担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.11203/jar.37.57

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1057/s41599-021-00994-5

Scopus

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature.com  

During the dry period of August–October 2015, a C-band Doppler weather radar of the BMKG station in a fire-prone peatland area, Palangka Raya, detected echoes with reflectivity values between − 19 and + 34 dBZ at a height below 2–3 km and a slant range of 100 km. The MERRA-2/NASA atmospheric reanalysis database is used to obtain the vertical profiles of refractive index and equivalent potential temperature of the air. The temporal variation of the radar image is due to the tropical diurnal cycle of planetary boundary layer formation, which is consistent with the results of the database analysis. The echo images are discussed in terms of Bragg scattering of microwaves at the top of the planetary boundary layer. Weather radar monitoring of the fire smoke layer-top images has a potential feasibility to support real-time management of peatland fires.

DOI： 10.1038/s41598-020-079486-6

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

The metropolitan area of Tokyo, the capital of Japan, emits a large amount of carbon dioxide (CO2), an anthropogenic greenhouse gas. We measured the day-time column-averaged dry-air molar mixing ratios of atmospheric CO2, XCO2, in the central area of Tokyo during September 2014 – August 2016 using a desktop optical spectrum analyzer. The observed seasonal cycle is compared with the seasonal cycle that is observed at the Total Carbon Column Observing Network (TCCON) site in Tsukuba, which is located 60 km to the northeastern direction of Tokyo. The differences in XCO2 between the two sites are high (∼5 ppm) during December – February and low (∼0.5 ppm) during June – September. The characteristic variations of XCO2 in Tokyo are interpreted in terms of local emission sources and surface meteorological data, by referring to the variations in the concentrations of surface CO2. The sharp peaks in XCO2 at both the Tokyo and Tsukuba sites in July are interpreted in terms of local air retention in the areas, as indicated by the aircraft profiles and wind-flow forward trajectory calculations. Finally, we compare the ground-based column measurements with the top-down satellite column observations.

DOI： 10.1016/j.aeaoa.2019.100022

Scopus

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Publishing Group  

Tropical peatlands in Indonesia have been disturbed over decades and are a source of carbon dioxide
(CO2) into the atmosphere by peat respiration and peatland fire. With a portable solar spectrometer,
we have performed measurements of column-averaged CO2 dry-air molar mixing ratios, XCO2, in
Palangka Raya, Indonesia, and quantify the emission dynamics of the peatland with use of the data for
weather, fire hotspot, ground water table, local airport operation visibility and weather radar images.
Total emission of CO2 from surface and underground peat fires as well as from peatland ecosystem is
evaluated by day-to-day variability of XCO2. We found that the peatland fire and the net ecosystem CO2
exchange contributed with the same order of magnitude to the CO2 emission during the non-El Niño
Southern Oscillation year of July 2014-August 2015.

DOI： 10.1038/s41598-018-26477-3

Scopus

総ページ数：602   担当ページ：pp.385-399   記述言語：英語

To reduce the effect of fire-induced peatland disruption on the global carbon balance, monitoring atmospheric carbon dioxide (CO2) concentrations in fire-prone peatlands is essential. In this study, we measured the column-averaged atmospheric mixing ratios, XCO2, using a portable instrument in the tropical peatlands of Central Kalimantan, Indonesia. Combining the measured increments above the background level and the estimated increments from airport visibility records, the raw mean increment, <ΔXCO2>, was 7.8 ppm during the fire season from September to November 2014. Droughts in peatlands lower the groundwater table and induce changes in the microbial communities of the aerobic soil zone to emit CO2 into the atmosphere. During the peat-respiration periods, July–August 2014 and April–May 2015, <ΔXCO2> was 4.8 ppm. CO2 emission from the ground peat soil was measured using the nocturnal temperature-inversion trap method.

記述言語：英語 著書種別：調査報告書

開催年月日： 2021年8月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：オンライン開催  

開催年月日： 2024年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：幕張メッセ、千葉、日本   国名：日本国  

開催年月日： 2023年11月

記述言語：日本語   会議種別：ポスター発表  

開催地：チトセピアホール, 長崎   国名：日本国  

開催年月日： 2023年11月

記述言語：日本語   会議種別：ポスター発表  

開催地：チトセピアホール, 長崎   国名：日本国  

開催年月日： 2023年11月

記述言語：日本語   会議種別：ポスター発表  

開催地：チトセピアホール, 長崎   国名：日本国