scholarly journals An improved glyoxal retrieval from OMI measurements

2014 ◽  
Vol 7 (6) ◽  
pp. 5559-5599 ◽  
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.

scholarly journals An improved glyoxal retrieval from OMI measurements

2014 ◽  
Vol 7 (12) ◽  
pp. 4133-4150 ◽  
Author(s):  
L. M. A. Alvarado ◽  
A. Richter ◽  
M. Vrekoussis ◽  
F. Wittrock ◽  
A. Hilboll ◽  
...  
Keyword(s):  
Cross Sections ◽  
Anthropogenic Activities ◽  
Absorption Cross ◽  
Fire Event ◽  
Data Set ◽  
Polynomial Degree ◽  
Temperature Boundary ◽  
Sensitivity Tests ◽  
Radiative Power ◽  
The Impact

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.

scholarly journals A Bi-Spectral Microbolometer Sensor for Wildfire Measurement

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3690
Author(s):  
Denis Dufour ◽  
Loïc Le Noc ◽  
Bruno Tremblay ◽  
Mathieu N. Tremblay ◽  
Francis Généreux ◽  
...  
Keyword(s):  
Low Resource ◽  
Long Wave ◽  
Radiative Power ◽  
Infrared Radiances ◽  
Moderate Scale ◽  
Long Wave Infrared ◽  
Detector Type ◽  
Experimental Burns ◽  
Fire Radiative Power

This study describes the development of a prototype bi-spectral microbolometer sensor system designed explicitly for radiometric measurement and characterization of wildfire mid- and long-wave infrared radiances. The system is tested experimentally over moderate-scale experimental burns coincident with FLIR reference imagery. Statistical comparison of the fire radiative power (FRP; W) retrievals suggest that this novel system is highly reliable for use in collecting radiometric measurements of biomass burning. As such, this study provides clear experimental evidence that mid-wave infrared microbolometers are capable of collecting FRP measurements. Furthermore, given the low resource nature of this detector type, it presents a suitable option for monitoring wildfire behaviour from low resource platforms such as unmanned aerial vehicles (UAVs) or nanosats.

scholarly journals Testudines as Sentinels for Monitoring the Dissemination of Antibiotic Resistance in Marine Environments: An Integrative Review

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 775
Author(s):  
Kezia Drane ◽  
Roger Huerlimann ◽  
Michelle Power ◽  
Anna Whelan ◽  
Ellen Ariel ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Anthropogenic Activities ◽  
Sea Turtles ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Marine Environments ◽  
Beta Lactam ◽  
Antibiotic Resistant ◽  
Sensitivity Tests ◽  
Standard Culture

Dissemination of antibiotic resistance (AR) in marine environments is a global concern with a propensity to affect public health and many ecosystems worldwide. We evaluated the use of sea turtles as sentinel species for monitoring AR in marine environments. In this field, antibiotic-resistant bacteria have been commonly identified by using standard culture and sensitivity tests, leading to an overrepresentation of specific, culturable bacterial classes in the available literature. AR was detected against all major antibiotic classes, but the highest cumulative global frequency of resistance in all represented geographical sites was against the beta-lactam class by a two-fold difference compared to all other antibiotics. Wastewater facilities and turtle rehabilitation centres were associated with higher incidences of multidrug-resistant bacteria (MDRB) accounting for an average of 58% and 49% of resistant isolates, respectively. Furthermore, a relatively similar prevalence of MDRB was seen in all studied locations. These data suggest that anthropogenically driven selection pressures for the development of AR in sea turtles and marine environments are relatively similar worldwide. There is a need, however, to establish direct demonstrable associations between AR in sea turtles in their respective marine environments with wastewater facilities and other anthropogenic activities worldwide.

scholarly journals Real-Time Detection of Daytime and Night-Time Fire Hotspots from Geostationary Satellites

