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New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)Kim, JhoonJeong, UkkyoAhn, Myoung-HwanKim, Jae H.Park, Rokjin J.Lee, HanlimSong, Chul HanChoi, Yong-SangLee, Kwon-HoYoo, Jung-MoonJeong, Myeong-JaePark, Seon KiLee, Kwang-MogSong, Chang-KeunKim, Sang-WooKim, Young JoonKim, Si-WanKim, MijinGo, SujungLiu, XiongChance, KellyChan Miller, ChristopherAl-Saadi, JayVeihelmann, BenBhartia, Pawan K.Torres, OmarGonzález-Abad, GonzaloHaffner, David P.Ko, Dai HoLee, Seung HoonWoo, Jung-HunChong, HeesungPark, Sang SeoNicks, DennisChoi, Won JunMoon, Kyung-JungCho, AraYoon, JongminKim, Sang-kyunHong, HyunkeeLee, KyunghwaLee, HanaLee, SeoyoungChoi, MyungjeVeefkind, PepijnLevelt, Pieternel F.Edwards, David P.Kang, MinaEo, MijinBak, JuseonBaek, KanghyunKwon, Hyeong-AhnYang, JiwonPark, JunsungHan, Kyung ManKim, Bo-RamShin, Hee-WooChoi, HaklimLee, EbonyChong, JihyoCha, YesolKoo, Ja-HoIrie, HitoshiHayashida, SachikoKasai, YaskoKanaya, YugoLiu, ChengLin, JintaiCrawford, James H.Carmichael, Gregory R.Newchurch, Michael J.Lefer, Barry L.Herman, Jay R.Swap, Robert J.Lau, Alexis K. H.Kurosu, Thomas P.Jaross, GlenAhlers, BeritDobber, MarcelMcElroy, C. ThomasChoi, YunsooDOI: info:10.1175/BAMS-D-18-0013.1v. 101E1–E22
Kim, Jhoon, Jeong, Ukkyo, Ahn, Myoung-Hwan, Kim, Jae H., Park, Rokjin J., Lee, Hanlim, Song, Chul Han, Choi, Yong-Sang, Lee, Kwon-Ho, Yoo, Jung-Moon, Jeong, Myeong-Jae, Park, Seon Ki, Lee, Kwang-Mog, Song, Chang-Keun, Kim, Sang-Woo, Kim, Young Joon, Kim, Si-Wan, Kim, Mijin, Go, Sujung, Liu, Xiong, Chance, Kelly, Chan Miller, Christopher, Al-Saadi, Jay, Veihelmann, Ben, Bhartia, Pawan K. et al. 2020. "New Era of Air Quality Monitoring from Space: Geostationary Environment Monitoring Spectrometer (GEMS)." Bulletin of the American Meteorological Society 101:E1– E22. https://doi.org/10.1175/BAMS-D-18-0013.1
ID: 155672
Type: article
Authors: Kim, Jhoon; Jeong, Ukkyo; Ahn, Myoung-Hwan; Kim, Jae H.; Park, Rokjin J.; Lee, Hanlim; Song, Chul Han; Choi, Yong-Sang; Lee, Kwon-Ho; Yoo, Jung-Moon; Jeong, Myeong-Jae; Park, Seon Ki; Lee, Kwang-Mog; Song, Chang-Keun; Kim, Sang-Woo; Kim, Young Joon; Kim, Si-Wan; Kim, Mijin; Go, Sujung; Liu, Xiong; Chance, Kelly; Chan Miller, Christopher; Al-Saadi, Jay; Veihelmann, Ben; Bhartia, Pawan K.; Torres, Omar; González-Abad, Gonzalo; Haffner, David P.; Ko, Dai Ho; Lee, Seung Hoon; Woo, Jung-Hun; Chong, Heesung; Park, Sang Seo; Nicks, Dennis; Choi, Won Jun; Moon, Kyung-Jung; Cho, Ara; Yoon, Jongmin; Kim, Sang-kyun; Hong, Hyunkee; Lee, Kyunghwa; Lee, Hana; Lee, Seoyoung; Choi, Myungje; Veefkind, Pepijn; Levelt, Pieternel F.; Edwards, David P.; Kang, Mina; Eo, Mijin; Bak, Juseon; Baek, Kanghyun; Kwon, Hyeong-Ahn; Yang, Jiwon; Park, Junsung; Han, Kyung Man; Kim, Bo-Ram; Shin, Hee-Woo; Choi, Haklim; Lee, Ebony; Chong, Jihyo; Cha, Yesol; Koo, Ja-Ho; Irie, Hitoshi; Hayashida, Sachiko; Kasai, Yasko; Kanaya, Yugo; Liu, Cheng; Lin, Jintai; Crawford, James H.; Carmichael, Gregory R.; Newchurch, Michael J.; Lefer, Barry L.; Herman, Jay R.; Swap, Robert J.; Lau, Alexis K. H.; Kurosu, Thomas P.; Jaross, Glen; Ahlers, Berit; Dobber, Marcel; McElroy, C. Thomas; Choi, Yunsoo
