Stratospheric ozone trends and variability as seen by SCIAMACHY during the last decade

Abstract. Vertical profiles of the rate of linear change (trend) in the altitude range 15–50 km are determined from decadal O3 time series obtained from SCIAMACHY/ENVISAT measurements in limb viewing geometry. The trends are calculated by using a multivariate linear regression in the zonal bands 5° S–5° N (tropics), 50–60° N, and 50–60° S (mid- to high latitudes). Seasonal terms, the quasi-biennial oscillation, and solar cycle variations are accounted for in the regression. In the tropics, positive trends between 15 and 30 km and negative trends between 30 and 35 km are identified. Moderately positive O3 trends are found in the upper stratosphere of the tropics and midlatitudes. The explanation favoured for the observed positive and negative trends in the tropical lower and middle stratosphere is NOx chemistry. Comparisons between SCIAMACHY and EOS MLS in the tropics and at midlatitudes show good agreement. In the tropics, measurements from OSIRIS/Odin and SHADOZ are analysed resulting in very similar vertical profiles of the rate of linear change of O3. Observed trends in the stratospheric column derived from integrated SCIAMACHY limb O3 profiles and nadir total columns are found to be consistent.

Download Full-text

Halogen Occultation Experiment (HALOE) and balloon-borne in situ measurements of methane in stratosphere and their relation to the quasi-biennial oscillation (QBO)

Atmospheric Chemistry and Physics ◽

10.5194/acp-3-1051-2003 ◽

2003 ◽

Vol 3 (4) ◽

pp. 1051-1062 ◽

Cited By ~ 11

Author(s):

P. K. Patra ◽

S. Lal ◽

S. Venkataramani ◽

D. Chand

Keyword(s):

Transport Model ◽

Measurement Techniques ◽

Vertical Profiles ◽

Quasi Biennial Oscillation ◽

Chemistry Transport Model ◽

The Tropics ◽

Biennial Oscillation ◽

Good Agreement ◽

Balloon Measurements

Abstract. Measurements of methane have been made from various observational platforms in the atmosphere. In this article, we have compared four high precision balloon-borne measurements from Hyderabad (17.5°N), India in the period of 1987 and 1998 with a part of HALOE/UARS global observations available since 1991. All the balloon measurements correspond to boreal spring (March and April) but belong to different years. A comparison shows fairly good agreement with each other. The gradient in CH4 profiles in the troposphere is controlled by the variation in vertical transport. The strongest effect of dynamical influence on methane vertical profiles is shown to be resulting from the dynamical quasi-biennial oscillation in the stratosphere, and that has been consistently derived from both the measurement techniques and chemistry-transport model simulations. It is observed that the QBO signal in CH4 anomaly exhibits interhemispheric asymmetry caused by the tropics to midlatitude circulation in the stratosphere. A mechanism is suggested to explain how and to what extent the methane vertical profiles over Hyderabad and higher latitudes could be modulated by the prevailing QBO winds in the tropics. We have also discussed how the same mechanism would affect ozone distribution in the stratosphere quite differently.

Download Full-text

Halogen Occultation Experiment (HALOE) and balloon-borne in situ measurements of methane in stratosphere and their relation to the quasi-biennial oscillation (QBO)

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-3-1925-2003 ◽

2003 ◽

Vol 3 (2) ◽

pp. 1925-1947

Author(s):

P. K. Patra ◽

S. Lal ◽

D. Chand

Keyword(s):

Measurement Techniques ◽

Vertical Profiles ◽

Interhemispheric Asymmetry ◽

Quasi Biennial Oscillation ◽

Ozone Distribution ◽

The Tropics ◽

Biennial Oscillation ◽

Good Agreement ◽

Balloon Measurements

Abstract. Measurements of methane have been made from various observational platforms in the atmosphere. In this article, we have compared four high precision balloon-borne measurements from Hyderabad (17.5° N), India in the period of 1987 and 1998 with a part of HALOE/UARS global observations available since 1991. All the balloon measurements correspond to boreal spring (March and April) but belong to different years. A comparison shows fairly good agreement with each other. The strongest effect of dynamical influence on methane vertical profiles is shown to be resulting from the quasi-biennial oscillation (QBO) in the stratosphere, and that has been consistently derived from both the measurement techniques. It is observed that the QBO signal in CH4 anomaly exhibits interhemispheric asymmetry caused by the tropics to midlatitude circulation in the stratosphere. A mechanism is suggested to explain how and to what extent the methane vertical profiles over Hyderabad and higher latitudes could be modulated by the prevailing QBO winds in the tropics. We have also discussed how the same mechanism would affect ozone distribution in the stratosphere quite differently.

