Biomass burning is an important and changing component of global and hemispheric carbon cycles. Boreal forest fires in Russia and Canada are significant sources of the greenhouse gases carbon dioxide ...(CO2) and methane (CH4). The influence of carbon monoxide (CO) on the greenhouse effect is practically absent; its main absorption bands of 4.6 and 2.3 μm are far away from the climatically important spectral regions. Meanwhile, CO concentrations in fire plumes are closely related to CO2 and CH4 emissions from fires. On the other hand, satellite measurements of CO are much simpler than those of the aforementioned gases. The Atmospheric Infrared Sounder (AIRS) operating in the Thermal IR spectral region has provided a satellite-based CO data set since October 2002. This satellite data allow to estimate CO emissions from biomass burning north of 30° N using a simple two-box mass-balance model. These results correlate closely with independently estimated CO emissions from the GFED4c bottom-up database. In 2021, both estimate record high emissions throughout the preceding two decades, double the annual emissions compared to previous periods. There have been two years with extremely high emissions (2003 and 2021) but for the rest of the data, an upward trend with a rate of 3.6 ± 2.2 Tg CO yr−2 (4.8 ± 2.7% yr−1) was found. A similar rate of CO emissions can be seen in the GFED4c data.
In the current era of rapid climate change, accurate characterization of climate-relevant gas dynamics – namely production, consumption, and net emissions – is required for all biomes, especially ...those ecosystems most susceptible to the impact of change. Marine environments include regions that act as net sources or sinks for numerous climate-active trace gases including methane (CH4) and nitrous oxide (N2O). The temporal and spatial distributions of CH4 and N2O are controlled by the interaction of complex biogeochemical and physical processes. To evaluate and quantify how these mechanisms affect marine CH4 and N2O cycling requires a combination of traditional scientific disciplines including oceanography, microbiology, and numerical modeling. Fundamental to these efforts is ensuring that the datasets produced by independent scientists are comparable and interoperable. Equally critical is transparent communication within the research community about the technical improvements required to increase our collective understanding of marine CH4 and N2O. A workshop sponsored by Ocean Carbon and Biogeochemistry (OCB) was organized to enhance dialogue and collaborations pertaining to marine CH4 and N2O. Here, we summarize the outcomes from the workshop to describe the challenges and opportunities for near-future CH4 and N2O research in the marine environment.
New results of CO global total column measurements using the Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite in comparison with Measurements of Pollution in the Troposphere (MOPITT) ...sensor aboard the Terra satellite are presented. Both data sets are validated using ground‐based total column measurements in Russia and Australia. A quality parameter based on the Profile Percent A Priori values from the standard MOPITT product is introduced. AIRS data (version 4) for biomass burning events are in agreement or lower than both MOPITT and ground measurements, but CO bursts can be seen by AIRS in most cases. For the cases of low CO amounts in the Southern Hemisphere AIRS has a positive bias of ∼30–40% compared to MOPITT and ground truth. MOPITT data were used to estimate interannual variations of CO sources assuming a standard seasonal cycle for the main CO remover OH. A positive trend of CO global emissions for the second half of the year between 2000 and 2006 was found with no visible trend for the first half of the year. CO annual emission in 2006 was 184 ± 40 Tg higher that that in 2000–2001. The monthly emission anomalies correlate well with an independently calculated Global Fire Emission Database (GFED2). Total carbon contribution from biomass burning in 1997, 1998 (both estimated by GFED2), and 2006 (according to MOPITT) were as high as (0.6–1) Pg C/year larger than in 2000, suggesting that fires can explain a substantial fraction of the interannual variability of CO2.