Abstract: The Geostationary Environment Monitoring Spectrometer (GEMS) is scheduled for launch in February 2020 to monitor air quality (AQ) at an unprecedented spatial and temporal resolution from a geostationary Earth orbit (GEO) for the first time. With the development of UV-visible spectrometers at sub-nm spectral resolution and sophisticated retrieval algorithms, estimates of the column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO, and aerosols) can be obtained. To date, all the UV-visible satellite missions monitoring air quality have been in low Earth orbit (LEO), allowing one to two observations per day. With UV-visible instruments on GEO platforms, the diurnal variations of these pollutants can now be determined. Details of the GEMS mission are presented, including instrumentation, scientific algorithms, predicted performance, and applications for air quality forecasts through data assimilation. GEMS will be on board the Geostationary Korea Multi-Purpose Satellite 2 (GEO- KOMPSAT-2) satellite series, which also hosts the Advanced Meteorological Imager (AMI) and Geostationary Ocean Color Imager 2 (GOCI-2). These three instruments will provide synergistic science products to better understand air quality, meteorology, the long-range transport of air pollutants, emission source distributions, and chemical processes. Faster sampling rates at higher spatial resolution will increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than is possible from LEO. GEMS will be joined by NASA's Tropospheric Emissions: Monitoring of Pollution (TEMPO) and ESA's Sentinel-4 to form a GEO AQ satellite constellation in early 2020s, coordinated by the Committee on Earth Observation Satellites (CEOS).
Corrigendum to 'Revisiting the effectiveness of HCHO/NO2 ratios for inferring ozone sensitivity to its precursors using high resolution airborne remote sensing observations in a high ozone episode during the KORUS-AQ campaign' [Atmos. Environ. 224 117341]Souri, Amir H.Nowlan, Caroline R.Wolfe, Glenn M.Lamsal, Lok N.Chan Miller, Christopher E.González Abad, GonzaloJanz, Scott J.Fried, AlanBlake, Donald R.Weinheimer, Andrew J.Diskin, Glenn S.Liu, XiongChance, KellyDOI: info:10.1016/j.atmosenv.2020.117792v. 240117792
Souri, Amir H., Nowlan, Caroline R., Wolfe, Glenn M., Lamsal, Lok N., Chan Miller, Christopher E., González Abad, Gonzalo, Janz, Scott J., Fried, Alan, Blake, Donald R., Weinheimer, Andrew J., Diskin, Glenn S., Liu, Xiong, and Chance, Kelly. 2020. "Corrigendum to "Revisiting the effectiveness of HCHO/NO2 ratios for inferring ozone sensitivity to its precursors using high resolution airborne remote sensing observations in a high ozone episode during the KORUS-AQ campaign" [Atmos. Environ. 224 117341]." Atmospheric Environment 240:117792. https://doi.org/10.1016/j.atmosenv.2020.117792
ID: 157460
Type: article
Authors: Souri, Amir H.; Nowlan, Caroline R.; Wolfe, Glenn M.; Lamsal, Lok N.; Chan Miller, Christopher E.; González Abad, Gonzalo; Janz, Scott J.; Fried, Alan; Blake, Donald R.; Weinheimer, Andrew J.; Diskin, Glenn S.; Liu, Xiong; Chance, Kelly
Abstract: The authors regret both Fig. S2 and Fig. S3 were inadvertently used a wrong day (06/10 instead of 06/09 due to a difference in the UTC vs local times) for plotting the NASA's LaRC box model output. The new figure shows that both F0AM and LaRC models are in a strong degree of agreement (<10%) suggesting that the non-linear ozone chemistry over Seoul can be reasonably represented by both models. This correction does not impact the conclusion drawn from this study. We thank James H. Crawford for pointing us at the bug.
