scholarly journals Biomass burning smoke measured using backscattered ultraviolet radiation: SCAR-B and Brazilian smoke interannual variability

1998 ◽  
Vol 103 (D24) ◽  
pp. 31969-31978 ◽  
Author(s):  
James F. Gleason ◽  
N. Christina Hsu ◽  
Omar Torres
Keyword(s):  
Ultraviolet Radiation ◽  
Interannual Variability ◽  
Biomass Burning

scholarly journals Interannual variability of global biomass burning emissions from 1997 to 2004

2006 ◽  
Vol 6 (2) ◽  
pp. 3175-3226 ◽  
Author(s):  
G. R. van der Werf ◽  
J. T. Randerson ◽  
L. Giglio ◽  
G. J. Collatz ◽  
P. S. Kasibhatla ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Biomass Burning ◽  
Satellite Data ◽  
Net Primary Production ◽  
Terrestrial Ecosystems ◽  
Total Carbon ◽  
Burned Area ◽  
Biogeochemical Model ◽  
Fuel Wood ◽  
Fire Emissions

Abstract. Biomass burning represents an important source of atmospheric aerosols and greenhouse gases, yet little is known about its interannual variability or the underlying mechanisms regulating this variability at continental to global scales. Here we investigated fire emissions during the 8 year period from 1997 to 2004 using satellite data and the CASA biogeochemical model. Burned area from 2001–2004 was derived using newly available active fire and 500 m burned area datasets from MODIS following the approach described by Giglio et al. (2005). ATSR and VIRS satellite data were used to extend the burned area time series back in time through 1997. In our analysis we estimated fuel loads, including peatland fuels, and the net flux from terrestrial ecosystems as the balance between net primary production (NPP), heterotrophic respiration (Rh), and biomass burning, using time varying inputs of precipitation (PPT), temperature, solar radiation, and satellite-derived fractional absorbed photosynthetically active radiation (fAPAR). For the 1997–2004 period, we found that on average approximately 58 Pg C year−1 was fixed by plants, and approximately 95% of this was returned back to the atmosphere via Rh. Another 4%, or 2.5 Pg C year−1 was emitted by biomass burning; the remainder consisted of losses from fuel wood collection and subsequent burning. At a global scale, burned area and total fire emissions were largely decoupled from year to year. Total carbon emissions tracked burning in forested areas (including deforestation fires in the tropics), whereas burned area was largely controlled by savanna fires that responded to different environmental and human factors. Biomass burning emissions showed large interannual variability with a range of more than 1 Pg C year−1, with a maximum in 1998 (3.2 Pg C year−1) and a minimum in 2000 (2.0 Pg C year−1).

scholarly journals Trends in Stratospheric Ozone: Lessons Learned from a 3D Chemical Transport Model

2006 ◽  
Vol 63 (3) ◽  
pp. 1028-1041 ◽  
Author(s):  
Richard S. Stolarski ◽  
Anne R. Douglass ◽  
Stephen Steenrod ◽  
Steven Pawson
Keyword(s):  
Time Series ◽  
Solar Cycle ◽  
Ultraviolet Radiation ◽  
Boundary Conditions ◽  
Interannual Variability ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
The Past

Abstract Stratospheric ozone is affected by external factors such as chlorofluorcarbons (CFCs), volcanoes, and the 11-yr solar cycle variation of ultraviolet radiation. Dynamical variability due to the quasi-biennial oscillation and other factors also contribute to stratospheric ozone variability. A research focus during the past two decades has been to quantify the downward trend in ozone due to the increase in industrially produced CFCs. During the coming decades research will focus on detection and attribution of the expected recovery of ozone as the CFCs are slowly removed from the atmosphere. A chemical transport model (CTM) has been used to simulate stratospheric composition for the past 30 yr and the next 20 yr using 50 yr of winds and temperatures from a general circulation model (GCM). The simulation includes the solar cycle in ultraviolet radiation, a representation of aerosol surface areas based on observations including volcanic perturbations from El Chichon in 1982 and Pinatubo in 1991, and time-dependent mixing ratio boundary conditions for CFCs, halons, and other source gases such as N2O and CH4. A second CTM simulation was carried out for identical solar flux and boundary conditions but with constant “background” aerosol conditions. The GCM integration included an online ozonelike tracer with specified production and loss that was used to evaluate the effects of interannual variability in dynamics. Statistical time series analysis was applied to both observed and simulated ozone to examine the capability of the analyses for the determination of trends in ozone due to CFCs and to separate these trends from the solar cycle and volcanic effects in the atmosphere. The results point out several difficulties associated with the interpretation of time series analyses of atmospheric ozone data. In particular, it is shown that lengthening the dataset reduces the uncertainty in derived trend due to interannual dynamic variability. It is further shown that interannual variability can make it difficult to accurately assess the impact of a volcanic eruption, such as Pinatubo, on ozone. Such uncertainties make it difficult to obtain an early proof of ozone recovery in response to decreasing chlorine.

