Our presentation.

Several GOSAT project members made presentations at the 2013 European Geophysical Union assembly in Vienna. My presentation was made at the section named “Remote-Sensing of Atmospheric Carbon Dioxide and Methane” and outlined the work on reconstructing the spatial distribution of the surface methane emissions around the world using observations by GOSAT satellite and measurements on the ground. We used an atmospheric tracer transport model to simulate the transport and atmospheric oxidation of methane and to optimize surface methane emission distributions so that they fit best to the data made available by ground based observation community via World data center for greenhouse gases in Tokyo, and methane column average concentration retrieved and provided by NIES GOSAT project as Level 2 product. The flux estimates and global distribution of methane concentrations in the atmosphere are prepared for a distribution as the GOSAT Level 4 research product. We used interannually varying CH₄ emissions by the GFED (Global Fire Emissions Database) and VISIT ecosystem model and the EDGAR database of the anthropogenic CH₄ emissions. The inverse problem of optimizing the CH₄ emissions separately for 42 land regions and each month was solved with a Kalman smoother. The inverse model estimate using ground-based data only estimated larger uncertainty of fluxes over tropical regions, South America and Temperate Asia where the data are sparse. Adding large number of the GOSAT data to the inversion leads to decreasing the flux uncertainty in Temperate Asia, northern South America, Tropical Asia, Europe and other regions. The methane emission estimates are available from GOSAT data distribution system as GOSAT research product to researchers participating in projects adopted in GOSAT Research Announcement framework. Questions and discussions after the presentation showed that there is an interest in looking into our flux estimates and comparing those with projections of large emissions from permafrost soils or methane seepage from arctic sea floor. However, GOSAT has only limited coverage in mid summer season over arctic, and our estimates require further refinements by improving both the accuracy of the satellite retrieval algorithm and inverse modeling procedures.

Notable events.

In 2013 EGU medals are awarded to our colleagues for outstanding contribution to the development of the carbon cycle research on land (flux tower observations) and from space (SCHIAMACHY).

The 2013 V. I. Vernadsky Medal is awarded to our colleague Han Dolman (Albertus J. Dolman) who is well known for leadership in flux tower observations of the CO₂ and other trace gases fluxes. Albertus J. Dolman is the Professor of Ecohydrology at the Vrije Universiteit of Amsterdam. From 1989 and until 1992 he worked at the Institute of Hydrology, UK. He published a paper on modeling rainfall interception in climate models and developed the land-surface scheme that is the basis of the Hadley Centre model. From 1993 to 2001 he was senior researcher in Alterra-Wageningen, The Netherlands, and worked on the use of the eddy-covariance technique for continuous measurements of water and carbon fluxes. He made large contribution to establishment of the EuroFlux project. Also, Han Dolman took part in international field experiments, including the Large Scale Biosphere-Atmosphere Experiment in Amazonia, and he led the validation effort of the Global Soil Wetness Project. Dolman was elected chair of the FP6 CarboEurope Cluster. He is currently taking a leading role in CarboEurope-GHG and Integrated Carbon Observation System infrastructures and is coordinating the European programme to harmonise global carbon observations. He and his colleagues like Prof. J. van Huissteden have long term interest in CO₂ flux observation in larch forest of Sakha in Central/East Siberia. (see also: http://www.egu.eu/awards-medals/vladimir-ivanovich-vernadsky/2013/albertus-j-dolman)

John Burrows of the Univ of Bremen, Germany, received the 2013 Vilhelm Bjerknes Medal in recognition of his outstanding scientific contributions and leadership in atmospheric photochemistry, spectroscopy and kinetics, and in satellite remote sensing and in situ measurement of atmospheric composition. John Burrows developed a team in the Institute of Remote Sensing/Environmental Physics at the University of Bremen in Germany that made an outstanding impact, especially in remote sensing of the atmospheric greenhouse gases, both from space and on the ground. He inspired a generation of European scientists in his field along with making important contributions to knowledge of atmospheric chemistry and to the implementation and application of space-based measurement of atmospheric composition. His contributions to the space-based measurements have covered all stages of the program, from initial proposals and designs though obtaining support to retrieval of information on species and interpretation of the data to provide new view of key tropospheric and stratospheric processes. Most noteworthy was his pioneering work on the Global Ozone Monitoring Experiment (GOME) on ESA’s Remote Sensing (ERS-2) satellite, an instrument that has provided invaluable information on many atmospheric constituents in addition to ozone. Importantly, John Burrows proposed the development of the SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) instrument on ESA’s subsequent Envisat mission, which provided data for some ten years until April 2012. Strong science community was developed around a problem of SCIAMACHY observations of methane and carbon dioxide, and is actively contributing now to the analysis of the GOSAT observations. (more details at http://www.egu.eu/awards-medals/vilhelm-bjerknes/2013/john-burrows)

Topic of interest.

Interesting topic came to my attention for the first time at EGU 2013. After Fukushima nuclear power plant accident in 2011 many people in Japan and around the world got interested in observation data on background radioactivity, originating both from soil/rocks and from space. There are some innovative uses of the radioactivity measurements that help solve environmental and climate system problems too. A COSMOS project led by Marek G. Zreda of the University of Arizona presented recent results of soil moisture observations in large scale using the measurements of the low-energy cosmic-ray neutrons above the ground. The background: Soil water is important for weather, climate, ecosystem, and water cycle. A serious difficulty in soil moisture measurements is the mismatch between limited point measurements and remote sensing estimates over large areas (10–50 km) with vegetation cover. A method: The proposed technique involves measuring low-energy cosmic-ray neutrons above the ground, whose intensity is inversely correlated with soil water content and with water in any form above ground level. The instrument, called a “cosmic-ray moisture probe,” is built on existing technologies.

The proposal targeted measuring soil moisture content (and snow/vegetation water) in a network of 500 cosmic ray water probes installed across the USA. (Current site map is at http://cosmos.hwr.arizona.edu/Probes/probemap.php). The data collected on each site include: neutron counts in two energy bands (fast, > 1 keV, and thermal, < 0.5 eV), soil water content, snow pack water equivalent (and possibly also vegetation water equivalent), temperature, pressure and relative humidity. Reported results show very good match with in-situ data. The continuous data streams from the continental-scale network is interesting for broad community including: hydrometeorology, land-atmosphere interactions, surface-water and groundwater modeling, agricultural science, understanding and predicting the relationship between soil moisture and crop yield, ecological research focused on the impact of soil water and frozen precipitation on ecological status and evolution, remote sensing for soil moisture calibration and validation.

日本語訳