Abstract
Abstract. Prior work indicates that the frequency of summertime mid-latitude cyclones tracking across the Great Lakes Storm Track (GLST, bounded by: 70° W, 90° W, 40° N, and 50° N) are strongly anticorrelated with ozone (O3) pollution episodes over the Northeastern United States (US). We apply the MAP Climatology of Mid-latitude Storminess (MCMS) algorithm to 6-hourly sea level pressure fields from over 2500 yr of simulations with the GFDL CM3 global coupled chemistry-climate model. These simulations include (1) 875 yr with constant 1860 emissions and forcings (Pre-industrial Control), (2) five ensemble members for 1860–2005 emissions and forcings (Historical), and (3) future (2006–2100) scenarios following the Representative Concentration Pathways (RCP 4.5 and RCP 8.5) and a sensitivity simulation to isolate the role of climate warming from changes in O3 precursor emissions (RCP 4.5*). The GFDL CM3 Historical simulations capture the mean and variability of summertime cyclones traversing the GLST within the range determined from four reanalysis datasets. Over the 21st century (2006–2100), the frequency of summertime mid-latitude cyclones in the GLST decreases under the RCP 8.5 scenario and in the RCP 4.5 ensemble mean. These trends are significant when assessed relative to the variability in the Pre-industrial Control simulation. In addition, the RCP 4.5* scenario enables us to determine the relationship between summertime GLST cyclones and high-O3 events (> 95th percentile) in the absence of emission changes. The summertime GLST cyclone frequency explains less than 10% of the variability in high-O3 events over the Northeastern US in the model, implying that other factors play an equally important role in determining high-O3 events.
Highlights
Climate warming can impact air quality through feedbacks in the chemistry-climate system (e.g. Weaver et al, 2009; Jacob and Winner, 2009; Isaksen et al, 2009; Fiore et al, 2012)
Building upon their (Leibensperger et al, 2008) work, which focused on the past few decades, we examine the spatial distribution, trends, and variability of mid-latitude cyclones in the Geophysical Fluid Dynamics Laboratory (GFDL) Climate Model version 3 (CM3) simulations of Pre-industrial, present, and future climate as well as in four reanalyses
We investigated trends and variability in the frequency of summertime mid-latitude cyclones tracking across the Great Lakes Storm Track (GLST; bounded by 70◦ W, 90◦ W, 40◦ N, and 50◦ N) over the 20th and 21st centuries in the GFDL CM3 chemistry-climate model, and assessed their significance relative to the natural variability in the GLST cyclone frequency in a Pre-industrial Control simulation (Table 1)
Summary
Climate warming can impact air quality through feedbacks in the chemistry-climate system (e.g. Weaver et al, 2009; Jacob and Winner, 2009; Isaksen et al, 2009; Fiore et al, 2012). Leibensperger et al (2008) found a strong anticorrelation between summertime mid-latitude cyclones and exceedances of the NAAQS ozone threshold ( 84 ppb) in the Northeastern US as well as a decreasing trend in mid-latitude cyclones over the “southern storm track” which we hereafter refer to as the “Great Lakes Storm Track” (GLST) from 1980– 2006 which they attribute to a warming climate Building upon their (Leibensperger et al, 2008) work, which focused on the past few decades, we examine the spatial distribution, trends, and variability of mid-latitude cyclones in the Geophysical Fluid Dynamics Laboratory (GFDL) Climate Model version 3 (CM3) simulations of Pre-industrial, present, and future climate as well as in four reanalyses. We examine the relationship between summertime mid-latitude cyclones and high-O3 events in future climate projections
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
