Joint Use of in-Scene Background Radiance Estimation and Optimal Estimation Methods for Quantifying Methane Emissions Using PRISMA Hyperspectral Satellite Data: Application to the Korpezhe Industrial Site

Methane (CH4) is one of the most contributing anthropogenic greenhouse gases (GHGs) in terms of global warming. Industry is one of the largest anthropogenic sources of methane, which are currently only roughly estimated. New satellite hyperspectral imagers, such as PRISMA, open up daily temporal monitoring of industrial methane sources at a spatial resolution of 30 m. Here, we developed the Characterization of Effluents Leakages in Industrial Environment (CELINE) code to inverse images of the Korpezhe industrial site. In this code, the in-Scene Background Radiance (ISBR) method was combined with a standard Optimal Estimation (OE) approach. The ISBR-OE method avoids the use of a complete and time-consuming radiative transfer model. The ISBR-OEM developed here overcomes the underestimation issues of the linear method (LM) used in the literature for high concentration plumes and controls a posteriori uncertainty. For the Korpezhe site, using the ISBR-OEM instead of the LM -retrieved CH4 concentration map led to a bias correction on CH4 mass from 4 to 16% depending on the source strength. The most important CH4 source has an estimated flow rate ranging from 0.36 ± 0.3 kg·s−1 to 4 ± 1.76 kg·s−1 on nine dates. These local and variable sources contribute to the CH4 budget and can better constrain climate change models.

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Space-borne measurements of mesospheric magnesium species – a retrieval algorithm and preliminary profiles

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-1963-2008 ◽

2008 ◽

Vol 8 (7) ◽

pp. 1963-1983 ◽

Cited By ~ 15

Author(s):

M. Scharringhausen ◽

A. C. Aikin ◽

J. P. Burrows ◽

M. Sinnhuber

Keyword(s):

Wavelength Range ◽

Optimal Estimation ◽

Global Scale ◽

Radiative Transfer Model ◽

Retrieval Algorithm ◽

Transfer Model ◽

Resonance Fluorescence ◽

Altitude Range ◽

Air Density ◽

Metallic Species

Abstract. We present a joint retrieval as well as first results for mesospheric air density and mesospheric Magnesium species (Mg and Mg+) using limb data from the SCIAMACHY instrument on board the European ENVISAT satellite.considered. These species feature Metallic species like neutral Mg, ionized Mg+ and others (Fe, Si, Li, etc.) ablate from meteoric dust, enter the gas phase and occur at high altitudes (≥70 km). Emissions from these species are clearly observed in the SCIAMACHY limb measurements. These emissions are used to retrieve total and thermospheric column densities as well as preliminary profiles of metallic species in the altitude range of 70–92 km. In this paper, neutral Magnesium as well as its ionized counterpart Mg+ is considered. These species feature resonance fluorescence in the wavelength range 279 and 285 nm and thus have a rather simple excitation process. A radiative transfer model (RTM) for the mesosphere has been developed and validated. Based on a ray tracing kernel, radiances in a large wavelength range from 240–300 nm covering limb as well as nadir geometry can be calculated. The forward model has been validated and shows good agreement with established models in the given wavelength range and a large altitude range. The RTM has been coupled to a retrieval based on Optimal Estimation. Air density is retrieved from Rayleigh backscattered light. Mesospheric Mg and Mg+ number densities are retrieved from their emission signals observed in the limb scans of SCIAMACHY. Other species like iron, silicon, OH and NO can be investigated in principle with the same algorithm. Based on the retrieval presented here, SCIAMACHY offers the opportunity to investigate mesospheric species on a global scale and with good vertical resolution for the first time.

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Inter-comparison of MAX-DOAS measurements of tropospheric HONO slant column densities and vertical profiles during the CINDI-2 Campaign

10.5194/amt-2019-464 ◽

2020 ◽

Cited By ~ 1

Author(s):

Yang Wang ◽

Arnoud Apituley ◽

Alkiviadis Bais ◽

Steffen Beirle ◽

Nuria Benavent ◽

...

