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w2.wrn message

Tue, 05/11/2010 - 1:11am — Oliver_O
Hi, I am running a model for approximately 1000 Julian Days but the model stops at JDAY= 607.150 and the w2.wrn files shows me the following message: Computational warning at Julian day = 607.150 at segment 2 timestep = 1.000 water surface deviation [Z] = 1.024 m layer thickness = -0.024 m How can I fix this problem? Thanks
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Hydrodynamics
Tue, 05/11/2010 - 12:20pm — chris

Hi, It sounds like the model is becoming numerical unstable. The first thing to try is reduce the maximum time step (DLTMAX) for the time period around JDAY 607. Another possibility is that the depth is becoming too shallow (due to reduced flow rates) which can cause numerical instability. You could try narrowing the bottom-most layer of segment 2 so that the water depth in the segment does not become too shallow. Hope this helps, Chris
Tue, 05/11/2010 - 10:23pm — Oliver_O

Hi Chris, Thanks for answering my question. However, I still have a couple of questions: 1) Should I specify DLTMAX for JDAY 607 as follows: DLT CON NDT DLTMIN 1 1.00000 DLT DATE DLTD DLTD DLTD DLTD DLTD DLTD DLTD DLTD DLTD 1.00000 607.00 DLT MAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX 3600.00 100.000 DLT FRN DLTF DLTF DLTF DLTF DLTF DLTF DLTF DLTF DLTF 0.90000 2) I made the following changes from the default values and the model did not crash: EDDY VISC AZC AZSLC AZMAX WB 1 W2 EXP 0.00010 and I set ETSR=0.000 The model did not crash but in the tsr1.opt file displayed negative horizontal velocities [U] which were not displayed before when I set ETSR=-1.00. Did I do something wrong? Thanks again for your help.
Wed, 06/02/2010 - 1:13pm — chris

Hi, You'll need to adjust your cards so the second DLTD is read in (set NDT to 2). You'll also need a second value for DLTF (it can still be 0.9): DLT CON NDT DLTMIN 2 1.00000 DLT DATE DLTD DLTD DLTD DLTD DLTD DLTD DLTD DLTD DLTD 1.00000 607.00 DLT MAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX DLTMAX 3600.00 100.000 DLT FRN DLTF DLTF DLTF DLTF DLTF DLTF DLTF DLTF DLTF 0.90000 0.90000 With ETSR set to 0.0 your time series output will correspond to a depth of 0, or the top active layer. With ETSR=-1.00 (the negative sign indicates to the model that you're specifying a layer number rather than a depth) you're specifying time series output for layer 1, which is always inactive. Hope this helps, Chris
Tue, 08/10/2010 - 5:11pm — Oliver_O

Hi Chris, I would like to know where I can get the Total water volume for specific output days? I have checked the snp.opt file but I only found the Spatial change [VOLSR] but I am interested in getting the total volume for different output days. I will appreciate any help. Thanks
Thu, 08/19/2010 - 3:14pm — chris

Hi, Have you tried reducing the maximum time step (DLTMAX) around Julian Day 607? Also, you might reduce the minimum possible time step DLTMIN (if it is set to 1 second) to 0.1 seconds. Chris