An improved glyoxal retrieval from OMI measurements

Abstract. Satellite observations from the SCIAMACHY, GOME-2 and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels were found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, a fitting window and a polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of the number of negative columns over clear water regions. The impact of using different absorption cross-sections for water vapour is evaluated and only small differences are found. Finally, a high-temperature (boundary layer ambient: 294 K) absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from GOME-2 and SCIAMACHY measurements over continental regions is performed, showing overall good consistency. However, SCIAMACHY CHOCHO columns are systematically higher than those obtained from the other instruments. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in Russia between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to elevated levels of MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the new OMI CHOCHO product.

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An improved glyoxal retrieval from OMI measurements

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-5559-2014 ◽

2014 ◽

Vol 7 (6) ◽

pp. 5559-5599 ◽

Cited By ~ 3

Author(s):

L. M. A. Alvarado ◽

A. Richter ◽

M. Vrekoussis ◽

F. Wittrock ◽

A. Hilboll ◽

...

Keyword(s):

Hot Spots ◽

Anthropogenic Activities ◽

Anthropogenic Emissions ◽

Fire Event ◽

Data Set ◽

Polynomial Degree ◽

Sensitivity Tests ◽

Good Consistency ◽

Radiative Power ◽

Fire Radiative Power

Abstract. Satellite observations from the SCIAMACHY, GOME-2, and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels are found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, an optimal fitting window and polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of negative columns over clear water regions. Moreover, a high temperature absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from measurements of the GOME-2 and SCIAMACHY instruments over continental regions is performed, showing overall good consistency. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in the east of Moscow between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the OMI CHOCHO product.

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Six years of total ozone column measurements from SCIAMACHY nadir observations

Atmospheric Measurement Techniques ◽

10.5194/amt-2-87-2009 ◽

2009 ◽

Vol 2 (1) ◽

pp. 87-98 ◽

Cited By ~ 39

Author(s):

C. Lerot ◽

M. Van Roozendael ◽

J. van Geffen ◽

J. van Gent ◽

C. Fayt ◽

...

Keyword(s):

Cross Sections ◽

Total Ozone ◽

Large Scale ◽

European Space Agency ◽

Data Sets ◽

Data Set ◽

Ozone Data ◽

Space Agency ◽

German Aerospace ◽

The Impact

Abstract. Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2–0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.

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MAX-DOAS formaldehyde slant column measurements during CINDI: intercomparison and analysis improvement

Atmospheric Measurement Techniques ◽

10.5194/amt-6-167-2013 ◽

2013 ◽

Vol 6 (1) ◽

pp. 167-185 ◽

Cited By ~ 60

Author(s):

G. Pinardi ◽

M. Van Roozendael ◽

N. Abuhassan ◽

C. Adams ◽

A. Cede ◽

...

Keyword(s):

Cross Sections ◽

Cross Correlation ◽

Optical Absorption Spectroscopy ◽

Integration Time ◽

Measuring Instruments ◽

Absorption Cross ◽

Correlation Effects ◽

Data Set ◽

Random Uncertainties ◽

Ring Effect

Abstract. We present intercomparison results for formaldehyde (HCHO) slant column measurements performed during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) that took place in Cabauw, the Netherlands, in summer 2009. During two months, nine atmospheric research groups simultaneously operated MAX-DOAS (MultiAXis Differential Optical Absorption Spectroscopy) instruments of various designs to record UV-visible spectra of scattered sunlight at different elevation angles that were analysed using common retrieval settings. The resulting HCHO data set was found to be highly consistent, the mean difference between instruments generally not exceeding 15% or 7.5 × 1015 molec cm−2, for all viewing elevation angles. Furthermore, a sensitivity analysis was performed to investigate the uncertainties in the HCHO slant column retrieval when varying key input parameters such as the molecular absorption cross sections, correction terms for the Ring effect or the width and position of the fitting interval. This study led to the identification of potentially important sources of errors associated with cross-correlation effects involving the Ring effect, O4, HCHO and BrO cross sections and the DOAS closure polynomial. As a result, a set of updated recommendations was formulated for HCHO slant column retrieval in the 336.5–359 nm wavelength range. To conclude, an error budget is proposed which distinguishes between systematic and random uncertainties. The total systematic error is estimated to be of the order of 20% and is dominated by uncertainties in absorption cross sections and related spectral cross-correlation effects. For a typical integration time of one minute, random uncertainties range between 5 and 30%, depending on the noise level of individual instruments.