Keyword(s):

Radiative Transfer ◽

Estimation Method ◽

Optimal Estimation ◽

Early Morning ◽

Radiative Transfer Model ◽

Measuring Instruments ◽

Transfer Model ◽

Vertical Profiles ◽

Near Surface ◽

Profile Inversion

Abstract. We present the inter-comparison of delta slant column densities (SCDs) and vertical profiles of nitrous acid (HONO) derived from measurements of different MAX-DOAS instruments and using different inversion algorithms during the Second Cabauw Inter-comparison campaign for Nitrogen Dioxide measuring Instruments (CINDI-2), in September 2016, at Cabauw, The Netherlands (51.97° N, 4.93° E). Systematic discrepancies of HONO delta SCDs are observed in the range of ±0.3 × 1015 molecules cm−2, which is half of the typical random discrepancy of 0.6 × 1015 molecules cm−2. For a typical high HONO delta SCD of 2 × 1015 molecules cm−2, the relative systematic and random discrepancies are about 15 % and 30 %, respectively. The inter-comparison of HONO profiles shows that both systematic and random discrepancies of HONO VCDs and near-surface volume mixing ratios (VMRs) are mostly in the range of ~ ±0.5 × 1015 molecules cm−2 and ~ ±0.1 ppb (typically ~ 20 %). Further we find that the discrepancies of the retrieved HONO profiles are dominated by discrepancies of the HONO delta SCDs. The profile retrievals only contribute to the discrepancies of the HONO profiles by ~ 5 %. However, some data sets with substantial larger discrepancies than the typical values indicate that inappropriate implementations of profile inversion algorithms and configurations of radiative transfer models in the profile retrievals can also be an important uncertainty source. In addition, estimations of measurement uncertainties of HONO dSCDs, which can significantly impact profile retrievals using the optimal estimation method, need to consider not only DOAS fit errors, but also atmospheric variability, especially for an instrument with a DOAS fit error lower than ~ 3 × 1015 molecules cm−2. The MAX-DOAS results during the CINDI-2 campaign indicate that the peak HONO levels (e.g. near-surface VMRs of ~ 0.4 ppb) often appeared in the early morning and below 0.2 km. The near-surface VMRs retrieved from the MAX-DOAS observations are compared with those measured using a co-located long-path DOAS instrument. The systematic differences are smaller than 0.15 ppb and 0.07 ppb during early morning and around noon, respectively. Since true HONO values at high altitudes are not known in the absence of real measurements, in order to evaluate the abilities of profile inversion algorithms to respond to different HONO profile shapes, we performed sensitivity studies using synthetic HONO delta SCDs simulated by a radiative transfer model with assumed HONO profiles. The tests indicate that the profile inversion algorithms based on the optimal estimation method with proper configurations can well reproduce the different HONO profile shapes. Therefore we conclude that the feature of HONO accumulated near the surface derived from MAX-DOAS measurements are expected to well represent the ambient HONO profiles.

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Global stratospheric aerosol extinction profile retrievals from SCIAMACHY limb-scatter observations

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-5-5993-2012 ◽

2012 ◽

Vol 5 (4) ◽

pp. 5993-6035 ◽

Cited By ~ 21

Author(s):

F. Ernst ◽

C. von Savigny ◽

A. Rozanov ◽

V. Rozanov ◽

K.-U. Eichmann ◽

...

