Temp on neptune
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Temperature on Neptune: An Overview
Upper Atmosphere Temperature on Neptune
The temperature of Neptune's upper atmosphere has been a subject of extensive study. Observations from the occultation of BD -17° 4388 by Neptune in 1968 revealed that the upper atmosphere temperatures are around 140 K near the 5 × 10^14 cm^-3 level, with a complex and nonisothermal structure1. Further analysis of the 1981 occultation of an uncatalogued star indicated mean temperatures of 140 ± 10 K and 154 ± 10 K at different latitudes, suggesting global atmospheric layering7. Another study reanalyzing the Mount Stromlo observations found a temperature of 135 K at a number density of 1000 trillion per cubic centimeter, with local fluctuations of 5 to 10 K8.
Stratospheric Temperature and Composition
Neptune's stratosphere has been observed to have a temperature of approximately 168 K near 1-10 μbar pressure, with an uncertainty of ±10 K2. High-resolution thermal-infrared observations in 2007 revealed global-average temperatures of 163.8 ± 0.8 K, 155.0 ± 0.9 K, and 123.8 ± 0.8 K at different pressure levels, with no significant meridional variations9. These temperatures are consistent with previous measurements, indicating a quasi-isothermal structure above the 0.1-mbar level10.
Tropospheric Temperature and Seasonal Variability
The tropospheric temperature profile of Neptune has been derived from various observations. Voyager 2 data indicated temperatures of 72 ± 2 K at the 1-bar pressure level, with the tropopause detected approximately 40 km above this level at a pressure of about 100 mbar and a temperature of 52 ± 2 K6. Infrared observations from Voyager 2 also provided temperature maps between 80°S and 30°N, showing a relatively warm pole and equator with cooler mid-latitudes, similar to the behavior found on Uranus4. Seasonal changes in Neptune's zonal mean temperatures between 2003 and 2007 showed that stratospheric temperatures remained consistent, with variations of less than ±5 K at 1 mbar and ±3 K at 0.1 mbar during the solstice period10.
Effective Temperature and Internal Heat Source
The effective temperature of Neptune has been estimated to be around 59.3 ± 1.0 K4, with another study suggesting an effective temperature of 58.4 K, implying the presence of an internal heat source equal to about 1.6 times the solar-absorbed power5. This internal heat source contributes to the overall thermal structure of the planet.
Conclusion
Neptune's atmospheric temperature varies significantly across different layers and latitudes. The upper atmosphere exhibits a complex temperature structure, while the stratosphere shows a quasi-isothermal profile with minimal seasonal variability. The troposphere has a distinct temperature profile with a warm equator and pole, and cooler mid-latitudes. The effective temperature and internal heat source play crucial roles in shaping Neptune's thermal environment. These findings provide a comprehensive understanding of the temperature dynamics on Neptune, contributing to our knowledge of the outer planets in our solar system.
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Most relevant research papers on this topic
The upper atmosphere of Neptune: An analysis of occultation observations
Neptune's upper atmosphere has temperatures of 140°K, with complex temperature structures and minimal diurnal variations, and an average temperature decrease of less than 15°K between 0° and 55° latitude.
Thermal spectroscopy of Neptune: the stratospheric temperature, hydrocarbon abundances, and isotopic ratios
Neptune's stratospheric temperature is 168 K near 1-10 bar pressure, with an uncertainty of 10 K, and its hydrocarbon abundances are consistent with previous measurements.
Ultraviolet Spectrometer Observations of Neptune and Triton
Neptune's upper atmosphere is mostly hydrogen, with methane, acetylene, and ethane at lower levels, and Triton's atmosphere mainly consists of molecular nitrogen with traces of methane near the surface.
Highly CitedInfrared Observations of the Neptunian System
Neptune has a warm pole and equator with cooler mid-latitudes, similar to Uranus, and strong longitudinal thermal structure.
Highly CitedIndications of supersaturated stratospheric methane in Neptune from its atmospheric thermal profile
Neptune's atmospheric thermal profile suggests a strong supersaturation of methane in the upper atmosphere, suggesting an internal heat source equal to 1.6 times solar-absorbed power.
The atmosphere of Neptune : an analysis of radio occultation data acquired with Voyager 2
Neptune's atmosphere consists of 78-84 percent hydrogen at the tropopause, with a temperature of 52 +/-2 K, and the 1-bar isobaric surface has a temperature of 72 +/-2 K.
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