2021 ◽  
Vol 13 (9) ◽  
pp. 1627
Author(s):  
Chermelle B. Engel ◽  
Simon D. Jones ◽  
Karin J. Reinke
Keyword(s):  
Real Time ◽  
Infrared Imaging ◽  
Night Time ◽  
Clear Link ◽  
Radiative Power ◽  
Biogeographical Region ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Fire Radiative Power

This paper introduces an enhanced version of the Biogeographical Region and Individual Geostationary HHMMSS Threshold (BRIGHT) algorithm. The algorithm runs in real-time and operates over 24 h to include both daytime and night-time detections. The algorithm was executed and tested on 12 months of Himawari-8 data from 1 April 2019 to 31 March 2020, for every valid 10-min observation. The resulting hotspots were compared to those from the Visible Infrared Imaging Radiometer Suite (VIIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS). The modified BRIGHT hotspots matched with fire detections in VIIRS 96% and MODIS 95% of the time. The number of VIIRS and MODIS hotspots with matches in the coincident modified BRIGHT dataset was lower (at 33% and 46%, respectively). This paper demonstrates a clear link between the number of VIIRS and MODIS hotspots with matches and the minimum fire radiative power considered.

scholarly journals Combining fire radiative power observations with the fire weather index improves the estimation of fire emissions

2017 ◽  
Author(s):  
Francesca Di Giuseppe ◽  
Samuel Rémy ◽  
Florian Pappenberger ◽  
Fredrik Wetterhall
Keyword(s):  
Biomass Burning ◽  
Atmospheric Composition ◽  
Composition Analysis ◽  
Fire Weather ◽  
Atmospheric Conditions ◽  
Weather Index ◽  
Fire Weather Index ◽  
Fire Emissions ◽  
Radiative Power ◽  
Fire Radiative Power

Abstract. The atmospheric composition analysis and forecast for the European Copernicus Atmosphere Monitoring Services (CAMS) relies on biomass burning fire emission estimates from the Global Fire Assimilation System (GFAS). GFAS converts fire radiative power (FRP) observations from MODIS satellites into smoke constituents. Missing observations are filled in using persistence where observed FRP from the previous day are progressed in time until a new observation is recorded. One of the consequences of this assumption is an overestimation of fire duration, which in turn translates into an overestimation of emissions from fires. In this study persistence is replaced by modelled predictions using the Canadian Fire Weather Index (FWI), which describes how atmospheric conditions affect the vegetation moisture content and ultimately fire duration. The skill in predicting emissions from biomass burning is improved with the new technique, which indicates that using an FWI-based model to infer emissions from FRP is better than persistence when observations are not available.

scholarly journals Satellite constraint for emissions of nitrogen oxides from anthropogenic, lightning and soil sources over East China on a high-resolution grid

2011 ◽  
Vol 11 (11) ◽  
pp. 29807-29843 ◽  
Author(s):  
J.-T. Lin
Keyword(s):  
High Resolution ◽  
Nitrogen Oxides ◽  
A Priori ◽  
East China ◽  
Anthropogenic Emissions ◽  
Ozone Monitoring Instrument ◽  
Vertical Column ◽  
The North ◽  
Sensitivity Tests ◽  
Soil Emissions

Abstract. Vertical column densities (VCDs) of tropospheric nitrogen dioxide (NO2) retrieved from space provide valuable information to estimate emissions of nitrogen oxides (NOx) inversely. Accurate emission attribution to individual sources, important both for understanding the global biogeochemical cycling of nitrogen and for emission control, remains difficult. This study presents a regression-based multi-step inversion approach to estimate emissions of NOx from anthropogenic, lightning and soil sources individually for 2006 over East China on a 0.25° long × 0.25° lat grid, employing the DOMINO product version 2 retrieved from the Ozone Monitoring Instrument. The nested GEOS-Chem model for East Asia is used to simulate the seasonal variations of different emission sources and impacts on VCDs of NO2 for the inversion purpose. Sensitivity tests are conducted to evaluate key assumptions embedded in the inversion process. The inverse estimate suggests annual budgets of about 7.1 TgN (±38%), 0.22 TgN (±46%), and 0.40 TgN (±48%) for the a posteriori anthropogenic, lightning and soil emissions, respectively, each about 24% higher than the respective a priori values. The enhancements in anthropogenic emissions are largest in cities and areas with extensive use of coal, particularly in the north in winter, as evident on the high-resolution grid. Derived soil emissions are consistent with recent bottom-up estimates. They are each less than 6% of anthropogenic emissions annually, increasing to about 13% for July. Overall, anthropogenic emissions are found to be the dominant source of NOx over East China with important implications for nitrogen control.