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NEUTRINO MASS AND MIXING: THE IMPACT OF EXCITED STATE CONTRIBUTIONS ON CAPTURE RATES OF Ga DETECTORS

International Journal of Modern Physics A ◽

10.1142/s0217751x95000073 ◽

1995 ◽

Vol 10 (01) ◽

pp. 133-143 ◽

Cited By ~ 1

Author(s):

KAMALES KAR ◽

SRUBABATI GOSWAMI ◽

AMITAVA RAYCHAUDHURI

Keyword(s):

Excited State ◽

Cross Sections ◽

Absorption Cross ◽

Neutrino Mixing ◽

Mixing Angle ◽

Neutrino Mass And Mixing ◽

Nuclear Models ◽

The Impact ◽

Neutrino Absorption ◽

Capture Rates

In this paper we calculate the neutrino absorption cross-sections for the reaction 71Ga(ν, e−)71Ge using two simple nuclear models to account for the giant GT resonances. In both models the excited state contributions are found to have significant ranges of variation and affect the solar neutrino capture rates. Nonetheless, the regions in the neutrino mixing angle-mass squared difference plane allowed by the data from the Gallium detectors, when taken together with those from the Chlorine and Kamioka experiments, are found to be comparatively stable.

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Abundance patterns (1984-1987 / 1994-1998) of polychaete worms (Annelida) from an estuarine tidal flat, Pacific, Costa Rica

UNED Research Journal ◽

10.22458/urj.v7i2.1150 ◽

2015 ◽

Vol 7 (2) ◽

pp. 233-248

Author(s):

José A. Vargas-Zamora ◽

Jeffrey A. Sobaja-Cordero ◽

Harlan K. Dean ◽

Sylvia Solano-Upate

Keyword(s):

Costa Rica ◽

Anthropogenic Activities ◽

Enso Event ◽

Additive Models ◽

Intertidal Flat ◽

Red Tides ◽

Data Set ◽

Abundance Patterns ◽

The Impact

The objectives of this report are to provide an updated list of the annelid polychaete worm species found at a tropical estuarine intertidal flat, describe long term oscillations of 11 of the species, and the impact of red tides as evidenced by PCA. From 1984 to 1987 (49 dates) 14 sediment cores (17.7 cm2 – 15 cm deep) were collected per date at low tide from a 400 m2 muddy-sand plot in the Gulf of Nicoya estuary (10oN-85oW), Pacific, Costa Rica. All cores were fixed in Rose Bengal stained formalin and sieved thru a 500 micron mesh screen. A total of 43 species of polychaetes were found and distributed among 25 families and 6600 individuals, of which 80% were represented by: Mediomastus californiensis (32.4%), Caraziella calafia (20.3%), Paraprionospio alata (9.2%), Scolotema tetraura (5.9%), Gymnonereis crosslandi (4.9%), Spiophanex duplex (3.8%), and Glycinde armigera (3.5%). M. californiensis was numerically dominant during most of the sampling dates. The Spionidae (6), Phyllodocidae (4), and Nereididae (3) were the more speciose polychaete families. Populations of all species were patchy in space and time. The abundance patterns of 11 species are illustrated for the 1984-1987 data set. These patterns may reflect declining populations at the beginning of 1984 perhaps influenced by the strong 1982-1983 ENSO event. During 1985 red tides may have influenced the abundances of polychaetes as indicated by the results of a PCA. This is the first time that population patterns of nine species of intertidal polychaetes over a three year period, and the impact of red tides on these worms are reported for this region of the eastern Pacific. General Additive Models (GAM) were applied to the abundances of M. californiensis and P. alata found during 1984-1987 and to additional data from 1994 to 1996 (28 dates) The GAM approach confirmed ealier observations of seasonal oscillations of these species during 1984-1987, but these trends were not found during 1994-1998. Previously unnoticed underlying patterns of unknown origin were also detected by the application of GAM. The theoretical framework needed for the interpretation of results from tropical benthic surveys could improve significantly from more long term monitoring. Long term abundance data is essential to evaluate the impacts of anthropogenic activities in estuaries.

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Six years of total ozone column measurements from SCIAMACHY nadir observations

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-1-249-2008 ◽

2008 ◽

Vol 1 (1) ◽

pp. 249-279

Author(s):

C. Lerot ◽

M. Van Roozendael ◽

J. van Geffen ◽

J. van Gent ◽

C. Fayt ◽

...

