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Bug #600

Nudging in the stratosphere

Added by Twan van Noije about 5 years ago. Updated about 5 years ago.

Status:
Closed
Priority:
Normal
Assignee:
-
Category:
-
Target version:
Start date:
06/29/2016
Due date:
% Done:

100%


Description

This is a continuating of the issue "HNO3 nudging in the stratosphere" from the TM5 project:

"As reported by Henk, there is a bug in the nudging of HNO3 in the stratosphere based on ODIN data.

The data are given as the ratio of the volume mixing ratios of HNO3 over O3. To calculate the corresponding target HNO3 mass in a grid box, the observed volume ratio should be multiplied by the O3 mass and the ratio of the molar mass of HNO3 over that of O3, which is about 1.31. The latter factor is currently missing.

A fix has been provided by Henk and committed to the repository (see r354)."

History

#1 Updated by Twan van Noije about 5 years ago

The code that fixes the nudging of HNO3 in the stratosphere looks alright. However, there are two remaining issues:

- The same bug as for HNO3 is also there for CO. When using ODIN, CO/O3 mass ratios are nudged to volume ratios provided in the input files (assuming the CO input files provide the same quantity as for HNO3). Thus, in the current code, stratospheric CO is nudged to much too high mixing ratios. The missing factor is about 0.58 (=28/48).

- In the code for nudging of stratospheric tracers (HNO3, CO, CH4, O3), the smoothing between consecutive months is not done in a standard way. I propose to simply apply a linear interpolation, as e.g. done in Narcisa's code for nudging surface methane.

#2 Updated by Philippe Le Sager about 5 years ago

  • Status changed from New to In Progress
  • Target version set to TM5-MP 2.0

#3 Updated by Philippe Le Sager about 5 years ago

  • Status changed from In Progress to Closed
  • % Done changed from 0 to 100

- The same bug as for HNO3 is also there for CO. When using ODIN, CO/O3 mass ratios are nudged to volume ratios provided in the input files (assuming the CO input files provide the same quantity as for HNO3). Thus, in the current code, stratospheric CO is nudged to much too high mixing ratios. The missing factor is about 0.58 (=28/48).

Fixed in r396.

- In the code for nudging of stratospheric tracers (HNO3, CO, CH4, O3), the smoothing between consecutive months is not done in a standard way. I propose to simply apply a linear interpolation, as e.g. done in Narcisa's code for nudging surface methane.

I think we agree to leave it like it is now. If not, please reopen the issue.

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