First retrieval of fire radiative power from COMS data using the mid-infrared radiance method

2016 ◽  
Vol 8 (2) ◽  
pp. 116-125 ◽  
Author(s):  
Daesun Kim ◽  
Jaeil Cho ◽  
Sungwook Hong ◽  
Hanlim Lee ◽  
Myoungsoo Won ◽  
...  
Keyword(s):  
Mid Infrared ◽  
Infrared Radiance ◽  
Radiative Power ◽  
Radiance Method ◽  
Fire Radiative Power

scholarly journals Influence of Satellite Sensor Pixel Size and Overpass Time on Undercounting of Cerrado/Savannah Landscape-Scale Fire Radiative Power (FRP): An Assessment Using the MODIS Airborne Simulator

Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 11
Author(s):  
Samuel Sperling ◽  
Martin J. Wooster ◽  
Bruce D. Malamud
Keyword(s):  
Landscape Scale ◽  
Low Noise ◽  
Pixel Size ◽  
Ir Detectors ◽  
Fire Cycle ◽  
Early Afternoon ◽  
Radiative Power ◽  
Satellite Sensor ◽  
Fire Radiative Power ◽  
Wide Swath

The fire radiative power (FRP) of active fires (AFs) is routinely assessed with spaceborne sensors. MODIS is commonly used, and its 1 km nadir pixel size provides a minimum per-pixel FRP detection limit of ~5–8 MW, leading to undercounting of AF pixels with FRPs of less than around 10 MW. Since most biomes show increasing AF pixel frequencies with decreasing FRP, this results in MODIS failing to detect many fires burning when it overpasses. However, the exact magnitude of the landscape-scale FRP underestimation induced by this type of AF undercounting remains poorly understood, as does its sensitivity to sensor pixel size and overpass time. We investigate these issues using both 1 km spaceborne MODIS data and 50 m MODIS Airborne Simulator (MAS) observations of the Brazilian cerrado, a savannah-like environment covering 2 million km2 (>20%) of Brazil where fires are a frequent occurrence. The MAS data were collected during the 1995 SCAR-B experiment, and are able to be spatially degraded to simulate data from sensors with a wide variety of pixel sizes. We explore multiple versions of these MAS data to deliver recommendations for future satellite sensor design, aiming to discover the most effective sensor characteristics that provide negligible pixel-area related FRP underestimation whilst keeping pixels large enough to deliver relatively wide swath widths. We confirm earlier analyses showing 1 km MODIS-type observations fail to detect a very significant number of active fires, and find the degree of undercounting gets worse away from the early afternoon diurnal fire cycle peak (~ 15:00 local time). However, the effect of these undetected fires on the assessment of total landscape-scale FRP is far less significant, since they are mostly low FRP fires. Using two different approaches we estimate that the MODIS-type 1 km data underestimates landscape scale FRP by around a third, and that whilst the degree of underestimation worsens away from the diurnal fire cycle peak the effect of this maybe less important since there are far fewer fires present. MAS data degraded to a 200 m spatial resolution provides landscape-scale FRP totals almost indistinguishable from those calculated with the original 50 m MAS observations, and still provides a pixel size consistent with a wide swath imaging instrument. Our work provides a potentially useful guide for future mission developers aiming at active fire and FRP applications, and we conclude that such missions need operate at spatial resolutions no higher than 200 m if they rely on cooled, low-noise IR detectors. Further work confirming this for fire-affected biomes beyond the savannah-type environments studied here is recommended.

Sign in / Sign up

Export Citation Format

Share Document