Needs for Emission Inventory Update in China Environmental

Monitoring

Environmental Satellite Center, the Ministry of Environmental Protection of China

Li Qing

Outline

1. The pollution source investigation in China

2. The importance for getting the emission by Remote Sensing technology

3. Specific needs for pollution inventory by top down method

4. Discussion

5. Conclusion

Pollution Sources are the places, fa

cilities, installations etc, from productio

n, living and other activities or other so

urces which can emit the pollutants or

have adverse effects on environment.

The pollution source investigation is

an important work to know the situatio

n of the country. It is a basic and strat

egical work for environmental protectio

n in China .

The pollution source investigation in China

1. 1985, the first pollution

source investigation, Just

concerning industrial sector

s.

2. 2008,the first national p

ollution source census. Stage summary meeting for national pollution source census

The first national pollution source census in China

includes three parts: 1. All industrial pollution sources, in order to get the following specifications: th

e basic information of pollution sources, the type, concentration ， emission quantity of the pollutants, and the pollution control facilities and their operation conditions .

2 . Agricultural sources, to know the pollutants emitted mainly from scaled breed aquatics and non-point pollution ， including scaled water usage and drainage, usage of chemical fertilizers, pesticides, feed and feed additives; and the conditions of disposing straw and other crop residues ； emission quantity and its regulation of the key pollutants, and also includes the situation of pollution control facilities and their operation status.

3. life sources : sewage, garbage and medical waste

Finally, the database of pollution source inventory will be established according to the technical specifications of the census.

sewagegarbage medical waste

The aim for pollution source census in China

investigate the number, sector and regional distribution of almost all kinds of pollution sources

find out the generation, emission and disposal of the key pollutants

establish and improve the database of the pollution source inventory

in order to provide evidence for establishing policy and plans for socio-economic development and environmental protection, especially important for making pollution control policy for environmental protection.

2. The importance for getting the air pollution emission by Remote Sensing Technology

The above source investigation introduced is a routine way, often called as down-top met

hod.

As to investigate the pollution source information: energy data, emission factor

s, socio-economic information. To energy data, emissions from fuel combustio

n sources in one of the main part ,but it includes many sectors and fuel types. I

t is difficult to quantify the uncertainties of some factors such as emission facto

rs and activity levels ， so sometimes judgment from expert is often used to a

ssign estimates uncertainties to emissions.

Questions: Is it reliable of the energy data and socio-economic

information? Is it applicable of the emission factor? Is it objective of the activity level? ………..??

These factors still limit to ensure the quality of data. The most of the aspects are difficult to be got comprehensively and accurately by traditional down-top way.

Besides, despite the importance of understanding the situation of annual, seasonal or even daily variations of air quality, it is very hard to do the time series of emissions work.

In China, national pollution source census concerning a

wide range and many departments. It is a very tough task.

It is time-consuming, and needs high technology to

support, also the result just represents the situation in a

fixed time. It is hard to satisfy the need of China

Environmental monitoring, management, and supervision.

Remote Sensing method can contribute to emission inventory

As we know, Emission inventory of pollution source is an

integrated list of various pollutants emitted by all kinds of

air pollution source in a specific geographical area at a

certain time interval. A complete list includes: background

information, description of geographical area, a detailed

description of various types of pollution sources, and the

estimation quantity for different types of pollutants and the

relative estimation method.

Now it is possible to improve the traditional investigation way by top-down methodThe space-based Global Observing System

Satellite Sensors for the Observation of air :

TOMS: （ Nimbers7(1978-1993) ;Meteor-3(1991-1994) ； Earth Probe (1996-2005) (O3, SO2 ）

GOME (1995-2003): O3, SO2,N2O, … IMG (1996-1997): O3,CO,CH4,HNO3 MOPITT(2000-): CO, CH4(?) SCHIMACHY(2002-):O3,SO2,N2O,CH4,CO2 AIRS (2002-): O3, CO,CH4, CO2,N2O,HNO3 MIPAS(2002-) ACE-FTS(2003-): O3,N2O,CO,CH4,HNO3 MLS,OMI,TES (AURA, 2004-) GOME-2 (2006-, METOP) IASI (2006-, METOP) GOSAT-FTS(2009.1.23)CO2 、 CH4

Now it is possible to improve the traditional investigation way by top-down method

At present, satellite remote sensing technology has achieved some results in monitoring pollutants. It can also estimate the emissions of some pollutants through further work.