Revisiting the effectiveness of HCHO/NO2 ratios for inferring ozone sensitivity to its precursors using high resolution airborne remote sensing observations in a high ozone episode during the KORUS-AQ campaignSouri, Amir HosseinNowlan, Caroline R.Wolfe, Glenn M.Lamsal, Lok N.Chan Miller, Christopher E.Abad, Gonzalo GonzálezJanz, Scott J.Fried, AlanBlake, Donald R.Weinheimer, Andrew J.Diskin, Glenn S.Liu, XiongChance, KellyDOI: info:10.1016/j.atmosenv.2020.117341v. 224117341
Souri, Amir Hossein, Nowlan, Caroline R., Wolfe, Glenn M., Lamsal, Lok N., Chan Miller, Christopher E., Abad, Gonzalo González, Janz, Scott J., Fried, Alan, Blake, Donald R., Weinheimer, Andrew J., Diskin, Glenn S., Liu, Xiong, and Chance, Kelly. 2020. "Revisiting the effectiveness of HCHO/NO2 ratios for inferring ozone sensitivity to its precursors using high resolution airborne remote sensing observations in a high ozone episode during the KORUS-AQ campaign." Atmospheric Environment 224:117341. https://doi.org/10.1016/j.atmosenv.2020.117341
ID: 156335
Type: article
Authors: Souri, Amir Hossein; Nowlan, Caroline R.; Wolfe, Glenn M.; Lamsal, Lok N.; Chan Miller, Christopher E.; Abad, Gonzalo González; Janz, Scott J.; Fried, Alan; Blake, Donald R.; Weinheimer, Andrew J.; Diskin, Glenn S.; Liu, Xiong; Chance, Kelly
Abstract: The nonlinear chemical processes involved in ozone production (P(O3)) have necessitated using proxy indicators to convey information about the primary dependence of P(O3) on volatile organic compounds (VOCs) or nitrogen oxides (NOx). In particular, the ratio of remotely sensed columns of formaldehyde (HCHO) to nitrogen dioxide (NO2) has been widely used for studying O3 sensitivity. Previous studies found that the errors in retrievals and the incoherent relationship between the column and the near-surface concentrations are a barrier in applying the ratio in a robust way. In addition to these obstacles, we provide calculational- observational evidence, using an ensemble of 0-D photochemical box models constrained by DC-8 aircraft measurements on an ozone event during the Korea-United States Air Quality (KORUS-AQ) campaign over Seoul, to demonstrate the chemical feedback of NO2 on the formation of HCHO is a controlling factor for the transition line between NOx-sensitive and NOx-saturated regimes. A fixed value (~2.7) of the ratio of the chemical loss of NOx (LNOx) to the chemical loss of HO2+RO2 (LROx) perceptibly differentiates the regimes. Following this value, data points with a ratio of HCHO/NO2 less than 1 can be safely classified as NOx-saturated regime, whereas points with ratios between 1 and 4 fall into one or the other regime. We attribute this mainly to the HCHO-NO2 chemical relationship causing the transition line to occur at larger (smaller) HCHO/NO2 ratios in VOC-rich (VOC-poor) environments. We then redefine the transition line to LNOx/LROx~2.7 that accounts for the HCHO-NO2 chemical relationship leading to HCHO = 3.7 × (NO2 - 1.14 × 1016 molec.cm-2). Although the revised formula is locally calibrated (i.e., requires for readjustment for other regions), its mathematical format removes the need for having a wide range of thresholds used in HCHO/NO2 ratios that is a result of the chemical feedback. Therefore, to be able to properly take the chemical feedback into consideration, the use of HCHO = a × (NO2 - b) formula should be preferred to the ratio in future works. We then use the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument to study O3 sensitivity in Seoul. The unprecedented spatial (250 × 250 m2) and temporal (~every 2 h) resolutions of HCHO and NO2 observations form the sensor enhance our understanding of P(O3) in Seoul; rather than providing a crude label for the entire city, more in-depth variabilities in chemical regimes are observed that should be able to inform mitigation strategies correspondingly.
