New Era of Air Quality Monitoring from Space Kim, Jhoon; Jeong, Ukkyo; Ahn, Myoung-Hwan ...
Bulletin of the American Meteorological Society,
01/2020, Volume:
101, Issue:
1
Journal Article
Peer reviewed
Open access
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).
Breast cancer, the second most common cause of cancer-related deaths in American women, varies substantially in incidence and mortality according to race and ethnicity in the United States. Although ...the overall incidence of breast cancer among African-American (AA) women is lower than in white American women, this cancer is more common in young premenopausal AA women, and AA breast cancer patients of all ages are more likely to have advanced disease at diagnosis, higher risk of recurrence, and poorer overall prognosis. Epidemiological studies indicate that these differences may be attributable in part to variation in obesity and body fat distribution. Additionally, AA women more frequently exhibit breast cancer with an aggressive and metastatic phenotype that may also be attributable to the endocrine and metabolic changes associated with upper body obesity. These changes include both elevated estrogen and androgen bioactivity, hyperinsulinemia, and perturbations of the adipokines. Type 2 diabetes and the metabolic syndrome, which are more common in AA women, have also been associated with breast cancer risk. Moreover, each of the individual components of the syndrome has been associated with increased breast cancer risk, including low levels of the adipocytokine, adiponectin. This review explores the specific roles of obesity, body fat distribution (particularly visceral and sc adipose tissue), type 2 diabetes, metabolic syndrome, and adipocytokines in explaining the differential patterns of breast cancer risk and prognosis between AA and white American women.
Unprecedented Arctic ozone loss in 2011 Manney, Gloria L; Santee, Michelle L; Rex, Markus ...
Nature (London),
10/2011, Volume:
478, Issue:
7370
Journal Article
Peer reviewed
Chemical ozone destruction occurs over both polar regions in local winter-spring. In the Antarctic, essentially complete removal of lower-stratospheric ozone currently results in an ozone hole every ...year, whereas in the Arctic, ozone loss is highly variable and has until now been much more limited. Here we demonstrate that chemical ozone destruction over the Arctic in early 2011 was--for the first time in the observational record--comparable to that in the Antarctic ozone hole. Unusually long-lasting cold conditions in the Arctic lower stratosphere led to persistent enhancement in ozone-destroying forms of chlorine and to unprecedented ozone loss, which exceeded 80 per cent over 18-20 kilometres altitude. Our results show that Arctic ozone holes are possible even with temperatures much milder than those in the Antarctic. We cannot at present predict when such severe Arctic ozone depletion may be matched or exceeded.
The continued interest in air pollution and stratospheric ozone variability has motivated the development of a Geostationary Environmental Monitoring Spectrometer (GEMS) for hourly ozone monitoring. ...This paper provides the atmospheric science community with the world's first assessment of GEMS total column ozone (TCO) retrieval performance and diurnal ozone variation. The algorithm used for GEMS is a more advanced version of its predecessor, the Total Ozone Mapping Spectrometer (TOMS) V8, that incorporates several improvements, including a new lookup table, a simple Lambertian-equivalent reflectivity model, and a spectral dependence correction. The GEMS algorithm also uses the optimal estimation method (OEM) to make error analysis more accessible and robust. The estimated retrieval errors range from 1.5 to 2 DU in September and 2 DU in December, with a constant degree of freedom of the signal (DFS) of 1 in September and a variable DFS of 1.25 to 1.4 in December throughout the day, depending on solar zenith angle (SZA). To assess the performance of the GEMS algorithm, the hourly GEMS total ozone was compared with ground-based measurements from Pandora instruments and other satellite platforms from TROPOMI (TROPOspheric Monitoring Instrument) and OMPS (Ozone Mapping and Profiler Suite Nadir Mapper). GEMS has a high correlation of 0.97 and small RMSE values compared to Pandora TCO at Busan and Seoul in South Korea. It is notable that despite exhibiting seasonal dependence in the mean bias of GEMS with Pandora, GEMS is capable of observing daily variations in ozone that are highly consistent with Pandora measurements, with a bias of approximately 1 %. The comparison of GEMS TCO data with TROPOMI and OMPS TCO data shows a high correlation of 0.99 and low RMSE compared to TROPOMI and OMPS TCO data, but the data have a negative bias of −2.38 % and −2.17 %, with standard deviations of 1.33 % and 1.57 %, respectively. Similar to OMPS, the influence of SO2 from volcanic eruptions is not properly removed in some regions, leading to GEMS overestimating TCO in those areas. The mean biases of GEMS TCO data with TROPOMI and OMPS TCO are within ±1 % at low latitudes but become negative at midlatitudes, with an increasingly negative dependence on latitude. Furthermore, this dependence becomes more prominent from summer to winter. The empirical correction applied to the GEMS irradiance data improves the dependence of the mean bias on season and latitude, but a consistent bias still remains, and a marginal positive trend was observed in December. Therefore, further investigation into correction methods is needed. The results are a meaningful scientific advance by providing the first validated, hourly UV ozone retrievals from a satellite in geostationary orbit. This experience can be used to advance research with future geostationary environmental satellite missions, including the incoming TEMPO (Tropospheric Emissions: Monitoring of Pollution) and Sentinel-4.
