IMPLICATIONS OF TEMPORAL CHANGE IN URBAN HEAT ISLAND INTENSITY OBSERVED AT BEIJING AND WUHAN STATIONS

[CSPP Note:  There has long been concern over the “adjustments” made to the surface temperature records by Hansen, Jones and Karl.  It is particularly disturbing that surface temperature trends used to drive fear-based public policies are black boxed and not available for independent verification.  If these records are overstated, as suggested by Ren et al, then the climate could slip into a cooling phase and not be reported. Such a fictional world would only benefit political NGOs and global warming grant merchants.]

GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L05711, doi:10.1029/2006GL027927, 2007

 HYPERLINK "javascript:ol('http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml');" http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml

Implications of temporal change in urban heat island intensity observed at

Beijing and Wuhan stations

G. Y. Ren

Laboratory for Climate Studies, National Climate Center, China Meteorological

Administration, Beijing, China

Z. Y. Chu

Laboratory for Climate Studies, National Climate Center, China Meteorological

Administration, Beijing, China

Z. H. Chen

Wuhan Regional Climate Center, China Meteorological Administration, Wuhan, China

Y. Y. Ren

Laboratory for Climate Studies, National Climate Center, China Meteorological

Administration, Beijing, China

Abstract

Temporal change in urbanization-induced warming at two national basic

meteorological stations of China and its contribution to the overall warming are

analyzed. Annual and seasonal mean surface air temperature for time periods of

1961~2000 and 1981~2000 at the two stations of Beijing and Wuhan Cities and

their nearby rural stations all significantly increase. Annual and seasonal

urbanization-induced warming for the two periods at Beijing and Wuhan stations

is also generally significant, with the annual urban warming accounting for

about 65~80% of the overall warming in 1961~2000 and about 40~61% of the overall warming in 1981~2000. This result along with the previous researches indicates a need to pay more attention to the urbanization-induced bias probably existing in the current surface air temperature records of the national basic stations.

Urbanization may have affected the surface air temperature (SAT) records at many

city stations in continents, especially in industrial regions like Europe, North

America and East Asia. However, this issue is still under debate at present. It

is generally held that urban heat island effect is of secondary importance, and

it is unlikely to surpass 0.05°C in the past a hundred years on global average,

a magnitude lower than the optimal estimation of the global average annual mean

SAT change of 0.6°C [Jones et al., 1990; Intergovernmental Panel on Climate

Change, 2001; Peterson, 2003; Li et al., 2004a]. On the other hand, some

researches have shown that the urban heat island effect may play a significant

role in the global and regional SAT trend estimated up to date, which should be

paid more attention to and should be amended [Hansen et al., 2001; Kalnay and

Cai, 2003; Zhou et al., 2004; Zhou and Ren, 2005]. [...] 

In summary, temporal trends of annual and seasonal mean SAT for time periods of

1961~2000 and 1981~2000 at Beijing and Wuhan stations and their nearby rural

stations are all significantly positive, and the annual and seasonal urban

warming for the two periods for Beijing and Wuhan stations is also positive and

significant. The annual urban warming at the city stations can account for about

65~80% of the overall warming in 1961~2000, and about 40~61% of the overall

warming in 1981~2000. The quality control and the in-homogeneity examination and

adjustment for the data of the stations used for the analysis have been made.

Citation: Ren, G. Y., Z. Y. Chu, Z. H. Chen, and Y. Y. Ren (2007), Implications

of temporal change in urban heat island intensity observed at Beijing and Wuhan

stations, Geophys. Res. Lett., 34, L05711, doi:10.1029/2006GL027927.

FULL PAPER at  HYPERLINK "javascript:ol('http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml');" http://www.agu.org/pubs/crossref/2007/2006GL027927.shtml

Copyright 2007 by the American Geophysical Union.