Spatial-time variations in the distribution of atmospheric methane at high latitudes of the northern hemisphere

A preliminary study of spatio-temporal variations of methane distribution at high latitudes of the northern hemisphere was conducted based on AIRS and JR-STATION data. The analysis showed a noticeable increase (~4%) in the methane concentration in the lower layers of the atmosphere and upper layers of the troposphere. According to the AIRS data, winter (February) and summer (July- August) peaks of the methane concentration were reported in the seasonal cycle of 2004-2018. Seasonal methane variations in the upper troposphere obtained from AIRS data have similarities to ground observations, but with a smaller amplitude

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Spatial and temporal variations of light rain events over China and the mid-high latitudes of the Northern Hemisphere

Chinese Science Bulletin ◽

10.1007/s11434-012-5593-1 ◽

2013 ◽

Vol 58 (12) ◽

pp. 1402-1411 ◽

Cited By ~ 16

Author(s):

Gang Huang ◽

GuanHuan Wen

Keyword(s):

Northern Hemisphere ◽

Temporal Variations ◽

Spatial And Temporal Variations ◽

High Latitudes ◽

Light Rain ◽

Rain Events

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Sources of atmospheric methane in Arctic: observations and model simulation

10.5194/egusphere-egu21-13688 ◽

2021 ◽

Author(s):

Yury Shtabkin ◽

Konstantin Moiseenko ◽

Andrey Skorokhod

Keyword(s):

Methane Concentration ◽

Transport Model ◽

Model Simulation ◽

Methane Emissions ◽

Atmospheric Methane ◽

Chemical Transport Model ◽

Noticeable Increase ◽

Regional Sources ◽

The Impact

The second most important greenhouse gas in atmosphere after carbon dioxide (CO2) is methane, CH4. The limited data of surface methane observations in Arctic makes it difficult to quantify the impact of methane emissions from major regional anthropogenic and biogenic sources on this region. This gap is partially filled by long-term observations at arctic and subarctic stations. According to these observations, since 2005, there has been a noticeable increase in the surface methane concentration. The reasons of this increase are still not fully understood. This work provides quantitative estimates of possible contribution into surface CH4 observed long-term variability from the most important regional sources of methane emissions.To analyze variations in surface methane concentration was used the data from observations at background monitoring stations, as well as numerical calculations performed by GEOS-Chem chemical-transport model, which is widely used in international community for calculating the fields of chemically active and greenhouse gases.

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Bipolar carbon and hydrogen isotope constraints of the Holocene methane budget

10.5194/bg-2018-107 ◽

2018 ◽

Author(s):

Jonas Beck ◽

Michael Bock ◽

Jochen Schmitt ◽

Barbara Seth ◽

Thomas Blunier ◽

...

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Methane Concentration ◽

Methane Emissions ◽

Anthropogenic Influence ◽

Atmospheric Methane ◽

The Holocene ◽

Ch4 Emissions ◽

Methane Budget ◽

Natural Emissions

Abstract. Atmospheric methane concentration shows a well-known decrease over the first half of the Holocene following the northern hemisphere summer insolation before it started to increase again to preindustrial values. There is a debate about what caused this change in the methane concentration trend, in particular, whether an early anthropogenic influence or natural emissions led to the reversal of the atmospheric CH4 concentration. Here, we present new methane concentration and stable hydrogen and carbon isotope data measured on ice core samples from both Greenland and Antarctica over the Holocene. With the help of a two-box model and the full suite of CH4 parameters, the new data allow us to quantify the total methane emissions in the northern and southern hemispheres separately as well as their isotopic signatures, while interpretation of isotopic records of only one hemisphere may lead to erroneous conclusions. For the first half of the Holocene our results indicate a decrease in northern and southern hemisphere CH4 emissions by more than 30 Tg CH4/yr in total accompanied by a drop in the northern carbon isotopic source signature of about −3 ‰. This cannot be explained by a change in the source mix alone, but requires shifts in the isotopic signature of the sources themselves caused by changes in the precursor material for the methane production. In the second half of the Holocene global CH4 emissions increased by about 30 Tg CH4/yr, while preindustrial isotopic emission signatures remained more a less constant. However, our results show that the increase of methane emissions starting in the mid-Holocene took place in the southern hemisphere, while northern hemisphere emissions started to increase only about 2000 years ago. Accordingly, natural emissions in the southern tropics appear to be the main cause of the CH4 increase starting 5000 years ago in contradiction to an early anthropogenic influence on the global methane budget by East Asian land use changes.

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