Tropopsphere

Lower Troposphere

February Lower Troposphere
February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.76 +1.37 Coolest 41st 1985 -0.48 -0.86 +0.16 +0.29
Warmest 2nd 2016 +0.86 +1.55
RSS +0.82 +1.48 Coolest 41st 1985 -0.43 -0.77 +0.21 +0.38
Warmest 2nd 2016 +1.03 +1.85
December-February Lower Troposphere
December–February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.63 +1.13 Coolest 41st 1985 -0.34 -0.61 +0.15 +0.27
Warmest 1st 2020, 2016 +0.63 +1.13
Ties: 2016
RSS +0.73 +1.31 Coolest 41st 1985 -0.40 -0.72 +0.20 +0.36
Warmest 2nd 2016 +0.80 +1.44
Year-to-Date Lower Troposphere
January–February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.66 +1.19 Coolest 41st 1985 -0.39 -0.70 +0.16 +0.28
Warmest 2nd 2016 +0.71 +1.28
RSS +0.76 +1.37 Coolest 41st 1989 -0.39 -0.70 +0.21 +0.37
Warmest 2nd 2016 +0.87 +1.57

Mid-troposphere

February Mid-troposphere
February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.68 +1.22 Coolest 41st 1986 -0.34 -0.61 +0.11 +0.20
Warmest 2nd 2016 +0.77 +1.39
RSS +0.75 +1.35 Coolest 41st 1986 -0.39 -0.70 +0.15 +0.28
Warmest 2nd 2016 +0.85 +1.53
December-February Mid-troposphere
December–February Anomaly Rank
(42 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.56 +1.01 Coolest 42nd 1984 -0.29 -0.52 +0.10 +0.18
Warmest 1st 2020 +0.54 +0.97
RSS +0.63 +1.13 Coolest 42nd 1984 -0.34 -0.61 +0.14 +0.25
Warmest 1st 2020 +0.62 +1.12
RATPAC* +0.97 +1.75 Coolest 62nd 1965 -1.02 -1.84 +0.19 +0.34
Warmest 2nd 2016 +1.02 +1.84

*RATPAC rank is based on 63 years of data

Year-to-Date Mid-troposphere
January–February Anomaly Rank
(42 years*)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.61 +1.10 Coolest 41st 1984 -0.32 -0.58 +0.11 +0.20
Warmest 2nd 2016 +0.62 +1.12
RSS +0.67 +1.21 Coolest 41st 1984 -0.37 -0.67 +0.15 +0.27
Warmest 2nd 2016 +0.70 +1.26
RATPAC* +0.97 +1.75 Coolest 62nd 1965 -0.96 -1.73 +0.18 +0.33
Warmest 2nd 2016 +1.13 +2.03

*RATPAC rank is based on 63 years of data

Stratosphere

Lower Stratosphere

February Lower Stratosphere
February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.23 +0.41 Coolest 33rd 2012 -0.67 -1.21 -0.27 -0.49
Warmest 10th 1983 +1.32 +2.38
RSS +0.29 +0.52 Coolest 33rd 2012 -0.58 -1.04 -0.21 -0.38
Warmest 10th 1983 +1.24 +2.23
December-February Lower Stratosphere
December–February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH -0.07 -0.13 Coolest 27th 2019 -0.64 -1.15 -0.29 -0.53
Warmest 16th 1983 +1.37 +2.47
RSS +0.01 +0.02 Coolest 29th 2006 -0.50 -0.90 -0.23 -0.42
Warmest 13th 1983 +1.29 +2.32
Ties: 1991
Year-to-Date Lower Stratosphere
January–February Anomaly Rank
(42 years)
Record Years Decadal Trend
°C °F Year °C °F °C °F
UAH +0.07 +0.13 Coolest 31st 2019 -0.66 -1.19 -0.29 -0.51
Warmest 12th 1983 +1.36 +2.45
RSS +0.15 +0.27 Coolest 33rd 2006 -0.55 -0.99 -0.23 -0.41
Warmest 10th 1983 +1.29 +2.32

Background

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, Monthly Upper Air Report for February 2020, published online March 2020, retrieved on March 18, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/upper-air/202002.