Validation of satellite formaldehyde (HCHO) retrievals using observations from 12 aircraft campaignsZhu, LeiAbad, Gonzalo GonzalezNowlan, Caroline R.Miller, Christopher ChanChance, KellyApel, Eric C.DiGangi, Joshua P.Fried, AlanHanisco, Thomas F.Hornbrook, Rebecca S.Hu, LuKaiser, JenniferKeutsch, Frank N.Permar, WadeSt Clair, Jason M.Wolfe, Glenn M.DOI: info:10.5194/acp-20-12329-2020v. 20No. 2012329–12345
Zhu, Lei, Abad, Gonzalo Gonzalez, Nowlan, Caroline R., Miller, Christopher Chan, Chance, Kelly, Apel, Eric C., DiGangi, Joshua P., Fried, Alan, Hanisco, Thomas F., Hornbrook, Rebecca S., Hu, Lu, Kaiser, Jennifer, Keutsch, Frank N., Permar, Wade, St Clair, Jason M., and Wolfe, Glenn M. 2020. "Validation of satellite formaldehyde (HCHO) retrievals using observations from 12 aircraft campaigns." Atmospheric Chemistry and Physics 20 (20):12329– 12345. https://doi.org/10.5194/acp-20-12329-2020
ID: 157528
Type: article
Authors: Zhu, Lei; Abad, Gonzalo Gonzalez; Nowlan, Caroline R.; Miller, Christopher Chan; Chance, Kelly; Apel, Eric C.; DiGangi, Joshua P.; Fried, Alan; Hanisco, Thomas F.; Hornbrook, Rebecca S.; Hu, Lu; Kaiser, Jennifer; Keutsch, Frank N.; Permar, Wade; St Clair, Jason M.; Wolfe, Glenn M.
Abstract: Formaldehyde (HCHO) has been measured from space for more than 2 decades. Owing to its short atmospheric lifetime, satellite HCHO data are used widely as a proxy of volatile organic compounds (VOCs; please refer to Appendix A for abbreviations and acronyms), providing constraints on underlying emissions and chemistry. However, satellite HCHO products from different satellite sensors using different algorithms have received little validation so far. The accuracy and consistency of HCHO retrievals remain largely unclear. Here we develop a validation platform for satellite HCHO retrievals using in situ observations from 12 aircraft campaigns with a chemical transport model (GEOS-Chem) as the intercomparison method. Application to the NASA operational OMI HCHO product indicates negative biases (- 44.5 % to -21.7 %) under high-HCHO conditions, while it indicates high biases (+66.1 % to +112.1 %) under low-HCHO conditions. Under both conditions, HCHO a priori vertical profiles are likely not the main driver of the biases. By providing quick assessment of systematic biases in satellite products over large domains, the platform facilitates, in an iterative process, optimization of retrieval settings and the minimization of retrieval biases. It is also complementary to localized validation efforts based on ground observations and aircraft spirals.
Potential of next-generation imaging spectrometers to detect and quantify methane point sources from spaceCusworth, Daniel H.Jacob, Daniel J.Varon, Daniel J.Chan Miller, ChristopherLiu, XiongChance, KellyThorpe, Andrew K.Duren, Riley M.Miller, Charles E.Thompson, David R.Frankenberg, ChristianGuanter, LuisRandles, Cynthia A.DOI: info:10.5194/amt-12-5655-2019v. 125655–5668
Cusworth, Daniel H., Jacob, Daniel J., Varon, Daniel J., Chan Miller, Christopher, Liu, Xiong, Chance, Kelly, Thorpe, Andrew K., Duren, Riley M., Miller, Charles E., Thompson, David R., Frankenberg, Christian, Guanter, Luis, and Randles, Cynthia A. 2019. "Potential of next-generation imaging spectrometers to detect and quantify methane point sources from space." Atmospheric Measurement Techniques 12:5655– 5668. https://doi.org/10.5194/amt-12-5655-2019
ID: 154635
Type: article
Authors: Cusworth, Daniel H.; Jacob, Daniel J.; Varon, Daniel J.; Chan Miller, Christopher; Liu, Xiong; Chance, Kelly; Thorpe, Andrew K.; Duren, Riley M.; Miller, Charles E.; Thompson, David R.; Frankenberg, Christian; Guanter, Luis; Randles, Cynthia A.
