40 research outputs found
Degradation of sea ice in the Western Arctic facilitates methane transport from sub-seabed sediments to atmosphere: satellite data for 2003 - 2019.
No full textПроанализированы 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
Degradation of sea ice in the Western Arctic facilitates methane transport from sub-seabed sediments to atmosphere: satellite data for 2003 - 2019.
No full textПроанализированы 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
Two Decades of Satellite Observations of Carbon Monoxide Confirm the Increase in Northern Hemispheric Wildfires
No full textBiomass 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
Seasonal cycles of carbon monoxide over the Arctic and Antarctic: total columns versus surface data
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No full textImpacts of enhanced biomass burning in the boreal forests in 1998 on tropospheric chemistry and the sensitivity of model results to the injection height of emission
Two Decades of Satellite Observations of Carbon Monoxide Confirm the Increase in Northern Hemispheric Wildfires
No full textBiomass burning is an important and changing component of the global and hemispheric
carbon cycles. Boreal forest fires in Russia and Canada are significant sources of 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 for the aforementioned gases. The Atmospheric Infrared Sounder (AIRS)
provides a satellite-based CO data set since October, 2002 up to now. This communication presents
estimates of CO emissions from biomass burning north of 30° N using a simple two-box massbalance model. These results correlate closely with independently estimated CO emissions from the
GFED4 bottom-up data base. Both ones reported record high emissions in 2021 throughout two
decades, double the annual emissions comparing to the previous years. There have been two years
with extremely high emissions (2003 and 2021), but for the rest of data 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 emission follows from the
GFED4 data.The study was funded in part by the Ministry of Science and Higher Education of the
Russian Federation under agreement # 075-15-2020-776.https://www.mdpi.com/2073-4433/13/9/147
Local, regional, and global views of tropospheric carbon monoxide from the Atmospheric Infrared Sounder (AIRS)
No full textMethane Increase over the Barents and Kara Seas after the Autumn Pycnocline Breakdown: Satellite Observations
Get PDFSeven operative thermal infrared (TIR) spectrometers launched at sun-synchronous polar orbits supply huge amounts of information about Arctic methane (CH 4 ) year-round, day and night. TIR data are unique for estimating CH 4 emissions from a Arctic warming, both terrestrial and marine. This report is based on publicly available CH 4 concentrations retrieved by NOAA and NASA from spectra of TIR radiation delivered by EU IASI and US AIRS sounders. Data were filtered for high thermal contrast in the troposphere. Validation versus aircraft measurements at three US continental sites reveal a reduced, but still significant sensitivity to CH 4anomalies in the troposphere below 4 km of altitude. The focus area is the Barents and Kara seas (BKS). BKS is impacted with warm Atlantic water and mostly free of sea ice. It is a shelf area with vast deposits of oil and natural gas (~90% CH 4 ), as well as methane hydrates and submarine permafrost. Although in summer AIRS and IASI observe no significant difference in CH 4 between BKS and N. Atlantic, a strong, monthly positive CH 4 spatial anomaly of up to 30 ppb occurs during late autumn–winter. One of explanations of this increase is a fall/winter pycnocline breakdown after a period of blocked mixing caused by a stable density seawater stratification in summer: enhanced mixing lets CH 4 to reach the sea surface and atmosphere
Ocean stratification and sea-ice cover in Barents and Kara seas modulate sea-air methane flux: satellite evidence
No full textThe diverse range of mechanisms driving the Arctic amplification are not completely understood and, moreover, the role of the greenhouse gas methane in Arctic warming remains unclear. Strong sources of methane at the ocean seabed in the Barents Sea and other polar regions are well documented. Nevertheless, those data suggest that negligible amounts of methane fluxed from the seabed enter the atmosphere, with roughly 90% of the methane consumed by bacteria. The observations are taken during summer, which is favorable for collecting data but also characterized by a strongly-stratified water column. In winter the stratification weakens and after a breakdown of the pycnocline, convection, storms, and turbulent diffusion can mix the full-depth water column in high latitudes.TheMixed Layer Depth (MLD) in the ice-free Central/Southern Barents Sea is deepening and the ocean-atmosphere methane exchange increases.. An additional barrier for the air-sea flux is seasonally and interannually variable sea-ice cover in partially ice-covered seas. We present Thermal IR space-based spectrometer data between 2002 and 2019 that shows increased methane concentration anomalies over the Barents and Kara seas in winter months. The seasonal methane cycle amplitude north of the Kara Sea has more than doubled since the beginning of the century; this may be interpreted as an effect of sea-ice decline and/or an evidence for growth of seabed emissions. A progressing degradation of Arctic sea-ice cover may lead to increased methane flux and, through a positive feedback loop, to further warming.We express our gratitude to personnel of NASA and NOAA that make publicly available satellite data on methane and sea ice concentration. Colm Sweeney (NOAA/GMD) kindly supplied data of aircraft sampling over the Trinidad Head, California.http://aps-polar.org/paper/2021/32/02/A21062400000
Increase in Arctic Oscillations explains most interannual variability in Russia’s wildfires
Get PDFOver 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 CO2eqv 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 CO2eqv, 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
