Hi Yogesh-
If the time-units of the data is in years, then the first derivative
would have units of ppm per year, correct? So read in your data (See
"ASCII data, reading" or "ASCII data, reading delimited" in the Ferret
Users Guide Index), and then define a variable
let /units="ppm_year" co2_per_year = co2[t=@ddf]
Yogesh Tiwari wrote:
Dear Ferret Users,
I have CO2 mixing ratio(ppm) time series data during the period of
1991-2000.
I would like to calculate CO2 growth rate /ppm.a-1
Kindly can any one advise how to calculate above in ferret.
My data file looks like;
time, year, month, day, hour, min, sec, lat, long, height, CO2
1991.476722 1991 6 24 0 5 0 -38.93 145.15 4270 353.680
1991.476741 1991 6 24 0 15 0 -39.20 145.22 4270 353.950
1991.476747 1991 6 24 0 18 0 -39.43 145.28 4270 353.510
-----------------------------------------------
2000.740788 2000 9 28 3 5 0 -38.00 145.00 2280 366.750
2000.740794 2000 9 28 3 8 0 -38.00 145.00 1830 366.550
2000.740803 2000 9 28 3 13 0 -38.00 145.00 1220 370.550
Many great thanks,
Best Regards,
Yogesh
--
Yogesh K. Tiwari (Dr.rer.nat),
Scientist,
Indian Institute of Tropical Meteorology,
Homi Bhabha Road,
Pashan,
Pune-411008
INDIA
Phone: 0091-99 2273 9513 (Cell)
: 0091-20-25904350 (O)
Fax : 0091-20-258 93 825
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