Assessing Equivalent Temperature Trends in

Major Eastern US Cities

Master’s Thesis ProposalBy: Mercedes Gomez

Advisor: Dr. Justin Schoof

Elevated temperatures in urban areas (relative to their rural counterparts) are well documented.

The role of humidity in heat wave impacts is also well documented, but has not been considered explicitly in the context of elevated urban temperatures.

The proposed study will focus on assessing changes in both temperature and humidity in major eastern U.S. cities to improve understanding of the role of humidity in urban heat waves.

The cities chosen for this study are geographically diverse and have populations ranging from 399,457to 8,175,133 and are collectively home to over 22 million people. (US CENSUS BUREAU,2010)

Introduction

Urban heat island effect US cities and population Heat waves Equivalent temperature

Literature Review

The built urban environment alters the natural surface energy and radiation balances. (Oke, 1982)

Temperatures are higher in cities compared to countryside. (Meir, 2013;Stewart and Oke,2012)

Urban Heat Island (UHI) Effect

Los Angeles, CA

Previous studies have found positive correlations between population rates and temperature in developed countries. (Oke,1973;Park,1987)

No study to date has quantified this relationship with consideration of urban humidity.

UHIs and Urban Populations

Heat waves in the U.S. are predicted to be more frequent and intense in the future. (Meehl and Tebaldi,2004).

Heat Waves

TE-Equivalent temperature in °C T-Temperature in °C Lv-Latent heat of vaporization (J kg-1) q-Specific humidity (kg kg-1) Cp-Specific heat of air at constant pressure

Equivalent Temperature

p

vE C

qLTT

TE=the temperature that an air parcel would have if all associated water vapor were condensed. The resulting latent heat is used to increase the temperature of the parcel.

Joint behavior of temperature and humidity (Schoof et al,2014).

Equivalent Temperature

p

vE C

qLTT

Elevated urban temperatures are a known health risk for urban populations. Despite knowledge that humidity also plays a role, there has been relatively little attention paid to the role of humidity in studies of urban climate hazards. The goal of the proposed research is to address this shortcoming by investigating urban equivalent temperature trends in large cities as they relate to urban characteristics.

Problem Statement

1) How do temperature and equivalent temperature trends differ in urban areas?

2) How do urban equivalent temperature trends vary in relation to urban characteristics?

Research Questions

Atlanta, GA Chesapeake, VA

20 selected Eastern cities in U.S. with available data

Coastal and Continental

National Oceanic and Atmospheric Administration (NOAA)-Integrated Surface Database (ISD)-National Climatic Data Center (NCDC)

Quality controlTrend estimation methods

Data and Methodology

1. NYC, NY* 8,175,133

2. Chicago, IL 2,695,598

3. Philadelphia, PA 1,526,006

4. Jacksonville, FL* 824,784

5. Indianapolis, IN 820,445

6. Columbus, OH 787,033

7. Charlotte, NC 731,424

8. Detroit, MI 713,777

9. Memphis, TN 646,889

10. Baltimore, MD* 620,961

Eastern US Cities and Population

US CENSUS BUREAU, 2010

* Coastal city

11. Boston, MA* 617,594

12. Washington, DC 601,723

13. Nashville, TN 601,222

14. Louisville, KY 597,337

15. Milwaukee, WI 594,833

16. Kansas City, MO 459,787

17. Virginia Beach, VA* 437,994

18. Atlanta, GA 420,003

19. Raleigh, NC 403,892

20. Miami, FL* 399,457

Eastern US Cities and Population

US CENSUS BUREAU, 2010

* Coastal city

The cities chosen for this study are home to over 22 million

people collectively. Heat waves claim many lives annually and

are predicted to become more intense and longer lasting.

Studies suggest that heat related illness and death will

continue to increase in future years. The proposed study will

assess trends in temperature and equivalent temperature in

order to create a better understanding of the role of humidity

in urban heat waves.

Conclusion

Davey, Christopher A., Roger A. Pielke, and Kevin P. Gallo. 2006. “Differences Between Near-surface Equivalent Temperature and Temperature Trends for the Eastern United States Equivalent Temperature as an Alternative Measure of Heat Content.” Global and Planetary Change 54: 19-32.

Fall, Souleymane, Noah S. Diffenbaugh, Dev Niyogi, Roger A. Pielke, and Gilbert Rochon. 2010. “Temperature and Equivalent Temperature Over the United States (1979-2005).” International Journal of Climatology 30 (13): 2045-2054. doi:10.1002/joc.2094.

Meehl, G. A., and C. Tebaldi. 2004. “More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century.” Science 305 (5686): 994-997. doi:10.1126/science.1098704.

Meir, Talmor, Philip M. Orton, Julie Pullen, Teddy Holt, William T. Thompson, and Mark F. Arend. 2013. “Forecasting the New York City Urban Heat Island and Sea Breeze During Extreme Heat Events.” Weather and Forecasting 28 (6): 1460-1477. doi:10.1175/WAF-D-13-00012.1.

“National Weather Service Weather Forecast Office.” 2014. Heat: A Major Killer. http://www.crh.noaa.gov/lmk/?n=noaaexcessiveheat.

Peterson, Thomas C., Richard R. Heim, Robert Hirsch, Dale P. Kaiser, Harold Brooks, Noah S. Diffenbaugh, Randall M. Dole, et al. 2013. “Monitoring and Understanding Changes in Heat Waves, Cold Waves, Floods, and Droughts in the United States: State of Knowledge.” Bulletin of the American Meteorological Society 94 (6): 821-834. doi:10.1175/BAMS-D-12-00066.1.

Pielke, R.A. 2005. “What Does Moist Enthalpy Tell Us?.” Climate Science Roger Pielke Sr. Roger Pielke Sr. July 18. http://pielkeclimatesci.wordpress.com/2005/07/18/what-does-moist-enthalpy-tell-us/.

Pielke, Roger A., Christopher Davey, and Jack Morgan. 2004. “Assessing "Global Warming" With Surface Heat Content.” Eos, Transactions American Geophysical Union 85 (21): 210-211.

Schoof, J.T., Z.A. Heern, and J.W.F. Remo. 2014. “Assessing Trends in Lower Tropospheric Heat Content in the Central United States Using Equivalent Temperature.” Wiley Online Library. International Journal of Climatology. September. http://onlinelibrary.wiley.com/doi/10.1002/joc.4175/full.

Stewart, I. D., and T. R. Oke. 2012. “Local Climate Zones for Urban Temperature Studies.” Bulletin of the American Meteorological Society 93 (12): 1879-1900. doi:10.1175/BAMS-D-11-00019.1

References

Questions?

Thank you