Observation of Fast Tropospheric Dynamics and Impacts on Humidity and Air Pollution During a Heatwave Event in New York City, as Observed by Lidars, Other Profilers and Surface Measurements

Fred Moshary,Adrian Diaz Fortich,Prathap Ramamurhty,Barry Gross,Mark Arend,Yonghua Wu,D Liu,Y Wu,B Gross,Y Wang,F Moshary

doi:10.1051/epjconf/202023703018

Abstract

Exposure to heatwaves in densely populated urban areas are of major health concern. Interaction of heatwaves with urban areas are complex; not only driven by mesoscale meteorology, but also by the topology and thermal properties of urban surfaces, as well as anthropogenic thermal and pollution loadings. The impact of heatwaves on population in coastal urban areas such as New York City depend on interplay of these factors as well as the effects of sea/land breeze. These mechanisms can lead to rapid changes in pollution levels and heat index during the day. High time resolution synergistic observations with surface and profiling measurements are needed to capture and understand these dynamics. We report on fast tropospheric dynamics during a heatwave in New York City in summer 2018, resulting in a transient event during which dramatic reduction of pollutants and humidity in the tropospheric column is observed by lidars and other synergistic measurements.

Highlights

The United Stated National Weather Service defines heatwaves as three consecutive days with temperature highs above 90 F (32 C)
Air conditioning is used to alleviate the impact of heatwaves in private and public spaces, which can create further adverse effects in densely populated urban areas by increasing the heat load on the urban atmosphere [3]
The combination of increased emissions together with ample heat and sunshine leads to efficient photochemical production of pollutants such as ozone and secondary aerosols (PM2.5), resulting in pollution exposure at levels exceeding the National Ambient Air Quality Standards (NAAQS) and posing additional health concerns for urban and downwind communities

Summary

INTRODUCTION

The United Stated National Weather Service defines heatwaves as three consecutive days with temperature highs above 90 F (32 C). As a consequence of climate change, the frequency and intensity of heatwaves are expected to increase, representing a major threat to populations This is especially exacerbated in urban areas, where surface roughness (urban topology), and thermal properties of surfaces (e.g. surface thermal potential and impervious surfaces) can lead to further elevated temperatures due to the Urban Heat Island effect [2]. The combination of increased emissions together with ample heat and sunshine leads to efficient photochemical production of pollutants such as ozone and secondary aerosols (PM2.5), resulting in pollution exposure at levels exceeding the National Ambient Air Quality Standards (NAAQS) and posing additional health concerns for urban and downwind communities. During the day-time high temperature periods, fast and anomalous dynamics in atmospheric column concentrations of particulates and trace gases were observed and are presented in this report. Preliminary analysis suggest that these are due to free-troposphereboundary layer exchanges and clear air subsidence

METHODOLOGY

OBSERVATIONS

DISCUSSIONS AND CONCLUSION