NASA satellite measurements show that ozone reductions throughout the Northern Hemisphere (NH) free troposphere reported for spring-summer 2020 during the Corona VIrus Disease 2019 (COVID-19) ...pandemic have occurred again in spring-summer 2021. The satellite measurements show that tropospheric column ozone (TCO) (mostly representative of the free troposphere) for 20oN-60oN during spring-summer for both 2020 and 2021 averaged ~3 Dobson Units (DU) (or ~7-8%) below normal. These ozone reductions in 2020 and 2021 were the lowest in the 2005- 2021 record. We also include satellite measurements of tropospheric NO2that exhibit reductions of ~10-20% in the NH in early spring-to-summer 2020 and 2021, suggesting that reduced pollution was the main cause for the low anomalies in NH TCO in 2020 and 2021. Reductions of TCO ~2DU (7 %) are also measured in the Southern Hemisphere in austral summer but are 26not associated with reduced NO2.
We examine the spectral effects of tropospheric absorbing aerosol types on backscattered UV radiation from 300 to 400 nm. First, using satellite observations, we show a non‐linear spectral dependence ...below 340 nm for scenes with significant aerosol absorption. Lambert‐equivalent reflectivity also follows a non‐linear behavior and may become negative, therefore non‐physical, at shorter wavelengths. We then present radiative transfer calculations of UV radiances accounting for ozone and aerosol attenuation. The effects are quantified as spectral residuals, calculated by comparing radiances simulated with aerosols to those with a molecular atmosphere assuming spectrally independent Lambert‐equivalent surface reflectivity. Simulations are carried out for carbonaceous smoke and mineral dust aerosols using the present‐day optical models applied successfully in the Ozone Monitoring Instrument aerosol algorithm, OMAERUV. The spectral residual has a complex dependence on wavelength, aerosol optical and physical properties, and surface conditions. In all simulated cases, the spectral residual has a maximum around 320 nm and then diminishes rapidly at shorter wavelengths due to increased photon absorption by ozone in the stratosphere. However, we find the relationship between the spectral residual and that at 340 nm nearly linear for a wide range of these conditions. The relationship depends somewhat on the total column ozone. The theoretical results presented offer a means for correcting the effects of UV‐absorbing aerosols in trace gas retrievals without a priori knowledge of aerosol and surface properties. Since our technique of estimating spectral effects of aerosols applies to radiance residuals, and not a specific retrieval algorithm, it may be used broadly to correct the effects in various retrieval algorithms.
Key Points
Spectral effects of absorbing aerosols on backscatter UV radiation are investigated using observations and aerosol modeling
Spectral dependence of aerosol effects on radiances and Lambert‐equivalent reflectivity is found to be non‐linear below 340 nm
Normalization of spectral residuals in the UV eliminates the need to assume aerosol and surface properties for correction in trace gas retrievals
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.
Black-sky cloud albedo (BCA) is derived from satellite UV 340 nm observations from NOAA and NASA satellites to infer long-term (1980–2018) shortwave cloud albedo variations induced by volcano ...eruptions, the El Niño–Southern Oscillation, and decadal warming. While the UV cloud albedo has shown no long-term trend since 1980, there are statistically significant reductions over the North Atlantic and over the marine stratocumulus decks off the coast of California; increases in cloud albedo can be seen over Southeast Asia and over cloud decks off the coast of South America. The derived BCA assumes a C-1 water cloud model with varying cloud optical depths and a Cox–Munk surface BRDF over the ocean, using radiances calibrated over the East Antarctic Plateau and Greenland ice sheets during summer.
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