Download Full-text

Stratospheric ozone trends and variability as seen by SCIAMACHY from 2002 to 2012

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-831-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 831-846 ◽

Cited By ~ 60

Author(s):

C. Gebhardt ◽

A. Rozanov ◽

R. Hommel ◽

M. Weber ◽

H. Bovensmann ◽

...

Keyword(s):

Southern Oscillation ◽

Stratospheric Ozone ◽

Environmental Research ◽

Time Range ◽

Linear Change ◽

Quasi Biennial Oscillation ◽

Earth Observing System ◽

Ozone Trends ◽

Scanning Imaging ◽

The Tropics

Abstract. Vertical profiles of the rate of linear change (trend) in the altitude range 15–50 km are determined from decadal O3 time series obtained from SCIAMACHY1/ENVISAT2 measurements in limb-viewing geometry. The trends are calculated by using a multivariate linear regression. Seasonal variations, the quasi-biennial oscillation, signatures of the solar cycle and the El Niño–Southern Oscillation are accounted for in the regression. The time range of trend calculation is August 2002–April 2012. A focus for analysis are the zonal bands of 20° N–20° S (tropics), 60–50° N, and 50–60° S (midlatitudes). In the tropics, positive trends of up to 5% per decade between 20 and 30 km and negative trends of up to 10% per decade between 30 and 38 km are identified. Positive O3 trends of around 5% per decade are found in the upper stratosphere in the tropics and at midlatitudes. Comparisons between SCIAMACHY and EOS MLS3 show reasonable agreement both in the tropics and at midlatitudes for most altitudes. In the tropics, measurements from OSIRIS4/Odin and SHADOZ5 are also analysed. These yield rates of linear change of O3 similar to those from SCIAMACHY. However, the trends from SCIAMACHY near 34 km in the tropics are larger than MLS and OSIRIS by a factor of around two. 1 SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY 2 European environmental research satellite 3 Earth Observing System (EOS) Microwave Limb Sounder (MLS) 4 Optical Spectrograph and InfraRed Imager System 5 Southern Hemisphere ADditional OZonesondes

Download Full-text

Development of a climate record of tropospheric and stratospheric ozone from satellite remote sensing: evidence of an early recovery of global stratospheric ozone

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-3169-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 3169-3211

Author(s):

J. R. Ziemke ◽

S. Chandra

Keyword(s):

Climate Models ◽

Stratospheric Ozone ◽

Steady Increase ◽

Ozone Monitoring Instrument ◽

Early Recovery ◽

Quasi Biennial Oscillation ◽

Time Record ◽

The Tropics ◽

Biennial Oscillation

Abstract. Ozone data beginning October 2004 from the Aura Ozone Monitoring Instrument (OMI) and Aura Microwave Limb Sounder (MLS) are used to evaluate the accuracy of the Cloud Slicing technique in effort to develop long data records of tropospheric and stratospheric ozone and for studying their long-term changes. Using this technique, we have produced a 32-yr (1979–2010) long record of tropospheric and stratospheric ozone from the combined Total Ozone Mapping Spectrometer (TOMS) and OMI. The analyses of these time series suggest that the quasi-biennial oscillation (QBO) is the dominant source of inter-annual variability of stratospheric ozone and is clearest in the Southern Hemisphere during the Aura time record with related inter-annual changes of 30–40 Dobson Units. Tropospheric ozone also indicates a QBO signal in the tropics with peak-to-peak changes varying from 2 to 7 DU. The stratospheric ozone record indicates a steady increase since the mid-1990's with current ozone levels comparable to the mid-1980's. This is earlier than predicted by many of the current climate models which suggest recovery to the mid-1980's levels by year 2020 or later.

Download Full-text

Stratospheric ozone interannual variability (1995–2011) as observed by Lidar and Satellite at Mauna Loa Observatory, HI and Table Mountain Facility, CA

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-30825-2012 ◽

2012 ◽

Vol 12 (11) ◽

pp. 30825-30867

Author(s):

G. Kirgis ◽

T. Leblanc ◽

I. S. McDermid ◽

T. D. Walsh

Keyword(s):

