Study of the Urban Heat Island and its Effect on the Planetary Boundary
Layer (PBL) for the El Paso - Juarez Airshed
Abstract
The planetary boundary layer (PBL) is a layer in the lowest part of the
atmosphere where Earth’s surface strongly influences temperature,
moisture, and wind through the turbulent transfer of air mass. It is a
key component of air pollution transport studies. An urban heat island
(UHI) is a metropolitan area which is significantly warmer than its
surrounding rural areas. The El Paso - Juarez Metropolitan area, with a
combined population of ~ 1.972 million (in 2010) and
growing urban infrastructure, can be studied as an UHI surrounded by
rural areas. In this study, we have analyzed the temperature fields for
the lower levels of the troposphere for the El Paso - Juarez
metropolitan area and neighboring rural areas during the day and night
hours both for the summer and winter seasons. The Vaisala Boundary Layer
View Software (BLView) was used to obtain the aerosol mixing layer
height (ML), a proxy for the PBL height, using data from a Vaisala
ceilometer, model CL31. The ceilometer is situated at the University of
Texas at El Paso (UTEP) campus. The BLView analyzes the ceilometer
backscatter profile data and provided the ML structure. In addition, the
Weather Research Forecast Model (WRF) was used to simulate PBL heights
for the El Paso - Juarez Airshed and its surrounding rural areas. The
overall objective of the project is to contribute to a better
understanding of the PBL structure and the effect the UHI has for the El
Paso - Juarez Airshed.