Joint Submission to the first Global Stocktake:Real-time anthropogenic emission observations from Japanesepassenger aircrafts in support of the monitoring of the climate
mitigation progress
The Japan Aerospace Exploration Agency (JAXA), ANA HOLDINGS INC.(ANAHD), and theInstitute for the Global Environmental Strategies (IGES) are pleased to submit an input to the Global
Stocktake of the Paris Agreement in response to the mandate of Decision 19/CMA.1, paragraph 19,
36 and 37. This submission provides inputs to a cross cutting guiding question 30 1:
Summary•

Real-time observation of local emissions of CO2 can inform local mitigation actors of theprogress of their mitigation actions and can assist them to enhance the effects andambition of those actions in a timely manner. This is complementary to the informationof CO2 inventories, which are estimates of CO2 emissions and removals only periodically,e.g., annually. In addition, visualizing the observation results can help a wide range ofstakeholders (e.g., citizens) intuitively understand the trends of emissions from the localcommunity. Therefore, it can motivate them to drive their efforts to mitigate climatechange.

•JAXA has developed a remote sensing technique that can be operated on a commercial
passenger aircraft, and JAXA and ANAHD. have started a new project called theGreenhouse gas Observations of Biospheric and Local Emissions from the Upper sky(GOBLEU). The GOBLEU instrument collects CO2, nitrogen dioxide (NO2) and SolarInduced Fluorescence (SIF) data. NO2 is one of major air pollutants co-emitted with CO2
via fossil fuel combustion. NO2 data should enables us to depict spatial patterns ofanthropogenic CO2 emissions over major populated and industrialized areas and attributethe emissions to specific sources, such as industries and traffic.

•The GOBLEU project has completed several test flights and collected NO2 data overmajor populated and industrialized areas. The NO2 data showed timely snapshots of NO2
spatial distributions, suggesting the utility of NO2 data as a proxy for anthropogenic CO2emissions that should enhance emission estimations and attribution ability.

•1The GOBLEU instrument can be operated in almost any passenger aircraft without any

What additional information is needed to enhance ambition, both of actions to take and support needed to achieve the long-termgoals of the Paris Agreement, including by enhancing international cooperation for climate action?

1modifications. Compared to other observation techniques, such as the ground-based
monitoring system, the GOBLEU operation requires less technical skill and it isinexpensive. JAXA is willing to promote the observation technique by expanding theobservation coverage and partnership to other countries through enhancing international
cooperation under the Paris Agreement.

Figure 1. The first GOBLEU flight collected NO2 data as emission proxy for CO2 emissions inOctober 2020. NOx inventory estimates 2 are superimposed on the observed NO2 map for indicating
local transportation source areas (purple dots).

2Formulation Committee for PM2.5 Emission Inventory and Source Profile, “PM2.5 Emission Inventory and Source Profile”, 2019,

600 pp. 380. (in Japanese)2

Table 1. A summary of GOBLEU observation
Items

GOBLEU contributions

Emissions and removals covered

Subnational ~ city

Indicator for CO2 emissions andNitrogen Dioxide (NO2) for emissions (anthropogenic); Solarremovals

inducedfluorescence(SIF)

foremissions/removals(anthropogenic/natural)
PeriodNov. 2020 (demonstration)-

Operational flight routeTokyo-Fukuoka, Tokyo-Wakkanai/Hokkaido

Spatial resolution

sub-km Instantaneous ground field of view (IGFOV)