scholarly journals Impact of El Niño Southern Oscillation on the interannual variability of methane and tropospheric ozone

2019 ◽  
Author(s):  
Matthew J. Rowlinson ◽  
Alexandru Rap ◽  
Stephen R. Arnold ◽  
Richard J. Pope ◽  
Martyn P. Chipperfield ◽  
...  
Keyword(s):  
Growth Rate ◽  
Interannual Variability ◽  
Biomass Burning ◽  
El Niño ◽  
Atmospheric Transport ◽  
El Nino ◽  
Southern Oscillation ◽  
Fire Emissions ◽  
Tropospheric O3 ◽  
Global Mean

Abstract. The growth rate of global methane (CH4) concentrations has a strong interannual variability which is believed to be driven largely by fluctuations in CH4 emissions from wetlands and wildfires, as well as changes to the atmospheric sink. The El Niño Southern Oscillation (ENSO) is known to influence fire occurrence, wetland emission and atmospheric transport, but there are still important uncertainties associated with the exact mechanism and magnitude of this influence. Here we use a modelling approach to investigate how fires and meteorology control the interannual variability of global carbon monoxide (CO), CH4 and ozone (O3) concentrations, particularly during large El Niño events. Using a three-dimensional chemical transport model (TOMCAT) coupled to a sophisticated aerosol microphysics scheme (GLOMAP) we simulate changes to CO, hydroxyl radical (OH) and O3 for the period 1997–2014. We then use an offline radiative transfer model to quantify the impact of changes to atmospheric composition as a result of specific drivers. During the El Niño event of 1997–1998, there were increased emissions from biomass burning globally. As a result, global CO concentrations increased by more than 40 %. This resulted in decreased global mass-weighted tropospheric OH concentrations of up to 9 % and a resulting 4 % increase in the CH4 atmospheric lifetime. The change in CH4 lifetime led to a 7.5 ppb yr−1 increase in global mean CH4 growth rate in 1998. Therefore biomass burning emission of CO could account for 72 % of the total effect of fire emissions on CH4 growth rate in 1998. Our simulations indicate variations in fire emissions and meteorology associated with El Niño have opposing impacts on tropospheric O3 burden. El Niño-related atmospheric transport changes decrease global tropospheric O3 concentrations leading to a −0.03 Wm−2 change in O3 radiative effect (RE). However, enhanced fire emission of precursors such as nitrous oxides (NOx) and CO increase O3 RE by 0.03 Wm−2. While globally the two mechanisms nearly cancel out, causing only a small change in global mean O3 RE, the regional changes are large   up to −0.33 Wm−2 with potentially important consequences for atmospheric heating and dynamics.

scholarly journals Interannual variability of tropospheric composition: the influence of changes in emissions, meteorology and clouds

2010 ◽  
Vol 10 (5) ◽  
pp. 2491-2506 ◽  
Author(s):  
A. Voulgarakis ◽  
N. H. Savage ◽  
O. Wild ◽  
P. Braesicke ◽  
P. J. Young ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Biomass Burning ◽  
Strong Influence ◽  
Transport Model ◽  
Global Scale ◽  
Meteorological Conditions ◽  
Shortwave Radiation ◽  
Chemistry Transport Model ◽  
Attribution Analysis ◽  
Emission Changes

