Atmospheric Measurement Techniques最新文献

{"title":"Assessment of the contribution of the Meteosat Third Generation Infrared Sounder (MTG-IRS) for the characterisation of ozone over Europe","authors":"Francesca Vittorioso, Vincent Guidard, Nadia Fourrié","doi":"10.5194/amt-17-5279-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5279-2024","url":null,"abstract":"Abstract. In the coming years, EUMETSAT's Meteosat Third Generation – Sounding (MTG-S) satellites will be launched with an instrument including valuable features on board. The MTG Infrared Sounder (MTG-IRS) will represent a major innovation for the monitoring of the chemical state of the atmosphere, since, at present, observations of these parameters mainly come from in situ measurements (geographically uneven) and from instruments on board polar-orbiting satellites (highly dependent on the scanning line of the satellite itself, which is limited, over a specific geographical area, to very few times per day). MTG-IRS will present a great deal of potential in the area of detecting different atmospheric species and will have the advantage of being based on a geostationary platform and acquiring data with a high temporal frequency (every 30 min over Europe), which makes it easier to track the transport of the species of interest. The present work aims to evaluate the potential impact, over a regional domain over Europe, of the assimilation of MTG-IRS radiances within a chemical transport model (CTM), Modèle de Chimie Atmosphérique de Grande Echelle (MOCAGE), operated by Météo-France. Since MTG-IRS is not yet in orbit, observations have been simulated using the observing system simulation experiment (OSSE) approach. Of the species to which MTG-IRS will be sensitive, the one treated in this study was ozone. The results obtained indicate that the assimilation of synthetic radiances of MTG-IRS always has a positive impact on the ozone analysis from MOCAGE. The relative average difference compared to the nature run (NR) in the ozone total columns improves from −30 % (no assimilation) to almost zero when MTG-IRS observations are available over the domain. Also remarkable is the reduction in the standard deviation of the difference with respect to the NR, which, in the area where MTG-IRS radiances are assimilated, reaches its lowest values (∼ 1.8 DU). When considering tropospheric columns, the improvement is also significant, from 15 %–20 % (no assimilation) down to 3 %. The error in the differences compared to the NR is lower than for total columns (minima ∼ 0.3 DU), due also to the lower concentrations of the tropospheric ozone field. Overall, the impact of assimilation is considerable over the whole vertical column: vertical variations are noticeably improved compared to what is obtained when no assimilation is performed (up to 25 % better).","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"287 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An information content approach to diagnosing and improving CLIMCAPS retrievals across instruments and satellites","authors":"Nadia Smith, Christopher D. Barnet","doi":"10.5194/egusphere-2024-2448","DOIUrl":"https://doi.org/10.5194/egusphere-2024-2448","url":null,"abstract":"<strong>Abstract.</strong> The Community Long-term Infrared Microwave Combined Atmospheric Product System (CLIMCAPS) characterizes the atmospheric state as vertical profiles (commonly known as soundings or retrievals) of temperature, water vapor, CO₂, CO, CH₄, O₃, HNO₃ and N₂O, together with a suite of Earth surface and cloud properties. The CLIMCAPS record spans more than two decades (2002–present) because it utilizes measurements from a series of different instruments on different satellite platforms. Most notably, these are AIRS+AMSU (Atmospheric Infrared Sounder + Advanced Microwave Sounding Unit) on Aqua and CrIS+ATMS (Cross-track Infrared Sounder + Advanced Thermal Microwave Sounder) on SNPP and the JPSS series. Both instrument suites are on satellite platforms in low-Earth orbit with local overpass times of ~1:30 am/pm. The CrIS interferometers are identical across the different platforms, but differ from AIRS, which is a grating spectrometer. At first order, CrIS+ATMS and AIRS+AMSU are similar enough to allow a continuous CLIMCAPS record, which was first released in 2020 as Version 2 (V2). In this paper, we take a closer look at CLIMCAPS V2 soundings from AIRS+AMSU (on Aqua) and CrIS+ATMS (on SNPP) to diagnose product continuity across the two instrument suites. We demonstrate how averaging kernels, as signal-to-noise ratio (SNR) indicators, can be used to understand and improve multi-instrument systems such as CLIMCAPS. We conclude with recommendations for future CLIMCAPS upgrades.