scholarly journals Decreases in wintertime total column ozone over the Tibetan Plateau during 1979–2017

2019 ◽  
Author(s):  
Yajuan Li ◽  
Martyn P. Chipperfield ◽  
Wuhu Feng ◽  
Sandip S. Dhomse ◽  
Richard J. Pope ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Regression Models ◽  
Total Ozone ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Enso Events ◽  
Column Ozone ◽  
Total Column ◽  
Ozone Variations

Abstract. We use the ozone dataset from the Copernicus Climate Change Service (C3S) during 1979–2017 to investigate the long-term variations of the total column ozone (TCO) and the relative total ozone low (TOL) over the Tibetan Plateau (TP) during different seasons. Based on various regression models, the wintertime TCO over the TP decreases overall during 1979–2017 with ongoing decreases since 1997. We perform multivariate regression analysis to quantify the influence of dynamical and chemical processes responsible for the long-term TCO variability over the TP. We use both piecewise linear trend (PWLT) and equivalent effective stratospheric chlorine loading (EESC)-based regression models that include explanatory variables such as the 11-year solar cycle, quasi-biennial oscillation (QBO) at 30 hPa and 10 hPa and the geopotential height (GH) at 150 hPa. The 150 hPa GH is found to be a major dynamical contributor to the total ozone variability (8 %) over the TP in wintertime. We also find strong correlation between TCO in DJF and the following JJA, indicating that negative/positive anomalies in the wintertime build up persist into summer. We also use the TOMCAT/SLIMCAT 3-D chemical transport model to investigate the contributions of different factors to the ozone variations over the TP. Using identical regression model on simulated TCO time series, we obtain consistent results with C3S-based data. We perform two sensitivity experiments with repeating dynamics of 2004 and 2008 to further study the role that the GH at 150 hPa plays in the ozone variations over the TP. The GH differences between the two years show an obvious, negative centre near 150 hPa over the TP in DJF. Composite analysis show that GH fluctuations associated with Inter Tropical Convergence Zone, ENSO events or Walker circulation play a key role in controlling TCO variability in the lower stratosphere.

scholarly journals Analysis and attribution of total column ozone changes over the Tibetan Plateau during 1979–2017

2020 ◽  
Vol 20 (14) ◽  
pp. 8627-8639 ◽  
Author(s):  
Yajuan Li ◽  
Martyn P. Chipperfield ◽  
Wuhu Feng ◽  
Sandip S. Dhomse ◽  
Richard J. Pope ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Regression Models ◽  
Positive Trend ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Latitude Band ◽  
Ozone Trends ◽  
Column Ozone ◽  
Total Column

Abstract. Various observation-based datasets have confirmed positive zonal mean column ozone trends at midlatitudes as a result of the successful implementation of the Montreal Protocol. However, there is still uncertainty about the longitudinal variation of these trends and the direction and magnitude of ozone changes at low latitudes. Here, we use the extended Copernicus Climate Change Service (C3S) dataset (1979–2017) to investigate the long-term variations in total column ozone (TCO) over the Tibetan Plateau (TP) for different seasons. We use piecewise linear trend (PWLT) and equivalent effective stratospheric chlorine loading (EESC)-based multivariate regression models with various proxies to attribute the influence of dynamical and chemical processes on the TCO variability. We also compare the seasonal behaviour of the relative total ozone low (TOL) over the TP with the zonal mean at the same latitude. Both regression models show that the TP column ozone trends change from negative trends from 1979 to 1996 to small positive trends from 1997 to 2017, although the later positive trend based on PWLT is not statistically significant. The wintertime positive trend starting from 1997 is larger than that in summer, but both seasonal TP recovery rates are smaller than the zonal means over the same latitude band. For TP column ozone, both regression models suggest that the geopotential height at 150 hPa (GH150) is a more suitable and realistic dynamical proxy compared to a surface temperature proxy used in some previous studies. Our analysis also shows that the wintertime GH150 plays an important role in determining summertime TCO over the TP through persistence of the ozone signal. For the zonal mean column ozone at this latitude, the quasi-biennial oscillation (QBO) is nonetheless the dominant dynamical proxy. We also use a 3-D chemical transport model to diagnose the contributions of different proxies for the TP region. The role of GH150 variability is illustrated by using two sensitivity experiments with repeating dynamics of 2004 and 2008. The simulated ozone profiles clearly show that wintertime TP ozone concentrations are largely controlled by tropics to midlatitude pathways, whereas in summer variations associated with tropical processes play an important role. These model results confirm that the long-term trends of TCO over the TP are dominated by different processes in winter and summer. The different TP recovery rates relative to the zonal means at the same latitude band are largely determined by wintertime dynamical processes.

