Changes between Version 12 and Version 13 of ticket/298/TicketSummary/IASISingleObsTest


Ignore:
Timestamp:
May 31, 2017 2:03:38 PM (2 years ago)
Author:
Jin Lee
Comment:

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  • ticket/298/TicketSummary/IASISingleObsTest

    v12 v13  
    33== Aim ==
    44
    5 This test is a part of the H-8 AHI trial. As the weighting functions of IASI channels peak sharply the analysis increments can be better understood.
     5The vertical profile of analysis increments from assimilating a single AHI CSR channel observation had complicated structure. For example when a channel observation whose weighting function was mostly in lower troposphere was assimilated the resulting analysis increments were not confined vertically to the peak of the weighting function. To better understand vertical spreading of analysis increments a single-observation test using IASI channel obs is attempted. As the weighting functions of IASI channels peak sharply the analysis increments should be more confined vertically.
    66
    77== Experimental Set-up ==
     
    1818Experiment was done using suite ID u-am568 (copy of u-aj730/trunk@40220). I made following modifications to progressively arrive at the target configuration outlined above,
    1919
    20    * ensemble and hybrid VAR are switched off (job !#1)
    21    * turned off VarBC (job !#2)
    22    * copied screen 3DVAR app config file then made following changes
    23      * point to locations of LS, varobs and varcx
    24      * turned on 3DVAR - it appears all observations supplied are used, so this is FGAT 3DVAR (job !#3)
    25    * following the changes in u-aj977 Ops_ExtractAndProcess for AHI CSR selected smaller number of IASI observations
    26      * turned on !SatRad NetCDF write
    27      * then a single FOV was selected using extractcontrolnl: this passed QC and thinning and was the only FOVS in varobs; the FOV had a coordinates of 83.77021 degE, -28.4431 degN (N.B. !SatRad 1DVAR identified a cloud with CTP=686 hPa)
    28    * following the changes in the Var_AnalysePF tasks of u-aj977 assimilated a single IASI FOV
    29       * a gridpoint nearest the FOV was selected: cubes[2].coord('longitude').points[148]=83.53125 and cubes[2].coord('latitude').points[164]=-28.3125
    30       * the max in the vertical profile of analysis increment for theta and u occurs near the model top; for qT it is below tropopause
    31    * Changed `IASI_channels_Var.nl` to assimilate a single channel obs: MetDB ch70
     201. Ensemble and hybrid VAR are switched off (job 01)
     21
     222. Turned off VarBC (job 02)
     23
     243. Set up 3DVAR task
     25   a. copied screen 3DVAR app config file then made following changes
     26      * point to locations of LS, varobs and varcx
     27      * turned on 3DVAR - it appears all observations supplied are used, so this is FGAT 3DVAR (job 03)
     28
     294. Selected a single FOV which passed to VAR
     30   a.following the changes in u-aj977 Ops_ExtractAndProcess for AHI CSR selected smaller number of IASI observations
     31   b. turned on !SatRad NetCDF write: using this selected a FOV that passed to VAR
     32   c. then a single FOV was selected using extractcontrolnl: this passed QC and thinning and was the only FOVS in varobs; the FOV had a coordinates of 83.77021 degE, -28.4431 degN (N.B. !SatRad 1DVAR identified a cloud with CTP=686 hPa)
     33
     345. Assimlated the single FOV using 3DVAR
     35   a. following the changes in the Var_AnalysePF tasks of u-aj977 assimilated a single IASI FOV
     36   b. a gridpoint nearest the FOV was selected: `cubes[2].coord('longitude').points[148]=83.53125` and `cubes[2].coord('latitude').points[164]=-28.3125`
     37   c. the max in the vertical profile of analysis increment for theta and u occurs near the model top; for qT it is below tropopause
     38
     396. Selected a single channel observation
     40   a. changed `/home/548/jtl548/da/suite/nwp_input/ops_var/Data/SatRad_coeffs/bom/users/u-am568/aps3_r00_my00.default@38138/IASI_channels.nl` to allow only MetDB channel 70 to be selected
     41
     42   '''Note''' I could have changed `IASI_channels_Var.nl` but decided to change OPS channel selection file as I could make sure that no other channels were selected
    3243
    3344== !ToDo ==