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"14 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drop size distribution retrieval using dual-polarization radar at C-band and S-band","authors":"Daniel Durbin, Yadong Wang, Pao-Liang Chang","doi":"10.5194/amt-17-5397-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5397-2024","url":null,"abstract":"Abstract. Having knowledge of the drop size distribution (DSD) is of particular interest to researchers as it is widely applied to quantitative precipitation estimation (QPE) methods. Polarimetric radar measurements have previously been utilized to derive DSD curve characteristics frequently modeled as a gamma distribution. Likewise, approaches using dual-frequency measurements have shown positive results. Both cases have relied on the need to constrain the relationship between the DSD parameters based on location or assumed weather conditions. This paper presents a methodology for retrieving the DSD parameters using the dual-frequency and polarimetric nature of measurements from a unique data set taken at co-located S-band and C-band dual-polarization radars. Using the reflectivity and differential-phase measurements from each radar, an optimization routine employing particle swarm optimization (PSO) and T-matrix computation of radar parameters is able to accurately retrieve the gamma distribution parameters without the constraints required in previous methods. Retrieved results are compared to known truth data collected using a network of OTT Parsivel disdrometers in Taiwan in order to assess the success of this procedure.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"63 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A solid-state IR laser for two-step desorption/ionization processes in single-particle mass spectrometry","authors":"Marco Schmidt, Haseeb Hakkim, Lukas Anders, Aleksandrs Kalamašņikovs, Thomas Kröger-Badge, Robert Irsig, Norbert Graf, Reinhard Kelnberger, Johannes Passig, Ralf Zimmermann","doi":"10.5194/egusphere-2024-2587","DOIUrl":"https://doi.org/10.5194/egusphere-2024-2587","url":null,"abstract":"<strong>Abstract.</strong> Recent advancements in single-particle mass spectrometry (SPMS) have enabled the detection of aromatic hydrocarbons at the individual particle level in conjunction with inorganic/refractory particle components. However, the laser desorption (LD) of organic material from particles prior to their ionization in a two-step process necessitates pulsed infrared lasers with adequate pulse energy that can be irregularly triggered on detected particles. Pulsed CO₂ lasers with a 10.6 µm wavelength have been traditionally utilized, yet these lasers are bulky, costly, and require regular maintenance, including gas exchange or a continuous laser gas supply. In this study, we present the application of a prototype solid-state laser based on an erbium-doped yttrium aluminum garnet (Er:YAG) crystal, emitting long pulses of 200 µs at 3 µm wavelength as a compact, cost-effective, and user-friendly alternative for LD. We directly compared the new laser with a commonly used CO₂ laser and found similar performance in LD for both laboratory particles and ambient air experiments. With the exception of slightly increased fragmentation observed with the CO₂ laser due to its beam profile, no qualitative differences were noted in the resulting mass spectra. Additionally, we compared the novel two-step ionization scheme for the combined detection of aromatic molecules and inorganics with conventional single-step laser desorption/ionization (LDI) for the detection of polycyclic aromatic hydrocarbons (PAH) in laboratory and field experiments. The combined methods demonstrated superior performance in the detection of PAHs, for both the CO₂ and the new Er:YAG laser. In addition to its higher sensitivity and lower fragmentation for PAHs when compared to single-step LDI, it is less dependent on the particle matrix, sharing the benefits of traditional two-step methods but extending its capability to combine PAH measurements with the LDI-based detection of inorganic particle compounds.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"217 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The EarthCARE lidar cloud and aerosol profile processor (A-PRO): the A-AER, A-EBD, A-TC, and A-ICE products","authors":"David Patrick Donovan, Gerd-Jan van Zadelhoff, Ping Wang","doi":"10.5194/amt-17-5301-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5301-2024","url":null,"abstract":"Abstract. ATLID (ATmospheric LIDar) is the lidar flown on the multi-instrument Earth Cloud Aerosol and Radiation Explorer (EarthCARE). EarthCARE is a joint ESA–JAXA mission that was launched in May 2024. ATLID is a three-channel, linearly polarized, high-spectral-resolution lidar (HSRL) system operating at 355 nm. Cloud and aerosol optical properties are key EarthCARE products. This paper provides an overview of the ATLID Level 2a (L2a; i.e., single instrument) retrieval algorithms being developed and implemented in order to derive cloud and aerosol optical properties. The L2a lidar algorithms that retrieve the aerosol and cloud optical property profiles and classify the detected targets are grouped together in the so-called A-PRO (ATLID-profile) processor. The A-PRO processor produces the ATLID L2a aerosol product (A-AER); the extinction, backscatter, and depolarization product (A-EBD); the ATLID L2a target classification product (A-TC); and the ATLID L2a ice microphysical estimation product (A-ICE). This paper provides an overview of the processor and its component algorithms.