关于wrf数据画温度平流的问题探讨

supersupergirl · 发表于 2019-8-25 18:04:41

听取小伙伴意见后重新设置了下等值线范围虽然看着还是很奇怪但好像原则上也没什么问题求大佬们帮忙看看

小其其格 · 发表于 2019-8-25 22:06:21

supersupergirl 发表于 2019-8-24 15:20
此时艾特下我的大神好友@小其其格

u = f->UGRD_P0_L100_GLL0 ; get u for January
v = f->VGRD_P0_L100_GLL0 ; get u for January
lat1d = f->lat_0
lon1d = f->lon_0
p = f->lv_ISBL0
t = f->TMP_P0_L100_GLL0 ;温度
printVarSummary(lat1d)
printVarSummary(t)
tlen = dimsizes(t)
Radians = 0.0174533
R = 6378388.
nlat = dimsizes(lat1d)
nlon = dimsizes(lon1d)
dTdX = new((/tlen(0),tlen(1),tlen(2)/),typeof(t),t@_FillValue)
dlon = (lon1d(2)-lon1d(1))*Radians
do nl=0,nlat-1
dX = R*cos(Radians*lat1d(nl))*dlon ;constant at this lat
dTdX(:,nl:nl,:) = center_finite_diff_n(t(:,nl:nl,:), dX, True, 0, 2) ;中央差分 (q(n+1)-q(n-1))/(r(n+1)-r(n-1))
end do
dTdY = new((/tlen(0),tlen(1),tlen(2)/),typeof(t),t@_FillValue)
dlat = (lat1d(2)-lat1d(1))*Radians
do ml=0,nlon-1
dY = R*dlat ;constant at this lat
dTdY(:,:,ml:ml) = center_finite_diff_n(t(:,:,ml:ml), dY, True, 0, 1) ;中央差分 (q(n+1)-q(n-1))/(r(n+1)-r(n-1))
end do
advT = -(u*dTdX/dX+v*dTdY/dY)
printVarSummary(advT)
advT = advT*1.e03
advT!0 = "p"
advT!1 = "lat"
advT!2 = "lon"
advT&p = p
advT&lat = lat1d
advT&lon = lon1d
advT@long_name = "advT"
advT@units = "le-3 ks-1"
printVarSummary(advT)

复制代码

以上是我用fnl资料绘制温度平流的脚本，你照着修改一下看看

PS：我不是啥大神……ncl新手而已

尽头的尽头 · 发表于 2019-8-25 23:53:55

river 发表于 2019-8-25 17:44
是GrADS的公式，主要是我不会NCL，你应该请教NCL大神@尽头的尽头 @兰溪之水

ncl6.3版本之后新加了求平流的函数，下面的例子就是求温度平流的
http://www.ncl.ucar.edu/Document ... vect_variable.shtml

supersupergirl · 发表于 2019-8-26 16:34:22

小其其格发表于 2019-8-25 22:06
以上是我用fnl资料绘制温度平流的脚本，你照着修改一下看看

PS：我不是啥大神……ncl新手而已

是呀我用fnl数据画也是一点问题都没有但是画wrf就不行了然后我问了ncl老师他说因为fnl数据是球坐标的我这种直接用wrf输出模拟的那个dy网格距就好不需要再计算。。我觉得好像不太行因为我都已经插值过了大神觉得呢还有之前你帖子里的问题求帮忙解答！

supersupergirl · 发表于 2019-8-26 17:48:49

尽头的尽头发表于 2019-8-25 23:53
ncl6.3版本之后新加了求平流的函数，下面的例子就是求温度平流的
http://www.ncl.ucar.edu/Document ... ...

啊啊感谢！我刚尝试了一下输出全是缺省值请问大神是什么原因呢脚本如下：
tc = wrf_user_getvar(a,"tc",it)    ; T in C
rh = wrf_user_getvar(a,"rh",it)    ; relative humidity
u = wrf_user_getvar(a,"ua",it)    ; 3D U at mass points
v = wrf_user_getvar(a,"va",it)    ; 3D V at mass points
p = wrf_user_getvar(a,"p",it)
z = wrf_user_getvar(a,"z",it)
x = wrf_user_getvar(a,"XLAT",it)       ;[south_north | 141] x [west_east | 153]
y = wrf_user_getvar(a,"XLONG",it)

pressure = 700.
  tk = wrf_user_intrp3d(tc,p,"h",pressure,0.,False)
  z_p = wrf_user_intrp3d(z,p,"h",pressure,0.,False)
  rh_p = wrf_user_intrp3d(rh,p,"h",pressure,0.,False)
  u_p = wrf_user_intrp3d(u,p,"h",pressure,0.,False)
  v_p = wrf_user_intrp3d(v,p,"h",pressure,0.,False)

  tc_p = tk+273.166
  copy_VarCoords(tk, tc_p)

