Discussion Overview
The discussion centers on the conditions required for gaseous H2O to emit infrared (IR) photons, specifically in the ten-micron wavelength range. Participants explore the temperature and pressure necessary for this emission, as well as the comparison of water vapor's IR radiation to that of a blackbody. The conversation also touches on the implications of these emissions in atmospheric science.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant inquires about the temperature and pressure conditions required for H2O gas to emit photons in the ten-micron range.
- Another participant suggests that the emission occurs at room temperature, but this claim is reiterated without further elaboration.
- A participant mentions that the emission is related to black body radiation and references the peak frequency corresponding to temperature.
- There is a question about the amount of IR light radiated by water vapor compared to a blackbody, with a suggestion that water vapor may not be a very good blackbody.
- One participant suggests looking into the context of weather forecasting, noting the use of IR satellite photos of water vapor.
- Another participant states that water vapor is fairly transparent to the ten-micron wavelength, contrasting it with liquid water, which absorbs this wavelength effectively.
- This same participant explains that the ten-micron band contributes to terrestrial IR emissions and affects nighttime temperatures in cloudy conditions.
Areas of Agreement / Disagreement
Participants express differing views on the conditions for IR emission from H2O gas, with some suggesting room temperature suffices while others provide additional context regarding transparency and absorption characteristics. The discussion remains unresolved regarding the specific temperature and pressure requirements.
Contextual Notes
Participants do not reach consensus on the exact conditions for IR photon emission, and there are varying interpretations of water vapor's properties in relation to blackbody radiation.