Upper Air - May 2018


Troposphere

Lower Troposphere

May Lower Troposphere
May Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.18 +0.32 Coolest 31st 1985 -0.32 -0.58 +0.11 +0.20
Warmest 10th 1998 +0.64 +1.15
RSS i +0.16 +0.29 Coolest 30th 1985 -0.41 -0.74 +0.12 +0.22
Warmest 11th 1998 +0.58 +1.04
March-May Lower Troposphere
March–
May
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.21 +0.38 Coolest 34th 1985 -0.36 -0.65 +0.12 +0.21
Warmest 7th 2016 +0.67 +1.21
RSS i +0.18 +0.32 Coolest 33rd 1985 -0.41 -0.74 +0.13 +0.23
Warmest 7th 2016 +0.63 +1.13
Ties: 2001, 2003, 2004
Year-to-Date Lower Troposphere
January–
May
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.22 +0.40 Coolest 33rd 1985 -0.37 -0.67 +0.13 +0.23
Warmest 7th 2016 +0.68 +1.22
Ties: 2003, 2005
RSS i +0.18 +0.32 Coolest 30th 1985 -0.40 -0.72 +0.13 +0.23
Warmest 11th 2016 +0.67 +1.21

Mid-troposphere

May Mid-troposphere
May Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.13 +0.23 Coolest 29th 2008 -0.29 -0.52 +0.07 +0.13
Warmest 12th 1998 +0.58 +1.04
RSS i +0.11 +0.20 Coolest 28th 1989 -0.31 -0.56 +0.08 +0.14
Warmest 12th 1998 +0.60 +1.08
Ties: 2004
STAR i +0.14 +0.25 Coolest 27th 1989 -0.35 -0.63 +0.11 +0.20
Warmest 13th 1998 +0.59 +1.06
Ties: 2007
UW-UAH +0.19 +0.34 Coolest 32nd 1989 -0.33 -0.59 +0.12 +0.21
Warmest 9th 1998 +0.66 +1.19
UW-RSS +0.16 +0.29 Coolest 31st 1989 -0.38 -0.68 +0.12 +0.21
Warmest 10th 1998 +0.68 +1.22
March-May Mid-troposphere
March–
May
Anomaly Rank
(out of 40 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.14 +0.25 Coolest 30th 1993 -0.30 -0.54 +0.07 +0.13
Warmest 10th 1998, 2016 +0.57 +1.03
Ties: 2003
RSS i +0.13 +0.23 Coolest 30th 1993 -0.32 -0.58 +0.08 +0.14
Warmest 11th 1998 +0.58 +1.04
UW-UAH +0.22 +0.40 Coolest 34th 1993 -0.36 -0.65 +0.12 +0.22
Warmest 6th 2016 +0.69 +1.24
Ties: 2002
UW-RSS +0.20 +0.36 Coolest 33rd 1993 -0.39 -0.70 +0.12 +0.22
Warmest 8th 2016 +0.68 +1.22
RATPAC* +0.42 +0.76 Coolest 57th 1965 -0.92 -1.66 +0.16 +0.29
Warmest 5th 2016 +0.94 +1.69

*RATPAC rank is based on 61 years of data

Year-to-Date Mid-troposphere
January–
May
Anomaly Rank
(out of 40 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.14 +0.25 Coolest 28th 1993 -0.28 -0.50 +0.08 +0.15
Warmest 12th 2016 +0.59 +1.06
Ties: 2007
RSS i +0.13 +0.23 Coolest 28th 1989, 1993 -0.30 -0.54 +0.09 +0.15
Warmest 13th 2016 +0.59 +1.06
STAR i +0.14 +0.25 Coolest 27th 1989 -0.33 -0.59 +0.11 +0.20
Warmest 13th 2016 +0.59 +1.06
Ties: 2006
UW-UAH +0.22 +0.40 Coolest 33rd 1993 -0.35 -0.63 +0.13 +0.24
Warmest 7th 2016 +0.70 +1.26
Ties: 2005, 2013, 2015
UW-RSS +0.20 +0.36 Coolest 29th 1993 -0.38 -0.68 +0.13 +0.24
Warmest 11th 2016 +0.70 +1.26
Ties: 2013
RATPAC* +0.46 +0.83 Coolest 56th 1965 -0.93 -1.67 +0.17 +0.30
Warmest 6th 2016 +1.02 +1.84

*RATPAC rank is based on 61 years of data

Stratosphere

May Stratosphere
May Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.32 -0.58 Coolest 9th 2011 -0.65 -1.17 -0.26 -0.47
Warmest 31st 1992 +0.91 +1.64
Ties: 2017
RSS i -0.27 -0.49 Coolest 10th 2011 -0.61 -1.10 -0.22 -0.39
Warmest 31st 1992 +0.89 +1.60
STAR i -0.22 -0.40 Coolest 12th 2011 -0.54 -0.97 -0.20 -0.36
Warmest 28th 1992 +0.90 +1.62
Ties: 1999
March-May Stratosphere
March–
May
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.45 -0.81 Coolest 4th 2012 -0.52 -0.94 -0.26 -0.47
Warmest 37th 1992 +1.04 +1.87
RSS i -0.39 -0.70 Coolest 6th 2012 -0.49 -0.88 -0.22 -0.40
Warmest 35th 1992 +1.02 +1.84
STAR i -0.39 -0.70 Coolest 3rd 2016 -0.46 -0.83 -0.22 -0.39
Warmest 37th 1992 +1.03 +1.85
Ties: 1999, 2008
Year-to-Date Stratosphere
January–
May
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.44 -0.79 Coolest 4th 2012 -0.55 -0.99 -0.28 -0.50
Warmest 37th 1983 +1.14 +2.05
RSS i -0.39 -0.70 Coolest 4th 2012 -0.51 -0.92 -0.24 -0.43
Warmest 36th 1983 +1.09 +1.96
Ties: 2016
STAR i -0.38 -0.68 Coolest 3rd 2012 -0.47 -0.85 -0.23 -0.41
Warmest 37th 1983 +1.06 +1.91
Ties: 2006

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 NCEI'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 Centers for Environmental Information, State of the Climate: Upper Air for May 2018, published online June 2018, retrieved on July 17, 2018 from https://www.ncdc.noaa.gov/sotc/upper-air/201805.

Metadata