Upper Air - May 2012


Troposphere

Lower Troposphere

May Lower Troposphere
May Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.29 +0.52 Coolest 31st 1985 -0.33 -0.59 +0.11 +0.20
Warmest 4th 1998 +0.57 +1.03
RSS +0.15 +0.27 Coolest 28th 1985 -0.41 -0.74 +0.12 +0.21
Warmest 7th 1998 +0.58 +1.04
March-May Lower Troposphere
March–
May
Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.23 +0.41 Coolest 30th 1993 -0.34 -0.61 +0.13 +0.23
Warmest 5th 1998 +0.55 +0.99
RSS +0.11 +0.20 Coolest 26th 1985 -0.41 -0.74 +0.13 +0.23
Warmest 9th 1998 +0.60 +1.08
Year-to-Date Lower Troposphere
January–
May
Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.10 +0.18 Coolest 25th 1993 -0.33 -0.59 +0.12 +0.22
Warmest 10th 1998 +0.56 +1.01
RSS -0.02 -0.04 Coolest 17th 1985 -0.40 -0.72 +0.12 +0.22
Warmest 17th 1998 +0.57 +1.03
Ties: 1981

Mid-troposphere

May Mid-troposphere
May Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.10 +0.18 Coolest 27th 1989 -0.33 -0.59 +0.04 +0.06
Warmest 8th 1998 +0.58 +1.04
RSS +0.04 +0.07 Coolest 21st 1989 -0.32 -0.58 +0.06 +0.10
Warmest 14th 1998 +0.60 +1.08
UW-UAH +0.18 +0.32 Coolest 27th 1989 -0.41 -0.74 +0.09 +0.16
Warmest 8th 1998 +0.67 +1.21
UW-RSS +0.19 +0.34 Coolest 30th 1989 -0.37 -0.67 +0.10 +0.19
Warmest 5th 1998 +0.68 +1.22
March-May Mid-troposphere
March–
May
Anomaly Rank
(out of 34 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.06 +0.11 Coolest 22nd 1993 -0.32 -0.58 +0.03 +0.05
Warmest 13th 1998 +0.58 +1.04
RSS +0.03 +0.05 Coolest 21st 1993 -0.33 -0.59 +0.06 +0.12
Warmest 13th 1998 +0.58 +1.04
Ties: 1990
UW-UAH +0.14 +0.25 Coolest 27th 1993 -0.39 -0.70 +0.09 +0.15
Warmest 7th 1998 +0.67 +1.21
Ties: 2007
UW-RSS +0.14 +0.25 Coolest 26th 1993 -0.39 -0.70 +0.12 +0.21
Warmest 9th 1998 +0.65 +1.17
RATPAC* +0.14 +0.25 Coolest 47th 1965 -0.93 -1.67 +0.14 +0.25
Warmest 9th 1998 +0.58 +1.04

*RATPAC rank is based on 55 years of data

Year-to-Date Mid-troposphere
January–
May
Anomaly Rank
(out of 34 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.06 -0.11 Coolest 14th 1993, 1989 -0.28 -0.50 +0.02 +0.04
Warmest 20th 1998 +0.57 +1.03
Ties: 1982
RSS -0.07 -0.13 Coolest 15th 1993, 1989 -0.30 -0.54 +0.07 +0.12
Warmest 20th 1998 +0.56 +1.01
UW-UAH 0.00 0.00 Coolest 17th 1993 -0.36 -0.65 +0.08 +0.14
Warmest 18th 1998 +0.66 +1.19
RATPAC* -0.03 -0.05 Coolest 37th 1965 -0.91 -1.64 +0.14 +0.25
Warmest 18th 2010 +0.66 +1.19
Ties: 1980

*RATPAC rank is based on 55 years of data

Stratosphere

May Stratosphere
May Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.45 -0.81 Coolest 3rd 2011 -0.65 -1.17 -0.34 -0.62
Warmest 31st 1992 +0.92 +1.66
Ties: 1996
RSS -0.42 -0.76 Coolest 2nd 2011 -0.60 -1.08 -0.26 -0.47
Warmest 33rd 1992 +0.89 +1.60
March-May Stratosphere
March–
May
Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.49 -0.88 Coolest 1st 2012 -0.49 -0.88 -0.34 -0.61
Warmest 34th 1983 +1.05 +1.89
RSS -0.48 -0.86 Coolest 1st 2012 -0.48 -0.86 -0.27 -0.49
Warmest 34th 1992 +1.02 +1.84
Year-to-Date Stratosphere
January–
May
Anomaly Rank
(out of 34 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.50 -0.90 Coolest 1st 2012 -0.50 -0.90 -0.35 -0.64
Warmest 34th 1983 +1.18 +2.12
RSS -0.51 -0.92 Coolest 1st 2012 -0.51 -0.92 -0.30 -0.53
Warmest 34th 1983 +1.09 +1.96

Background Information

Temperatures above the Earth's surface are measured within the lower troposphere, middle troposphere, and stratosphere using in-situ balloon-borne instruments (radiosondes) and polar-orbiting satellites (NOAA's TIROS-N). The radiosonde and satellite records have been adjusted to remove time-dependent biases (artificialities caused by changes in radiosonde instruments and measurement practices as well as changes in satellite instruments and orbital features through time). Global averages from radiosonde data are available from 1958 to present, while satellite measurements date back to 1979.

The mid-troposphere temperatures are centered in the in the atmospheric layer approximately 3–10 km [2–6 miles] above the Earth's surface, which also includes a portion of the lower stratosphere. (The Microwave Sounding Unit [MSU] channel used to measure mid-tropospheric temperatures receives about 25 percent of its signal above 10 km [6 miles].) Because the stratosphere has cooled due to increasing greenhouse gases in the troposphere and losses of ozone in the stratosphere, the stratospheric contribution to the tropospheric average, as measured from satellites, creates an artificial component of cooling to the mid-troposphere temperatures. The University of Washington (UW) versions of the UAH and RSS analyses attempt to remove the stratospheric influence from the mid-troposphere measurements, and as a result the UW versions tend to have a larger warming trend than either the UAH or RSS versions. For additional information, please see NCDC's Microwave Sounding Unit page.

The radiosonde data used in this global analysis were developed using the Lanzante, Klein, Seidel (2003) ("LKS") bias-adjusted dataset and the First Difference Method (Free et al. 2004) (RATPAC). Additional details are available. Satellite data have been adjusted by the Global Hydrology and Climate Center at the University of Alabama in Huntsville (UAH). An independent analysis is also performed by Remote Sensing Systems (RSS) and a third analysis has been performed by Dr. Qiang Fu of the University of Washington (UW) (Fu et al. 2004)** to remove the influence of the stratosphere on the mid-troposphere value. Global averages from radiosonde data are available from 1958 to present, while satellite measurements began in 1979.

References

Citing This Report

NOAA National Climatic Data Center, State of the Climate: Upper Air for May 2012, published online June 2012, retrieved on October 1, 2014 from http://www.ncdc.noaa.gov/sotc/upper-air/2012/5.