Characterization of ozone profiles derived from Aura TES and OMI Radiances

Abstract. We present satellite based ozone profile estimates derived by combining radiances measured at thermal infrared (TIR) wavelengths from the Aura Tropospheric Emission Spectrometer (TES) and ultraviolet (UV) wavelengths measured by the Aura Ozone Monitoring Instrument (OMI). The advantage of using these combined wavelengths and instruments for sounding ozone over either instrument alone is improved sensitivity near the surface as well as the capability to consistently resolve the lower troposphere, upper troposphere, and lower stratosphere for scenes with varying geophysical states. For example, the vertical resolution of ozone estimates from either TES or OMI varies strongly by surface albedo and temperature. Typically, TES provides 1.6 degrees of freedom for signal (DOFS) and OMI provides less than 1 DOFS in the troposphere. The combination provides 2 DOFS in the troposphere with approximately 0.4 DOFS for near surface ozone (surface to 700 hPa). We evaluated these new ozone profile estimates with ozonesonde measurements and found that calculated errors for the joint TES and OMI ozone profile estimates are in reasonable agreement with actual errors as derived by the root-mean-square (RMS) difference between the ozonesondes and the joint TES/OMI ozone estimates. We also used a common a priori profile in the retrievals in order to evaluate the capability of different retrieval approaches on capturing near-surface ozone variability. We found that the vertical resolution of the joint TES/OMI ozone profile estimates shows significant improvements on quantifying variations in near-surface ozone with RMS differences of 49.9% and correlation coefficient of R = 0.58 for the TES/OMI near-surface estimates as compared to 67.2% RMS difference and R = 0.33 for TES and 115.8% RMS difference and R = 0.09 for OMI. This comparison removes the impacts of using the climatological a priori in the retrievals. However, it results in artificially large sonde/retrieval differences. The TES/OMI ozone profiles from the production code of joint retrievals will use climatological a priori and therefore will have more realistic ozone estimates than those from using a common a priori volume mixing ratio profile.

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A novel tropopause-related climatology of ozone profiles

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-283-2014 ◽

2014 ◽

Vol 14 (1) ◽

pp. 283-299 ◽

Cited By ~ 12

Author(s):

V. F. Sofieva ◽

J. Tamminen ◽

E. Kyrölä ◽

T. Mielonen ◽

P. Veefkind ◽

...

Keyword(s):

Climate Model ◽

A Priori ◽

Stratospheric Aerosol ◽

Ozone Monitoring Instrument ◽

Earth Observing System ◽

Ozone Profile ◽

High Vertical Resolution ◽

Climate Model Simulations ◽

Longitudinal Variability

Abstract. A new ozone climatology, based on ozonesonde and satellite measurements, spanning the altitude region between the earth's surface and ~60 km is presented (TpO3 climatology). This climatology is novel in that the ozone profiles are categorized according to calendar month, latitude and local tropopause heights. Compared to the standard latitude–month categorization, this presentation improves the representativeness of the ozone climatology in the upper troposphere and the lower stratosphere (UTLS). The probability distribution of tropopause heights in each latitude–month bin provides additional climatological information and allows transforming/comparing the TpO3 climatology to a standard climatology of zonal mean ozone profiles. The TpO3 climatology is based on high-vertical-resolution measurements of ozone from the satellite-based Stratospheric Aerosol and Gas Experiment II (in 1984 to 2005) and from balloon-borne ozonesondes from 1980 to 2006. The main benefits of the TpO3 climatology are reduced standard deviations on climatological ozone profiles in the UTLS, partial characterization of longitudinal variability, and characterization of ozone profiles in the presence of double tropopauses. The first successful application of the TpO3 climatology as a priori in ozone profile retrievals from Ozone Monitoring Instrument on board the Earth Observing System (EOS) Aura satellite shows an improvement of ozone precision in UTLS of up to 10% compared with the use of conventional climatologies. In addition to being advantageous for use as a priori in satellite retrieval algorithms, the TpO3 climatology might be also useful for validating the representation of ozone in climate model simulations.