Yearly averagesfor 2004to 2008

Spatial and temporal distribution of some pollutants

SO2

Comparison of SO2 concentration in DU from satellite data with the predictions of

atmospheric model GEOS-Chem for January and July of averaged over 2004-2009.

(a) Jan

(b) Jul

Tropospheric SO2 vertical columns in DU averaged during 2004 - 2008 over China

(1) east of China; (2) Sichuan basin; (3) Pearl River Delta region; (4) west of China

Regional NO2 of 19 November 2009 Total column (left)Tropospheric column (right)

NO2 in October 2009

NO2

Difference of Methane (Sept-May)from AIRS and Model

Nov. 30,2008 : Global CO monitoring by MOPITT（ http://www.acd.ucar.edu/mopitt/MOPITT/data/plots4/mapsv4.html

） 2005 : Global CH4 monitoring by SCIMACHY

（ http://www.acd.ucar.edu/mopitt/MOPITT/data/plots4/mapsv4.html）

Oct.12-13 : Global O3 monitoring by OMI

HJ-1 is composed of three satellites. HJ-1A,HJ-1B,HJ-1C. HJ-1A,HJ-1B were launched in Sep. 2008.

China Environmental Satellite One(HJ-1)China Environmental Satellite One(HJ-1)

HJ-1A ： HSI ， CCD HJ-1B ： CCD ， IRS HJ-1C ： Radar

HJ-1 constellation

HJ-System

HJ-1 and its Atmospheric Application

• AOD retrieval - PM quality concentration monitoring• Fog and haze monitoring• Straw burning monitoring• Dust monitoring

From the above achieved results, we can see there have

some examples in some countries to monitor the pollution

situation. But in China, for lacking of regular RS data and

technology measures, the RS way is still not widely

adopted in daily environmental monitoring.

What’s the need ? 1. What’s the distribution （ spatial and temporal) conditions of the pollutants?

PMl0, PM2.5, NOX, S02 ， CO ， BC 、OC

In China now, among them PM,SO2 ， NO2 ,CO2 , CH4 are the important pollutants needed to be monitored and controlled.

Density (concentration) , emission quantity

Natural or anthropogenic? Volcanic eruption, Biomass burning , industry emission , soil

emission, transportation emission, aircraft, lightning

2. Where are the pollutants come from?

CH4 Emission may caused by Rice Fields, Black Soil ….

CO2 may caused by industrial emission, Black Soil ….

CO may caused by car emission, biomass burning ….      

Do they come from somePollution events ?

Example: Biomass burning, as a global problem, is becoming the focus

by the public. As we know, Straw burning is an important part of it. Straw

burning will produce a large amount of harmful gases.

What’s ration of the pollutants is caused by the pollution events?

Straw Uti l i zaton i n Chi na

50%

30%

20% f ert i l i zer andani mal f eed

i ndust ry rawmater i al s and f uel

not eff ect i vel yused

CO2CONOx……

C6H6 PAHsPM…

…

2. Where are the pollutants come from?

3. What’s the amount of emission of the pollutants?

For those pollutants whose lifetime is short, such as SO2 , NO2 , CH4 etc. It

may be reasonable to discuss the relationship between the emission inven

tory and satellite vertical column densities (VCDs).

SO2, is one of the main pollutants in China. Its emission control is one

of the two total quantity control indexes in China Environment protection po

licy.