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"217 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of NO and NH3 Concentrations in Atmospheric Simulation Chamber Using Direct Absorption Spectroscopy","authors":"Nakwon Jeong, Seungryong Lee, Soonho Song, Daehae Kim, Miyeon Yoo, Changyeop Lee","doi":"10.5194/egusphere-2024-2762","DOIUrl":"https://doi.org/10.5194/egusphere-2024-2762","url":null,"abstract":"<strong>Abstract.</strong> In urban atmospheric chemistry, nitrogen oxides and ammonia in the atmosphere are major species participating in the secondary aerosol formation process, causing severe environmental problems such as decreased visibility and acid rain. In order to respond effectively to particulate matter problems, the correlation of precursors should be identified in detail. This study used UV-C light to convert gaseous substances into particulate substances in the atmospheric simulation chamber to simulate the photochemical reaction. The effects of several operating variables, such as UV-C light intensity, relative humidity, and initial concentrations of O₂, NO, and NH₃, on the NH₄NO₃ formation were investigated. Since atmospheric gas species are short-lived, they require a measurement technique with an ultra-fast response and high sensitivity. Therefore, the concentrations of NO and NH₃ were measured using Direct Absorption Spectroscopy techniques with the wavenumber regions of 1926 and 6568 cm^-1, respectively. NO and NH₃ were precisely measured with an error rate of less than 3 % with the reference gas. The results show that NO and NH₃ were converted over 98 % when UV-C light intensity was 24 W and relative humidity was about 30 % at 1 atm, 296 K. It also showed that higher UV-C light intensity, O₃ concentration, and relative humidity induced higher conversion rates and secondary aerosol generation. In particular, it was experimentally confirmed that the secondary aerosol generation and growth process was greatly influenced by relative humidity.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"66 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-accuracy dynamic dilution method for generating reference gas mixtures of carbonyl sulfide at sub-nanomole-per-mole levels for long-term atmospheric observation","authors":"Hideki Nara, Takuya Saito, Taku Umezawa, Yasunori Tohjima","doi":"10.5194/amt-17-5187-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5187-2024","url":null,"abstract":"Abstract. Atmospheric carbonyl sulfide (COS) has received increasing attention as a potential tracer for investigating the global carbon cycle. Owing to the irreversible photosynthetic absorption of COS, changes in the atmospheric COS mole fraction can be related to terrestrial gross primary production. However, the instability of COS in high-pressure cylinders has hampered the accurate determination of atmospheric COS. Here, we report a dynamic dilution method for generating reference gas mixtures containing COS at ambient levels (ca. 500 pmol mol−1). Our method combined a dynamic dilution system employing a high-accuracy mass flow measurement system and a dry reference gas mixture prepared gravimetrically as a parent gas mixture containing a micromole-per-mole level of COS filled in a high-pressure aluminium cylinder. The storage stability of COS at this level was experimentally validated for three gravimetrically prepared dry reference gases over a period of more than 1 decade. We evaluated the dilution performance of the developed method using a gravimetric parent gas mixture containing approximately 1 µmol mol−1 of COS and chlorodifluoromethane (HCFC-22). Excellent repeatability (0.2 % for COS and 0.4 % for HCFC-22 in terms of relative standard deviation; RSD), reproducibility (COS: 0.1 %; HCFC-22: 0.3 %), and dilution linearity (R2>0.99 for both COS and HCFC-22) were obtained and were corroborated by the nearly constant ratio of the normalized gas chromatography–mass spectrometry (GC/MS) response of COS to HCFC-22. The dilution accuracy was examined by comparing the determined HCFC-22 mole fractions in a dynamically diluted parent gas mixture from a mass flow rate measurement system and GC/MS calibrated using a gravimetrically diluted parent gas mixture. The mole fractions of HCFC-22 from these two methods agreed within an acceptable difference of approximately 2 pmol mol−1, validating the dilution accuracy of the developed method. By re-evaluating the experimental data, we determined the mole fractions of COS and HCFC-22 in an ambient-air-based reference gas mixture, with relative standard deviations of 0.1 % for COS and 0.3 % for HCFC-22. These results demonstrated that the developed method can accurately generate reference gas mixtures containing COS at ambient levels, which we expect will support long-term observations of atmospheric COS.