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Validation of six years of TES tropospheric ozone retrievals with ozonesonde measurements: implications for spatial patterns and temporal stability in the bias

Atmospheric Measurement Techniques ◽

10.5194/amt-6-1413-2013 ◽

2013 ◽

Vol 6 (5) ◽

pp. 1413-1423 ◽

Cited By ~ 23

Author(s):

W. W. Verstraeten ◽

K. F. Boersma ◽

J. Zörner ◽

M. A. F. Allaart ◽

K. W. Bowman ◽

...

Keyword(s):

Degrees Of Freedom ◽

A Priori ◽

Temporal Stability ◽

Lower Troposphere ◽

Temporal Variations ◽

Upper Troposphere ◽

The World ◽

The Difference ◽

The Tropics

Abstract. In this analysis, Tropospheric Emission Spectrometer (TES) V004 nadir ozone (O3) profiles are validated with more than 4400 coinciding ozonesonde measurements taken across the world from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC) during the period 2005–2010. The TES observation operator was applied to the sonde data to ensure a consistent comparison between TES and ozonesonde data, i.e. without the influence of the a priori O3 profile needed to regulate the retrieval. Generally, TES V004 O3 retrievals are biased high by 2–7 ppbv (7–15%) in the troposphere, consistent with validation results from earlier studies. Because of two degrees of freedom for signal in the troposphere, we can distinguish between upper and lower troposphere mean biases, respectively ranging from −0.4 to +13.3 ppbv for the upper troposphere and +3.9 to +6.0 ppbv for the lower troposphere. Focusing on the 464 hPa retrieval level, broadly representative of the free tropospheric O3, we find differences in the TES biases for the tropics (+3 ppbv, +7%), sub-tropics (+5 ppbv, +11%), and northern (+7 ppbv, +13%) and southern mid-latitudes (+4 ppbv, +10%). The relatively long-term record (6 yr) of TES–ozonesonde comparisons allowed us to quantify temporal variations in TES biases at 464 hPa. We find that there are no discernable biases in each of these latitudinal bands; temporal variations in the bias are typically within the uncertainty of the difference between TES and ozonesondes. Establishing these bias patterns is important in order to make meaningful use of TES O3 data in applications such as model evaluation, trend analysis, or data assimilation.

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Characterization and Correction of OMPS Nadir Mapper Measurements for Ozone Profile Retrievals

10.5194/amt-2017-298 ◽

2017 ◽

Author(s):

Juseon Bak ◽

Xiong Liu ◽

Jae-Hwan Kim ◽

David P. Haffner ◽

Kelly Chance ◽

...

Keyword(s):

Tropospheric Ozone ◽

Degrees Of Freedom ◽

Optimal Estimation ◽

Inversion Method ◽

Radiometric Calibration ◽

Ozone Monitoring Instrument ◽

Ozone Profile ◽

Noise Error ◽

Significant Wavelength ◽

Cross Track

Abstract. This paper verifies and corrects the Ozone Mapping and Profiler Suite (OMPS) Nadir Mapper (NM) Level 1B v2.0 measurements with the aim of producing accurate ozone profile retrievals using an optimal estimation based inversion method to fit measurements in the spectral range 302.5–340 nm. The evaluation of available slit functions demonstrates that preflight-measured slit functions well represent OMPS measurements compared to derived Gaussian slit functions. Our initial OMPS fitting residuals contain significant wavelength and cross-track dependent biases, resulting into serious cross-track striping errors in the tropospheric ozone retrievals. To eliminate the systematic component of the fitting residuals, we apply “soft calibration” to OMPS radiances. With the soft calibration the amplitude of fitting residuals decreases from ~ 1 % to 0.2 % over low/mid latitudes, and thereby the consistency of tropospheric ozone retrievals between OMPS and the Ozone Monitoring Instrument (OMI) is substantially improved. A common mode correction is also implemented for additional radiometric calibration; it improves retrievals especially at high latitudes where the amplitude of fitting residuals decreases by a factor of ~ 2. We estimate the floor noise error of OMPS measurements from standard deviations of the fitting residuals. The derived error in the Huggins band (~ 0.1 %) is twice the OMPS L1B measurement error. OMPS floor noise errors better constrains our retrievals, leading to improving information content of ozone and reducing fitting residuals. The final precision of the fitting residuals is less than 0.1 % in the low/mid latitude, with ~ 1 degrees of freedom for signal for the tropospheric ozone, meeting the general requirements for successful tropospheric ozone retrievals.