;Return the advected variable only (opt=0)

advT_0 = advect_var(u_p,v_p,tc_p,0,"advection of temperature","K/s",0)

printVarSummary(advT_0)

; Return the advected variable and the longitudinal (dT/dx) and latitudinal (dT/dy) gradients
; of the scalar variable (opt=1). The returned variable is of type list containing three variable

advT_1 = advect_var(u_p,v_p,tc_p,0,"advection of temperature","K/s",1)
printVarSummary(advT_1)  ; variable of type list: 3 items

; For clarity: explicitly extract the returned elements of the list variable. All meta data is present.

Tadv = advT_1[0]          ; advected quantity
Tgrx = advT_1[1]          ; longitudinal gradient
Tgry = advT_1[2]          ; latitudinal  gradient
printVarSummary(Tadv) ; advection of temperature
printVarSummary(Tgrx) ; longitudinal gradient
printVarSummary(Tgry) ; latitudinal gradient

然后各变量输出如下：
(0)    Working on time: 2018-02-28_00:30:00
(0)    advect_var: Warning: No named dimensions. Can not check grid order.
warning:gradsg: 1 2-dimensional input array(s) contained missing values. No interpolation performed on these arrays

Variable: advT_0
Type: float
Total Size: 86292 bytes
         21573 values
Number of Dimensions: 2
Dimensions and sizes: [south_north | 141] x [west_east | 153]
Coordinates:
Number Of Attributes: 3
  _FillValue :  9.96921e+36
  long_name : advection of temperature
  units :    K/s
(0)    advect_var: Warning: No named dimensions. Can not check grid order.
warning:gradsg: 1 2-dimensional input array(s) contained missing values. No interpolation performed on these arrays

Variable: advT_1
Type: list <fifo>
Total items: 3

Variable: Tadv
Type: float
Total Size: 86292 bytes
         21573 values
Number of Dimensions: 2
Dimensions and sizes: [south_north | 141] x [west_east | 153]
Coordinates:
Number Of Attributes: 3
  _FillValue :  9.96921e+36
  long_name : advection of temperature
  units :    K/s

Variable: Tgrx
Type: float
Total Size: 86292 bytes
         21573 values
Number of Dimensions: 2
Dimensions and sizes: [south_north | 141] x [west_east | 153]
Coordinates:
Number Of Attributes: 2
  _FillValue :  9.96921e+36
  long_name : longitudinal gradient

Variable: Tgry
Type: float
Total Size: 86292 bytes
         21573 values
Number of Dimensions: 2
Dimensions and sizes: [south_north | 141] x [west_east | 153]
Coordinates:
Number Of Attributes: 2
  _FillValue :  9.96921e+36
  long_name : latitudinal gradient

还出现了一些warning，求大神解答疑惑！

supersupergirl · 发表于 2019-8-26 18:14:46

尽头的尽头发表于 2019-8-25 23:53
ncl6.3版本之后新加了求平流的函数，下面的例子就是求温度平流的
http://www.ncl.ucar.edu/Document ... ...

而且我用了advect_variable_cfd 报错说没有这个函数。。

尽头的尽头 · 发表于 2019-8-27 09:29:35

supersupergirl 发表于 2019-8-26 18:14
而且我用了advect_variable_cfd 报错说没有这个函数。。

advect_variable必须是全球数据，advect_variable_cdf可以是区域数据，后者是ncl6.6.2新增函数，使用之前多看看函数的说明

supersupergirl · 发表于 2019-8-27 09:37:28

尽头的尽头发表于 2019-8-27 09:29
advect_variable必须是全球数据，advect_variable_cdf可以是区域数据，后者是ncl6.6.2新增函数，使用之前 ...

好吧看来我只能用计算的方法来画平流了感谢大神！那请问我之前计算是对的嘛

supersupergirl · 发表于 2019-8-27 11:11:07

小其其格发表于 2019-8-25 22:06
以上是我用fnl资料绘制温度平流的脚本，你照着修改一下看看

PS：我不是啥大神……ncl新手而已

还有我看了很多脚本最后算平流的时候都没有/dx和/dy 所以也不知道哪个是对的求大神指点

杜杜杜 · 发表于 2019-8-27 11:14:09

ut = advect_variable(u, v, air, 1, long_name, units, opt)
你可以试试这个函数，算温度平流前面要乘-1

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