scholarly journals Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY

2011 ◽  
Vol 11 (6) ◽  
pp. 2863-2880 ◽  
Author(s):  
O. Schneising ◽  
M. Buchwitz ◽  
M. Reuter ◽  
J. Heymann ◽  
H. Bovensmann ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Boreal Forest ◽  
Large Scale ◽  
Retrieval Algorithm ◽  
Steady Increase ◽  
Absorption Bands ◽  
Longitudinal Gradients ◽  
Surface Measurements ◽  
Concentration Changes

Abstract. Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002) was the first and is now with TANSO onboard GOSAT (launch 2009) one of only two satellite instruments currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest. We present long-term SCIAMACHY retrievals (2003–2009) of column-averaged dry air mole fractions of both gases (denoted XCO2 and XCH4) derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR) spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2) of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4) being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics. The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved global annual mean XCO2 increase agrees with CarbonTracker within the error bars (1.80±0.13 ppm yr−1 compared to 1.81±0.09 ppm yr−1). The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3±0.2 ppm for the Northern Hemisphere and 1.4±0.2 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker. An investigation of the boreal forest carbon uptake during the growing season via the analysis of longitudinal gradients shows good agreement between SCIAMACHY and CarbonTracker concerning the overall magnitude of the gradients and their annual variations. The analysis includes a discussion of the relative uptake strengths of the Russian and North American boreal forest regions. The retrieved XCH4 results show that after years of stability, atmospheric methane has started to rise again in recent years which is consistent with surface measurements. The largest increase is observed for the tropics and northern mid- and high-latitudes amounting to about 7.5±1.5 ppb yr−1 since 2007. Due care has been exercised to minimise the influence of detector degradation on the quantitative estimate of this anomaly.

scholarly journals Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY

2010 ◽  
Vol 10 (11) ◽  
pp. 27479-27522 ◽  
Author(s):  
O. Schneising ◽  
M. Buchwitz ◽  
M. Reuter ◽  
J. Heymann ◽  
H. Bovensmann ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Large Scale ◽  
Near Infrared ◽  
Retrieval Algorithm ◽  
Steady Increase ◽  
Absorption Bands ◽  
Longitudinal Gradients ◽  
Surface Measurements ◽  
Concentration Changes

Abstract. Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002) was the first and is now together with TANSO onboard GOSAT (launch 2009) the only satellite instrument currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest. We present long-term SCIAMACHY retrievals (2003–2009) of column-averaged mole fractions of both gases (denoted XCO2 and XCH4) derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR) spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2) of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4) being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics. The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved annual mean XCO2 increase over both hemispheres agrees with CarbonTracker within the error bars but is on average somewhat smaller (1.8 ppm yr−1 compared to 1.9 ppm yr−1). The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3 ppm for the Northern Hemisphere and 1.4 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker. An investigation of the boreal forest carbon uptake during the growing season via the analysis of longitudinal gradients shows good agreement between SCIAMACHY and CarbonTracker concerning the overall magnitude of the gradients and their annual variations. The retrieved XCH4 results show that after years of stability, atmospheric methane has started to rise again in recent years which is consistent with surface measurements. The largest increase is observed for the tropics and northern mid- and high-latitudes amounting to about 8 ppb yr−1 since 2007. Due care has been exercised to minimise the influence of detector degradation on the quantitative estimate of this anomaly.

scholarly journals Space-based geoengineering: Challenges and requirements

2009 ◽  
Vol 224 (3) ◽  
pp. 571-580 ◽  
Author(s):  
C R McInnes
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Large Scale ◽  
Climate Model ◽  
Carbon Dioxide Concentration ◽  
Complex Solution ◽  
Lagrange Point ◽  
Simple Climate Model ◽  
Earth’S Climate

The prospect of engineering the Earth's climate (geoengineering) raises a multitude of issues associated with climatology, engineering on macroscopic scales, and indeed the ethics of such ventures. Depending on personal views, such large-scale engineering is either an obvious necessity for the deep future, or yet another example of human conceit. In this article a simple climate model will be used to estimate requirements for engineering the Earth's climate, principally using space-based geoengineering. Active cooling of the climate to mitigate anthropogenic climate change due to a doubling of the carbon dioxide concentration in the Earth's atmosphere is considered. This representative scenario will allow the scale of the engineering challenge to be determined. It will be argued that simple occulting discs at the interior Lagrange point may represent a less complex solution than concepts for highly engineered refracting discs proposed recently. While engineering on macroscopic scales can appear formidable, emerging capabilities may allow such ventures to be seriously considered in the long term. This article is not an exhaustive review of geoengineering, but aims to provide a foretaste of the future opportunities, challenges, and requirements for space-based geoengineering ventures.