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Potential of multispectral synergism for observing ozone pollution by combining IASI-NG and UVNS measurements from EPS-SG satellite

10.5194/amt-2016-374 ◽

2016 ◽

Author(s):

Lorenzo Costantino ◽

Juan Cuesta ◽

Emanuele Emili ◽

Adriana Coman ◽

Gilles Foret ◽

...

Keyword(s):

Degrees Of Freedom ◽

Transport Model ◽

Lower Troposphere ◽

Real Data ◽

Satellite Observations ◽

Maximum Sensitivity ◽

Ozone Pollution ◽

Chemical Transport Model ◽

Near Surface ◽

Multispectral Method

Abstract. Present and future satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit satellites do not allow using a single sensor to probe accurately surface concentrations of gaseous pollutants such as tropospheric ozone (Liu et al., 2010). Using single-band approaches based on spaceborne measurements of either thermal infrared radiance (TIR, Eremenko et al., 2008) or ultraviolet reflectance (UV, Liu et al., 2010) only ozone down to the lower troposphere (3 km) may be observed. A recent multispectral method (referred to as IASI+GOME-2) combining the information of IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the TIR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere (LMT, below 3 km of altitude) with maximum sensitivity down to 2.20 km a.s.l. over land, while sensitivity for IASI or GOME-2 only peaks at 3 to 4 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years, such as EPS-SG, carrying new-generation sensors of IASI and GOME-2 (respectively IASI-NG and UVNS) that will enhance the capacity to observe ozone pollution and particularly by synergism of TIR and UV measurements. In this work we develop a pseudo-observation simulator and evaluate the potential of future EPS-SG satellite observations through IASI-NG+UVNS multispectral method to observer near-surface O3. The pseudo-real state of atmosphere (nature run) is provided by the MOCAGE (MOdèle de Chimie Atmosphérique à Grande Échelle) chemical transport model. Simulations are calibrated by careful comparisons with real data, to ensure the best consistency between pseudo-reality and reality, as well as between the pseudo-observation simulator and existing satellite products. We perform full and accurate forward and inverse radiative transfer calculations for a period of 4 days (8–11 July 2010) over Europe. In the LMT, there is a remarkable agreement in the geographical distribution of O3 partial columns, calculated between the surface and 3 km of altitude, between IASI-NG+UVNS pseudo-observations and the corresponding MOCAGE pseudo-reality. With respect to synthetic IASI+GOME-2 products, IASI-NG+UVNS shows a higher correlation between pseudo-observations and pseudo-reality, enhanced by about 11 %. The bias on high ozone retrieval is reduced and the average accuracy increases by 22 %. The sensitivity to LMT ozone is enhanced on average with 154 % (from 0.29 to 0.75, over land) and 208 % (from 0.21 to 0.66, over ocean) higher degrees of freedom. The mean height of maximum sensitivity for the LMT peaks at 1.43 km over land and 2.02 km over ocean, respectively 1.03 km and 1.30 km below that of IASI+GOME-2. IASI-NG+UVNS shows also good retrieval skill in the surface-2 km altitude range with a mean DOF (degree of freedom) of 0.52 (land) and 0.42 (ocean), and an average Hmax (altitude of maximum sensitivity) of 1.29 km (land) and 1.96 km (ocean). Unique of its kind for retrieving ozone layers of 2–3 km thickness, in the first 2–3 km of the atmosphere, IASI-NG+UVNS is expected to largely enhance the capacity to observe ozone pollution from space.