Abstract: We examine the potential for global detection of methane plumes from individual point sources with the new generation of spaceborne imaging spectrometers (EnMAP, PRISMA, EMIT, SBG, CHIME) scheduled for launch in 2019-2025. These instruments are designed to map the Earth's surface at high spatial resolution (30 m×30 m) and have a spectral resolution of 7-10 nm in the 2200-2400 nm band that should also allow useful detection of atmospheric methane. We simulate scenes viewed by EnMAP (10 nm spectral resolution, 180 signal-to-noise ratio) using the EnMAP end-to- end simulation tool with superimposed methane plumes generated by large- eddy simulations. We retrieve atmospheric methane and surface reflectivity for these scenes using the IMAP-DOAS optimal estimation algorithm. We find an EnMAP precision of 3 %-7 % for atmospheric methane depending on surface type. This allows effective single-pass detection of methane point sources as small as 100 kg h-1 depending on surface brightness, surface homogeneity, and wind speed. Successful retrievals over very heterogeneous surfaces such as an urban mosaic require finer spectral resolution. We tested the EnMAP capability with actual plume observations over oil/gas fields in California from the Airborne Visible/Infrared Imaging Spectrometer - Next Generation (AVIRIS-NG) sensor (3 m×3 m pixel resolution, 5 nm spectral resolution, SNR 200-400), by spectrally and spatially downsampling the AVIRIS-NG data to match EnMAP instrument specifications. Results confirm that EnMAP can successfully detect point sources of ̃100 kg h-1 over bright surfaces. Source rates inferred with a generic integrated mass enhancement (IME) algorithm were lower for EnMAP than for AVIRIS- NG. Better agreement may be achieved with a more customized IME algorithm. Our results suggest that imaging spectrometers in space could play an important role in the future for quantifying methane emissions from point sources worldwide.
Five decades observing Earth's atmospheric trace gases using ultraviolet and visible backscatter solar radiation from spaceGonzalez Abad, GonzaloSouri, Amir HosseinBak, JuseonChance, KellyFlynn, Lawrence E.Krotkov, Nickolay A.Lamsal, LokLi, CanLiu, XiongChan Miller, ChristopherNowlan, Caroline R.Suleiman, RaidWang, HuiqunDOI: info:10.1016/j.jqsrt.2019.04.030v. 238106478
Gonzalez Abad, Gonzalo, Souri, Amir Hossein, Bak, Juseon, Chance, Kelly, Flynn, Lawrence E., Krotkov, Nickolay A., Lamsal, Lok, Li, Can, Liu, Xiong, Chan Miller, Christopher, Nowlan, Caroline R., Suleiman, Raid, and Wang, Huiqun. 2019. "Five decades observing Earth's atmospheric trace gases using ultraviolet and visible backscatter solar radiation from space." Journal of Quantitative Spectroscopy and Radiative Transfer 238:106478. https://doi.org/10.1016/j.jqsrt.2019.04.030
ID: 154602
Type: article
Authors: Gonzalez Abad, Gonzalo; Souri, Amir Hossein; Bak, Juseon; Chance, Kelly; Flynn, Lawrence E.; Krotkov, Nickolay A.; Lamsal, Lok; Li, Can; Liu, Xiong; Chan Miller, Christopher; Nowlan, Caroline R.; Suleiman, Raid; Wang, Huiqun
Abstract: Over the last five decades, Earth's atmosphere has been extensively monitored from space using different spectral ranges. Early efforts were directed at improving weather forecasts with the first meteorological satellites launched in the 1960s. Soon thereafter, the intersection between weather, climate and atmospheric chemistry led to the observation of atmospheric composition from space. During the 1970s the Nimbus satellite program started regular monitoring of ozone integrated columns and water vapor profiles using the Backscatter Ultraviolet Spectrometer, the Infrared Interferometer Spectrometer and the Satellite Infrared Spectrometer instruments. Five decades after these pioneer efforts, continuous progress in instrument design, and retrieval techniques allow researchers to monitor tropospheric concentrations of a wide range of species with implications for air quality, climate and weather. The time line of historic, present and future space-borne instruments measuring ultraviolet and visible backscattered solar radiation designed to quantify atmospheric trace gases is presented. We describe the instruments technological evolution and the basic concepts of retrieval theory. We include a review of algorithms developed for ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, bromine monoxide, water vapor and glyoxal, a selection of studies using these algorithms, the challenges they face and how these challenges can be addressed. The paper ends by providing insights on the opportunities that new instruments will bring to the atmospheric chemistry, weather and air quality communities and how to address the pressing need for long-term, inter-calibrated data records necessary to monitor the response of the atmosphere to rapidly changing ecosystems.