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"18 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-instrumental analysis of ozone vertical profiles and total columns in South America: comparison between subtropical and equatorial latitudes","authors":"Gabriela Dornelles Bittencourt, Hassan Bencherif, Damaris Kirsch Pinheiro, Nelson Begue, Lucas Vaz Peres, José Valentin Bageston, Douglas Lima de Bem, Francisco Raimundo da Silva, Tristan Millet","doi":"10.5194/amt-17-5201-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5201-2024","url":null,"abstract":"Abstract. The behavior of ozone gas (O3) in the atmosphere varies according to the region of the globe. Its formation occurs mainly in the tropical stratosphere through the photodissociation of molecular oxygen with the aid of the incidence of ultraviolet solar radiation. Still, the highest concentrations of O3 content are found in high-latitude regions (poles) due to the Brewer–Dobson circulation, a large-scale circulation that takes place from the tropics to the pole in the winter hemisphere. This work presents a multi-instrumental analysis at two Brazilian sites, a subtropical one (Santa Maria – 29.72° S, 53.41° W) and an equatorial one (Natal – 5.4° S, 35.4° W), to investigate ozone distributions in terms of vertical profiles (2002–2020) and total abundance in terms of total columns of ozone (1979–2020). The study is based on the use of ground-based and satellite observations. Ozone profiles over Natal, from the ground up to the mesosphere, are obtained by radiosonde experiments (0–30 km) in the framework of the SHADOZ program and by satellite measurements from the SABER instrument (15–60 km). This enabled the construction of a continuous time series for ozone, including monthly values and climatological trends. There is a good agreement between the two measurements in the common observation layer, mainly for altitudes above 20 km. Below 20 km, SABER ozone profiles showed high variability and overestimated ozone mixing ratios by over 50 %. Dynamic and photochemical effects can interfere with O3 formation and distribution along higher latitudes through the Brewer–Dobson circulation. The measurements of the total ozone columns used are in good agreement with each other (TOMS/OMI × Dobson for Natal and TOMS/OMI × Brewer for Santa Maria) in time and space, in line with previous studies for these latitudes. Wavelet analysis was used over 42 years. The investigation revealed a significant annual cycle in both data series for both sites. The study highlighted that the quasi-biennial oscillation (QBO) plays a significant role in the variability of stratospheric ozone at the two study sites – Natal and Santa Maria. The QBO's contribution was found to be stronger at the Equator (Natal) than at the subtropics (Santa Maria). Additionally, the study showed that the 11-year solar cycle also has a significant impact on ozone variability at both locations. Given the study latitudes, the ozone variations observed at the two sites showed different patterns and amounts. Only a limited number of studies have been conducted on stratospheric ozone in South America, particularly in the region between the Equator and the subtropics. The primary aim of this work is to investigate the behavior of stratospheric ozone at various altitudes and latitudes using ground-based and satellite measurements in terms of vertical profiles and total columns of ozone.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"74 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the potential of free-tropospheric water vapour isotopologue satellite observations for improving the analyses of convective events","authors":"Matthias Schneider, Kinya Toride, Farahnaz Khosrawi, Frank Hase, Benjamin Ertl, Christopher J. Diekmann, Kei Yoshimura","doi":"10.5194/amt-17-5243-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5243-2024","url":null,"abstract":"Abstract. Satellite-based observations of free-tropospheric water vapour isotopologue ratios (HDO / H2O, expressed in form of the δ value δD) with good global and temporal coverage have become available recently. We investigate the potential of these observations for constraining the uncertainties of the atmospheric analyses fields of specific humidity (q), temperature (T), and δD