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Long-range air transport in Northern Eurasia: Seasonal ozone variations and implications for regional ozone budget

10.5194/egusphere-egu2020-14701 ◽

2020 ◽

Author(s):

Yury Shtabkin ◽

Konstantin Moiseenko ◽

Andrey Skorokhod ◽

Elena Berezina

Keyword(s):

Long Range ◽

Total Mass ◽

Transport Model ◽

Surface Ozone ◽

Lower Troposphere ◽

Chemical Transport ◽

Air Transport ◽

Ozone Production ◽

Northern Eurasia ◽

Near Surface

Effect of photochemically active species emissions on near-surface air composition in industrial regions is non-local and in many cases can be traced in transcontinental scale. Largescaled plumes of polluted air defined by observations of tracer species on background stations and calculations with chemical-transport models are examples of this effect. In this work we use GEOS-Chem chemical transport model to make an assessment of influence have anthropogenic and biogenic emissions in Europe, European territory of Russia (ETR) and Siberia on total ozone generation taking into account common non-linear properties of O3&#8211;NOx&#8211;&#1057;&#1054;&#8211;VOC system. It is shown that increasing of ozone production rate due to regional anthropogenic emissions of NOx leads to substantial (up to 20 ppbv) increase of near-surface ozone concentrations in mid-latitudes traced up to 120E. The predominant role of long-range air transport against regional sources of photochemical ozone production was determined for the most part of European Russia and Siberia. We also make a numerical assessment of ozone balance in Europe, ETR and Siberia. Annual ozone total mass in lower troposphere (from surface to 800 hPa) for Europe, ETR and Siberia depending on region is 1.5&#8211;2.4 Tg in warm period (1 April &#8211; 30 September) and 1.3&#8211;2.2 Tg in cold period (1 October - 31 March). Ozone production in chemical processes with a high degree of accuracy (about 99%) is balanced by total atmospheric transport, while absolute variations in O3 total mass do not exceed 0.5 Tg/year in Europe and 0.4 Tg/year in Siberia. This work was supported by the Russian Foundation for Basic Research under grant 18-35-20031.

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Ozone profile retrievals from the Ozone Monitoring Instrument

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-2521-2010 ◽

2010 ◽

Vol 10 (5) ◽

pp. 2521-2537 ◽

Cited By ~ 172

Author(s):

X. Liu ◽

P. K. Bhartia ◽

K. Chance ◽

R. J. D. Spurr ◽

T. P. Kurosu

Keyword(s):

Degrees Of Freedom ◽

Optimal Estimation ◽

Anthropogenic Pollution ◽

Horizontal Resolution ◽

Ozone Monitoring Instrument ◽

Monitoring Instrument ◽

Ozone Profile ◽

Ozone Monitoring ◽

The Tropics ◽

Middle Stratosphere

Abstract. Ozone profiles from the surface to about 60 km are retrieved from Ozone Monitoring Instrument (OMI) ultraviolet radiances using the optimal estimation technique. OMI provides daily ozone profiles for the entire sunlit portion of the earth at a horizontal resolution of 13 km×48 km for the nadir position. The retrieved profiles have sufficient accuracy in the troposphere to see ozone perturbations caused by convection, biomass burning and anthropogenic pollution, and to track their spatiotemporal transport. However, to achieve such accuracy it has been necessary to calibrate OMI radiances carefully (using two days of Aura/Microwave Limb Sounder data taken in the tropics). The retrieved profiles contain ~6–7 degrees of freedom for signal, with 5–7 in the stratosphere and 0–1.5 in the troposphere. Vertical resolution varies from 7–11 km in the stratosphere to 10–14 km in the troposphere. Retrieval precisions range from 1% in the middle stratosphere to 10% in the lower stratosphere and troposphere. Solution errors (i.e., root sum square of precisions and smoothing errors) vary from 1–6% in the middle stratosphere to 6–35% in the troposphere, and are dominated by smoothing errors. Total, stratospheric, and tropospheric ozone columns can be retrieved with solution errors typically in the few Dobson unit range at solar zenith angles less than 80°.