Time Series ◽

Solar Cycle ◽

Interannual Variability ◽

Southern Oscillation ◽

Stratospheric Ozone ◽

Montreal Protocol ◽

Quasi Biennial Oscillation ◽

Mauna Loa ◽

Table Mountain ◽

Biennial Oscillation

Abstract. The Jet Propulsion Laboratory (JPL) lidars, at the Mauna Loa Observatory, Hawaii (MLO, 19.5° N, 155.6° W) and the JPL Table Mountain Facility (TMF, California, 34.5° N, 117.7° W), have been measuring vertical profiles of stratospheric ozone routinely since the early 1990's and late-1980s respectively. Interannual variability of ozone above these two sites was investigated using a multi-linear regression analysis on the deseasonalized monthly mean lidar and satellite time-series at 1 km intervals between 20 and 45 km from January 1995 to April 2011, a period of low volcanic aerosol loading. Explanatory variables representing the 11-yr solar cycle, the El Niño Southern Oscillation, the Quasi-Biennial Oscillation, the Eliassen–Palm flux, and horizontal and vertical transport were used. A new proxy, the mid-latitude ozone depleting gas index, which shows a decrease with time as an outcome of the Montreal Protocol, was introduced and compared to the more commonly used linear trend method. The analysis also compares the lidar time-series and a merged time-series obtained from the space-borne stratospheric aerosol and gas experiment II, halogen occultation experiment, and Aura-microwave limb sounder instruments. The results from both lidar and satellite measurements are consistent with recent model simulations which propose changes in tropical upwelling. Additionally, at TMF the ozone depleting gas index explains as much variance as the Quasi-Biennial Oscillation in the upper stratosphere. Over the past 17 yr a diminishing downward trend in ozone was observed before 2000 and a net increase, and sign of ozone recovery, is observed after 2005. Our results which include dynamical proxies suggest possible coupling between horizontal transport and the 11-yr solar cycle response, although a dataset spanning a period longer than one solar cycle is needed to confirm this result.

Download Full-text

Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (CLaMS)

Geoscientific Model Development Discussions ◽

10.5194/gmdd-7-5087-2014 ◽

2014 ◽

Vol 7 (4) ◽

pp. 5087-5139 ◽

Cited By ~ 6

Author(s):

R. Pommrich ◽

R. Müller ◽

J.-U. Grooß ◽

P. Konopka ◽

F. Ploeger ◽

...

Keyword(s):

Carbon Monoxide ◽

Large Scale ◽

Lower Stratosphere ◽

Lagrangian Model ◽

Quasi Biennial Oscillation ◽

Data Set ◽

Model Version ◽

The Tropics ◽

The Impact ◽

Good Agreement

Abstract. Variations in the mixing ratio of trace gases of tropospheric origin entering the stratosphere in the tropics are of interest for assessing both troposphere to stratosphere transport fluxes in the tropics and the impact of these transport fluxes on the composition of the tropical lower stratosphere. Anomaly patterns of carbon monoxide (CO) and long-lived tracers in the lower tropical stratosphere allow conclusions about the rate and the variability of tropical upwelling to be drawn. Here, we present a simplified chemistry scheme for the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the simulation, at comparatively low numerical cost, of CO, ozone, and long-lived trace substances (CH4, N2O, CCl3F (CFC-11), CCl2F2 (CFC-12), and CO2) in the lower tropical stratosphere. For the long-lived trace substances, the boundary conditions at the surface are prescribed based on ground-based measurements in the lowest model level. The boundary condition for CO in the free troposphere is deduced from MOPITT measurements (at &approx; 700–200 hPa). Due to the lack of a specific representation of mixing and convective uplift in the troposphere in this model version, enhanced CO values, in particular those resulting from convective outflow are underestimated. However, in the tropical tropopause layer and the lower tropical stratosphere, there is relatively good agreement of simulated CO with in-situ measurements (with the exception of the TROCCINOX campaign, where CO in the simulation is biased low &approx; 10–20 ppbv). Further, the model results are of sufficient quality to describe large scale anomaly patterns of CO in the lower stratosphere. In particular, the zonally averaged tropical CO anomaly patterns (the so called "tape recorder" patterns) simulated by this model version of CLaMS are in good agreement with observations. The simulations show a too rapid upwelling compared to observations as a consequence of the overestimated vertical velocities in the ERA-interim reanalysis data set. Moreover, the simulated tropical anomaly patterns of N2O are in good agreement with observations. In the simulations, anomaly patterns for CH4 and CFC-11 were found to be consistent with those of N2O; for all long-lived tracers, positive anomalies are simulated because of the enhanced tropical upwelling in the easterly phase of the quasi-biennial oscillation.