Observation frequency*

Every 0.5 sec

1. Methodology
The Japan Aerospace Exploration Agency (JAXA) and the ANA HOLDINGS INC.(ANAHD)
launched a new project called the Greenhouse gas Observations of Biospheric and Local Emissions
from the Upper sky (GOBLEU), which conducts airborne remote sensing from an ANA passenger
aircraft and collects CO2, NO2, and SIF data to contribute to the climate mitigation monitoring.
One of the challenges in anthropogenic CO2 emission estimation from atmospheric data isdisentangling anthropogenic and natural CO2 emissions. NO2 is often co-emitted with CO2 in fossil
combustion. NO2 can serve as a proxy for fossil fuel CO2 emissions and improve our ability to detectand estimate anthropogenic CO2 emissions in the presence of other CO2 contributions. SIF can serveas an indicator of CO2 removals due to photosynthetic activities by plants.
GOBLEU prototypes multi-species observations and provides direct technical and scientificimplications to the proposed use of CO2, NO2, and SIF data to improve CO2 emission estimation.
JAXA developed an imaging spectrometer as small as carry-on luggage to collect high spatial
resolution 3 spectra of NO2 (420-490 nm), CO2 (1560-1640 nm), and SIF (670-780 nm). SIF should
indicate the plant production level (carbon removals) of the terrestrial biosphere (e.g., forests and othervegetated areas) with a moderated spectral resolution during domestic passenger flights.
Three modules are coupled with optical fibers to relay the solar light reflected the Earth’s surface,packaged in two pieces of luggage and occupying two passenger seats. The GOBLEU instrument areeasily mounted on a passenger seat without modifications. The “passenger” instrument can complete
all the inspections required to be on board before gate arrival. The instrument images are shown inFig. 2.

3~100 m along track spatial resolution and 10 times higher spatial resolution than the start of art satellite remote sensing

32. Results
In October 2020, we conducted the first high-resolution multi-species (CO2 and NO2) observationsfrom Japanese passenger aircraft on one of ANAs domestic flight routes (Tokyo-Fukuoka). Theobservational area from Tokyo to Fukuoka city generates approximately 30% of Japan’s total CO2emissions. The two-hour flight allowed us to collect data ranging from 130° E to 140° E in longitude
and 33.5° N to 36° N in latitude (also in about 900 km). The data were collected every 0.5 s (nominal)and created up to 5 million data points during the single flight. The observed NO2 spatial distribution
is presented in Fig. 1. with the NOx emission inventory map. Comparing our data with the emission
inventory map, the obtained data depicted spatial patterns of NO2 concentrations over the cities andindustrial areas, which highly correlated with emission sources.
Figure. 3 presents a comparison between the satellite observations of NO2 and GOBLEU over theOsaka megacity. The spatial resolution sizes of the state-of-the-art satellite observation, whichachieved by TROPOMI, was 7 km x 7 km for each observation. As shown in Fig. 3, GOBLEU data
has finer spatial resolution than TROPOMI observations; GOBLEU data can indicate the NO2enhanced region. Especially, GOBLEU can detect transportation emissions along the road, whilecurrent satellite observations are challenging.
After the COVID-19 pandemic, the observation flights will be conducted on other routes like TokyoWakkanai/Hokkaido. Future GOBLEU flights also plan to collect SIF data. The TokyoWakkanai/Hokkaido flight route should be ideal for collecting SIF data over Japan’s densely forested
northeast area.

4

Figure 2. The GOBLEU remote sensing equipment onboard an ANA passenger aircraft.

Figure 3. Emission proxy NO2 data over the Osaka megacity collected by ESA’s TROPOMI satellite(left) and GOBLEU (right). Note that two observations were not made at the same time. The color
scales for the two plots are different.

53. Contact Persons
Hiroshi Suto, Japan Aerospace Exploration Agency, suto.hiroshi@jaxa.jp
Ayako Matsumoto, ANA HOLDINGS INC., a.matsumoto@anahd.co.jp
Akibi Tsukui, Institute for Global Environmental Strategies, tsukui@iges.or.jp

4. Reference
Suto, H., Kuze, A., Oda, T., Kataoka, F., Matsumoto, A., Mori, S., Hoshino, C., Kosaki, S., Shiomi,
K., Nakamura, Y., Miyashita, Y., Tsubakihara, Y., The Greenhouse gas Observations ofBiospheric and Local Emissions from the Upper sky (GOBLEU): Multi-species (CO2, NO2 andSIF) observations from Japanese passenger aircraft in support of the monitoring of Japan’sclimate mitigation progress, AGU fall meeting. 2022.

6