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Validation of three different scientific ozone products retrieved from IASI spectra using ozonesondes

Atmospheric Measurement Techniques ◽

10.5194/amt-5-611-2012 ◽

2012 ◽

Vol 5 (3) ◽

pp. 611-630 ◽

Cited By ~ 73

Author(s):

G. Dufour ◽

M. Eremenko ◽

A. Griesfeller ◽

B. Barret ◽

E. LeFlochmoën ◽

...

Keyword(s):

Tropospheric Ozone ◽

Degrees Of Freedom ◽

Lower Troposphere ◽

Natural Variability ◽

Vertical Resolution ◽

Random Errors ◽

Research Teams ◽

Atmospheric Sounding ◽

Systematic And Random Errors ◽

The Tropics

Abstract. Three scientific ozone products from the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A, retrieved in three different research teams (LA, LATMOS/ULB, LISA) with different retrieval schemes, are characterized and validated using ozonesondes measurements. The characteristics of the products are analyzed in terms of retrieval sensitivity, systematic and random errors, and ability to retrieve the natural variability of ozone and focus on different partial columns from the lower troposphere up to 30 km. The validation covers the midlatitudes and the tropics and the period from January to December 2008. The products present degrees of freedom (DOF) in the troposphere between 1 and 1.2 on average in the midlatitudes and between 1 and 1.4 in the tropics. The DOF are distributed differently on the vertical depending on the profiles and the season: summer leading to a better sensitivity to the lower troposphere, as expected. The error estimates range between 10 and 20% from the lower tropospheric partial columns (0–6 km and 0–8 km for the midlatitudes and the tropics respectively) to the UTLS partial columns (8–16 km and 11–20 km for the midlatitudes and the tropics respectively) for all the products and are about 5% in the stratosphere (16–30 km) and for the column up to 30 km. The main feature that arises from the comparison with the ozonesondes is a systematic overestimation of ozone in the UTLS (between 10 and 25%) by the three products in the midlatitudes and the tropics, attributed to the moderate vertical resolution of IASI and possibly to spectroscopic inconsistencies. The ability of the products to reproduce natural variability of tropospheric ozone is fairly good and depends on the considered season and region.

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Characterization and correction of OMPS nadir mapper measurements for ozone profile retrievals

Atmospheric Measurement Techniques ◽

10.5194/amt-10-4373-2017 ◽

2017 ◽

Vol 10 (11) ◽

pp. 4373-4388 ◽

Cited By ~ 9

Author(s):

Juseon Bak ◽

Xiong Liu ◽

Jae-Hwan Kim ◽

David P. Haffner ◽

Kelly Chance ◽

...

Keyword(s):

