ICOS Science Conference 2022: Day 3, Session 17

2. GOBLEU:
Greenhouse gas Observations of Biospheric and Local Emissions from the Upper sky
- Cities are responsible for more than 70 % of the
global total GHG emissions.
- 30 % of the Japan’s total CO2 emissions are emitted
between Tokyo and Fukuoka area (shaded in red).
- To achieve the net zero goal, the sectoral emissions
and their relative magnitude are expected to change
drastically over the next decade.
Our objectives:
- Monitoring Japan’s subnational ~ local climate
mitigation progress (e.g. emission reduction and sink
enlargement) using high-resolution GHG and AQ
measurements.
- Providing an objective evaluation for reported
inventory emission estimates.
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3. Remote sensing from a commercial airliner
Our concepts:
- NO hardware modification to aircraft*
- Compact instruments on cabin seats
- Observing through cabin window
- Small power consumption with mobile
battery operation
- 3 modules: 450nm, 740nm and 1.6um
bands for NO2, SIF and CO2 with fiber
coupling.
*Limitation of size and wight, the capacity of
battery, electronical magnetic conduction from
instruments have to be passed the certifications.
Suto et al., in prep.
Commercial airliners can make repeatable and
frequent observations over mega-cites with lower
cost than research flights!.
3

4. The first high resolution NO2 observations
from GOBLEU (GB)
- High NO2 were observed over emission hot spots (cities, point sources, and traffic)
- In megacity Nagoya, spatial pattern of NO2 is different from GB and emission inventory.
4
Suto et al., in prep.

5. Observing NO2 as a CO2 emission marker
- GB provides fine spatial structures of NO2 concentration.
- GB clearly indicate the emission from industry while it was not
clear in satellite observation (due to time and spatial resolution).
35.0
34.8
34.6
34.4
34.2
34.0
Lat
[deg]
135.6
135.4
135.2
135.0
134.8
134.6
Lon [deg]
GB 10:45 LT
50 x 10
15
40
30
20
10
0
NO2 [mol/cm^2]
GB: NO2 observation
0.005°x 0.005°grid
Local time 10:45 (UT+9)
TROPOMI: NO2 observation
0.05°x 0.05°grid
Local time 12:30 (UT+9)
35.0
34.8
34.6
34.4
34.2
34.0
Lat.
[deg]
135.6
135.4
135.2
135.0
134.8
134.6
Lon. [deg]
TROP 12:30 LT
20 x 10
15
15
10
5
0
NO2 [mol/cm^2]
Note: observation time of TROPOMI and GB
are different.
35.0
34.8
34.6
34.4
34.2
34.0
Lat.
[deg]
135.6
135.4
135.2
135.0
134.8
134.6
Lon. [deg]
GB LT10:45
10 x 10
15
8
6
4
2
0
NO2 [mol/cm^2]
GB: NO2 observation
0.05°x 0.05°grid
Local time 10:45 (UT+9)
(TROP. grid)
Suto et al., in prep. 5
EDGAR: CO2 inventory
0.1°x 0.1°grid
35.0
34.8
34.6
34.4
34.2
34.0
Lat
[deg]
135.6
135.4
135.2
135.0
134.8
134.6
Lon [deg]
5 x 10
-6
4
3
2
1
0
CO2 emissions [tons/yr]
EDGAR v50 2018 CO2 Inventory

6. NO2 spatial correlation with ground-based
observation
- NO2 spatial correlation between GB and ground-based observation are in good agreement.
- Especially in megacity Nagoya, TROP show less agreement with ground-based NO2 observation.
- The result highlight the significance of the co-located CO2 and NO2.
0.8
0.6
0.4
0.2
0.0
Spatial
correlation
15
14
13
12
11
10
9
Local time (JST)
500
400
300
200
100
0
NOx
emission
[kg/hour]
GB_Osaka
TROP_Osaka
NOx Inventory_Osaka
GBobs_Osaka
0.8
0.6
0.4
0.2
0.0
Spatial
correlation
15
14
13
12
11
10
9
Local time (JST)
500
400
300
200
100
0
NOx
emission
[kg/hour]
GB_Nagoya
TROP_Nagoya
NOx Inventory_Nagoya
GBobs_Nagoya
TROPobs TROPobs
6
Suto et al., in prep.

7. Outlook
- Frequent observations (more than once per month)
with full imaging spectrometer suites.
- SIF observation over forested areas between Tokyo
and Wakkanai/Hokkaido since this Summer.
- Comparison satellite data with GB
Flight route in 2022.
7