Keyword(s):

Cross Sections ◽

Total Ozone ◽

Large Scale ◽

European Space Agency ◽

Data Sets ◽

Data Set ◽

Ozone Data ◽

Space Agency ◽

German Aerospace ◽

The Impact

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High-resolution smoke forecasting for the 2018 Camp Fire in California

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-20-0329.1 ◽

2021 ◽

Keyword(s):

Anthropogenic Pollution ◽

Satellite Observation ◽

Test Case ◽

Observation Data ◽

Fire Event ◽

Pressure System ◽

Fire Smoke ◽

Radiative Power ◽

The Impact ◽

First Time

Abstract Smoke from the 2018 Camp Fire in Northern California blanketed a large part of the region for two weeks, creating poor air quality in the “unhealthy” range for millions of people. The NOAA Global System Laboratory’s HRRR-Smoke model was operating experimentally in real time during the Camp Fire. Here, output from the HRRR-Smoke model is compared to surface observations of PM2.5 from AQS and PurpleAir sensors as well as satellite observation data. The HRRR-Smoke model grid at 3-km resolution successfully simulated the evolution of the plume during the initial phase of the fire (8-10 November 2018). Stereoscopic satellite plume height retrievals were used to compare with model output (for the first time, to the authors’ knowledge), showing that HRRR-Smoke is able to represent the complex 3D distribution of the smoke plume over complex terrain. On 15-16 November, HRRR-Smoke was able to capture the intensification of PM2.5 pollution due to a high pressure system and subsidence that trapped smoke close to the surface; however, HRRR-Smoke later underpredicted PM2.5 levels due to likely underestimates of the fire radiative power (FRP) derived from satellite observations. The intensity of the Camp Fire smoke event and the resulting pollution during the stagnation episodes make it an excellent test case for HRRR-Smoke in predicting PM2.5 levels, which were so high from this single fire event that the usual anthropogenic pollution sources became insignificant. The HRRR-Smoke model was implemented operationally at NOAA/NCEP in December 2020, now providing essential support for smoke forecasting as the impact of US wildfires continues to increase in scope and magnitude.

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Impact of using a new ultraviolet ozone absorption cross-section dataset on OMI ozone profile retrievals

Atmospheric Measurement Techniques ◽

10.5194/amt-13-5845-2020 ◽

2020 ◽

Vol 13 (11) ◽

pp. 5845-5854

Author(s):

Juseon Bak ◽

Xiong Liu ◽

Manfred Birk ◽

Georg Wagner ◽

Iouli E. Gordon ◽

...

Keyword(s):

Cross Section ◽

Cross Sections ◽

Absorption Cross Section ◽

High Latitudes ◽

Absorption Cross ◽

Cross Section Data ◽

Ozone Absorption ◽

Section Data ◽

Ozone Profile ◽

The Impact

Abstract. We evaluate different sets of high-resolution ozone absorption cross-section data for use in atmospheric ozone profile measurements in the Hartley and Huggins bands with a particular focus on BDM 1995 (Daumont et al. 1992; Brion et al., 1993; Malicet et al., 1995), currently used in our retrievals, and a new laboratory dataset by Birk and Wagner (2018) (BW). The BDM cross-section data have been recommended to use for retrieval of ozone profiles using spaceborne nadir-viewing backscattered ultraviolet (BUV) measurements since its improved performance was demonstrated against other cross-sections including Bass and Paur (1985) (BP) and those of Serdyuchenko et al. (2014) and Gorshelev et al. (2014) (SER) by the “Absorption Cross-Sections of Ozone” (ACSO) activity. The BW laboratory data were recently measured within the framework of the European Space Agency (ESA) project SEOM-IAS (Scientific Exploitation of Operational Missions – Improved Atmospheric Spectroscopy Databases) to provide an advanced absorption cross-section database. The BW cross-sections are made from measurements at more temperatures and in a wider temperature range than BDM, especially for low temperatures. Relative differences of cross-sections between BW and BDM range from ∼2 % at shorter UV wavelengths to ∼5 % at longer UV wavelengths at warm temperatures. Furthermore, these differences dynamically increase by up to ±40 % at cold temperatures due to no BDM measurements having been made below 218 K. We evaluate the impact of using different cross-sections on ozone profile retrievals from Ozone Monitoring Instrument (OMI) measurements. Correspondingly, this impact leads to significant differences in individual ozone retrievals by up to 50 % in the tropopause where the coldest atmospheric temperatures are observed. Bottom atmospheric layers illustrate the significant change of the retrieved ozone values, with differences of 20 % in low latitudes, which is not the case in high latitudes because the ozone retrievals are mainly controlled by a priori ozone information in high latitudes due to less photon penetration down to the lower troposphere. Validation with ozonesonde observations demonstrates that BW and BDM retrievals show altitude-dependent bias oscillations of similar magnitude relative to ozonesonde measurements, much smaller than those of both BP and SER retrievals. However, compared to BDM, BW retrievals show significant reduction in standard deviation, by up to 15 %, especially at the coldest atmospheric temperatures. Such improvement is achieved mainly by the better characterization of the temperature dependence of ozone absorption.