Over the past two decades, the escalating emissions of greenhouse gases from boreal wildfires in the Northern Hemisphere have drawn significant attention, underscoring an unprecedented wildfire ...season in 2021. Our calculations indicate that between 2002 and 2020, wildfires in Russia released approximately 726 ± 280 Tg CO
2eqv
yr
−1
. This aligns closely with similar estimates derived from remote sensing data, far surpassing the earlier approximations found in the Russian National Inventory Report (NIR) by a factor of 2 to 3. Notably, in 2021 alone, Russia’s wildfires emitted an exceptionally high amount of 1,700 Tg CO
2eqv
, exceeding the carbon emissions from the country’s fossil fuel consumption. Consequently, this situation led to an almost complete counterbalance of carbon assimilation by Russian forests. Our analysis attributes over 50% of the variation in wildfire frequency between 2002 and 2021 to shifts in the Arctic Oscillation (AO). This suggests a potential for utilizing AO as a predictive variable for wildfires. It’s noteworthy that the AO itself is influenced by the sustained regression of Arctic sea-ice. From this, it can be inferred that in the foreseeable future, Russian forests might undergo a transition from their role as carbon sinks to the potential net contributors of carbon to the atmosphere.
Carbon monoxide reached record high levels in the northern extratropics in the late summer and fall of 1998 as a result of anomalously large boreal fires in eastern Russia and North America. We ...investigated the effects of these fires on CO and tropospheric oxidants using a global chemical transport model (GEOS‐Chem) and two independently derived inventories for the fire emissions that differ by a factor of two. We find that it is essential to use both surface and column observations of CO to constrain the magnitude of the fire emissions and their injection altitude. Our results show that the larger of the two inventories appears more reliable and that about half of the emissions were injected above the boundary layer. The boreal fire emissions cause a much larger enhancement in ozone when about half the emissions are released above the boundary layer than when they are released exclusively in the boundary layer, as a consequence of the role of PAN as a source of NOx as air descends in regions far from the fires.
Проанализированы ИК спутниковые данные о концентрации метана в слое атмосферы 0-4 кмнад Карским и Баренцевым морями. Данные по метану сравнивались с микроволновымиспутниковыми измерениями ледового ...покрова Карского моря. Амплитуда сезонных вариацийметана над северной частью Карского моря выросла в 3 раза за последние 16 лет. Площадьповерхности того же района, свободная ото льда, выросла в 4 раза. Сделан вывод орешающей роли ледового покрова в экранировании потока метана в атмосферу.
Methane (CH4) and ammonia (NH3) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal ...InfraRed (TIR) that can be studied by remote sensing, with NH3 allowing discrimination of husbandry from other CH4 sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH4, carbon dioxide (CO2) and NH3 data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20 km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1 × 105 kg CH4, 2.2 × 105 kg NH3, and 2.3 × 107 kg CO2, suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42 Gg CH4 and 8.4 Gg NH3 implying ∼200k cows, ∼30% more than Peischl et al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH3 occurs within the confines of the Los Angeles Basin on a four to six h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others.
On surface: Map of IASI ammonia, NH3, columns for the Eastern Los Angeles Basin for 2014. Floating: Mako NH3 column map. Surface shows pink outline of the Chino Diary Complex, grey outlines 70 ppm-m contour of NH3 column. IASI map slightly transparent to provide better surface rendering. The excellent spatial agreement indicates that conditions for Mako were typical. Display omitted
•Airborne remote sense mapping of a dairy trace gas plume for over 20 km.•In situ identification of far-field (70-km) downwind plume by surface in situ and satellite.•Good herd size agreement for a dairy and the Chino Dairy Complex based on multiple gas emissions estimates.•NH3 lifetime was rapid, ∼6 h, likely due to increased oxidation from the higher oxidant loads in Los Angeles.•IASI satellite NH3 and CH4 confirmed downwind plume and transport patterns identified in airborne imaging spectroscopy and surface in situ data.
Airborne remote sensing mapped dairy NH3 and CH4 plumes with good agreement with satellite and in situ data, the latter of which were used to derive emissions and infer herd size.
Mobile in situ concentration and meteorology data were collected for the Chino Dairy Complex in the Los Angeles Basin by AMOG (AutoMObile trace Gas) Surveyor on 25 June 2015 to characterize husbandry ...emissions in the near and far field in convoy mode with MISTIR (Mobile Infrared Sensor for Tactical Incident Response), a mobile upwards-looking, column remote sensing spectrometer. MISTIR reference flux validated AMOG plume inversions at different information levels including multiple gases, GoogleEarth imagery, and airborne trace gas remote sensing data. Long-term (9-yr.) Infrared Atmospheric Sounding Interferometer satellite data provided spatial and trace gas temporal context.
