Since 1983, the World Meteorological Organization (WMO) has coordinated global in-situ measurement of methane. Quantification of methane emissions still has large uncertainties, mainly because of undersampling over most regions of the globe by surface observation networks. In particular, spatiotemporal variations of mid-upper tropospheric methane in China are not well understood, because of limited in-situ measurements.
Dr. ZHANG Xingying and his group at the National Satellite Meteorological Center of the China Meteorological Administration tackled this problem using satellite observations. Using Atmospheric Infrared Sounder (AIRS) methane data from 2003 to 2008, they revealed spatiotemporal variations of mid-upper tropospheric methane in China.
Their study shows that in the mid troposphere, a center of low CH4 concentration is located over western China, attributable to minimal industrial and agricultural activity. The lowest CH4 mixing ratio in the upper troposphere is over southern China, related to atmospheric transport from the ocean.
A seasonal cycle of methane has been discovered. One peak in summer and the other in winter over eastern, northeastern and northwestern China. Only one peak (in summer) occurs over southern and western China.
Before 2007, CH4 mixing ratio was nearly stable. The average mixing ratio during the last 6 years over major northern hemispheric countries is similar. However, there has been a significant increase in tropospheric CH4 concentrations after 2007 in most northern hemispheric areas, with slightly larger increases over China.
Dr. ZHANG Xingying has stated that the trend of CH4 based on satellite observation is still somewhat uncertain, because of the short, 6-year dataset. More satellite data of higher quality are needed for further trend analysis.
To understand the profile of methane in China and provide data for validation of satellite products, Fourier Transform Infrared Spectroscopy (FTIR) measurements were made at a ground-based hyperspectral remote sensing laboratory at the National Satellite Meteorological Center. A Bruker FTIR instrument (IFS 120 M, made in Ettlingen, Germany) with 0.008 cm-1 spectral resolution, was used for observations. Several years of data have been collected.
Implementation and promotion of this work will publicize methane spatiotemporal variations and their potential sources. In so doing, informed efforts may be mounted to reduce methane emission and resulting global climate change.
The National Satellite Meteorological Center manages satellite climate products in China. Two payloads for greenhouse gas monitoring are in development for the next satellite. One of the payloads is similar to AIRS for mid-upper tropospheric greenhouse gases. The other is for low tropospheric greenhouse gases, and uses a near-infrared (NIR) spectrometer. Meanwhile, more in-situ measurements have been carried out in China for more detailed investigation of greenhouse gases.
Dr. XIONG Xiaozhen, an expert from NOAA, is in charge of AIRS methane product retrieval. He believes that this study is the first to use satellite data for analyzing mid-upper tropospheric methane over China, and represents important step in the study of climate change.
See the article: Xingying Zhang, Wenguang Bai, Peng Zhang, 2011, Study on three-dimensional structure of tropospheric methane over China based on satellite observations, Chinese Science BulletinC56(31): 3321-3327
Zhang Xingying | EurekAlert!
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences