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### How to calculate total mass accumulated in a colum?

Posted: **May 21st, 2013, 2:57 pm**

by **tschonholz**

I was wondering how to calculate accumulated mass in a column (in tn/ km^2 maybe) for a volcanic ash run.

I was using concentration but it's not representative of the case.

Thanks for any advice.

### Re: How to calculate total mass accumulated in a colum?

Posted: **May 23rd, 2013, 7:52 am**

by **barbara.stunder**

To get the mass in a column, multiply the concentration by the depth of the column over which the concentration is calculated.

Amount of mass in the eruption, height of the eruption, and how quickly the particles fall out can all affect the results.

### Re: How to calculate total mass accumulated in a colum?

Posted: **May 26th, 2013, 11:50 pm**

by **tschonholz**

Thank you for your reply.

But there is no way to actually get it done by GUI, right?

I want to compare the outcome of HYSPLIT with other dispersion models, and they seem to show results in mass accumulated in a colum.

May it be possible?

Thanks a lot! I´m learning so much!

### Re: How to calculate total mass accumulated in a colum?

Posted: **May 28th, 2013, 8:07 am**

by **barbara.stunder**

We plan to add output as mass loading for volcanic ash, but that is not available yet.

Through the web, it is not possible to multiply the output by a constant. Through the PC GUI, on the "Concentration Display" window there is an entry "Concentration multiplier" where this can be done.

### Re: How to calculate total mass accumulated in a colum?

Posted: **March 6th, 2014, 4:13 pm**

by **tschonholz**

Do we have any advance in this or still planning?

Thanks!!

### Re: How to calculate total mass accumulated in a colum?

Posted: **March 18th, 2014, 2:34 pm**

by **barbara.stunder**

Yes, for volcanic ash simulations, mass loading is output under the "(NEW) Compute archive volcanic ash concentrations" at

http://www.ready.noaa.gov/HYSPLIT_ash.php