For the Chino dairies, MISTIR-AMOG ammonia (NH3) agreement was within 5% (15.7 versus 14.9 Gg yr−1, respectively) using all information. Methane (CH4) emissions were 30 Gg yr−1 for a 45,200 herd size, indicating that Chino emission factors are greater than previously reported.
Single dairy inversions were much less successful. AMOG-MISTIR agreement was 57% due to wind heterogeneity from downwind structures in these near-field measurements and emissions unsteadiness. AMOG CH4, NH3, and CO2 emissions were 91, 209, and 8200 Mg yr−1, implying 2480, 1870, and 1720 head using published emission factors. Plumes fingerprinting identified likely sources including manure storage, cowsheds, and a structure with likely natural gas combustion.
NH3 downwind of Chino showed a seasonal variation of a factor of ten, three times larger than literature suggests. Chino husbandry practices and trends in herd size and production were reviewed and unlikely to add seasonality. Higher emission seasonality was proposed as legacy soil emissions, the results of a century of husbandry, supported by airborne remote sensing data showing widespread emissions from neighborhoods that were dairies 15 years prior, and AMOG and MISTIR observations. Seasonal variations provide insights into the implications of global climate change and must be considered when comparing surveys from different seasons.
Eight-plume informed (8I) Gaussian inversion model for I-15 downwind (north to south) transect with respect to arbitrary lateral distance (y) for A) ammonia anomaly (NH3′) and winds (u) versus relative northing (x). Plume peaks labeled. Arrows show transect features modeled that indicated the six-plume uninformed model (not shown). B)In situ NH3 and u data superimposed on Mako column ammonia (XNH3) data for 25 Jul. 2014, 1820-1846 UTC (1020-1046 LT), and the 8I model-projected plumes’ origins in the Google Earth environment. Selected transect plume features labeled. White arrows bracket the transect line onto which transect data are projected. Data key on figure. Shown in the Google Earth environment. Display omitted
•Herd size from three different trace gases converge to ±20% of the average value.•Seasonality is observed in NH3 and CH4 satellite data, affecting annualized rates.•Seasonality must be considered when comparing campaigns in different seasons.•NH3 seasonality was 900%; proposed legacy soil emissions, observed in airborne data.•Midsummer Chino dairy emissions were 15.7 Gg NH3 yr−1 and 30 Gg CH4 yr−1.
Where sufficient information from multiple gases and number of likely sources, high emissions accuracy can be achieved for in situ data plume inversion.
Carbon monoxide total column amounts in the atmosphere have been measured in the High Northern Hemisphere (30°-90° N, HNH) between January 2002 and December 2003 using infrared spectrometers of high ...and moderate resolution and the Sun as a light source. They were compared to ground-level CO mixing ratios and to total column amounts measured from space by the Terra/MOPITT instrument. All these data reveal increased CO abundances in 2002-2003 in comparison to the unperturbed 2000-2001 period. Maximum anomalies were observed in September 2002 and August 2003. Using a simple two-box model, the corresponding annual CO emission anomalies (referenced to 2000-2001 period) have been found equal to 95Tg in 2002 and 130Tg in 2003, thus close to those for 1996 and 1998. A good correlation with hot spots detected by a satellite radiometer allows one to assume strong boreal forest fires, occurred mainly in Russia, as a source of the increased CO burdens.
The analysis of total column spectroscopic CO observations over Russia revealed an upward linear trend between 1970 and 1995 with a rate of about 1.0 ppbv/year or 0.96%/year. A similar trend was ...reported earlier for the CO total column over Switzerland between 1950 and 1987. This rate is almost 3 times higher, than the rate of CO increase between 1920 and 1950, obtained from ice core data. Main disturbances of CO tropospheric concentration coincided with vast wildfires in the central Russia in 1972 and volcanic eruptions. Stratospheric volcanic aerosol probably influence the concentration of tropospheric OH radicals, which destroy CO molecules. The aerosol scatters photochemically active UV radiation and, in the same time, triggers the stratospheric ozone photochemical destruction. Diminished total column ozone UV absorption can offset the increase of UV scattering due to additional aerosol. Studying these processes is important for a prediction of further CO and OH long‐term variations in the global atmosphere.
PDF
