
Near Real-time CO2Emissions Based on Carbon Satellite And Artificial Intelligence A PREPRINT
these methods need extra verification and the estimation frequency is unable to meet the requirements for real-time
carbon emission estimation. In some industrial sectors, continuous emission monitoring systems (CEMS) are being
deployed for accurate and real-time carbon emission estimation Jahnke [1997]. But considering their high cost, it is
impractical to build a comprehensive carbon emission monitoring system based on CEMS.
Recently, carbon satellite monitoring is a new technical means that can directly provide CO
2
column-average dry-air
mole fractions (XCO
2
), which denotes the column-average regional CO
2
concentration in atmosphere. Owing to the
potential of supporting CO
2
emissions estimation, carbon satellite monitoring has been a fast-growing research topic.
Previous studies qualified CO2emissions by building a Gaussian plume model to simulate the CO2flux movement in
the atmosphere Nassar et al. [2017]. In this paper, to estimate carbon emissions from carbon satellite observations at
the individual facility level, we propose a pure data-driven methods based on a novel deep learning algorithm. To the
best of our knowledge, this is the first carbon measurement method based on carbon satellite data and state-of-the-art
artificial intelligence technologies. We anticipate this work to open up new research paradigms in carbon measurement.
Our research is based on the observations of NASA’s Orbiting Carbon Observatory 2 (OCO-2) satellite Crisp et al.
[2017]. OCO-2 makes high spectral resolution measurements of reflected solar radiation at wavelengths in the 0.76, 1.61,
and 2.06
µ
m regions to derive XCO
2
. OCO-2 has limited imaging capabilities, it measures XCO
2
in 8 parallelogram
footprints (each is about 1.29 ×2.25 km2) over a narrow swath (less than 10.3 km).
CO
2
plumes derived from large emission sources may cause local enhancement in the OCO-2 observational near-source
data because of diffusion and flow of gases, separating it from the background XCO
2
. This local enhancement recorded
in satellite data is viewed as reflecting the patterns of CO
2
emissions and subsequent movement. Thus we can utilize
this pattern to estimate the emissions of carbon source. Detecting this enhancement and establishing the map from
near-source satellite data to CO
2
emissions are central to this task. We choose to design a deep neural network suitable
for carbon satellite’s unique data structure based on a Transformer architecture Vaswani et al. [2017]. After well-
training, given a range of carbon satellite data with local enhancement, carbon source location, and some environmental
information, this neural network directly predicts carbon emissions for the location it queried.
However, several challenges make this work not a naive utilization of deep learning on carbon satellite data.
•
First, the OCO-2 has only limited imaging capabilities, and its data is in the form of discrete measurement
locations and the carbon concentrations measured at that location. This presents a challenge to the design of
deep learning methods.
•
Second, the excess XCO
2
generated by large emission sources typically reaches 1% at the best, which is
about 4ppm compared with an instrument noise typically around 0.3–0.6ppm. This non-negligible noise in the
XCO
2
measurement hampers the imaging and detection of emission plumes and the precision of emission
quantification. In the case of severe measurement noise, it is not even possible to confirm whether there is
significant local enhancement with a single measurement. Similar to the case of carbon measurements, it
is also extremely difficult to obtain an accurate wind field situation, which is another important basis for
quantifying the plumes caused by carbon emissions. Usually, we can only obtain average wind speed and
direction data over a large spatial scale and over a long period of time. And this only provides a very limited
clue for estimating the emission plume.
•
Third, data acquisition is also challenged due to space satellites’ unique measurement orbital limitations. Only
on rare occasions do the OCO-2 tracks cross CO
2
plumes downwind of large cities or power plants, limiting
the possibility of quantifying the corresponding CO
2
emissions to a few cases within a year. This also limits
our possibilities for multiple measurements of the same carbon source. By matching the location of known
carbon sources, wind direction, and the location of the satellite detection swath, we are only able to match the
hundreds of available data from millions of OCO-2 records, which also suffer from noise.
•
The last challenge is the complexity of emission source data. In this work, we select real hourly emission
sources from continuous emission monitoring system (CEMS) data for our research. However, not only are the
emissions data recorded by CMES facing missing and inaccurate challenges, but the situation of their emission
sources is sometimes extremely complex. Multiple closely located emission sources may influence each other,
making estimation more difficult.
To solve above problem, this work makes a three-step data retrieval algorithm and a two-step data-driven solution based
on AI. The data retrieval algorithm is designed to find effective satellite data that contains local enhancement and to
match auxiliary information geographically and temporally. We apply three steps to achieve this goals:(1) retrieval
based on carbon sources for extracting satellite data near carbon source; (2) processing of abnormal data for filtering
extremely noisy data; (3) retrieval based on pattern detection for finding effective satellite data with local enhancement.
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