Tropospheric Ozone ◽

Degrees Of Freedom ◽

Optimal Estimation ◽

Inversion Method ◽

Radiometric Calibration ◽

Ozone Monitoring Instrument ◽

Noise Floor ◽

Middle Latitudes ◽

Ozone Profile ◽

Cross Track

Abstract. This paper verifies and corrects the Ozone Mapping and Profiler Suite (OMPS) nadir mapper (NM) level 1B v2.0 measurements with the aim of producing accurate ozone profile retrievals using an optimal-estimation-based inversion method to fit measurements in the spectral range 302.5–340 nm. The evaluation of available slit functions demonstrates that preflight-measured slit functions represent OMPS measurements well compared to derived Gaussian slit functions. Our initial OMPS fitting residuals contain significant wavelength and cross-track-dependent biases, resulting in serious cross-track striping errors in the tropospheric ozone retrievals. To eliminate the systematic component of the fitting residuals, we apply soft calibration to OMPS radiances. With the soft calibration the amplitude of fitting residuals decreases from ∼  1 to 0.2 % over low and middle latitudes, and thereby the consistency of tropospheric ozone retrievals between OMPS and the Ozone Monitoring Instrument (OMI) is substantially improved. A common mode correction is also implemented for additional radiometric calibration; it improves retrievals especially at high latitudes where the amplitude of fitting residuals decreases by a factor of ∼  2. We estimate the noise floor error of OMPS measurements from standard deviations of the fitting residuals. The derived error in the Huggins band ( ∼  0.1 %) is twice the OMPS L1B measurement error. OMPS noise floor errors constrain our retrievals better, leading to improving information content of ozone and reducing fitting residuals. The final precision of the fitting residuals is less than 0.1 % in the low and middle latitudes, with ∼  1 degrees of freedom for signal for the tropospheric ozone, meeting the general requirements for successful tropospheric ozone retrievals.

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Evaluation of ozone profile and tropospheric ozone retrievals from GEMS and OMI spectra

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-5-6733-2012 ◽

2012 ◽

Vol 5 (5) ◽

pp. 6733-6762 ◽

Cited By ~ 1

Author(s):

J. Bak ◽

J. H. Kim ◽

X. Liu ◽

K. Chance ◽

J. Kim

Keyword(s):

Spectral Resolution ◽

Tropospheric Ozone ◽

Degrees Of Freedom ◽

Stratospheric Ozone ◽

A Priori ◽

Ozone Monitoring Instrument ◽

Ozone Profile ◽

Retrieval Errors ◽

Standard Deviations ◽

Column Ozone

Abstract. Korea is planning to launch the GEMS (Geostationary Environment Monitoring Spectrometer) instrument into a Geostationary (GEO) platform in 2018 to monitor tropospheric air pollutants on an hourly basis over East Asia. GEMS will measure backscattered UV radiances covering the 300–500 nm wavelength range with a spectral resolution of 0.6 nm. The main objective of this study is to evaluate ozone profiles and stratospheric column ozone amounts retrieved from simulated GEMS measurements. Ozone Monitoring Instrument (OMI) Level 1B radiances, which have the spectral range 270–500 nm at spectral resolution of 0.42–0.63 nm, are used to simulate the GEMS radiances. An optimal estimation-based ozone profile algorithm is used to retrieve ozone profiles from simulated GEMS radiances. Firstly, we compare the retrieval characteristics (including averaging kernels, degrees of freedom for signal, and retrieval error) derived from the 270–330 nm (OMI) and 300–330 nm (GEMS) wavelength ranges. This comparison shows that the effect of not using measurements below 300 nm on tropospheric ozone retrievals is insignificant. However, the stratospheric ozone information decreases greatly from OMI to GEMS, by a factor of ∼2. The number of the independent pieces of information available from GEMS measurements is estimated to 3 on average in the stratosphere, with associated retrieval errors of ∼1% in stratospheric column ozone. The difference between OMI and GEMS retrieval characteristics is apparent for retrieving ozone layers above ∼20 km, with a reduction in the sensitivity and an increase in the retrieval errors for GEMS. We further investigate whether GEMS can resolve the stratospheric ozone variation observed from high vertical resolution EOS Microwave Limb Sounder (MLS). The differences in stratospheric ozone profiles between GEMS and MLS are comparable to those between OMI and MLS above ∼3 hPa (∼40 km) except with slightly larger biases and larger standard deviations by up to 5%. At pressure altitudes above ∼3 hPa, GEMS retrievals show strong influence of a priori and large differences with MLS, which, however, can be sufficiently improved by using better a priori information. The GEMS-MLS differences show negative biases of less than 4% for stratospheric column ozone, with standard deviations of 1–3%, while OMI retrievals show similar agreements with MLS except for 1% smaller biases at mid and high latitudes. Based on the comparisons, we conclude that GEMS will measure tropospheric ozone and stratospheric ozone columns with accuracy comparable to that of OMI and ozone profiles with slightly worse performance than that of OMI below ∼3 hPa.

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