Abstract. We have run a chemistry transport model (CTM) to systematically examine the drivers of interannual variability of tropospheric composition during 1996–2000. This period was characterised by anomalous meteorological conditions associated with the strong El Niño of 1997–1998 and intense wildfires, which produced a large amount of pollution. On a global scale, changing meteorology (winds, temperatures, humidity and clouds) is found to be the most important factor driving interannual variability of NO2 and ozone on the timescales considered. Changes in stratosphere-troposphere exchange, which are largely driven by meteorological variability, are found to play a particularly important role in driving ozone changes. The strong influence of emissions on NO2 and ozone interannual variability is largely confined to areas where intense biomass burning events occur. For CO, interannual variability is almost solely driven by emission changes, while for OH meteorology dominates, with the radiative influence of clouds being a very strong contributor. Through a simple attribution analysis for 1996–2000 we conclude that changing cloudiness drives 25% of the interannual variability of OH over Europe by affecting shortwave radiation. Over Indonesia this figure is as high as 71%. Changes in cloudiness contribute a small but non-negligible amount (up to 6%) to the interannual variability of ozone over Europe and Indonesia. This suggests that future assessments of trends in tropospheric oxidizing capacity should account for interannual variability in cloudiness, a factor neglected in many previous studies.

scholarly journals Free tropospheric peroxyacetyl nitrate (PAN) and ozone at Mount Bachelor: potential causes of variability and timescale for trend detection

2011 ◽  
Vol 11 (12) ◽  
pp. 5641-5654 ◽  
Author(s):  
E. V. Fischer ◽  
D. A. Jaffe ◽  
E. C. Weatherhead
Keyword(s):  
Interannual Variability ◽  
Pacific Northwest ◽  
Biomass Burning ◽  
Transport Model ◽  
Relative Increase ◽  
Trend Detection ◽  
Positive Trend ◽  
Chemical Transport Model ◽  
Mixing Ratios ◽  
Observational Estimate

Abstract. We report on the first multi-year springtime measurements of PAN in the free troposphere over the US Pacific Northwest. The measurements were made at the summit of Mount Bachelor (43.979° N, 121.687° W; 2.7 km a.s.l.) by gas chromatography with electron capture detector during spring 2008, 2009 and 2010. This dataset provides an observational estimate of the month-to-month and springtime interannual variability of PAN mixing ratios in this region. Springtime seasonal mean (1 April–20 May) PAN mixing ratios at Mount Bachelor varied from 100 pptv to 152 pptv. The standard deviation of the three seasonal means was 28 pptv, 21 % of the springtime mean. We summarize the interannual variability in three factors expected to drive PAN variability: biomass burning, transport efficiency over the central and eastern Pacific, and transport temperature. Zhang et al. (2008) used the GEOS-Chem global chemical transport model to show that rising Asian NOx emissions from 2000 to 2006 resulted in a relatively larger positive trend in PAN than O3 over western North America. However the model results only considered monotonic changes in Asian emissions, whereas other factors, such as biomass burning, isoprene emissions or climate change can induce greater variability in the atmospheric concentrations and thus extend the time needed for trend detection. We combined the observed variability in PAN and O3 at Mount Bachelor with a range of possible future trends in these species to determine the observational requirements to detect such trends. Though the relative increase in PAN is expected to be larger than that of O3, PAN is more variable. If PAN mixing ratios are currently increasing at a rate of 4 % per year due to rising Asian emissions, we would detect a trend with 13 years of measurements at a site like Mount Bachelor. If the corresponding trend in O3 is 1 % per year, the trends in O3 and PAN would be detected on approximately the same timescale.

scholarly journals On the use of ATSR fire count data to estimate the seasonal and interannual variability of vegetation fire emissions

2002 ◽  
Vol 2 (4) ◽  
pp. 1159-1179 ◽  
Author(s):  
M. G. Schultz
Keyword(s):  
Interannual Variability ◽  
Biomass Burning ◽  
Seasonal Pattern ◽  
Burned Area ◽  
Time Resolved ◽  
Fire Emissions ◽  
Seasonal And Interannual Variability ◽  
Active Fire ◽  
Time Period ◽  
Along Track

