Astronomy - Ch. 9.1: Earth's Atmosphere (32 of 61) What is the Lapse Rate?
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- čas přidán 9. 10. 2018
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In this video I will explain what is the lapse rate in the troposphere. The lapse in the troposphere is -6.5 degrees Celsius for every kilometer increase in elevation.
Next video in this series can be seen at:
• Astronomy - Ch. 9.1: E...
Excellent explanation, thank you!
Wonderful sir ....
Doctor please help me. I have 15 years radiosonde temperature data, so how can I determine the lapse rate tropopause temperature and the lapse rate tropopause height at these given data? thank you
Without seeing the data, it will be difficult for me to give you advise. But assuming that you have temperature data at various altitudes and for various locations, I would do two things. First I would place columns of data on a map showing how the temperature changes at different locations (and also noting the time of year, since that will change with the seasons). Then I would average out the columns of temperature data for a number of sets, depending how they were geographically distributed. Hope that helps.
@@MichelvanBiezen I appreciate your help. I have gotten the new idea from you. in theory cold point tropopause temperature is the coldest temperature at a given data and th corresponding this temperature is cold point tropopause height but I haven't any idea how to determine the lapse rate tropopause temperature and its corresponding height? anyway thank you
But what about the Adiabatic Lapse Rate in the atmosphere ?
That is 9.8 °C per km.
That accounts for a huge portion of the stratification of temperatures in the atmosphere.
For example - on Jupiter the Adiabatic Lapse Rate is around 10 °C per 10 km and there are no greenhouse gases
in Jupiter's atmosphere. (primarily hydrogen and helium)
What is the question? Any question starting with "what about ......" can be interpreted in many ways.
@@MichelvanBiezen
I apologise - its a cultural difference in language use.
My question is regarding my own confusion about the temperature lapse rate you describe in this
video of 6.5°C/Km *due to greenhouse gasses* and how it relates to The Adiabatic Lapse Rate (dry)
at 9.8°C/Km. - with gravity being the force applied.(ideal gas laws)
I know that the two are not combined to give 16.3°C/Km but how do they inter-relate?
Many thanks for your response.
The adiabatic lapse rate (also known as the dry adiabatic lapse rate) is the theoretical rate at which temperature of the air should be cooling down with increasing altitude. In the real world we don't have dry air, and the water vapor concentration varies a lot over time, over regions, and due to weather changes. With the additional moisture in the air, the lapse rate is typically less than the theoretical rate. Also keep in mind that convection currents, jet streams, wind, and other weather phenomenon will cause a lot of variation in the lapse rate.
@@MichelvanBiezen
Many thanks for your response. I appreciate it.
I am really enjoying your videos on earths atmosphere - and learning so much.
Your presentation style is excellent.
As I now understand it - the stratification of temperature in the atmosphere is the result
of both the green house effect and the adiabatic lapse rate combined.
@@burgesspark685 "its a cultural difference in language use". Absolutely it is if the culture is Muppet from Fraggle Rock. Fraggle Culture !
the average lapse rate between this level and all higher levels within 2 km
does not exceed 2 K/km. What does that mean, Sir?
That means that on average (many points sampled and averaged out), the change in temperature with increasing height, does not exceed 2 degrees per 1000 m gained.
@@MichelvanBiezen I appreciate your politeness, but some journals said above the tropopause it exceeds 3K/km
Yes, the comment was referencing the troposphere. The rate will be different for the higher atmospheric layers.
That is the wrongest explanation I have ever seen. The 9.8K/km lapse rate can be calculated quite simply using the force of gravity and specific heat capacity of air. Basically, there is a trade off between kinetic/thermal energy and potential energy. The total 'potential temperature' (Google it) is the same at all altitudes, because it is kinetic/thermal energy plus potential energy. Then that comes down to 6.5 K/km because the latent heat of evaporation works in the other direction - it cools the surface where evaporation happens and warms higher altitudes when it condenses. It has nothing to do with 'greenhouse gases'. Must try harder!
The waffle about the slow migration of heat from GHG was probably a giveaway that the incorrect explanation was given. It is supposed to be an adiabatic process, so there should not be heat transfer between molecules. Of course the real world lapse rate does have some heat transfer especially from water vapour.
dont think i can trust a guy who wears a bowtie like that