Analysis of trends in the variability of daily and monthly historical temperature measurements

Abstract

This investigation analyzes trends in the variability of daily and monthly near-surface air temperatures. We examined the 5°latitude by 5°longitude monthly temperature anomalies available for many grids around the world. Overall, the trend in intra-annual temperature variance is towards reduced variability and is highly significant over the past 50 and 100 yr. We then examined daily maximum and minimum temperatures from the United States, China, and the former Soviet Union for intra-monthly variability in January and July. Most of the trends also indicated declining variability. A final approach examined the occurrence of record-setting daily maximum and minimum temperatures from the same countries. We found no evidence for an increase in record temperatures. The fact that intra-annual and intra-monthly variance is declining suggests that we should see fewer record temperatures in recent years. There is some evidence for this in the daily data. In general, our results argue against the proposition that temperatures have become more variable as global temperatures have changed in this century.

Nature of observed temperature changes across the United States during the 20th century

“…The temperature rise has taken place predominantly in the days of the year with some of the lowest maximum and minimum temperatures, while the days with the highest temperatures have exhibited far less of an increase. These findings add to the growing evidence (Balling et al 1998, Michaels et al 1998, Michaels et al 2000 that the surface air temperature change that has occurred during the period of the greatest human influence on the climate is one in which increases of extremely low temperatures have dominated over those of high temperatures -a climate tending toward moderation rather than the extreme. Prognostications of dire consequences built upon model projections of a climate change dominated by increasing high temperatures should be reassessed based upon a growing body of evidence to the contrary.…”

Seasonality of climate-human mortality relationships in US cities and impacts of climate change

“…Michaels et al 1998, IPCC 2001b. By coupling these seasonal warming and mortality patterns, some researchers have suggested that future mortality rates will exhibit a net decline (Bentham 1997, Moore 1998, Michaels & Balling Jr 2000.…”

Trends in Intra- and Inter-Annual Temperature Variabilities Across Sudan

“…Both for the transient and double CO 2 climate simulations, the results showed that the temperature variability tends to decrease in the warmer climate (Rind et al 1989). In the light of the increasing awareness of the importance of the study of climate variability (Katz and Brown 1992), a number of investigators examined the long-term temperature observations (Karl et al 1995;Przybylak 1997;Michaels et al 1998;Elagib and Mansell 2000a;Pal and Al-Tabbaa 2009) in a search for changing variability in a changing climate.…”