Glyoxal yield from isoprene oxidation and relation to formaldehyde: chemical mechanism, constraints from SENEX aircraft observations, and interpretation of OMI satellite dataChan Miller, ChristopherJacob, Daniel J.Marais, Eloise A.Yu, KarenTravis, Katherine R.Kim, Patrick S.Fisher, Jenny A.Zhu, LeiWolfe, Glenn M.Hanisco, Thomas F.Keutsch, Frank N.Kaiser, JenniferMin, Kyung-EunBrown, Steven S.Washenfelder, Rebecca A.González Abad, GonzaloChance, KellyDOI: info:10.5194/acp-17-8725-2017v. 178725–8738
Chan Miller, Christopher, Jacob, Daniel J., Marais, Eloise A., Yu, Karen, Travis, Katherine R., Kim, Patrick S., Fisher, Jenny A., Zhu, Lei, Wolfe, Glenn M., Hanisco, Thomas F., Keutsch, Frank N., Kaiser, Jennifer, Min, Kyung-Eun, Brown, Steven S., Washenfelder, Rebecca A., González Abad, Gonzalo, and Chance, Kelly. 2017. "Glyoxal yield from isoprene oxidation and relation to formaldehyde: chemical mechanism, constraints from SENEX aircraft observations, and interpretation of OMI satellite data." Atmospheric Chemistry & Physics 17:8725– 8738. https://doi.org/10.5194/acp-17-8725-2017
ID: 143830
Type: article
Authors: Chan Miller, Christopher; Jacob, Daniel J.; Marais, Eloise A.; Yu, Karen; Travis, Katherine R.; Kim, Patrick S.; Fisher, Jenny A.; Zhu, Lei; Wolfe, Glenn M.; Hanisco, Thomas F.; Keutsch, Frank N.; Kaiser, Jennifer; Min, Kyung-Eun; Brown, Steven S.; Washenfelder, Rebecca A.; González Abad, Gonzalo; Chance, Kelly
Abstract: Glyoxal (CHOCHO) is produced in the atmosphere by the oxidation of volatile organic compounds (VOCs). Like formaldehyde (HCHO), another VOC oxidation product, it is measurable from space by solar backscatter. Isoprene emitted by vegetation is the dominant source of CHOCHO and HCHO in most of the world. We use aircraft observations of CHOCHO and HCHO from the SENEX campaign over the southeast US in summer 2013 to better understand the CHOCHO time-dependent yield from isoprene oxidation, its dependence on nitrogen oxides (NOx ≡ NO + NO2), the behavior of the CHOCHO-HCHO relationship, the quality of OMI CHOCHO satellite observations, and the implications for using CHOCHO observations from space as constraints on isoprene emissions. We simulate the SENEX and OMI observations with the Goddard Earth Observing System chemical transport model (GEOS-Chem) featuring a new chemical mechanism for CHOCHO formation from isoprene. The mechanism includes prompt CHOCHO formation under low-NOx conditions following the isomerization of the isoprene peroxy radical (ISOPO2). The SENEX observations provide support for this prompt CHOCHO formation pathway, and are generally consistent with the GEOS-Chem mechanism. Boundary layer CHOCHO and HCHO are strongly correlated in the observations and the model, with some departure under low-NOx conditions due to prompt CHOCHO formation. SENEX vertical profiles indicate a free-tropospheric CHOCHO background that is absent from the model. The OMI CHOCHO data provide some support for this free-tropospheric background and show southeast US enhancements consistent with the isoprene source but a factor of 2 too low. Part of this OMI bias is due to excessive surface reflectivities assumed in the retrieval. The OMI CHOCHO and HCHO seasonal data over the southeast US are tightly correlated and provide redundant proxies of isoprene emissions. Higher temporal resolution in future geostationary satellite observations may enable detection of the prompt CHOCHO production under low-NOx conditions apparent in the SENEX data.
