Are there any linked Issues or Pull Requests?
MetOffice/um#61 / MetOffice/um#71
MetOffice/ukca#30 / MetOffice/ukca#32
Brief description
Within UKCA, N2O5 hydrolysis
N2O5 + H2O --> HONO2 + HONO2
is actually covered by 2 separate reactions, H04 and B85. There is actually considerable overlap of these reactions in the troposphere, leading to overcounting.
A fix is to ensure, using the tropospheric mask, that only H04 works in the stratosphere and B85 only works in the troposphere.
This will be controlled with a temporary logical and changes are required to the UKCA (MetOffice/ukca#30) to account for this. This issue was originally identified by Dr Yao Ge (@yg460-cam) in Cambridge and she provided the original code changes at UM13.9.
Further details of the issue.
Initially the logical, l_fix_ukca_n2o5_h2o, will be hard-coded to .false. in the UKCA interface, as this fix is targetting UKESM2. Later changes will be made to allow for this logical to be passed via namelist.
Are there any linked Issues or Pull Requests?
MetOffice/um#61 / MetOffice/um#71
MetOffice/ukca#30 / MetOffice/ukca#32
Brief description
Within UKCA, N2O5 hydrolysis
N2O5 + H2O --> HONO2 + HONO2
is actually covered by 2 separate reactions, H04 and B85. There is actually considerable overlap of these reactions in the troposphere, leading to overcounting.
A fix is to ensure, using the tropospheric mask, that only H04 works in the stratosphere and B85 only works in the troposphere.
This will be controlled with a temporary logical and changes are required to the UKCA (MetOffice/ukca#30) to account for this. This issue was originally identified by Dr Yao Ge (@yg460-cam) in Cambridge and she provided the original code changes at UM13.9.
Further details of the issue.
Initially the logical,
l_fix_ukca_n2o5_h2o, will be hard-coded to.false.in the UKCA interface, as this fix is targetting UKESM2. Later changes will be made to allow for this logical to be passed via namelist.