Download Full-text

Large internal variability dominates over global warming signal in observed lower stratospheric QBO amplitude

Journal of Climate ◽

10.1175/jcli-d-21-0270.1 ◽

2021 ◽

pp. 1-43

Author(s):

Aaron Match ◽

Stephan Fueglistaler

Keyword(s):

Global Warming ◽

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Internal Variability ◽

Dynamical Process ◽

Quasi Biennial Oscillation ◽

Amplitude Profile ◽

Biennial Oscillation ◽

Middle Stratosphere

AbstractGlobal warming projections of dynamics are less robust than projections of thermodynamics. However, robust aspects of the thermodynamics can be used to constrain some dynamical aspects. This paper argues that tropospheric expansion under global warming (a thermodynamical process) explains changes in the amplitude of the Quasi-Biennial Oscillation (QBO) in the lower and middle stratosphere (a dynamical process). A theoretical scaling for tropospheric expansion of approximately 6 hPa K−1 is derived, which agrees well with global climate model (GCM) experiments. Using this theoretical scaling, the response of QBO amplitude to global warming is predicted by shifting the climatological QBO amplitude profile upwards by 6 hPa per Kelvin of global warming. In global warming simulations, QBO amplitude in the lower- to mid-stratosphere shifts upwards as predicted by tropospheric expansion. Applied to observations, the tropospheric expansion framework suggests a historical weakening of QBO amplitude at 70 hPa of 3% decade−1 from 1953-2020. This expected weakening trend is half of the 6% decade−1 from 1953-2012 detected and attributed to global warming in a recent study. The previously reported trend was reinforced by record low QBO amplitudes during the mid-2000s, from which the QBO has since recovered. Given the modest weakening expected on physical grounds, past decadal modulations of QBO amplitude are reinterpreted as a hitherto unrecognized source of internal variability. This large internal variability dominates over the global warming signal, such that despite 65 years of observations, there is not yet a statistically significant weakening trend.

Download Full-text

Ozone and temperature decadal trends in the stratosphere, mesosphere and lower thermosphere, based on measurements from SABER on TIMED

Annales Geophysicae ◽

10.5194/angeo-32-935-2014 ◽

2014 ◽

Vol 32 (8) ◽

pp. 935-949 ◽

Cited By ~ 19

Author(s):

F. T. Huang ◽

H. G. Mayr ◽

J. M. Russell ◽

M. G. Mlynczak

Keyword(s):

Stratospheric Ozone ◽

Lower Thermosphere ◽

Definitive Evidence ◽

Broadband Emission ◽

Stratospheric Temperature ◽

Temperature Trends ◽

Time Period ◽

Ozone Trends ◽

Ozone Trend ◽

The Tropics

Abstract. We have derived ozone and temperature trends from years 2002 through 2012, from 20 to 100 km altitude, and 48° S to 48° N latitude, based on measurements from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite. For the first time, trends of ozone and temperature measured at the same times and locations are obtained, and their correlations should provide useful information about the relative importance of photochemistry versus dynamics over the longer term. We are not aware of comparable results covering this time period and spatial extent. For stratospheric ozone, until the late 1990s, previous studies found negative trends (decreasing amounts). In recent years, some empirical and modeling studies have shown the occurrence of a turnaround in the decreasing ozone, possibly beginning in the late 1990s, suggesting that the stratospheric ozone trend is leveling off or even turning positive. Our global results add more definitive evidence, expand the coverage, and show that at mid-latitudes (north and south) in the stratosphere, the ozone trends are indeed positive, with ozone having increased by a few percent from 2002 through 2012. However, in the tropics, we find negative ozone trends between 25 and 50 km. For stratospheric temperatures, the trends are mostly negatively correlated to the ozone trends. The temperature trends are positive in the tropics between 30 and 40 km, and between 20 and 25 km, at approximately 24° N and at 24° S latitude. The stratospheric temperature trends are otherwise mostly negative. In the mesosphere, the ozone trends are mostly flat, with suggestions of small positive trends at lower latitudes. The temperature trends in this region are mostly negative, showing decreases of up to ~ −3 K decade−1. In the lower thermosphere (between ~ 85 and 100 km), ozone and temperature trends are both negative. The ozone trend can approach ~ −10% decade−1, and the temperature trend can approach ~ −3 K decade−1. Aside from trends, these patterns of ozone–temperature correlations are consistent with previous studies of ozone and temperature perturbations such as the quasi-biennial (QBO) and semiannual (SAO) oscillations, and add confidence to the results.

