V. 7.03

 
     
Home
What's New?
FAQ
Overview
Future Updates
Sample Domain
Presentations
What's new about version 7.03?

Version 7.03 includes a revision to the convergence criteria in the gas phase chemistry that avoids overestimation of NOx and/or ozone during extremely stagnant meteorological conditions. Our testing indicates that on days that had run without problems, the changes are small, about 5% or so, with the largest changes in gas phase species such as NO, NO2, and ozone. Some smaller changes appear in species that are influenced by the gas phase chemistry, such as SO4 and PNO3. Species that should not be affected by gas phase chemistry (e.g., PEC) remained unchanged in our tests. The cpu time in our tests was increased by less than 10%.

For those of you who are interested in the new code, here is the change made to subroutine  step4_fst.f:

      if (hold(l).gt.1.0e-9) then
      err=abs(rate(l)/hold(l))
      else
      err=abs(rate(l))
      endif
      hold(l)=tmphh + rate(l)
      if (err.gt.tmpmax) then
      tmpmax=err
      endif
c     if (hold(l).le. 0.0) hold(l)=tmphh/10.                     ! comment out this line
      if (hold(l).le. -bdnl(l)) tmpmax = 10.*rerror             ! add this line
      160 continue

 

Back to What's New

Back to Software