Introduction
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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 Europe, eastern Asia and
much of the United States, with cooler temperatures over central
and western Canada as well as Turkey to Turkmenistan. |
Temperature
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- Based on data available at the time of this report, the global
land and ocean temperature in April 2002 was the second warmest in
the 1880-2002 record, 0.57°C (1.03°F) above the long-term
average
- Temperatures averaged across ocean areas
were second warmest on record globally, or 0.43°C
(0.77°F) above the long-term April mean
- Land
areas were third warmest during April, or 0.94°C
(1.69°F) above the 1880-2001 average which is 0.28°C
(0.50°F) less than in 1998
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- The global average land and ocean temperature for the period
January-April 2002 was 0.70°C (1.26°F) above the
1880-2001 mean, the second warmest such period on record
- Temperatures averaged across land areas were warmest on record
for January-April 2002, or 1.33°C (2.39°F) above
average
- Two of the past four months (January and
March) were
the warmest such months on record (combined land and ocean
temperature)
- Global temperatures have increased at an average rate of
approximately 0.6°C (1°F) per century since 1900, but the
rate of warming during the past 25 years is almost three times
higher
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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 monthly global temperatures (land and
ocean) have been warmer than the 1971-2000 average for the last 72
consecutive months
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Precipitation
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- During April, much above average precipitation fell across
parts of northern Brazil, Uruguay and the Argentinian Pampas
region
- Drier than average weather prevailed across much of southeast
China, Australia and interior Europe
- Additional regional analysis can be found on the Global
Regional page
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Microwave Sounding Unit Data
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- Temperatures in the lowest 8km (5 miles) of the troposphere
were 0.20°C (0.36°F)
above average, tied with 1995 as the second warmest April in the
24-year satellite record
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- April temperatures were below average in the lower
stratosphere, with a departure of -0.19°C (-0.34°F)
- April temperatures in the lower stratosphere have been below
average each year since 1993. The overall cooling trend is
consistent with the response to losses in stratospheric ozone while the
warm anomalies in 1992-1993 are due to the warming influence of the
Mount Pinatubo eruption which occurred in the Philippines in June
1991.
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Lower tropospheric and lower stratospheric temperature data are
collected by NOAA's TIROS-N polar-orbiting satellites and adjusted
for time-dependent biases by NASA and the Global Hydrology and
Climate Center at the University of Alabama in Huntsville.
For additional details on precipitation and
temperatures in April see the Global
Regional page .
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.
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