scholarly journals Climate warming and decreasing total column ozone over the Tibetan Plateau during winter and spring

Tellus B ◽  
2014 ◽  
Vol 66 (1) ◽  
pp. 23415 ◽  
Author(s):  
Jiankai Zhang ◽  
Wenshou Tian ◽  
Fei Xie ◽  
Hongying Tian ◽  
Jiali Luo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Climate Warming ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Column Ozone ◽  
Total Column

Effects of the Tibetan Plateau on total column ozone distribution

Tellus B ◽  
2008 ◽  
Vol 60 (4) ◽  
pp. 622-635 ◽  
Author(s):  
Wenshou Tian ◽  
Martyn Chipperfield ◽  
Qian Huang
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Ozone Distribution ◽  
Column Ozone ◽  
Total Column

Effects of the Tibetan Plateau on total column ozone distribution

Tellus B ◽  
2008 ◽  
Vol 60 (4) ◽  
Author(s):  
Wenshou Tian ◽  
Martyn Chipperfield ◽  
Qian Huang
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Ozone Distribution ◽  
Column Ozone ◽  
Total Column

scholarly journals Supplementary material to "Decreases in wintertime total column ozone over the Tibetan Plateau during 1979–2017"

2019 ◽  
Author(s):  
Yajuan Li ◽  
Martyn P. Chipperfield ◽  
Wuhu Feng ◽  
Sandip S. Dhomse ◽  
Richard J. Pope ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Total Column Ozone ◽  
Supplementary Material ◽  
Column Ozone ◽  
Total Column

scholarly journals Spatial mapping of ground-based observations of total ozone

2015 ◽  
Vol 8 (10) ◽  
pp. 4487-4505 ◽  
Author(s):  
K.-L. Chang ◽  
S. Guillas ◽  
V. E. Fioletov
Keyword(s):  
Spatial Interpolation ◽  
Stochastic Partial Differential Equation ◽  
Positive Impact ◽  
The Novel ◽  
Total Column Ozone ◽  
Column Ozone ◽  
Source Of Information ◽  
Total Column ◽  
Ozone Levels

Abstract. Total column ozone variations estimated using ground-based stations provide important independent source of information in addition to satellite-based estimates. This estimation has been vigorously challenged by data inhomogeneity in time and by the irregularity of the spatial distribution of stations, as well as by interruptions in observation records. Furthermore, some stations have calibration issues and thus observations may drift. In this paper we compare the spatial interpolation of ozone levels using the novel stochastic partial differential equation (SPDE) approach with the covariance-based kriging. We show how these new spatial predictions are more accurate, less uncertain and more robust. We construct long-term zonal means to investigate the robustness against the absence of measurements at some stations as well as instruments drifts. We conclude that time series analyzes can benefit from the SPDE approach compared to the covariance-based kriging when stations are missing, but the positive impact of the technique is less pronounced in the case of drifts.

scholarly journals Comparison of profile total ozone from SBUV(v8.6) with GOME-type and ground-based total ozone for 16-yr period (1996 to 2011)

