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bas

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About bas

  1. Thanks a lot MONS, I will give it a try. Cheers,
  2. Hi there, i have 'U' and 'V' wind components and wants to calculate monthly and seasonal average wind driection. I wonder what is the best way to do it? Thanks, Bas
  3. Hi guys, Its probably a very basic question but i've never been clear on this and also could not get a clear answer from the text books. I want to know if the residual layer is part of the atmospheric boundary layer at any time of the day both on land and water and in both high and lows pressure situations? I personally think that residul layer should be treated as part of ABL since it is resulted from diurnal and dynamical variations of ABL which means it is an affect of the surface processes. I would greatly appreciate response, comments and guidance from experts. Cheers, bas:)
  4. Hello, I want to simulate shallow convection (wet and dry) along the sea-breeze front. I am using WRF 3.5.1 in a nested grid configuration with the highest resolution gird of 500 m while i have turned off cumulus physics so that model should resolve vertical fluxes explicitly. I have two questions; a) Is this grid resolution i.e. 500 m appropriate to capture shallow convection. In the WRF physics namelist there are two options for shallow convection, first is "ishallow" which is used with cumulus parametrization and second is "shcu_physics". I wonder what "shcu_physics" actually does? is it a substitute to cu_physics and what difference it will make compared to the one with explicitly resolved vertical fluxes? I ran two test simulations with and without shcu_physics (cu_physics = 0 in both sims) and did not find any difference. Secondly is it necessary to use this scheme with YSU PBL only? I also used Mellor-Yamada and the model ran fine without any stability issues. I would appreciate if any of the wrf physics expert could respond on this. Bas:)
  5. Hi there; thanks for your help. The QCloud field does not show any clouds at any (low, middle and high) level and the entire field has 0 values, however when i use low middle and high clouds (clflo, clfmi and clfhi) from GrADS, i can see some middle level clouds at almost the same location as i get from satellite imagery. GrADS calculates clflo, clfmi, and clfhi using RH and not qc field. I just can't understand why there is such a large discrepency and which calc is should consider correct. I would appreciate if you could comment on this. Since its a high res simulation (500 m) i am not using any cumulus parameterization. I used three different micro-physics schemes (WSM6, Lin et al. and Thompson) and getting the same results. best, bas:)
  6. Hi everyone, I want to calculate low, middle and high clouds from my WRF output. I have many cloud related fields in the wrfout file such as cloud fraction, cloud water mixing ratio, RH, graupel mixing ratio, water vapor mixing ratio etc., but not sure how to calculate what i want. Will greatly appreciate any help. bas:)
  7. Thanks. I am now clear on this. I have few more questions but first want to complete some analysis. Cheers, bas:)
  8. Thanks for this. Ok, i will try this and plot delta T over the vertical layers. I have simulated sea breeze over the red sea and trying to see if convection initiated along the front over the dry desert boundary layer. I could not very well understand the plot on the SPC's mesoanalysis page though. Would appreciate if you could explain it in a bit detail. cheers, bas:)
  9. Hi everyone, I am new to the forum. I have a question about convection. We can identify moist convection by cloud formation and rardar reflectivity; I wonder how could i capture/indentify dry convection especially in the model output? Regards, bas:)