Keyword(s):

Surface Albedo ◽

Optimal Estimation ◽

Stratospheric Aerosol ◽

Visible Spectral Range ◽

Radiative Transfer Model ◽

Retrieval Algorithm ◽

Transfer Model ◽

Aerosol Extinction ◽

Index Approach ◽

The Impact

Abstract. Stratospheric aerosol extinction profiles are retrieved from SCIAMACHY/Envisat limb-scatter observations in the visible spectral range. The retrieval algorithm is based on a colour-index approach using the normalized limb-radiance profiles at 470 nm and 750 nm wavelength. The optimal estimation approach in combination with the radiative transfer model SCIATRAN is employed for the retrievals. This study presents a detailed description of the retrieval algorithm, and a sensitivity analysis investigating the impact of the most important parameters that affect the aerosol extinction profile retrieval accuracy. It is found that the parameter with the largest impact is surface albedo, particularly for SCIAMACHY observations in the Southern Hemisphere where the error in stratospheric aerosol extinction can be up to 50% if the surface albedo is not well known. The effect of errors in the assumed ozone and neutral density profiles on the aerosol profile retrievals is with generally less than 6% relatively small. The aerosol extinction profiles retrieved from SCIAMACHY are compared with co-located SAGE II solar occultation measurements of stratospheric aerosol extinction during the period 2003–2005. The mean aerosol extinction profiles averaged over all co-locations agree to within 20% between 15 and 35 km altitude. However, larger differences are observed at specific latitudes.

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The Successive-Order-of-Interaction Radiative Transfer Model. Part II: Model Performance and Applications

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2409.1 ◽

2006 ◽

Vol 45 (10) ◽

pp. 1403-1413 ◽

Cited By ~ 24

Author(s):

Christopher W. O’Dell ◽

Andrew K. Heidinger ◽

Thomas Greenwald ◽

Peter Bauer ◽

Ralf Bennartz

Keyword(s):

Radiative Transfer ◽

Data Assimilation ◽

Weather Prediction ◽

Model Performance ◽

Optimal Estimation ◽

Radiative Transfer Model ◽

Transfer Model ◽

Computationally Efficient ◽

Wide Range ◽

Infrared Wavelengths

Abstract Radiative transfer models for scattering atmospheres that are accurate yet computationally efficient are required for many applications, such as data assimilation in numerical weather prediction. The successive-order-of-interaction (SOI) model is shown to satisfy these demands under a wide range of conditions. In particular, the model has an accuracy typically much better than 1 K for most microwave and submillimeter cases in precipitating atmospheres. Its speed is found to be comparable to or faster than the commonly used though less accurate Eddington model. An adjoint has been written for the model, and so Jacobian sensitivities can be quickly calculated. In addition to a conventional error assessment, the correlation between errors in different microwave channels is also characterized. These factors combine to make the SOI model an appealing candidate for many demanding applications, including data assimilation and optimal estimation, from microwave to thermal infrared wavelengths.

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H<sub>2</sub><sup>16</sup>O and HDO measurements with IASI/MetOp

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-9-9267-2009 ◽

2009 ◽

Vol 9 (2) ◽

pp. 9267-9290 ◽

Cited By ~ 10

Author(s):

H. Herbin ◽

D. Hurtmans ◽

C. Clerbaux ◽

L. Clarisse ◽

P.-F. Coheur

Keyword(s):

Water Vapour ◽

Estimation Method ◽

Optimal Estimation ◽

Temporal Variations ◽

Radiative Transfer Model ◽

Transfer Model ◽

Inversion Procedure ◽

Spatio Temporal ◽

The Vertical Distribution

Abstract. In this paper we analyze distributions of water vapour isotopologues in the troposphere using infrared spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI), which operates onboard the Metop satellite in nadir geometry. The simultaneous uncorrelated retrieval of H216O and HDO was performed on radiance measurements using a line-by-line radiative transfer model and an inversion procedure based on the Optimal Estimation Method (OEM). The characterizations of the retrieved products in terms of vertical sensitivity and error budgets show that IASI measurements contain up to 6 independent pieces of information on the vertical distribution of H216O and up to 3.5 for HDO from the surface up to the upper troposphere (0–20 km). The H216O retrieved profiles are in good agreement with local sonde measurements at different latitudes during different times of the year. Our results demonstrate the ability of the IASI instrument to monitor atmospheric isotopologic water vapour distributions with unprecedented sensitivity. As a case study, we analyse concentration distributions and spatio-temporal variations of H216O and HDO during the October 2007 Krosa super-typhoon over South-East Asia and show with this example the IASI potential to capture variations in the HDO/H216O isotopologic ratio values over space and time.

