Upper Air - September 2018


Troposphere

Lower Troposphere

September Lower Troposphere
September Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.14 +0.25 Coolest 25th 1984 -0.51 -0.92 +0.15 +0.27
Warmest 15th 2017 +0.54 +0.97
Ties: 1996, 2003, 2006
RSS i +0.19 +0.34 Coolest 29th 1984 -0.57 -1.03 +0.16 +0.30
Warmest 12th 2017 +0.56 +1.01
Year-to-Date Lower Troposphere
January–
September
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.22 +0.40 Coolest 34th 1985 -0.37 -0.67 +0.12 +0.22
Warmest 6th 1998, 2016 +0.56 +1.01
Ties: 2015
RSS i +0.21 +0.38 Coolest 33rd 1985 -0.38 -0.68 +0.14 +0.25
Warmest 8th 2016 +0.56 +1.01

Mid-troposphere

September Mid-troposphere
September Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.09 +0.16 Coolest 23rd 1984 -0.56 -1.01 +0.12 +0.22
Warmest 17th 2017 +0.49 +0.88
Ties: 2003, 2007
RSS i +0.09 +0.16 Coolest 21st 1984 -0.56 -1.01 +0.13 +0.24
Warmest 19th 2017 +0.47 +0.85
Ties: 1996
STAR i +0.11 +0.20 Coolest 22nd 1984 -0.63 -1.13 +0.16 +0.30
Warmest 18th 2017 +0.49 +0.88
Ties: 2004
UW-UAH +0.18 +0.32 Coolest 27th 1984 -0.64 -1.15 +0.18 +0.32
Warmest 14th 2017 +0.57 +1.03
UW-RSS +0.17 +0.31 Coolest 25th 1984 -0.63 -1.13 +0.18 +0.33
Warmest 16th 2017 +0.55 +0.99
Year-to-Date Mid-troposphere
January–
September
Anomaly Rank
(out of 40 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.15 +0.27 Coolest 32nd 1985 -0.29 -0.52 +0.09 +0.16
Warmest 8th 1998 +0.51 +0.92
Ties: 2005
RSS i +0.15 +0.27 Coolest 31st 1985 -0.28 -0.50 +0.09 +0.17
Warmest 9th 1998 +0.52 +0.94
Ties: 2013
STAR i +0.17 +0.31 Coolest 29th 1984, 1985 -0.34 -0.61 +0.12 +0.22
Warmest 11th 1998 +0.52 +0.94
Ties: 2004
UW-UAH +0.24 +0.43 Coolest 35th 1984 -0.34 -0.61 +0.14 +0.25
Warmest 6th 1998, 2016 +0.59 +1.06
UW-RSS +0.23 +0.41 Coolest 33rd 1984 -0.33 -0.59 +0.14 +0.25
Warmest 8th 1998, 2016 +0.60 +1.08
RATPAC* +0.46 +0.83 Coolest 56th 1965 -0.85 -1.53 +0.17 +0.31
Warmest 6th 2016 +0.87 +1.57

*RATPAC rank is based on 61 years of data

Stratosphere

September Stratosphere
September Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.45 -0.81 Coolest 9th 2016 -0.60 -1.08 -0.31 -0.55
Warmest 32nd 1991 +1.52 +2.74
RSS i -0.35 -0.63 Coolest 10th 2016 -0.56 -1.01 -0.25 -0.45
Warmest 30th 1991 +1.51 +2.72
Ties: 1995
STAR i -0.48 -0.86 Coolest 5th 2016 -0.67 -1.21 -0.30 -0.53
Warmest 36th 1991 +1.50 +2.70
Year-to-Date Stratosphere
January–
September
Anomaly Rank
(out of 40 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.43 -0.77 Coolest 3rd 2016 -0.52 -0.94 -0.28 -0.50
Warmest 37th 1992 +1.01 +1.82
Ties: 2008
RSS i -0.37 -0.67 Coolest 5th 2016 -0.48 -0.86 -0.24 -0.43
Warmest 36th 1992 +0.99 +1.78
STAR i -0.39 -0.70 Coolest 4th 2016 -0.49 -0.88 -0.23 -0.42
Warmest 37th 1992 +0.99 +1.78

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 September 2018, published online October 2018, retrieved on November 14, 2018 from https://www.ncdc.noaa.gov/sotc/upper-air/201809.

Metadata