Tropospheric emissions: Monitoring of pollution (TEMPO)Zoogman, P.Liu, X.Suleiman, R. M.Pennington, W. F.Flittner, D. E.Al-Saadi, J. A.Hilton, B. B.Nicks, D. K.Newchurch, M. J.Carr, J. L. Janz, S. J.Andraschko, M. R.Arola, A.Baker, B. D.Canova, B. P.Chan Miller, C.Cohen, R. C.Davis, J. E.Dussault, M. E.Edwards, D. P.Fishman, J.Ghulam, A.González Abad, GonzaloGrutter, M.Herman, J. R.Houck, J.Jacob, D. J.Joiner, J.Kerridge, B. J.Kim, J.Krotkov, N. A.Lamsal, L.Li, C.Lindfors, A.Martin, R. V.McElroy, C. T.McLinden, C.Natraj, V.Neil, D. O.Nowlan, C. R.O'Sullivan, E. J.Palmer, P. I.Pierce, R. B.Pippin, M. R.Saiz-Lopez, A.Spurr, R. J. D.Szykman, J. J.Torres, O.Veefkind, J. P.Veihelmann, B.Wang, H.Wang, J.Chance, Kelly V.DOI: info:10.1016/j.jqsrt.2016.05.008v. 18617–39
Zoogman, P., Liu, X., Suleiman, R. M., Pennington, W. F., Flittner, D. E., Al-Saadi, J. A., Hilton, B. B., Nicks, D. K., Newchurch, M. J., Carr, J. L., Janz, S. J., Andraschko, M. R., Arola, A., Baker, B. D., Canova, B. P., Chan Miller, C., Cohen, R. C., Davis, J. E., Dussault, M. E., Edwards, D. P., Fishman, J., Ghulam, A., González Abad, Gonzalo, Grutter, M., Herman, J. R. et al. 2017. "Tropospheric emissions: Monitoring of pollution (TEMPO)." Journal of Quantitative Spectroscopy and Radiative Transfer 186:17– 39. https://doi.org/10.1016/j.jqsrt.2016.05.008
ID: 142310
Type: article
Authors: Zoogman, P.; Liu, X.; Suleiman, R. M.; Pennington, W. F.; Flittner, D. E.; Al-Saadi, J. A.; Hilton, B. B.; Nicks, D. K.; Newchurch, M. J.; Carr, J. L. ; Janz, S. J.; Andraschko, M. R.; Arola, A.; Baker, B. D.; Canova, B. P.; Chan Miller, C.; Cohen, R. C.; Davis, J. E.; Dussault, M. E.; Edwards, D. P.; Fishman, J.; Ghulam, A.; González Abad, Gonzalo; Grutter, M.; Herman, J. R.; Houck, J.; Jacob, D. J.; Joiner, J.; Kerridge, B. J.; Kim, J.; Krotkov, N. A.; Lamsal, L.; Li, C.; Lindfors, A.; Martin, R. V.; McElroy, C. T.; McLinden, C.; Natraj, V.; Neil, D. O.; Nowlan, C. R.; O'Sullivan, E. J.; Palmer, P. I.; Pierce, R. B.; Pippin, M. R.; Saiz-Lopez, A.; Spurr, R. J. D.; Szykman, J. J.; Torres, O.; Veefkind, J. P.; Veihelmann, B.; Wang, H.; Wang, J.; Chance, Kelly V.
Abstract: TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution ( 2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (H2CO), glyoxal (C2H2O2), bromine monoxide (BrO), IO (iodine monoxide), water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.