scholarly journals The use of relaxation methods in the WRF model for the analysis of meteorological conditions in Ukraine over a long period

2020 ◽  
Vol 2 ◽  
pp. 30-42
Author(s):  
O.V. Khalchenkov ◽  
◽  
I.V. Kovalets ◽  
Keyword(s):  
Large Scale ◽  
Mesoscale Model ◽  
Soil Layer ◽  
Meteorological Conditions ◽  
Optimal Combination ◽  
Relaxation Methods ◽  
Advantages And Disadvantages ◽  
Long Period ◽  
Surface Measurements

The possibility of using grid and spectral relaxation methods and other options in the WRF mesoscale model for long-term continuous calculations has been investigated. Results of comparison of selected me-teorological parameters with surface measurements are presented. The basic recommendations for select-ing the optimal combination of long-term calculation parameters are given. The use of the selected param-eters allowed to obtain continuous meteorological fields over a long period (several months), which are well consistent with surface measurements, retain large scale synoptic structures and have a deviation from measurements commensurate with the results of short-term simulations over corresponding time peri-od. The selected optimal combination of parameters allowed us to perform continuous calculation for the period from January 1, 2019 to November 6, 2019 without accumulating errors. In a long-run calculation of meteorological conditions in Ukraine with spatial resolution 0.15 deg. for a temperature at a height of 2 meters was obtained a mean absolute error of MAE=2,05 ºC, a correlation coefficient of Corr=0,97, for a wind speed at a height of 10 meters of MAE=1.4 m/s, of Corr=0,75, and for a wind direction at a height of 10 meters of MAE=24,6 degrees, Corr=0,66. The influence of the parametrizations of the underlying sur-face and the active soil layer on the quality of calculation of meteorological fields is studied. Using the option to update the water surface temperature allowed to reduce the MAE for the temperature from 2,17 ºС to 2,05 ºС. Each of the investigated surface models showed its advantages and disadvantages. The pa-rameterizations RUC and NOAH LSM showed good agreement with the measurements for all studied pa-rameters and can be recommended for use in long-term continuous calculations. A long calculation made it possible to describe the process of accumulation and melting of snow correctly, and made it possible to reproduce the temperature of the upper soil layer correctly as well. The paper shows that the disadvantage of long- term calculations is the inability to determine the temperature of the lower layers of the soil cor-rectly.

Improvements in XCO2 accuracy from OCO-2 with the latest ACOS v10 product

2021 ◽  
Author(s):  
Christopher ODell ◽  
Annmarie Eldering ◽  
Michael Gunson ◽  
David Crisp ◽  
Brendan Fisher ◽  
...  
Keyword(s):  
Power Plants ◽  
Large Scale ◽  
Regional Scale ◽  
Surface Fluxes ◽  
Retrieval Algorithm ◽  
The Past ◽  
Tropical Oceans ◽  
Desert Areas ◽  
Global Carbon

<p>While initial plans for measuring carbon dioxide from space hoped for 1-2 ppm levels of accuracy (bias) and precision in the CO<sub>2</sub> column mean dry air mole fraction (XCO<sub>2</sub>), in the past few years it has become clear that accuracies better than 0.5 ppm are required for most current science applications.  These include measuring continental (1000+ km) and regional scale (100s of km) surface fluxes of CO<sub>2</sub> at monthly-average timescales.  Considering the 400+ ppm background, this translates to an accuracy of roughly 0.1%, an incredibly challenging target to hit. </p><p>Improvements in both instrument calibration and retrieval algorithms have led to significant improvements in satellite XCO<sub>2</sub> accuracies over the past decade.  The Atmospheric Carbon Observations from Space (ACOS) retrieval algorithm, including post-retrieval filtering and bias correction, has demonstrated unprecedented accuracy with our latest algorithm version as applied to the Orbiting Carbon Observatory-2 (OCO-2) satellite sensor.   This presentation will discuss the performance of the v10 XCO<sub>2</sub> product by comparisons to TCCON and models, and showcase its performance with some recent examples, from the potential to infer large-scale fluxes to its performance on individual power plants.  The v10 product yields better agreement with TCCON over land and ocean, plus reduced biases over tropical oceans and desert areas as compared to a median of multiple global carbon inversion models, allowing better accuracy and faith in inferred regional-scale fluxes.  More specifically, OCO-2 has single sounding precision of ~0.8 ppm over land and ~0.5 ppm over water, and RMS biases of 0.5-0.7 ppm over both land and water.  Given the six-year and growing length of the OCO-2 data record, this also enables new studies on carbon interannual variability, while at the same time allowing identification of more subtle and temporally-dependent errors.  Finally, we will discuss the prospects of future improvements in the next planned version (v11), and the long-term prospects of greenhouse gas retrievals in the coming years. </p><p> </p>