Download Full-text

Variability in the speed of the Brewer–Dobson circulation as observed by Aura/MLS

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4563-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4563-4575 ◽

Cited By ~ 34

Author(s):

T. Flury ◽

D. L. Wu ◽

W. G. Read

Keyword(s):

Time Series ◽

Interannual Variability ◽

Lower Stratosphere ◽

Meridional Circulation ◽

Time Lag ◽

Quasi Biennial Oscillation ◽

One Year ◽

The Tropics ◽

Biennial Oscillation ◽

Stratospheric Water Vapour

Abstract. We use Aura/MLS stratospheric water vapour (H2O) measurements as tracer for dynamics and infer interannual variations in the speed of the Brewer–Dobson circulation (BDC) from 2004 to 2011. We correlate one-year time series of H2O in the lower stratosphere at two subsequent pressure levels (68 hPa, ~18.8 km and 56 hPa, ~19.9 km at the Equator) and determine the time lag for best correlation. The same calculation is made on the horizontal on the 100 hPa (~16.6 km) level by correlating the H2O time series at the Equator with the ones at 40° N and 40° S. From these lag coefficients we derive the vertical and horizontal speeds of the BDC in the tropics and extra-tropics, respectively. We observe a clear interannual variability of the vertical and horizontal branch. The variability reflects signatures of the Quasi Biennial Oscillation (QBO). Our measurements confirm the QBO meridional circulation anomalies and show that the speed variations in the two branches of the BDC are out of phase and fairly well anti-correlated. Maximum ascent rates are found during the QBO easterly phase. We also find that transport of H2O towards the Northern Hemisphere (NH) is on the average two times faster than to the Southern Hemisphere (SH) with a mean speed of 1.15 m s−1 at 100 hPa. Furthermore, the speed towards the NH shows much more interannual variability with an amplitude of about 21% whilst the speed towards the SH varies by only 10%. An amplitude of 21% is also observed in the variability of the ascent rate at the Equator which is on the average 0.2 mm s−1.

Download Full-text

Drift-corrected trends and periodic variations in MIPAS IMK/IAA ozone measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-2571-2014 ◽

2014 ◽

Vol 14 (5) ◽

pp. 2571-2589 ◽

Cited By ~ 67

Author(s):

E. Eckert ◽

T. von Clarmann ◽

M. Kiefer ◽

G. P. Stiller ◽

S. Lossow ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Recent Literature ◽

Michelson Interferometer ◽

Quasi Biennial Oscillation ◽

Significance Level ◽

Tropical Tropopause ◽

Time Period ◽

Ozone Trends ◽

Institute Of Technology ◽

Good Agreement

Abstract. Drifts, trends and periodic variations were calculated from monthly zonally averaged ozone profiles. The ozone profiles were derived from level-1b data of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) by means of the scientific level-2 processor run by the Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research (IMK). All trend and drift analyses were performed using a multilinear parametric trend model which includes a linear term, several harmonics with period lengths from 3 to 24 months and the quasi-biennial oscillation (QBO). Drifts at 2-sigma significance level were mainly negative for ozone relative to Aura MLS and Odin OSIRIS and negative or near zero for most of the comparisons to lidar measurements. Lidar stations used here include those at Hohenpeissenberg (47.8° N, 11.0° E), Lauder (45.0° S, 169.7° E), Mauna Loa (19.5° N, 155.6° W), Observatoire Haute Provence (43.9° N, 5.7° E) and Table Mountain (34.4° N, 117.7° W). Drifts against the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) were found to be mostly insignificant. The assessed MIPAS ozone trends cover the time period of July 2002 to April 2012 and range from −0.56 ppmv decade−1 to +0.48 ppmv decade−1 (−0.52 ppmv decade−1 to +0.47 ppmv decade−1 when displayed on pressure coordinates) depending on altitude/pressure and latitude. From the empirical drift analyses we conclude that the real ozone trends might be slightly more positive/less negative than those calculated from the MIPAS data, by conceding the possibility of MIPAS having a very small (approximately within −0.3 ppmv decade−1) negative drift for ozone. This leads to drift-corrected trends of −0.41 ppmv decade−1 to +0.55 ppmv decade−1 (−0.38 ppmv decade−1 to +0.53 ppmv decade−1 when displayed on pressure coordinates) for the time period covered by MIPAS Envisat measurements, with very few negative and large areas of positive trends at mid-latitudes for both hemispheres around and above 30 km (~10 hPa). Negative trends are found in the tropics around 25 and 35 km (~25 and 5 hPa), while an area of positive trends is located right above the tropical tropopause. These findings are in good agreement with the recent literature. Differences of the trends compared with the recent literature could be explained by a possible shift of the subtropical mixing barriers. Results for the altitude–latitude distribution of amplitudes of the quasi-biennial, annual and the semi-annual oscillation are overall in very good agreement with recent findings.

Download Full-text