[Reddyproc-users] A matter of units

[Efren Lopez Blanco]

Hello Jon,

Thanks for the support. It’s crystal clear now. 

Wish you and your support team a very good day.

Best,
Efren

On 22 Apr 2015, at 12:04, Jon Paul McCalmont [jpm8] <jpm8 at aber.ac.uk> wrote:

> Hi Efron,
> 
> I don't think it's g C m-2 day-1 anyway, I had a look at a Daily Sum plot from my gapfilling and it extends down to around -300 at the height of the growing season, if this was g C m-2 this would translate to an accumulation of 3 tonnes of carbon per hectare per day which would be very unrealistic. I summed a typical day in umol m-2 s-1 (i.e. half-hour mean multiplied by 1800 to get the half hour sum then sum all half hours for that day) and that comes to nearly 1 million umol so the units are not umol m-2 day-1 either.
> You would probably be better to produce your own integration sums from the half hour gapfilled data and produce your own plots, you then know exactly what units you're using.
> Remember that original NEE units are a half hour mean (umol m-2 s-1) so must be converted into half hour totals (ideally in g C m2) before summing across the year.
> To convert from umol m-2 s-1 to g C m-2 halfhour-1... 
> ((umol m-2 s-1 *1800)*10^-6)*12
> 
> Sorry if you know all this anyway but thought it might be helpful.
> 
> Regards,
> Jon
> 
> 
> 
> 
> 
> -----Original Message-----
> From: reddyproc-users-bounces at lists.r-forge.r-project.org [mailto:reddyproc-users-bounces at lists.r-forge.r-project.org] On Behalf Of Efren Lopez Blanco
> Sent: 22 April 2015 10:38
> To: General information about usage and problems with the REddyProc package
> Subject: Re: [Reddyproc-users] A matter of units
> 
> Hi Kersin,
> 
> I am talking about this:
> 
> 	EddyProc.C$sPlotDailySumsY('NEE_f','NEE_fsd', Year.i=2013) #Plot of sums with uncertainties
> 
> Are the NEE daily sums calculated in umol/m2/day? gC/m2/day? I am interested in the accumulated NEE over a year.
> 
> Best,
> Efren
> 
> 
> On 22 Apr 2015, at 11:03, Kerstin Sickel <ksickel at bgc-jena.mpg.de> wrote:
> 
>> Hello Efron,
>> 
>> unfortunately there is probably a bug, it will be fixed in new version.
>> The calculation is in the plotting routines.
>> 
>> Sorry for no  better answer.
>> 
>> Have a nice day.
>> Kerstin
>> 
>> On 4/22/2015 10:23 AM, Efren Lopez Blanco wrote:
>>> Hello,
>>> 
>>> Does anyone recognise the units from "Daily sums with uncertainties of NEE_f" graph?. How is it calculated? I should clarify this before I introduce these graphs on my presentation. Thanks in advance!
>>> 
>>> Best,
>>> Efren
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>> 
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