2013 ◽  
Vol 6 (6) ◽  
pp. 10081-10115 ◽  
Author(s):  
E. W. Chiou ◽  
P. K. Bhartia ◽  
R. D. McPeters ◽  
D. G. Loyola ◽  
M. Coldewey-Egbers ◽  
...  
Keyword(s):  
Strong Evidence ◽  
Total Ozone ◽  
Time Dependent ◽  
Total Column Ozone ◽  
Monthly Data ◽  
Latitude Band ◽  
Ozone Data ◽  
Standard Deviations ◽  
Column Ozone ◽  
Total Column

Abstract. This paper describes the comparison of the variability of total column ozone inferred from the three independent multi-year data records, namely, (i) SBUV(v8.6) profile total ozone, (ii) GTO(GOME-Type total ozone), and (iii) Ground-based total ozone data records covering the 16-yr overlap period (March 1996 through June 2011). Analyses are conducted based on area weighted zonal means for (0–30° S), (0–30° N), (50–30° S), and (30–60° N). It has been found that on average, the differences in monthly zonal mean total ozone vary between −0.32 to 0.76 % and are well within 1%. For "GTO minus SBUV", the standard deviations and ranges (maximum minus minimum) of the differences regarding monthly zonal mean total ozone vary between 0.58 to 0.66% and 2.83 to 3.82% respectively, depending on the latitude band. The corresponding standard deviations and ranges regarding the differences in monthly zonal mean anomalies show values between 0.40 to 0.59% and 2.19 to 3.53%. The standard deviations and ranges of the differences "Ground-based minus SBUV" regarding both monthly zonal means and anomalies are larger by a factor of 1.4 to 2.9 in comparison to "GTO minus SBUV". The Ground-based zonal means, while show no systematic differences, demonstrate larger scattering of monthly data compared to satellite-based records. The differences in the scattering are significantly reduced if seasonal zonal averages are analyzed. The trends of the differences "GTO minus SBUV" and "Ground-based minus SBUV" are found to vary between −0.04 and 0.12% yr−1 (−0.11 and 0.31 DU yr−1). These negligibly small trends have provided strong evidence that there are no significant time dependent differences among these multi-year total ozone data records. Analyses of the deviations from pre-1980 level indicate that for the overlap period of 1996 to 2010, all three data records show gradual recovery at (30–60° N) from −5% in 1996 to −2% in 2010. The corresponding recovery at (50–30° S) is not as obvious until after 2006.

scholarly journals Uncertainty analysis of total ozone derived from direct solar irradiance spectra in the presence of unknown spectral deviations

2018 ◽  
Vol 11 (6) ◽  
pp. 3595-3610 ◽  
Author(s):  
Anna Vaskuri ◽  
Petri Kärhä ◽  
Luca Egli ◽  
Julian Gröbner ◽  
Erkki Ikonen
Keyword(s):  
Solar Irradiance ◽  
Total Ozone ◽  
Monte Carlo Model ◽  
Spectral Irradiance ◽  
Total Column Ozone ◽  
Column Ozone ◽  
Ozone Column ◽  
Total Column ◽  
Local Noon ◽  
Good Agreement

Abstract. We demonstrate the use of a Monte Carlo model to estimate the uncertainties in total ozone column (TOC) derived from ground-based direct solar spectral irradiance measurements. The model estimates the effects of possible systematic spectral deviations in the solar irradiance spectra on the uncertainties in retrieved TOC. The model is tested with spectral data measured with three different spectroradiometers at an intercomparison campaign of the research project “Traceability for atmospheric total column ozone” at Izaña, Tenerife on 17 September 2016. The TOC values derived at local noon have expanded uncertainties of 1.3 % (3.6 DU) for a high-end scanning spectroradiometer, 1.5 % (4.4 DU) for a high-end array spectroradiometer, and 4.7 % (13.3 DU) for a roughly adopted instrument based on commercially available components and an array spectroradiometer when correlations are taken into account. When neglecting the effects of systematic spectral deviations, the uncertainties reduce by a factor of 3. The TOC results of all devices have good agreement with each other, within the uncertainties, and with the reference values of the order of 282 DU during the analysed day, measured with Brewer spectrophotometer #183.

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