring 2020. Minimum total ozone column values around or below 220 Dobson units (DU) were seen over the Arctic for 5 weeks in March and early April 2020. Usually the persistence of such low total ozone column values in spring is only observed in the polar Southern Hemisphere (Antarctic) and not over the Arctic. These record low total ozone columns were caused by a particularly strong polar vortex in the stratosphere with a persistent cold stratosphere at higher latitudes, a prerequisite for ozone depletion through heterogeneous chemistry. Based on the ERA5, which is the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis, the Northern Hemisphere winter 2019/2020 (from December to March) showed minimum polar cap temperatures consistently below 195 K around 20 km altitude, which enabled enhanced formation of polar stratospheric clouds. The special situation in spring 2020 is compared and discussed in context with two other Northern Hemisphere spring seasons, namely those in 1997 and 2011, which also displayed relatively low total ozone column values. However, during these years, total ozone columns below 220 DU over several consecutive days were not observed in spring. The similarities and differences of the atmospheric conditions of these three events and possible explanations for the observed features are presented and discussed. It becomes apparent that the monthly mean of the minimum total ozone column value for March 2020 (221 DU) was clearly below the respective values found in March 1997 (267 DU) and 2011 (252 DU), which highlights the special evolution of the polar stratospheric ozone layer in the Northern Hemisphere in spring 2020. A comparison with a typical ozone hole over the Antarctic (e.g., in 2016) indicates that although the Arctic spring 2020 situation is remarkable, with total ozone column values around or below 220 DU observed over a considerable area (up to 0.9 million km2), the Antarctic ozone hole shows total ozone columns typically below 150 DU over a much larger area (of the order of 20 million km2). Furthermore, total ozone columns below 220 DU are typically observed over the Antarctic for about 4 months.

scholarly journals The influence of polar vortex ozone depletion on NH mid-latitude ozone trends in spring

2006 ◽  
Vol 6 (10) ◽  
pp. 2837-2845 ◽  
Author(s):  
S. B. Andersen ◽  
B. M. Knudsen
Keyword(s):  
Lower Limit ◽  
Ozone Depletion ◽  
Total Ozone ◽  
Polar Vortex ◽  
Major Fraction ◽  
Total Ozone Column ◽  
Trajectory Calculations ◽  
Ozone Trends ◽  
Decadal Variations ◽  
Ozone Column

Abstract. Reverse domain-filling trajectory calculations have been performed for the years 1993, 1995, 1996, 1997, and 2000 to calculate the spreading of ozone depleted air from the polar vortex to midlatitudes in spring. We find that for these years with massive Arctic ozone depletion the zonal mean total ozone column at midlatitudes is reduced with between 7 and 12 DU in the April-May period. The polar vortex and remnants have preferred locations which leads to longitudinal differences in the midlatitude ozone trends. Together with decadal variations in circulation the dilution of ozone depleted air may explain the major fraction of longitudinal differences in midlatitude ozone trends. For the period 1979–1997 the dilution may explain 50% of the longitudinal differences in ozone trends and for the period 1979–2002 it may explain 45%. The dilution also has a significant impact on the zonal mean ozone trends in the April-May period. Although uncertainties are large due to uncertainties in the ozone depletion values and neglect of ozone depletion in other years than 1993, 1995, 1996, 1997, and 2000 we have tried to calculate the size of this effect. We estimate that dilution may explain 29% of the trend in the period 1979–1997 and 33% of the trend in the period 1979–2002 as a lower limit.

scholarly journals Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

2018 ◽  
Author(s):  
Anna Maria Siani ◽  
Francesco Scarlatti ◽  
Arianna Religi ◽  
Henri Diémoz ◽  
Giuseppe R. Casale ◽  
...  
Keyword(s):  
Total Ozone ◽  
Terrestrial Ecosystem ◽  
Ozone Monitoring Instrument ◽  
Web Based ◽  
Software Packages ◽  
Short And Long Term ◽  
Processing Software ◽  
Ozone Column ◽  
Standard Lamp

Abstract. The availability of long-term records of the total ozone content (TOC) represents a valuable source of information in studies on the assessment of short and long-term changes and their impact on the terrestrial ecosystem. In addition, ground-based observations represent a valuable tool to validate satellite-derived products. To our knowledge, details about processing software packages to retrieve the TOC from Brewer spectrophotometer measurements are seldom specified in studies concerning such datasets, although some discrepancies can arise from the use of different algorithms and implementations. The deviations among retrieved TOCs from the Brewer instruments located at Rome and Aosta (Italy), using different processing software (Brewer Processing Software, O3Brewer software and EUBREWNET products (Level 1.5) are investigated. Ground-based TOCs are also compared with the Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites, are available. Although the overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is clearly very good (as expected) and in most cases within the Brewer declared uncertainty less than 2 %, it is worth noticing that slight differences have been seen depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a long-term drift and even in short-term episodes due to the different algorithm for the standard lamp correction. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometry and for stakeholders of the Brewer data products available at web-based platforms.

Sign in / Sign up

Export Citation Format

Share Document