Abstract. Biomass burning has long been recognised as an important source of trace gases and aerosols in the atmosphere. The burning of vegetation has a repeating seasonal pattern, but the intensity of burning and the exact localisation of fires vary considerably from year to year. Recent studies have demonstrated the high interannual variability of the emissions that are associated with biomass burning. In this paper we present a methodology using active fire counts from the Along-Track Scanning Radiometer (ATSR) sensor on board the ERS-2 satellite to estimate the seasonal and interannual variability of global biomass burning emissions in the time period 1996--2000. From the ATSR data, we compute relative scaling factors of burning intensity for each month, which are then applied to a standard inventory for carbon monoxide emissions from biomass burning. The new, time-resolved inventory is evaluated using the few existing multi-year burned area observations on continental scales.

scholarly journals Interannual variability of long-range transport as seen at the Mt. Bachelor Observatory

2008 ◽  
Vol 8 (4) ◽  
pp. 16335-16379 ◽  
Author(s):  
D. R. Reidmiller ◽  
D. A. Jaffe ◽  
D. Chand ◽  
S. Strode ◽  
P. Swartzendruber ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Interannual Variability ◽  
Long Range ◽  
Biomass Burning ◽  
Transport Model ◽  
Long Range Transport ◽  
Naval Research ◽  
Chemical Transport Model ◽  
Northeast Pacific ◽  
Range Transport

Abstract. Interannual variations in background tropospheric trace gases (such as carbon monoxide, CO) are largely driven by variations in emissions (especially wildfires), transport pathways and tropospheric oxidizing capacity. Understanding this variability is essential to quantify the intercontinental contribution to US air quality. We investigate the interannual variability of long-range transport of Asian pollutants to the Northeast Pacific via measurements from the Mt. Bachelor Observatory (MBO: 43.98° N, 121.69° W; 2.7 km above sea level) and GEOS-Chem chemical transport model simulations in spring 2005 vs. the INTEX-B campaign during spring 2006. Measurements of CO at MBO were significantly enhanced during spring 2005 relative to the same time in 2006 (the INTEX-B study period); a monthly mean decline in CO of 41 ppbv was observed between April 2005 and April 2006. Meteorological indices show that long-range transport of CO from the heavily industrialized region of East Asia was significantly greater in 2005 than in 2006. In addition, spring 2005 was an anomalously strong biomass burning season in Southeast Asia. Data presented by Yurganov et al. (2008) using MOPITT satellite retrievals from this area reveal an average CO burden anomaly (referenced to March 2000–February 2002 mean values) between October 2004 through April 2005 of 2.6 Tg CO vs. 0.6 Tg CO for the same period a year later. The Naval Research Laboratory's global aerosol transport model shows that emissions from these fires were efficiently transported to MBO throughout April 2005. Asian dust transport, however, was substantially greater in 2006 than 2005, particularly in May. Monthly mean aerosol light scattering coefficient at 532 nm (σsp) at MBO more than doubled from 2.7 Mm−1 in May 2005 to 6.2 Mm−1 in May 2006. We also evaluate CO interannual variability throughout the western US via Earth System Research Laboratory ground site data and throughout the Northern Hemisphere via MOPITT and TES satellite observations. Both in the Northeast Pacific and on larger scales, we reveal a significant decrease (from 2–21%) in springtime maximum CO between 2005 and 2006, evident in all platforms and the GEOS-Chem model. We attribute this to (a) anomalously strong biomass burning in Southeast Asia during winter 2004 through spring 2005, and (b) the transport pattern in 2006 which limited the inflow of Asian pollution to the lower free troposphere over western North America.

scholarly journals Interannual variability of sugars in Arctic aerosol: Biomass burning and biogenic inputs

2020 ◽  
Vol 706 ◽  
pp. 136089 ◽  
Author(s):  
Matteo Feltracco ◽  
Elena Barbaro ◽  
Silvia Tedeschi ◽  
Andrea Spolaor ◽  
Clara Turetta ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Biomass Burning ◽  
Arctic Aerosol

scholarly journals Air–sea exchange and gas–particle partitioning of polycyclic aromatic hydrocarbons in the Mediterranean

