Towards a Better Prediction and Mitigation of Heat Waves in Urban India

In a changing climate, health effects due to extreme weather such as heat and cold waves are becoming a matter of growing global concern especially in highly populated urban areas, where urban heat island effects are exacerbating regional temperature trends. While these changes may result in increased vulnerability in developed countries such as the U.S. [1],[2], developing countries are at much higher risk due in part to existing infrastructure deficiencies. The built-environment often lacks widespread electricity-availability, air conditioning, water, and medical care, and emergency action plans often do not utilize early warning systems for disaster preparation and planning.

Currently we are participating in a coordinated effort together with the Ahmedabad Heat and Climate Study Group to produce 1) a heat preparedness plan and 2) an early warning system for Ahmedabad (Gujarat, India). The group is comprised of a series of U.S. and international partners such as the Ahmedabad municipality managers, Public Health Foundation of India (PHFI), Indian Institute of Public Health-Gandhinagar (IIPH-G), the Natural Resources Defense Council (NRDC), Emory University, the Icahn School of Medicine at Mount Sinai, Georgia Institute of Technology and Climate Forecast Applications Network (CFAN) [3]. Specifically, our group has been providing 7-day probabilistic maximum temperature guidance during the pre-monsoon hot season. During the Ahmadabad hot season and just prior to monsoon rainfall, maximum daily temperatures are on average around 41°C (106°F), with record values exceeding 46°C (~115°C). Record heat recently occurred in May 2010 leading to excessive mortality rates [4] and increased adverse health impacts to an already vulnerable population [5]. A key element in our forecast methodology is distributional and mean bias corrections applied to the ECMWF Ensemble Forecast System, in which systematic model errors are removed using the ECMWF hindcasts and in-situ historical observations.

In this study, we provide a description of the synoptic setup for the extreme 2010 heat wave in west India, which motivated the development of the heat action plan in Ahmadabad, and a comparison relative to the 2015 Indian heat wave. The predictability of the 2010 heat event and of the 2013–2015 real-time forecasts produced for the heat action plan is also presented. It will be shown that the statistically-adjusted forecasts are skillful through 7 days in advance.

References:

1. Kristen Guirguis, Alexander Gershunov, Alexander Tardy, and Rupa Basu, 2014: The Impact of Recent Heat Waves on Human Health in California. J. Appl. Meteor. Climatol., 53, 3–19.

2. Knowlton, K., M. Rotkin-Ellman, G. King, H. G. Margolis, D. Smith, G. Solomon, R. Trent, and P. English, 2009: The 2006 California heat wave: Impacts on hospitalizations and emergency department visits. Environ. Health Perspect., 117, 61–67.

3. Knowlton K., Kulkarni S. P., Azhar G. S., Mavalankar D., Jaiswal A., Connolly M., Nori-Sarma A., Rajiva A., Dutta P., Deol B., Sanchez L., Khosla R., Webster P. J., Toma V. E., Sheffield P., Hess J. J., the Ahmedabad Heat and Climate Study Group. 2014. "Development and Implementation of South Asia's First Heat-Health Action Plan in Ahmedabad (Gujarat, India)." Int. J. Environ. Res. Public Health 11, no. 4: 3473-3492.

4. Azhar G. S., Mavalankar D., Nori-Sarma A., Rajiva A., Dutta P., et al. (2014) Heat-Related Mortality in India: Excess All-Cause Mortality Associated with the 2010 Ahmedabad Heat Wave. PLoS ONE 9(3): e91831 doi:10.1371/journal.pone.0091831.

5. Khyati K., M. L. Barzaga, S. Wallenstein, G. S. Azhar, and P. E. Sheffield, “Neonates in Ahmedabad, India, during the 2010 Heat Wave: A Climate Change Adaptation Study,” Journal of Environmental and Public Health, vol. 2014, Article ID 946875, 8 pages, 2014. doi:10.1155/2014/946875.