Hotspot of glyoxal over the Pearl River delta seen from the OMI satellite instrument: implications for emissions of aromatic hydrocarbonsChan Miller, ChristopherJacob, Daniel J.González Abad, GonzaloChance, Kelly V.DOI: info:10.5194/acp-16-4631-2016v. 164631–4639
Chan Miller, Christopher, Jacob, Daniel J., González Abad, Gonzalo, and Chance, Kelly V. 2016. "Hotspot of glyoxal over the Pearl River delta seen from the OMI satellite instrument: implications for emissions of aromatic hydrocarbons." Atmospheric Chemistry & Physics 16:4631– 4639. https://doi.org/10.5194/acp-16-4631-2016
ID: 139639
Type: article
Authors: Chan Miller, Christopher; Jacob, Daniel J.; González Abad, Gonzalo; Chance, Kelly V.
Abstract: The Pearl River delta (PRD) is a densely populated hub of industrial activity located in southern China. OMI (Ozone Monitoring Instrument) satellite observations reveal a large hotspot of glyoxal (CHOCHO) over the PRD that is almost twice as large as any other in Asia. Formaldehyde (HCHO) and NO2 observed by OMI are also high in the PRD but no more than in other urban/industrial areas of China. The CHOCHO hotspot over the PRD can be explained by industrial paint and solvent emissions of aromatic volatile organic compounds (VOCs), with toluene being a dominant contributor. By contrast, HCHO in the PRD originates mostly from VOCs emitted by combustion (principally vehicles). By applying a plume transport model to wind-segregated OMI data, we show that the CHOCHO and HCHO enhancements over the PRD observed by OMI are consistent with current VOC emission inventories. Prior work using CHOCHO retrievals from the SCIAMACHY satellite instrument suggested that emission inventories for aromatic VOCs in the PRD were too low by a factor of 10-20; we attribute this result in part to bias in the SCIAMACHY data and in part to underestimated CHOCHO yields from oxidation of aromatics. Our work points to the importance of better understanding CHOCHO yields from the oxidation of aromatics in order to interpret space-based CHOCHO observations in polluted environments.
Water vapor retrieval from OMI visible spectraWang, H.Liu, X.Chance, Kelly V.González Abad, GonzaloMiller, C. ChanDOI: info:10.5194/amtd-7-541-2014v. 7541–567
Wang, H., Liu, X., Chance, Kelly V., González Abad, Gonzalo, and Miller, C. Chan. 2014. "Water vapor retrieval from OMI visible spectra." Atmospheric Measurement Techniques Discussions 7:541– 567. https://doi.org/10.5194/amtd-7-541-2014
ID: 118850
Type: article
Authors: Wang, H.; Liu, X.; Chance, Kelly V.; González Abad, Gonzalo; Miller, C. Chan
Abstract: There are distinct spectral features of water vapor in the wavelength range covered by the Ozone Monitoring Instrument (OMI) visible channel. Although these features are much weaker than those at longer wavelengths, they can be exploited to retrieve useful information about water vapor. They have an advantage in that their small optical depth leads to fairly simple interpretation as measurements of the total water vapor column density. We have used the Smithsonian Astrophysical Observatory (SAO)'s OMI operational retrieval algorithm to derive the Slant Column Density (SCD) of water vapor from OMI measurements using the 430-480 nm spectral region after extensive optimization of retrieval windows and parameters. The Air Mass Factor (AMF) is calculated using look-up tables of scattering weights and monthly mean water vapor profiles from the GEOS-5 assimilation products. We convert from SCD to Vertical Column Density (VCD) using the AMF and generate associated retrieval averaging kernels and shape factors. Our standard water vapor product has a median SCD of ~ 1.3 × 1023 molecule cm-2 and a median relative uncertainty of ~ 11% in the tropics, about a factor of 2 better than that from a similar OMI algorithm but using narrower retrieval window. The corresponding median VCD is ~ 1.2 × 1023 molecule cm-2. We have also explored the sensitivities to various parameters and compared our results with those from the Moderate-resolution Imaging Spectroradiometer (MODIS) and the Aerosol Robotic NETwork (AERONET).