Top of Model Setting
Posted: February 10th, 2023, 7:21 am
Hello,
I'm trying to compare HYSPLIT simulation concentration results (Horizontal Gaussian with vertical particle motion) to satellite-inferred concentration data. As the satellite data is integrated over the total column (according to documentation approx. 35-40km), the dispersion model is set at the same top of model.
Here is where my question comes in:
As I'm using the GDAS meteorological dataset, the lowest pressure level is 20 hPa, which corresponds to about 24km. How is HYSPLIT calculating the (average) column concentration above 25km? On a particle faction basis (pollutant to air, molar) , the results of maximum concentration difference is ~40% when comparing dispersion simulations conducted at 25 vs 35km.
From my understanding, the amount (moles) of air should not be contributing that much to the average concentration.
Thank you in advance.
I'm trying to compare HYSPLIT simulation concentration results (Horizontal Gaussian with vertical particle motion) to satellite-inferred concentration data. As the satellite data is integrated over the total column (according to documentation approx. 35-40km), the dispersion model is set at the same top of model.
Here is where my question comes in:
As I'm using the GDAS meteorological dataset, the lowest pressure level is 20 hPa, which corresponds to about 24km. How is HYSPLIT calculating the (average) column concentration above 25km? On a particle faction basis (pollutant to air, molar) , the results of maximum concentration difference is ~40% when comparing dispersion simulations conducted at 25 vs 35km.
From my understanding, the amount (moles) of air should not be contributing that much to the average concentration.
Thank you in advance.