NOAA REPORTS 2002 WAS MARKED BY WIDESPREAD DROUGHT IN THE U.S., RETURN OF EL NIÑO, AND WARM GLOBAL TEMPERATURE
December 17, 2002 — The climate of 2002 in the United States was characterized by warmer than normal temperatures and below average precipitation that led to persistent or worsening drought throughout much of the nation, according to NOAA scientists.
Working from the world’s largest statistical weather database, NOAA scientists at the National Climatic Data Center also found that 2002 is very likely to be the second warmest year on record for the globe. The return of El Niño affected hurricanes in the Atlantic and precipitation patterns in some parts of the world.
The year 2002 began with another anomalously warm winter, the fourth much warmer-than-average winter in the last five years, and the summer season was one of the warmest since the 1930s. Temperatures in Alaska were above average in all four seasons, and 2002 will approach or exceed the warmest year on record for the state.
Overall the contiguous United States temperature has risen at a rate of 1.0 degree F/Century (0.6 degrees C/Century) since 1895. Much of that increase has occurred in two periods, 1910-1940 and again from the 1970s to the present. Temperatures in Alaska have increased at a rate near 2.8 degrees F/Century (1.5 degrees C/Century) since the early 1900s, most rapidly in the past 25 to 30 years.
Precipitation, Drought and Flooding
The most extensive national drought coverage during the past 100 years (the period of instrumental record) occurred in July 1934 when 80 percent of the contiguous United States was in moderate to extreme drought. Although the current drought and others of the 20th century have been widespread and of lengthy duration, tree ring records indicate that the severity of these droughts was likely surpassed by other droughts, including that of the 1570s and 1580s over much of the Southwest and northern Mexico.
In the western United States where precipitation for 2002 is on pace to set record or near-record lows in many states, the lack of adequate rain and snow and the resulting low snowpack stressed water supplies and caused devastating impacts on agriculture. Severe drought in Montana that began in some places more than four years ago forced farmers to abandon more than 20 percent of the winter wheat crop for the second consecutive year, the first such occurrence since the Dust Bowl era of the 1930s. The extremely dry conditions also contributed to an extremely active wildfire season that included the largest wildfires of the past century for the states of Colorado, Arizona and Oregon.
Extremely dry conditions in the Northeast improved with four consecutive months of above-normal precipitation for the region from March through June, and abnormally dry conditions were largely absent near the end of the year. Above-average rainfall from September through November also brought significant drought relief to the Southeast, where more than four years of drought had affected much of the region from Georgia to Virginia.
In Texas, heavy rainfall alleviated drought but led to severe flooding in southern and central parts of the state in early July. Strong thunderstorms also brought widespread flooding to western Minnesota and North Dakota and resulted in hundreds of millions of dollars in damage and crop losses in June.
*This drought statistic is based on the Palmer Drought Index, a widely used measure of drought. The Palmer Drought Index uses numerical values derived from weather and climate data to classify moisture conditions throughout the contiguous United States and includes drought categories on a scale from mild to moderate, severe and extreme.
With the exception of 2002 and 1997, years that were both affected by El Niño, at least three major hurricanes have developed in every season since 1995 with five or more major hurricanes occurring in three of those seasons (1995, 1996 and 1999). However no long-term trend in hurricane strength or frequency has been observed in the Atlantic Basin.
Other conditions common during an El Niño episode included a drier-than-average summer monsoon season in India and drier than normal conditions in Indonesia during May-October. The June-September monsoon season for India as a whole was characterized by large-scale drought with seasonal rainfall (June-September) 19 percent below normal.
In contrast, heavy rainfall in northeastern India, Nepal and Bangladesh brought severe flooding and caused approximately one thousand deaths in June. The most damaging typhoon to affect Korea since 1959, Typhoon Rusa, made landfall on the Korean Peninsula at the end of August.
In parts of central Europe heavy rains fell during the first 13 days of August, causing disastrous floods on the Elbe and Danube rivers with more than 100 lives lost and damages estimated at $30 billion.
In Africa, severe drought continued across parts of the Greater Horn of Africa, and widespread flooding occurred in Morocco during November and in parts of Madagascar during January-May as four tropical cyclones impacted the island nation.
Data collected by NOAA polar orbiting satellites and analyzed for NOAA by the University of Alabama in Huntsville and Remote Sensing Systems in Santa Rosa, Calif., indicate that temperatures centered in the middle troposphere at altitudes from 2 to 6 miles are also on pace to make 2002 the second-warmest year for the globe. The average lower troposphere temperature (surface to about 5 miles) for 2002 will also very likely be the second warmest on record.
Analysis of the satellite record that began in 1979 shows that the global average temperature in the middle troposphere has increased, but the differing analysis techniques of the two teams result in different trends. The UAH team found an increase of 0.06 degrees F/decade (0.035 degrees C/decade) while a trend of 0.21° F/decade (0.115° C/decade) was found by the RSS team. This compares to surface temperature increases approaching 0.3 degrees F/decade during the same period.
The NOAA National Environmental Satellite, Data, and Information Service (NOAA Satellites and Information) is the nation’s primary source of space-based and surface-based meteorological and climate data. NOAA Satellites and Information operates the nation's environmental satellites, which are used for weather forecasting, climate monitoring and other environmental applications such as fire detection, ozone monitoring and sea surface temperature measurements.
NOAA Satellites and Information also operates three data centers, which house global data bases in climatology, oceanography, solid earth geophysics, marine geology and geophysics, solar-terrestrial physics, and paleoclimatology.