Chinese Urban Air Quality, Spring 2001
            ----------------------------------------

This directory contains an archive of Chinese Urban Air Quality data
and related material collected from internet sources during the TRACE-P
and ACE-Asia period. The data set covers the period from 1 February to 
30 April 2001; additional data and background material is available at 
the web site   "http://www.ess.uci.edu/~oliver/tracep/" including a 
GIF animation of the whole spring period, press clippings, etc.


BACKGROUND

As of July 2000, each city in China has been required to publish an 
Air Pollution Index (API) measured for the urban region each day.
Observations are made of NOx, SO2 and TSP (also CO and O3 for Beijing).
An API is derived for each of these species, based on a scale from 0-500
defined by the State Environmental Protection Agency, and then the
highest of these API values is published, labelled with the name of the
offending species. If all APIs are below 50, then the air is considered 
clean and no species is specified. The API are released late afternoon 
for the current day, and are based on the mean of measurements made over
the previous 24 hours (O3 in Beijing is reported as maximum hourly
concentration).

For Beijing and Shanghai, API are available for each species individually,
and these have been converted to more useful units (ppbv). Officially,
data are provided for PM10 and NO2 rather than TSP and NOx, respectively;
however, there are no standard formulae for converting these API values,
and the same values appear in the 42-city EPA list under the headings
of TSP and NOx. For the purpose of converting to ppbv or ug/m3, these
values are assumed to represent TSP and NOx in the current analysis.
Note also that the Beijing data is not updated regularly, and that
there are therefore a number of 'holes' in the time series.


CONTENTS

 PMCAQ_**.TRP   API data separated into time series for each city, with
                conversion to micrograms/m3 or ppbv where appropriate.

 20010***.pdf   Summary plots for each day in PDF format, showing the 
                API values by location, with meteorological pictures 
                superimposed to provide some context.

 Summ_API.pdf   Summary API time series for coastal cities grouped by 
                region

 Summ_bj.pdf    Summary time series (micrograms/m3 or ppbv) for Beijing
 Summ_sh.pdf    and Shanghai.


NOTES

The summary plots are made by plotting circles at the appropriate location
for each of the 42 cities considered. The radius of each circle is
proportional to the API, and they are coloured by the respective constituent.
These are compared with the noontime Geostationary Meteorological Satellite
(GMS) view of the East Asian region, and with the noontime analyses from 
the Japan Weather Association (JWA). Model forecasts for precipitation
and geopotential height are taken from the WeatherOnline UK web site.


DATA AVAILABILITY

Pollution indices for 42 major cities have been officially published on 
the web and in Chinese newspapers. The meteorological pictures used in the 
summaries have been collected from the Web and are subject to copyright - 
they should be used for reference purposes only.


INDEX OF CITIES

The data sets are labelled as follows; approximate longitude and latitude
are included here for reference.

01  Beijing          116.4  39.9
02  Tianjin          117.2  39.2
03  Shijiazhuang     114.4  38.0
04  Taiyuan          112.5  37.8
05  Hohhot           111.6  40.9
06  Shenyang         123.4  41.8
07  Dalian           121.5  39.0
08  Changchun        125.3  43.9
09  Harbin           126.6  45.7
10  Shanghai         121.5  31.3
11  Nanjing          118.7  32.1
12  Suzhou           120.6  31.4
13  Nantong          120.8  32.0
14  Hangzhou         120.2  30.3
15  Wenzhou          120.6  28.0
16  Hefei            117.3  31.8
17  Fuzhou           119.3  26.1
18  Xiamen           118.1  24.5
19  Nanchang         115.9  28.7
20  Jinan            116.9  36.7
21  Qingdao          120.3  36.2
22  Yantai           121.4  37.5
23  Zhengzhou        113.6  34.7
24  Wuhan            114.3  30.6
25  Changsha         112.9  27.9
26  Guangzhou        113.3  23.2
27  Shenzhen         114.1  22.6
28  Zhuhai           113.6  22.3
29  Shantou          116.7  23.4
30  Zhanjiang        110.3  21.3
31  Nanning          108.4  22.9
32  Haikou           110.4  20.0
33  Chengdu          104.2  30.7
34  Chongqing        106.6  29.6
35  Guiyang          106.7  26.6
36  Kunming          102.7  25.1
37  Lhasa             91.2  29.7
38  Xi'an            108.9  34.3
39  Lanzhou          103.8  36.1
40  Xining           101.8  36.7
41  Yinchuan         106.3  38.5
42  Urumchi           87.6  43.7


                                                Oliver Wild  (25/6/2001)