TITLE:
Addressing the Challenge of Interpreting Microclimatic Weather Data Collected from Urban Sites
AUTHORS:
L. Bourikas, T. Shen, P. A. B. James, D. H. C. Chow, M. F. Jentsch, J. Darkwa, A. S. Bahaj
KEYWORDS:
Urban Microclimate Observations; Installation Challenges; Weather Data Time Series Analysis; Missing Data
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.1 No.5,
November
26,
2013
ABSTRACT:
This paper presents some installation and data analysis issues from an
ongoing urban air temperature and humidity measurement campaign in Hangzhou and Ningbo,
China. The
location of the measurement sites, the positioning of the sensors and the harsh
conditions in an urban environment can result in missing values and
observations that are unrepresentative of the local urban microclimate. Missing
data and erroneous values in micro-scale weather time series can produce bias
in the data analysis, false correlations and wrong conclusions when deriving
the specific local weather patterns. A methodology is presented for the
identification of values that could be false and for determining whether these
are “noise”. Seven statistical methods were evaluated in their performance for
replacing missing and erroneous values in urban weather time series. The two
methods that proposed replacement with the mean values from sensors in
locations with a Sky View Factor similar to that of the target sensor and the
sensors closest to the target’s location performed well for all Day-Night and
Cold-Warm days scenarios. However, during night time in warm weather the replacement
with the mean values for air temperature of the nearest locations outperformed
all other methods. The results give some initial evidence of the distinctive
urban microclimate development in time and space under different regional
weather forcings.