2014 ◽  
Vol 14 (17) ◽  
pp. 8905-8915 ◽  
Author(s):  
M. D. Mulder ◽  
A. Heil ◽  
P. Kukučka ◽  
J. Klánová ◽  
J. Kuta ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Biomass Burning ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Fire Season ◽  
Secondary Source ◽  
Deposition Flux ◽  
Regional Sources ◽  
Polycyclic Aromatic ◽  
The Mediterranean

Abstract. Polycyclic aromatic hydrocarbon (PAH) concentration in air of the central and eastern Mediterranean in summer 2010 was 1.45 (0.30–3.25) ng m−3 (sum of 25 PAHs), with 8 (1–17)% in the particulate phase, almost exclusively associated with particles < 0.25 μm. The total deposition flux of particulate PAHs was 0.3–0.5 μ g m−2 yr−1. The diffusive air–sea exchange fluxes of fluoranthene and pyrene were mostly found net-depositional or close to phase equilibrium, while retene was net-volatilisational in a large sea region. Regional fire activity records in combination with box model simulations suggest that seasonal depositional input of retene from biomass burning into the surface waters during summer is followed by an annual reversal of air–sea exchange, while interannual variability is dominated by the variability of the fire season. One-third of primary retene sources to the sea region in the period 2005–2010 returned to the atmosphere as secondary emissions from surface seawaters. It is concluded that future negative emission trends or interannual variability of regional sources may trigger the sea to become a secondary PAH source through reversal of diffusive air–sea exchange. Capsule: In late summer the seawater surface in the Mediterranean has turned into a temporary secondary source of PAH, obviously related to biomass burning in the region.

scholarly journals Source attribution and interannual variability of Arctic pollution in spring constrained by aircraft (ARCTAS, ARCPAC) and satellite (AIRS) observations of carbon monoxide

2010 ◽  
Vol 10 (3) ◽  
pp. 977-996 ◽  
Author(s):  
J. A. Fisher ◽  
D. J. Jacob ◽  
M. T. Purdy ◽  
M. Kopacz ◽  
P. Le Sager ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Interannual Variability ◽  
Biomass Burning ◽  
El Niño ◽  
Model Simulation ◽  
El Nino ◽  
The Arctic ◽  
Anthropogenic Emissions ◽  
Large Contribution ◽  
Pollution Transport

Abstract. We use aircraft observations of carbon monoxide (CO) from the NASA ARCTAS and NOAA ARCPAC campaigns in April 2008 together with multiyear (2003–2008) CO satellite data from the AIRS instrument and a global chemical transport model (GEOS-Chem) to better understand the sources, transport, and interannual variability of pollution in the Arctic in spring. Model simulation of the aircraft data gives best estimates of CO emissions in April 2008 of 26 Tg month−1 for Asian anthropogenic, 9.4 for European anthropogenic, 4.1 for North American anthropogenic, 15 for Russian biomass burning (anomalously large that year), and 23 for Southeast Asian biomass burning. We find that Asian anthropogenic emissions are the dominant source of Arctic CO pollution everywhere except in surface air where European anthropogenic emissions are of similar importance. Russian biomass burning makes little contribution to mean CO (reflecting the long CO lifetime) but makes a large contribution to CO variability in the form of combustion plumes. Analysis of two pollution events sampled by the aircraft demonstrates that AIRS can successfully observe pollution transport to the Arctic in the mid-troposphere. The 2003–2008 record of CO from AIRS shows that interannual variability averaged over the Arctic cap is very small. AIRS CO columns over Alaska are highly correlated with the Ocean Niño Index, suggesting a link between El Niño and Asian pollution transport to the Arctic. AIRS shows lower-than-average CO columns over Alaska during April 2008, despite the Russian fires, due to a weakened Aleutian Low hindering transport from Asia and associated with the moderate 2007–2008 La Niña. This suggests that Asian pollution influence over the Arctic may be particularly large under strong El Niño conditions.

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