Because SO2 emissions in China depended strongly on the sulfur conten

t of coal, China have adopted a series measures to desulfurize the sulfur co

ntent of coal in recent years. But we often need to know if these desulfurize

equipments have been normally operated and have deduced the emission a

s expected.

So we need satellite to monitor its control effects.

As to NO2 , some researches has reported the

rapid emission increases over China based on Satellite

instrument GOME and SCIMARCHY monitoring result.

High emission can lead to high pollutant columns. But

how to get the exact emission magnitude through the

satellite-derived column still need to be studied.

• GOME/ERS-2(1995-2003) :320×40 km2 standard mode)

• GOME-2/Metop A(2006-): 40×80 km2

• SCIAMACHY/Envisat (2002-): 60×30 km2

• OMI/Aura(2004-): 24×13 km2

40 km

320 km

30 km

60 km

40 km

80 km

13 km24 km

GOME

GOME2

SCIA

OMI

4. Spatial and temporal needs for pollution inventory by top- down way

High spatial and temporal resolution would be need

For environmental monitoring spatial resolution demand:

Horizontal spatial resolution. For environmental monitoring in city, it needs a higher horizontal spatial resolution of 0.01◦×0.01◦ . For district and country level, 0.1◦×0.1◦ spatial resolution is needed.

Vertical spatial resolution: Total Column - troposphere -near surface

Temporal demand: To environmental monitoring, daily pollutants density and distribution, emission quantity is needed.

5-1. Need to resolve the uncertainties of the emission estimates by top down way

Although satellite results can retrieve the emission, there exist some uncertainties:

The retrieval result is very sensitive to several factors including cloud screening and other chemical/meteorological conditions. For an example, a rough estimate of the GOME NO2 errors is an additive error of 0.5–1.0×1015 moleculecm−2 and a relative error of 40–60% over polluted areas. In addition, the uncertainty for the annual average is approximately 15% (e.g. Richter et al.,2005).

5. Technical Need

5-2. Need to establish a set of technical criteria

There are several different satellite instruments （ with different bands, observing way ,spatial resolution, temporal resolution )may be used as tool to do the emission work, the different methods may lead to the different result.

tropospheric column retrieval : it need to remove the stratospheric part by CTM.

VCD retrieval: air mass factor is needed, different RTM (radiative transfer model)

emission estimation: CTM. Different inventory may be used was as input to some model to simulate some parameters in the estimation.

Priori information : surface spectral reflectance, surface altitude, aerosol loading, cloud screening etc.

Satellite remote sensing

Airplane cruises measurement

Tools for measurementVertical measurement by tower

Insitu measurement

For the different methods may lead to difference in result. So Validation work should be done.

From the view of technology, an uniform technology criteria wo

uld be needed. A series of technology criteria may concern data

preprocessing 、 column inverse method based on satellite, valid

ation, etc. All these can contribute to get a comparable, relatively

objective and scientific results.

In China, from the view of atmospheric monitoring application

we need to improve:

Satellite and the instruments technology

Satellite Remote Sensing Data

Monitoring methods and the results

Discussion

Improve the Satellite monitoring result

the satellite VCDs may be combined with in situ observation VCDs - to improve the algorithm suitable for different region

Establishing the good relationship between the VCDs and the emission data

For some species such as NOx ， SO2 ,etc. with short life in the atmosphere, it is very useful to find a relationship between emission data and the RS result. There still exits some uncertainty in this field, the accurate estimates is urgently needed in environmental monitoring and management.

Establishing the relationship between the Mode and Satellite results

In order to reduce the uncertainty in the estimation of emissions .

Conclusion

Tough some results in the pollution inventories based on

top down way have been achieved, there still exits many u

ncertainty factors for us to resolve. Hope researches and o

rganizations from diversity fields can join and cooperate tog

ether to overcome the difficulties, for the application develo

pment of the Satellite RS technology ,for the environment s

afety of the whole world.