Gas-Compositional Effects on Mineralogical Reactions in Carbon Dioxide Sequestration

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 949-958 ◽  
Author(s):  
Prashanth Mandalaparty ◽  
Milind Deo ◽  
Joseph Moore
Keyword(s):  
Carbon Dioxide ◽  
Carbon Capture ◽  
Carbon Dioxide Sequestration ◽  
Ionic Concentration ◽  
Experimental Apparatus ◽  
Different Temperatures ◽  
Geochemical Reactions ◽  
Concentration Changes ◽  
Carbon Dioxide Co2

Summary It may be possible to lower costs of carbon capture and sequestration by keeping constituents such as sulfur dioxide (SO2) in the flue-gas stream. The reactive behavior of pure carbon dioxide (CO2) and CO2+SO2 mixtures within a geologically realistic environment was examined in this paper. The experimental apparatus consisted of a series of high-pressure reactors operated at different conditions and with different feed-gas compositions to observe changes in both the rock and water compositions. The rock consisted of equal proportions of quartz, calcite, andesine, dolomite, chlorite, and magnesite (constituents in arkose or dirty sandstone). The brine was prepared from laboratory-grade sodium chloride. Several long-term batch experiments with pure CO2 were carried out at different temperatures. Each mineral in the mixture showed evidence of participating in the geochemical reactions. Layers of calcite were seen growing on the surface of the arkose. Analcime deposits were omnipresent, occurring either as large connected aggregates or as deposits on the surfaces of other minerals (quartz). Calcite depositions were observed as amorphous masses intergrown with the feed. The CO2+SO2 mixture experiments showed growth of euhedral anhydrite crystals and pronounced dissolution patterns over the examined surfaces. The growth of these new phases would lead to significant changes in the petrophysical properties of the rock. The trends in ionic-concentration changes in the aqueous phase complemented the changes in the rock chemistry.

An 11 year record of GOSAT XCO2 measurements from NASA's ACOS version 9 retrieval algorithms: comparisons to models, TCCON, and OCO-2

2021 ◽  
Author(s):  
Thomas Taylor ◽  
Christopher O'Dell ◽  
Annmarie Eldering ◽  
David Crisp ◽  
Michael Gunson ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Total Carbon ◽  
High Spectral Resolution ◽  
Absorption Bands ◽  
Software Suite ◽  
Aggregated Data ◽  
Observation Network ◽  
Shortwave Infrared ◽  
Total Column

<p>The GOSAT TANSO-FTS sensor has been collecting high spectral resolution measurements of reflected solar radiation in the Oxygen A-band (0.76 microns) and two shortwave-infrared carbon dioxide (CO<sub>2</sub>) absorption bands (1.6 and 2.0 microns) since April, 2009. The measured radiances allow for estimates of the total column carbon dioxide (XCO<sub>2</sub>) via retrieval inversion. An eleven year long record of XCO<sub>2 </sub>retrieved via NASA’s Atmospheric Carbon Observations from Space (ACOS) build 9 software suite is analyzed and discussed. The v9 XCO<sub>2 </sub>data has been publicly available on the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) since the spring of 2020.</p><p>The ACOS GOSAT v9 XCO<sub>2  </sub>is evaluated against CO<sub>2 </sub>flux inversion models, observations from the Total Carbon Column Observation Network (TCCON), as well as against collocated measurements from NASA’s OCO-2 satellite. The results indicate a product that agrees with OCO-2 and models within approximately 0.25 ppm with less than 1 ppm standard deviation (σ). Agreement with TCCON is within approximately 0.1 ppm with approximately 1 ppm σ for daily overpass mean aggregated data. The ACOS GOSAT v9 XCO<sub>2 </sub>product will allow CO<sub>2 </sub>flux inversion modelers and terrestrial ecologists to address questions about long term (decadal) carbon cycle dynamics related to net and gross carbon fluxes.</p>

scholarly journals Global and regional trends of aerosol optical depth over land and ocean using SeaWiFS measurements from 1997 to 2010