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Vertical profile of tropospheric ozone derived from synergetic retrieval using three different wavelength ranges, UV, IR, and microwave: sensitivity study for satellite observation

Atmospheric Measurement Techniques ◽

10.5194/amt-11-1653-2018 ◽

2018 ◽

Vol 11 (3) ◽

pp. 1653-1668 ◽

Cited By ~ 3

Author(s):

Tomohiro O. Sato ◽

Takao M. Sato ◽

Hideo Sagawa ◽

Katsuyuki Noguchi ◽

Naoko Saitoh ◽

...

Keyword(s):

Radiative Transfer ◽

Tropospheric Ozone ◽

Vertical Profile ◽

Reduction Rate ◽

Estimation Method ◽

Optimal Estimation ◽

Sensitivity Study ◽

Maximum Sensitivity ◽

Radiative Transfer Model ◽

Transfer Model

Abstract. We performed a feasibility study of constraining the vertical profile of the tropospheric ozone by using a synergetic retrieval method on multiple spectra, i.e., ultraviolet (UV), thermal infrared (TIR), and microwave (MW) ranges, measured from space. This work provides, for the first time, a quantitative evaluation of the retrieval sensitivity of the tropospheric ozone by adding the MW measurement to the UV and TIR measurements. Two observation points in East Asia (one in an urban area and one in an ocean area) and two observation times (one during summer and one during winter) were assumed. Geometry of line of sight was nadir down-looking for the UV and TIR measurements, and limb sounding for the MW measurement. The retrieval sensitivities of the ozone profiles in the upper troposphere (UT), middle troposphere (MT), and lowermost troposphere (LMT) were estimated using the degree of freedom for signal (DFS), the pressure of maximum sensitivity, reduction rate of error from the a priori error, and the averaging kernel matrix, derived based on the optimal estimation method. The measurement noise levels were assumed to be the same as those for currently available instruments. The weighting functions for the UV, TIR, and MW ranges were calculated using the SCIATRAN radiative transfer model, the Line-By-Line Radiative Transfer Model (LBLRTM), and the Advanced Model for Atmospheric Terahertz Radiation Analysis and Simulation (AMATERASU), respectively. The DFS value was increased by approximately 96, 23, and 30 % by adding the MW measurements to the combination of UV and TIR measurements in the UT, MT, and LMT regions, respectively. The MW measurement increased the DFS value of the LMT ozone; nevertheless, the MW measurement alone has no sensitivity to the LMT ozone. The pressure of maximum sensitivity value for the LMT ozone was also increased by adding the MW measurement. These findings indicate that better information on LMT ozone can be obtained by adding constraints on the UT and MT ozone from the MW measurement. The results of this study are applicable to the upcoming air-quality monitoring missions, APOLLO, GMAP-Asia, and uvSCOPE.

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Mid-tropospheric δD observations from IASI/MetOp at high spatial and temporal resolution

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-10817-2012 ◽

2012 ◽

Vol 12 (22) ◽

pp. 10817-10832 ◽

Cited By ~ 49

Author(s):

J.-L. Lacour ◽

C. Risi ◽

L. Clarisse ◽

S. Bony ◽

D. Hurtmans ◽

...

