Hi, i have several problems with setting the wind files in EE. The EE introduction about the wind file is as follows:
WIND FORCING FILE, USE WITH 7 APRIL 97 AND LATER VERSIONS OF EFDC
C **
C ** MASER(NW) =NUMBER OF TIME DATA POINTS
C ** TCASER(NW) =DATA TIME UNIT CONVERSION TO SECONDS
C ** TAASER(NW) =ADDITIVE ADJUSTMENT OF TIME VALUES SAME UNITS AS INPUT TIMES
C ** WINDSCT(NW) =WIND SPEED CONVERSION TO M/SEC
C ** ISWDINT(NW) =DIRECTION CONVENTION
C ** 0 DIRECTION TO
C ** 1 DIRECTION FROM
C ** 2 WINDS IS EAST VELOCITY, WINDD IS NORTH VELOCITY
C **
EE EFDC_DS_WIND_HEIGHT (m):10.0
EE EFDC_DS_ICE_PERIOD_START (days):0.000
EE EFDC_DS_ICE_PERIOD_END (days):0.000
C ** MASER TCASER TAASER WINDSCT ISWDINT
C ** TASER(M) WINDS(M) WINDD(M)
i have no idea what’s the default setting of the parameters such as TCASER(NW) and WINDSCT(NW).
Also, i’m confused about the wind direction definition, what’s the default setting of the ISWDINT(NW) parameter? o or 1? and under those condition, what’s the 0 degree (wind direciton=0) means, the North or the East wind?
Those are my questions, waiting for your reply. Thank you very much!
Hello Bin,
TCASER(NW) is data time unit conversion to seconds. The default number for this variable is 86400. Please try to prepare your input files in Julian days so there would be less confusion. Again, by default WINDSCT(NW) would be 1 assuming that you provide wind speed in m/s.
The wind direction ISWINDT(NW) is 0 by default meaning the “direction to”.
Thank you for your reply. But i still have a problem with the wind direction. i can understand that ISWINDT(NW)= 0 and means the "“direction to”, however, how to relate the wind direction with the real orientation? For example, if the wind direction is 90 degree, where does the wind blowing towards or direction to ? The East or the South?
Hi Bin,
When ISWINDT = 0, it means “direction to”. So, when your wind direction is 90 degrees, then it means wind is blowing towards east. However, when ISWINDT = 1, it means “direction from” and 90 degrees of wind direction means wind is flowing from east to west.
So, it is very important to figure out how your wind direction is measured. Usually, the meteorological data is available as ISWINDT = 1, i.e., direction from. So, if you are directly pasting your wind data into EFDC Explorer wind editing form there are two options:
1. Just copy the data as it is and when you go to your wser.inp, you will notice that ISWDINT = 0. However, it is supposed to be 1. So, go ahead and change that value to 1 and load the model again in EFDC Explorer. Then when you save the model you will notice that all the values will be automatically adjusted and ISWDINT will be equal to 0.
2. If you don’t want to edit that way, you should convert your wind direction manually outside of EE and then copy that information into EFDC wind series editing form.
The conversion is as follows:
a. IF WINDD < 180, WINDD = WINDD + 180
b. IF WINDD > 180, WINDD = WINDD - 180
c. IF WINDD = 360, WINDD = 0
where WINDD = wind direction
You can verify the conversion formulas I provided doing a test case with first option.
I hope it is clear now.
Best,
Janesh Devkota
Thank you very much for your help. And it is very clear. Thanks again!