TY - JOUR
T1 - Loss of a lake system in a megacity
T2 - The impact of urban expansion on seasonal meteorology in Mexico City
AU - Benson-Lira, V.
AU - Georgescu, Matei
AU - Kaplan, S.
AU - Vivoni, Enrique
N1 - Funding Information:
This work was funded by NSF grants CNH-1414052 and EAR-1204774 and NSF Sustainable Research Network grant CBET-1444758. We thank Hallie Eakin, Marisa Mazari, and Luis Bojorquez for providing motivations regarding land cover changes in Mexico City. We appreciate the constructive comments and suggestions of two anonymous reviewers. Model simulation output data are available on request from M. Georgescu (Matei.Georgescu@asu.edu).
Publisher Copyright:
© 2016. American Geophysical Union. All Rights Reserved.
PY - 2016
Y1 - 2016
N2 - The Mexico City Metropolitan Area (MCMA) has undergone significant urban expansion in a closed basin that once supported a large lacustrine system. While urbanization has been mentioned as a factor in observed meteorological trends, a systematic study of the effects of land use-land cover change (LULCC) on seasonal meteorology is lacking. In this study, we utilize theWeather Research and Forecasting (WRF) systemto determine the spatiotemporal changes in near-surface air temperature, precipitation, and boundary layer conditions induced by the modern-day urban landscape relative to presettlement conditions. We capture the MCMA extent through an improved Landsat-based multicategory urban classification and therefore account for intraurban spatial heterogeneity and further conduct additional experiments to examine the sensitivity to anthropogenic heating within WRF. We find that accounting for these factors produced the best simulations of thermal conditions, with RMSE values less than 1.5°C at all measurement stations, and an improved diurnal cycle of air temperature and precipitation.We then assessed the impacts of LULCC in the MCMA, finding that thermal changes were largest during daytime hours, with temperature increasing, on average, by more than 4°C. Furthermore, we utilize these simulations to mechanistically link the built environment-induced increase in air temperature to simulated increases in rainfall during the evening hours. To our knowledge, this study provides the first dynamical and thermodynamical evidence to support the rainfall enhancements documented through observations in the MCMA and link it quantitatively to the warming effects associated with urbanization. These results have important implications for understanding the meteorological conditions leading to widespread urban flooding in the MCMA.
AB - The Mexico City Metropolitan Area (MCMA) has undergone significant urban expansion in a closed basin that once supported a large lacustrine system. While urbanization has been mentioned as a factor in observed meteorological trends, a systematic study of the effects of land use-land cover change (LULCC) on seasonal meteorology is lacking. In this study, we utilize theWeather Research and Forecasting (WRF) systemto determine the spatiotemporal changes in near-surface air temperature, precipitation, and boundary layer conditions induced by the modern-day urban landscape relative to presettlement conditions. We capture the MCMA extent through an improved Landsat-based multicategory urban classification and therefore account for intraurban spatial heterogeneity and further conduct additional experiments to examine the sensitivity to anthropogenic heating within WRF. We find that accounting for these factors produced the best simulations of thermal conditions, with RMSE values less than 1.5°C at all measurement stations, and an improved diurnal cycle of air temperature and precipitation.We then assessed the impacts of LULCC in the MCMA, finding that thermal changes were largest during daytime hours, with temperature increasing, on average, by more than 4°C. Furthermore, we utilize these simulations to mechanistically link the built environment-induced increase in air temperature to simulated increases in rainfall during the evening hours. To our knowledge, this study provides the first dynamical and thermodynamical evidence to support the rainfall enhancements documented through observations in the MCMA and link it quantitatively to the warming effects associated with urbanization. These results have important implications for understanding the meteorological conditions leading to widespread urban flooding in the MCMA.
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U2 - 10.1002/2015JD024102
DO - 10.1002/2015JD024102
M3 - Article
AN - SCOPUS:84962791757
SN - 0148-0227
VL - 121
SP - 3079
EP - 3099
JO - Journal of geophysical research
JF - Journal of geophysical research
IS - 7
ER -