2012 ◽  
Vol 12 (17) ◽  
pp. 8037-8053 ◽  
Author(s):  
N. C. Hsu ◽  
R. Gautam ◽  
A. M. Sayer ◽  
C. Bettenhausen ◽  
C. Li ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Large Scale ◽  
Transport Processes ◽  
Saharan Dust ◽  
Global Ocean ◽  
Retrieval Algorithm ◽  
Sensor Calibration ◽  
Aerosol Emission

Abstract. Both sensor calibration and satellite retrieval algorithm play an important role in the ability to determine accurately long-term trends from satellite data. Owing to the unprecedented accuracy and long-term stability of its radiometric calibration, SeaWiFS measurements exhibit minimal uncertainty with respect to sensor calibration. In this study, we take advantage of this well-calibrated set of measurements by applying a newly-developed aerosol optical depth (AOD) retrieval algorithm over land and ocean to investigate the distribution of AOD, and to identify emerging patterns and trends in global and regional aerosol loading during its 13-yr mission. Our correlation analysis between climatic indices (such as ENSO) and AOD suggests strong relationships for Saharan dust export as well as biomass-burning activity in the tropics, associated with large-scale feedbacks. The results also indicate that the averaged AOD trend over global ocean is weakly positive from 1998 to 2010 and comparable to that observed by MODIS but opposite in sign to that observed by AVHRR during overlapping years. On regional scales, distinct tendencies are found for different regions associated with natural and anthropogenic aerosol emission and transport. For example, large upward trends are found over the Arabian Peninsula that indicate a strengthening of the seasonal cycle of dust emission and transport processes over the whole region as well as over downwind oceanic regions. In contrast, a negative-neutral tendency is observed over the desert/arid Saharan region as well as in the associated dust outflow over the north Atlantic. Additionally, we found decreasing trends over the eastern US and Europe, and increasing trends over countries such as China and India that are experiencing rapid economic development. In general, these results are consistent with those derived from ground-based AERONET measurements.

scholarly journals Comparison of PM10 washout on urban and rural areas

2017 ◽  
Vol 24 (3) ◽  
pp. 381-395 ◽  
Author(s):  
Tomasz Olszowski
Keyword(s):  
Rural Area ◽  
Rural Areas ◽  
Large Scale ◽  
Reference Method ◽  
Ambient Air ◽  
Constant Intensity ◽  
Continuous Precipitation ◽  
Concentration Changes ◽  
Urban And Rural Areas

Abstract This paper reports the results of research into the effectiveness of scavenging of PM10, resulting from the occurrence of solid and liquid hydrometeors. The measurement campaign was undertaken over 7 years and involved the registration of PM10 in areas which have different aerosanitary conditions (i.e. urban and undeveloped rural area). The analysis involved 426 observations taken at constant time intervals of 0.5 hour. The measurements of the concentration of PM10 were performed by means of a reference method accompanied by concurrent registration of basic meteorological parameters. It was indicated that in a urban location, the intensity of the local emission sources is a principal factor influencing the value of mass concentration changes and the effectiveness of the dust scavenging that accompanies a given type of precipitation. It was also noted that for the same intensity of precipitation, only the deposition of convective rainfall and long-term large-scale precipitation do not lead to statistically relevant differences in the value of mass concentrations of dust for both areas. It was indicated that during solid and liquid frontal precipitation of light intensity (< 0.5 mm·h−1), the effectiveness of PM10 removing is less in rural area. It was statistically proven that continuous precipitation of constant intensity and duration exceeding 2 hours has a similar effect of purifying the ambient air in both locations. The study revealed that short-term solid precipitation provides better characteristics of scavenging of PM10 compared with classic rainfall

Towards a continuous formic acid synthesis: a two-step carbon dioxide hydrogenation in flow

2018 ◽  
Vol 3 (6) ◽  
pp. 912-919 ◽  
Author(s):  
Helena Reymond ◽  
Juan José Corral-Pérez ◽  
Atsushi Urakawa ◽  
Philipp Rudolf von Rohr
Keyword(s):  
Carbon Dioxide ◽  
Technological Innovation ◽  
Large Scale ◽  
Acid Synthesis ◽  
Low Carbon ◽  
Low Carbon Economy ◽  
Storage Solutions ◽  
Carbon Dioxide Hydrogenation ◽  
Carbon Economy

The need for long term, large-scale storage solutions to match surplus renewable energy with demand drives technological innovation towards a low-carbon economy.

Sign in / Sign up

Export Citation Format

Share Document