Global Analysis - June 2002

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Note: GHCN-M Data Notice

An omission in processing a correction algorithm led to some small errors on the Global Historical Climatology Network-Monthly dataset (GHCN-M v3.2.0). This led to small errors in the reported land surface temperatures in the October, November, December and Annual U.S. and global climate reports. On February 14, 2013, NCDC fixed this error in its software, included an additional improvement (described below), and implemented both changes as GHCN-M version 3.2.1. With this update to GHCN-M, the Merged Land and Ocean Surface Temperature dataset also is subsequently revised as MLOST version 3.5.3.

The net result of this new version of GHCN-M reveals very small changes in temperature and ranks. The 2012 U.S. temperature is 0.01°F higher than reported in early January, but still remains approximately 1.0°F warmer than the next warmest year, and approximately 3.25°F warmer than the 20th century average. The U.S. annual time series from version 3.2.1 is almost identical to the series from version 3.2.0 and that the 1895-2012 annual temperature trend remains 0.13°F/decade. The trend for certain calendar months changed more than others (discussed below). For the globe, ranks of individual years changed in some instances by a few positions, but global land temperature trends changed no more than 0.01°C/century for any month since 1880.

NCDC uses two correction processes to remove inhomogeneities associated with factors unrelated to climate such as changes in observer practices, instrumentation, and changes in station location and environment that have occurred through time. The first correction for time of observation changes in the United States was inadvertently disabled during late 2012. That algorithm provides for a physically based correction for observing time changes based on station history information. NCDC also routinely runs a .pairwise correction. algorithm that addresses such issues, but in an indirect manner. It successfully corrected for many of the time of observation issues, which minimized the effect of this processing omission.

The version 3.2.1 release also includes the use of updated data to improve quality control and correction processes of other U.S. stations and neighboring stations in Canada and Mexico.

Compared to analyses released in January 2013, the trend for certain calendar months has changed more than others. This effect is related to the seasonal nature of the reintroduced time-of-observation correction. Trends in U.S. winter temperature are higher while trends in summer temperatures are lower. For the globe, ranks of individual years changed in some instances by a few positions, but global temperature trends changed no more than 0.01°C/century for any month since 1880.

More complete information about this issue is available at this supplemental page.

NCDC will not update the static reports from October through December 2012 and the 2012 U.S and Global annual reports, but will use the current dataset (GHCN-M v. 3.2.1 and MLOST v. 3.5.3) for the January 2013 report and other comparisons to previous months and years.

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Global Highlights:

  • Global average combined land and sea surface temperature was the second warmest on record for June
  • January-June 2002 global temperature was the second warmest such 6-month period on record
  • June temperatures were 3-5°C (5.4-9°F) warmer than average over much of Europe, eastern Asia and parts of the U.S.
  • Above average precipitation during June occurred across parts of interior China and Europe, with drier than average conditions observed from the Philippines, Taiwan and across much of Japan
  

Contents of this Section:
This is a break in the document The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. The most current data may be accessed via the Global Surface Temperature Anomalies page. This is a break in the document

Top of Page Introduction

The June 2002 mean temperature was above the 1988-2002 average across Europe, much of the United States and the eastern half of Asia as shown in the adjacent map of blended satellite and in-situ data. Much cooler than average temperatures occurred across most of Argentina, southern Chile and parts of central Russia. The mean position of upper level ridges and troughs of low pressure (depicted by positive and negative 500 millibar height anomalies), are generally reflected by areas of positive and negative temperature anomalies at the surface, respectively. Warmer-than-average sea surface temperatures were observed throughout the tropical Pacific during June, as weak El Niño conditions developed. Global Blended Temperature in June 2002
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Global Temperature Anomalies in June 2002
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 June temperature anomalies calculated from the Global Historical Climatology Network data set of land surface stations using a 1961-1990 base period also show the warmer than average temperatures across much of the United States, Europe and the Mediterranean region and much of eastern Asia. Cooler than average temperatures were observed over much of Chile and Argentina .
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Top of PageTemperature

  • For June 2002, the global average land and ocean surface temperature was 0.50°C (0.90°F) above the 1880-2001 average, ranking as the second warmest June on record
  • The warmest June occurred 4 years ago during the last El Niño episode
  • The June land surface temperature average was second warmest on record, 0.75°C (1.35°F) above average
  • Globally averaged ocean surface tempeatures were 0.39°C (0.70°F) above the 1880-2001 mean, or third warmest
 Global Temp Anomalies in June 2002
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  • The global land and ocean surface temperature average (January-June 2002) was the second warmest such 6-month period in the 1880-2002 record, 0.64°C (1.15°F) above the long-term mean and 0.05°C (0.09°F) cooler than during the El Niño year of 1998
  • However, land areas were warmest on record for the 6-month period from January-June 2002, or 1.14°C (2.05°F) above the 1880-2001 average
 Global Temp Anomalies in January-June 2002
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  • Serial monthly global surface temperature departures with respect to a 1971-2000 mean are shown in the figure to the right
  • The recent return to record or near record temperature departures is evident, and globally averaged surface temperatures (land and ocean) have been warmer than the 1971-2000 average for the last 74 consecutive months
 Global Temperature Timeseries
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Top of Page Precipitation

  • During June 2002, much above average precipitation fell across interior China, parts of Europe and across Micronesia
  • Drier than average weather prevailed across coastal China, the Philippines, Taiwan and Japan, as well as parts of the central and western United States
  • Additional regional analysis can be found on the Global Hazards page
 Global Precip Anomalies in June 2002
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References:

Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global Historical Climatology Network Database. Bull. Amer. Meteorol. Soc., 78, 2837-2849.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: Global Analysis for June 2002, published online July 2002, retrieved on June 18, 2013 from http://www.ncdc.noaa.gov/sotc/global/2002/6.