and of variables that capture important properties of the atmospheric water cycle, namely the vertical velocity (ω), the latent heating rate (Q2), and the precipitation rate (Prcp). Our focus is on the impact of the δD observations relative to the impact achieved by the observation of q and T, which are much more easily observed by satellites and are routinely in use for atmospheric analyses. For our investigations we use an Observing System Simulation Experiment; i.e. we simulate the satellite observations of q, T, and δD with known uncertainties and coverage (e.g. observations are not available for cloudy conditions, i.e. at locations where the atmosphere is vertically unstable). Then we use the simulated observations within a Kalman-filter-based assimilation framework in order to evaluate their potential for improving the quality of atmospheric analyses. The study is made for low latitudes (30° S to 30° N) and for 40 d between mid-July and the end of August 2016. We find that q observations generally have the largest impacts on the analyses' quality and that T observations have stronger impacts overall than δD observations. We show that there is no significant impact of δD observations for stable atmospheric conditions; however, for very unstable conditions, the impact of δD observations is significant and even slightly stronger than the respective impact of T observations. Very unstable conditions are rare but are related to extreme events (e.g. storms, flooding); i.e. the δD observations significantly impact the analyses' quality of the events that have the largest societal consequences. The fact that no satellite observations are available at the location and time of the unstable conditions indicates a remote impact of δD observations that are available elsewhere. Concerning real-world applications, we conclude that the situation of δD satellite observations is very promising but that further improving the model's linkage between convective processes and the larger-scale δD fields might be needed for optimizing the assimilation impact of real-world δD observations.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"14 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current potential of CH4 emission estimates using TROPOMI in the Middle East","authors":"Mengyao Liu, Ronald van der A, Michiel van Weele, Lotte Bryan, Henk Eskes, Pepijn Veefkind, Yongxue Liu, Xiaojuan Lin, Jos de Laat, Jieying Ding","doi":"10.5194/amt-17-5261-2024","DOIUrl":"https://doi.org/10.5194/amt-17-5261-2024","url":null,"abstract":"Abstract. An improved divergence method has been developed to estimate annual methane (CH4) emissions from TROPOspheric Monitoring Instrument (TROPOMI) observations. It has been applied to the period of 2018 to 2021 over the Middle East, where the orography is complicated, and the mean mixing ratio of methane (XCH4) might be affected by albedos or aerosols over some locations. To adapt to extreme changes of terrain over mountains or coasts, winds are used with their divergent part removed. A temporal filter is introduced to identify highly variable emissions and to further exclude fake sources caused by retrieval artifacts. We compare our results to widely used bottom-up anthropogenic emission inventories: Emissions Database for Global Atmospheric Research (EDGAR), Community Emissions Data System (CEDS), and Global Fuel Exploitation Inventory (GFEI) over several regions representing various types of sources. The NOx emissions are from EDGAR and Daily Emissions Constrained by Satellite Observations (DECSO), and the industrial heat sources identified by Visible Infrared Imaging Radiometer Suite (VIIRS) are further used to better understand our resulting methane emissions. Our results indicate possibly large underestimations of methane emissions in metropolises like Tehran (up to 50 %) and Isfahan (up to 70 %) in Iran. The derived annual methane emissions from oil/gas production near the Caspian Sea in Turkmenistan are comparable to GFEI but more than 2 times higher than EDGAR and CEDS in 2019. Large discrepancies in the distribution of methane sources in Riyadh and its surrounding areas are found between EDGAR, CEDS, GFEI, and our emissions. The methane emission from oil/gas production to the east of Riyadh seems to be largely overestimated by EDGAR and CEDS, while our estimates as well as GFEI and DECSO NOx indicate much lower emissions from industrial activities. On the other hand, regions like Iran, Iraq, and Oman are dominated by sources from oil and gas exploitation that probably include more irregular releases of methane, with the result that our estimates, which include only invariable sources, are lower than the bottom-up emission inventories.","PeriodicalId":8619,"journal":{"name":"Atmospheric Measurement Techniques","volume":"36 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}