Keyword(s):

Large Scale ◽

A Priori ◽

Optimal Estimation ◽

Added Value ◽

Radiative Transfer Model ◽

Transfer Model ◽

Short Term ◽

Individual Measurement ◽

One Year ◽

The One

Abstract. In this paper we retrieve atmospheric HDO, H2O concentrations and their ratio δD from IASI radiances spectra. Our method relies on an existing radiative transfer model (Atmosphit) and an optimal estimation inversion scheme, but goes further than our previous work by explicitly considering correlations between the two species. A global HDO and H2O a priori profile together with a covariance matrix were built from daily LMDz-iso model simulations of HDO and H2O profiles over the whole globe and a whole year. The retrieval parameters are described and characterized in terms of errors. We show that IASI is mostly sensitive to δD in the middle troposphere and allows retrieving δD for an integrated 3–6 km column with an error of 38‰ on an individual measurement basis. We examine the performance of the retrieval to capture the temporal (seasonal and short-term) and spatial variations of δD for one year of measurement at two dedicated sites (Darwin and Izaña) and a latitudinal band from −60° to 60° for a 15 day period in January. We report a generally good agreement between IASI and the model and indicate the capabilities of IASI to reproduce the large scale variations of δD (seasonal cycle and latitudinal gradient) with good accuracy. In particular, we show that there is no systematic significant bias in the retrieved δD values in comparison with the model, and that the retrieved variability is similar to the one in the model even though there are certain local differences. Moreover, the noticeable differences between IASI and the model are briefly examined and suggest modeling issues instead of retrieval effects. Finally, the results further reveal the unprecedented capabilities of IASI to capture short-term variations in δD, highlighting the added value of the sounder for monitoring hydrological processes.

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Global distributions of water vapour isotopologues retrieved from IMG/ADEOS data

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-3957-2007 ◽

2007 ◽

Vol 7 (14) ◽

pp. 3957-3968 ◽

Cited By ~ 33

Author(s):

H. Herbin ◽

D. Hurtmans ◽

S. Turquety ◽

C. Wespes ◽

B. Barret ◽

...

Keyword(s):

Water Vapour ◽

Experimental Studies ◽

Estimation Method ◽

Optimal Estimation ◽

Temporal Variations ◽

Global Scale ◽

Radiative Transfer Model ◽

Small Scale ◽

Transfer Model ◽

Water Isotopologues

Abstract. The isotopologic composition of water vapour in the atmosphere provides valuable information on many climate, chemical and dynamical processes. The accurate measurements of the water isotopologues by remote-sensing techniques remains a challenge, due to the large spatial and temporal variations. Simultaneous profile retrievals of the main water isotopologues (i.e. H216O, H218O and HDO) and their ratios are presented here for the first time, along their retrieved global distributions. The results are obtained by exploiting the high resolution infrared spectra recorded by the Interferometric Monitor for Greenhouse gases (IMG) instrument, which has operated in the nadir geometry onboard the ADEOS satellite between 1996 and 1997. The retrievals are performed on cloud-free radiances, measured during ten days of April 1997, considering two atmospheric windows (1205–1228 cm−1; 2004–2032 cm−1) and using a line-by-line radiative transfer model and an inversion procedure based on the Optimal Estimation Method (OEM). Characterizations in terms of vertical sensitivity and error budget are provided. We show that a relatively high vertical resolution is achieved for H216O (~4–5 km), and that the retrieved profiles are in fair agreement with local sonde measurements, at different latitudes. The retrieved global distributions of H216O, H218O, HDO and their ratios are presented and found to be consistent with previous experimental studies and models. The Ocean-Continent difference, the latitudinal and vertical dependence of the water vapour amount and the isotopologic depletion are notably well reproduced. Others trends, possibly related to small-scale variations in the vertical profiles are also discussed. Despite the difficulties encountered for computing accurately the isotopologic ratios, our results demonstrate the ability of infrared nadir sounding for monitoring atmospheric isotopologic water vapour distributions on a global scale.

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A first comparison of TROPOMI aerosol layer height (ALH) to CALIOP data

Atmospheric Measurement Techniques ◽

10.5194/amt-13-3043-2020 ◽

2020 ◽

Vol 13 (6) ◽

pp. 3043-3059 ◽

Cited By ~ 2

Author(s):

Swadhin Nanda ◽

Martin de Graaf ◽

J. Pepijn Veefkind ◽

Maarten Sneep ◽

Mark ter Linden ◽

...

