Revisiting the Water Vapor Feedback

[blizzard1024]

I have been looking at the monthly upper level specific humidities recently from the NCEP reanalysis data and there continues to be a downward trend evident at the high levels of the troposphere. Radiatively, this is where is counts. Lower level humidities or vapor pressure do little to contribute to the greenhouse effect so a rise in low-level water vapor is not important to the radiative balance at the theoretical TOA.  See: 

 

It is also interesting to look at NASA's NVAP data which apparently was goes to 2011 but they only released the data 1988 to 2001. (Hmm, I wonder why...).

 

This data from satellite confirms the  drop in upper level moisture. This is very close to the radiosonde measurements too which validates them at least since the late 1980s. Maybe the earlier records of radiosonde water vapor were bad as the alarmists say, who knows? But you can see a downward trend in upper level water vapor at least since the late 1980s. This would cancel all the effect of increasing CO2 and hence invalidate the whole theory that CO2 is leading to warming.  This is very inconvenient. It shows a negative water vapor feedback. And where can I find the rest of the NVAP data? Also where is the AIRS data? I really would like to see that dataset. I have read it shows moistening up high. It is impossible to find. If you can find it please share. Thank you.  

 

 

[chubbs]

Below is upper troposphere humidity (UTH) chart from recently released AMS state of the climate report. As expected, relative humidity in the upper troposphere is flat, indicating an increase in water vapor since temperatures are increasing.  Many of the charts on the "climate4you" site are bad data or misleading.

https://www.ametsoc.org/index.cfm/ams/publications/bulletin-of-the-american-meteorological-society-bams/state-of-the-climate/

[blizzard1024]

why does the upper tropospheric specific humidity fall on the NVAP and upper air sounding data? They just swept this under the rug. I want to see specific humidities and also compare it to ENSO.  Are you saying NCEP/NOAA is unreliable?  climate4you  is taking their datasets. 

[chubbs]

5 hours ago, blizzard1024 said:

why does the upper tropospheric specific humidity fall on the NVAP and upper air sounding data? They just swept this under the rug. I want to see specific humidities and also compare it to ENSO.  Are you saying NCEP/NOAA is unreliable?  climate4you  is taking their datasets. 

Yes, NCEP is unreliable vs other re-analysis products. This was established 10 years ago, yet climate4you continues to display the unreliable data.  I don't trust any chart from that site.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JD014192

 

[chubbs]

Water vapor feedback is very well established in climate models and observations. The feedback is well explained by basic thermodynamic theory (below).

https://journals.ametsoc.org/jcli/article/27/19/7432/34587/An-Analytical-Model-for-Tropical-Relative-Humidity

[blizzard1024]

Thanks for the papers Chubbs. Where can I find the latest specific humidity q for the upper troposphere from these other datasets?  This is really needed. It assess the greenhouse effect in real-time. More q at 300 mb worldwide means more warming. Why is NCEP the only dataset available? I can see NCEPII also. But none of these other datasets are easily available. I would love to see a real-time comparison.   Also where can I look at the AIRs data curves for q at 300 mb?  NVAP is available until 2001 and it shows drying just like NCEP. So why are these other datasets so hidden? they would be smoking guns in the positive water vapor feedback controversy.  Thanks again for your assistance. This is at the root of the climate sensitivity issue. I wish it was easier to find said data.  That is the main reason why I started this topic....

[chubbs]

6 hours ago, blizzard1024 said:

Thanks for the papers Chubbs. Where can I find the latest specific humidity q for the upper troposphere from these other datasets?  This is really needed. It assess the greenhouse effect in real-time. More q at 300 mb worldwide means more warming. Why is NCEP the only dataset available? I can see NCEPII also. But none of these other datasets are easily available. I would love to see a real-time comparison.   Also where can I look at the AIRs data curves for q at 300 mb?  NVAP is available until 2001 and it shows drying just like NCEP. So why are these other datasets so hidden? they would be smoking guns in the positive water vapor feedback controversy.  Thanks again for your assistance. This is at the root of the climate sensitivity issue. I wish it was easier to find said data.  That is the main reason why I started this topic....

You can get some re-analysis data from KNMI climate explorer, including NCEP.  ERA5 is the most recent re-analysis product and it looks like 200+300 mb humidity is available at KNMI.  RSS has satellite total column water vapor, which is increasing as expected.

[blizzard1024]

1 hour ago, chubbs said:

You can get some re-analysis data from KNMI climate explorer, including NCEP.  ERA5 is the most recent re-analysis product and it looks like 200+300 mb humidity is available at KNMI.  RSS has satellite total column water vapor, which is increasing as expected.

Thanks Chubbs.  This is a neat tool.