Substantial increase in concurrent droughts and heatwaves in the United States

Abstract

A combination of climate events (e.g., low precipitation and high temperatures) may cause a significant impact on the ecosystem and society, although individual events involved may not be severe extremes themselves. Analyzing historical changes in concurrent climate extremes is critical to preparing for and mitigating the negative effects of climatic change and variability. This study focuses on the changes in concurrences of heatwaves and meteorological droughts from 1960 to 2010. Despite an apparent hiatus in rising temperature and no significant trend in droughts, we show a substantial increase in concurrent droughts and heatwaves across most parts of the United States, and a statistically significant shift in the distribution of concurrent extremes. Although commonly used trend analysis methods do not show any trend in concurrent droughts and heatwaves, a unique statistical approach discussed in this study exhibits a statistically significant change in the distribution of the data.

Extreme wildfire events are linked to global-change-type droughts in the northern Mediterranean

“…2) while the anomalously warm temperatures were less extreme than in 2003. Interestingly, these two events closely reflect the expected impacts of climate change on drought that are projected in the Mediterranean (Sousa et al, 2011;Hoerling et al, 2012) and in other regions of the world (e.g., Mazdiyasni and Aghakouchak, 2015).…”

Record-Breaking Heat in Northwest China in July 2015: Analysis of the Severity and Underlying Causes

“…We used the data at the 53 stations with continuous July TMX records throughout the period of 1961-2015. We defined the extreme threshold as the 90th percentile of area-averaged July TMX between 1961and 1990(Mazdiyasni and AghaKouchak 2015. Heat wave duration was defined as the total number of days within July that TMX exceeded the threshold (Meehl and Tebaldi 2004).…”

Using GRACE Satellite Gravimetry for Assessing Large-Scale Hydrologic Extremes

“…Identifying occurrences of hydrologic extremes has become critically important in light of a significantly larger number of recent extreme events [3][4][5] and the expected more widespread emergence of such events in the future [1,6]. Among all possible indicators for quantifying hydrologic extremes [7][8][9], the terrestrial total water storage (TWS), which is a holistic and unique measure of the status of the Earth's water resources, has attracted significant attention in the recent decade [10][11][12][13][14][15].…”