Keyword(s):

Optimal Estimation ◽

Satellite Observation ◽

Radiative Transfer Model ◽

Orthogonal Polarization ◽

Ultraviolet Region ◽

Transfer Model ◽

Aerosol Layer ◽

Layer Height ◽

Significant Difference ◽

Level 2

Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) level-2 aerosol layer height (ALH) product has now been released to the general public. This product is retrieved using TROPOMI's measurements of the oxygen A-band, radiative transfer model (RTM) calculations augmented by neural networks and an iterative optimal estimation technique. The TROPOMI ALH product will deliver ALH estimates over cloud-free scenes over the ocean and land that contain aerosols above a certain threshold of the measured UV aerosol index (UVAI) in the ultraviolet region. This paper provides background for the ALH product and explores its quality by comparing ALH estimates to similar quantities derived from spaceborne lidars observing the same scene. The spaceborne lidar chosen for this study is the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission, which flies in formation with NASA's A-train constellation since 2006 and is a proven source of data for studying ALHs. The influence of the surface and clouds is discussed, and the aspects of the TROPOMI ALH algorithm that will require future development efforts are highlighted. A case-by-case analysis of the data from the four selected cases (mostly around the Saharan region with approximately 800 co-located TROPOMI pixels and CALIOP profiles in June and December 2018) shows that ALHs retrieved from TROPOMI using the operational Sentinel-5 Precursor Level-2 ALH algorithm is lower than CALIOP aerosol extinction heights by approximately 0.5 km. Looking at data beyond these cases, it is clear that there is a significant difference when it comes to retrievals over land, where these differences can easily go over 1 km on average.

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Measurement report: The importance of biomass burning in light extinction and direct radiative effect of urban aerosol during the COVID-19 lockdown in China

10.5194/acp-2021-947 ◽

2021 ◽

Author(s):

Jie Tian ◽

Qiyuan Wang ◽

Huikun Liu ◽

Yongyong Ma ◽

Suixin Liu ◽

...

Keyword(s):

Climate Change ◽

Biomass Burning ◽

Anthropogenic Activities ◽

Anthropogenic Sources ◽

Light Extinction ◽

Radiative Transfer Model ◽

Transfer Model ◽

Chemical Calculation ◽

Radiative Effect ◽

Normal Period

Abstract. To mitigate climate change in China, a better understanding of optical properties of aerosol is required due to the complexity in emission sources. Here, an intensive real-time measurement was conducted in an urban area of China before and during the lockdown of Coronavirus Disease 2019 (COVID-19), to explore the impacts of anthropogenic activities on aerosol light extinction and direct radiative effect (DRE). The mean light extinction coefficient (bext) reduced from 774.7 ± 298.1 Mm−1 during the normal period to 544.3 ± 179.4 Mm−1 during the lockdown period. The generalized addictive model analysis indicated that the large decline of bext (29.7 %) was entirely attributed to the sharp reductions in anthropogenic emissions. Chemical calculation of bext based on the ridge regression analysis showed that organic aerosol (OA) was the largest contributor to bext in both periods (45.1–61.4 %), and contributions of two oxygenated OAs to bext increased by 3.0–14.6 % during the lockdown. A hybrid environmental receptor model combining with chemical and optical variables identified six sources of bext. It was found that bext from traffic-related emission, coal combustion, fugitive dust, nitrate plus secondary OA (SOA) source, and sulfate plus SOA source decreased by 21.4–97.9 % in the lockdown, whereas bext from biomass burning increased by 27.1 % mainly driven by undiminished needs of residential cooking and heating. The atmospheric radiative transfer model was further used to illustrate that biomass burning instead of traffic-related emission became the largest positive effect (10.0 ± 10.9 W m−2) on aerosol DRE in the atmosphere during the lockdown. Our study provides insights into aerosol bext and DRE from anthropogenic sources, and the results implied the importance of biomass burning for tackling climate change in China in the future.

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