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Application of Chemometric Analysis to the Study of Snow at the Sudety Mountains, Poland

Ecological Chemistry and Engineering S ◽

10.1515/eces-2016-0044 ◽

2016 ◽

Vol 23 (4) ◽

pp. 621-637

Author(s):

Marek Błaś ◽

Żaneta Polkowska ◽

Vasil Simeonov ◽

Stefan Tsakovski ◽

Mieczysław Sobik ◽

...

Keyword(s):

Principal Components Analysis ◽

Principal Components ◽

Anthropogenic Activities ◽

Time Factors ◽

Significance Test ◽

Fixed Number ◽

Data Set ◽

Components Analysis ◽

Sudety Mountains ◽

The Impact

Abstract Snow samples were collected during winter 2011/2012 in three posts in the Western Sudety Mountains (Poland) in 3 consecutive phases of snow cover development, i.e. stabilisation (Feb 1st), growth (Mar 15th) and its ablation (Mar 27th). To maintain a fixed number of samples, each snow profile has been divided into six layers, but hydrochemical indications were made for each 10 cm section of core. The complete data set was subjected in the first run of chemometric data interpretation to Cluster Analysis as well as Principal Components Analysis. Further, Self-Organizing Maps, type of neutral network described by Kohonen were used for visualization and interpretation of large high-dimensional data sets. For each site the hierarchical Ward’s method of linkage, squared Euclidean distance as similarity measure, standardized raw data, cluster significance test according to Sneath’s criterion clustering of the chemical variables was done. Afterwards this grouping of the chemical variables was confirmed by the results from Principal Components Analysis. The major conclusion is that the whole system of three sampling sites four patterns of variable groupings are observed: the first one is related to the mineral salt impact; the second one - with the impact of secondary emissions and organic pollutants; next one - with dissolved matter effect and the last one - with oxidative influence, again with relation to anthropogenic activities like smog, coal burning, traffic etc. It might be also concluded that specificity of the samples is determined by the factors responsible for the data set structure and not by particular individual or time factors.

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Age at Exposure to Parental Suicide and the Subsequent Risk of Suicide in Young People

Crisis ◽

10.1027/0227-5910/a000468 ◽

2018 ◽

Vol 39 (1) ◽

pp. 27-36 ◽

Cited By ~ 5

Author(s):

Kuan-Ying Lee ◽

Chung-Yi Li ◽

Kun-Chia Chang ◽

Tsung-Hsueh Lu ◽

Ying-Yeh Chen

Keyword(s):

Young People ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Birth Registry ◽

Data Set ◽

Parental Suicide ◽

The Impact ◽

Age At Exposure

Abstract. Background: We investigated the age at exposure to parental suicide and the risk of subsequent suicide completion in young people. The impact of parental and offspring sex was also examined. Method: Using a cohort study design, we linked Taiwan's Birth Registry (1978–1997) with Taiwan's Death Registry (1985–2009) and identified 40,249 children who had experienced maternal suicide (n = 14,431), paternal suicide (n = 26,887), or the suicide of both parents (n = 281). Each exposed child was matched to 10 children of the same sex and birth year whose parents were still alive. This yielded a total of 398,081 children for our non-exposed cohort. A Cox proportional hazards model was used to compare the suicide risk of the exposed and non-exposed groups. Results: Compared with the non-exposed group, offspring who were exposed to parental suicide were 3.91 times (95% confidence interval [CI] = 3.10–4.92 more likely to die by suicide after adjusting for baseline characteristics. The risk of suicide seemed to be lower in older male offspring (HR = 3.94, 95% CI = 2.57–6.06), but higher in older female offspring (HR = 5.30, 95% CI = 3.05–9.22). Stratified analyses based on parental sex revealed similar patterns as the combined analysis. Limitations: As only register-based data were used, we were not able to explore the impact of variables not contained in the data set, such as the role of mental illness. Conclusion: Our findings suggest a prominent elevation in the risk of suicide among offspring who lost their parents to suicide. The risk elevation differed according to the sex of the afflicted offspring as well as to their age at exposure.

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