Precision lower stratospheric temperature monitoring with the MSU: Technique, validation, and results 1979-1991

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Journal of Climate; (United States)

DOI:https://doi.org/10.1175/1520-0442(1993)006<1194:PLSTMW>2.0.CO;2· OSTI ID:6019338

Spencer, R W ^[1]; Christy, J R ^[2]

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1. NASA Marshall Space Flight Center, AL (United States)
2. Univ. of Alabama, Huntsville (United States)

Microwave Sounding Unit channel 4 data from the TIROS-N series of NOAA satellites provide a continuous global record of deep-layer averaged lower stratospheric temperatures during 1979-1991. A 13-year record of temperature anomalies is time averaged into pentads and months on a 2.5[degrees] grid. The monthly gridpoint anomalies are validated with ten years of radiosonde data during 1979-88. Each satellite's measurements no measurable instrumental drift at the level of 0.01[degrees]C yr[sup [minus]1]. Intercomparisons between NOAA-6 and NOAA-7 anomalies indicate monthly gridpoint precision of 0.05[degrees] C in the tropics to around 0.10[degrees]C in the extratropics, and signal-to-noise ratios generally over 500, while global monthly precision is 0.01[degrees] to 0.02[degrees]C. These precision and stability statistics are much better than have been previously reported by other investigators for MSU channel 4. Investigations of the possible sources of the discrepancy lead us to suspect that the gradual transition from on-site calibration of sondes with thermometers to factory calibration of sondes around 1982 might have caused a change in the calibration. The largest globally averaged temperature variations during 1979-91 occur after the El Chichon (1982) and Pinatubo (1991) volcanic eruptions. These warm events are superimposed upon a net downward trend in temperatures during the period. This cooling trend has more of a step function than linear character, with the step occurring during the El Chichon warm event. It is strongest in polar regions and the Northern Hemisphere middle latitudes. These characteristics are qualitatively consistent with radiative adjustments expected to occur with observed ozone depletions. 28 refs., 9 figs., 1 tab.

• OSTI ID: 6019338
• Journal Information: Journal of Climate; (United States), Journal Name: Journal of Climate; (United States) Vol. 6:6; ISSN JLCLEL; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
540120 -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (1990-)
ANNUAL VARIATIONS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CLIMATIC CHANGE
CRYOSPHERE
EARTH ATMOSPHERE
EARTH PLANET
ELECTRONIC EQUIPMENT
EQUIPMENT
GLOBAL ASPECTS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
MONITORING
NORTHERN HEMISPHERE
OXIDES
OXYGEN COMPOUNDS
OZONE
PLANETS
POLAR REGIONS
SATELLITES
STRATOSPHERE
TEMPERATURE MONITORING
THERMOMETERS
VARIATIONS
VOLCANOES