1,635
edits
Charts - Misc charts: Difference between revisions
From Cumulus Wiki
Jump to navigationJump to search
m
→Thermal Seasons
| (6 intermediate revisions by the same user not shown) | |||
| Line 32: | Line 32: | ||
== Thermal Seasons == | == Thermal Seasons == | ||
[[File:Thermal Seasons.jpg|thumb|right|Thermal Seasons]] | [[File:Thermal Seasons.jpg|thumb|right|Thermal Seasons]] | ||
A variation on the [https://jussilanet.com/chartstermiset.htm Thermal Seasons] chart by [https://cumulus.hosiene.co.uk/memberlist.php?mode=viewprofile&u=16853 @Pes]. This interesting chart, together with the Temperature Sum and the Growing Degree Days it forms the set of | A variation on the [https://jussilanet.com/chartstermiset.htm Thermal Seasons] chart by [https://cumulus.hosiene.co.uk/memberlist.php?mode=viewprofile&u=16853 @Pes]. This interesting chart, together with the Temperature Sum and the Growing Degree Days it forms the set of Agriculture related charts, displays the proportional contribution of the seasons in the year where the boundaries between the seasons is simply defined by average temperature of the day. | ||
This graph will be more important in the Nordic region where the growing season is short and requires careful planning. While The plant breeders are forcing the plants northbound, the farmers need to make it work. This type of charts helps. | |||
And on the other hand: the temperature limits of the seasons thermal season vary with latitude: where Finland lets the spring start at 0 °C, in the Netherlands it is more 5 °C simply because otherwise there would not be a winter at all (which would not be correct because plants and animals are in rest). The temperature must be '''higher/lower than the limit for 10 days at least''' before the season changes. | |||
This chart is also an heuristic and the limits can be defined by the user with the inifile parameters ''WinterToSpringTemperatureLimit'' and ''SpringToSummerTemperatureLimit'' which hold defaults of 0 °C and 10 °C (based on Finland). If the user uses Fahrenheit, just give the equivalent values of the limits in Fahrenheit. | |||
As an indication for the limits the following is suggested (on the southern hemisphere use absolute value of latitude): | |||
#Latitude > 55° => use limits of 0° and 10° Celsius for '''the average day temperature'''. | |||
#Latitude between 45° and 55° => use limits of 5° and 15° Celsius | |||
#Latitude between 35° and 45° => use limits of 10° and 20° Celsius | |||
#Latitude < 35° => This chart most likely has no value, if it does, please notify). | |||
== Daily EVT (Evapotranspiration) == | == Daily EVT (Evapotranspiration) == | ||
| Line 48: | Line 60: | ||
At least two times there was a discussion on the forum about the way the daily average for temperature was or should be calculated (see [https://cumulus.hosiene.co.uk/viewtopic.php?p=138513#p138513 here] and [https://cumulus.hosiene.co.uk/viewtopic.php?p=152909#p152909 here]). CumulusMX uses an ''integration method'' which means it samples the temperature continuously at the sampling frequency and stores the average of those samples at the logging frequency. It creates the sum of the logged entries and at the end of day it divides them by the number of observations giving the arithmetic average of all values logged which acts as an estimator of the physical average. | At least two times there was a discussion on the forum about the way the daily average for temperature was or should be calculated (see [https://cumulus.hosiene.co.uk/viewtopic.php?p=138513#p138513 here] and [https://cumulus.hosiene.co.uk/viewtopic.php?p=152909#p152909 here]). CumulusMX uses an ''integration method'' which means it samples the temperature continuously at the sampling frequency and stores the average of those samples at the logging frequency. It creates the sum of the logged entries and at the end of day it divides them by the number of observations giving the arithmetic average of all values logged which acts as an estimator of the physical average. | ||
<math>(Max+Min)/2</math> is used with the argument is that comparison with observations from before the computer era must be made. Note that the KNMI (the Dutch Meteorological Service) takes hourly measurements so there is no consistency between countries to start with. | |||
As an argument in this discussion this chart was made to make the difference between the institutional method and the Cumulus Integral Method visible. What is shown is the Cumulus Method Daily Average Temperature (one minute sampling): <math>(\sum_{minute=1}^{1440} {(Temp\ measurement)) \div 1440}</math>, the <math>(Max+Min)/2</math> and the difference between the two. It is clear that the first is the more accurate estimator of the two sample estimators (note they both are estimators for the statistic <math>average temperature of the day</math>). | As an argument in this discussion this chart was made to make the difference between the institutional method and the Cumulus Integral Method visible. What is shown is the Cumulus Method Daily Average Temperature (one minute sampling): <math>(\sum_{minute=1}^{1440} {(Temp\ measurement)) \div 1440}</math>, the <math>(Max+Min)/2</math> and the difference between the two. It is clear that the first is the more accurate estimator of the two sample estimators (note they both are estimators for the statistic <math>average temperature of the day</math>). | ||
The difference has a pretty even distributed noise around the zero line so comparison of current ''integral'' with observations from the past (for climatic studies) should be possible with statistical proof and a consolidation of past and current measurements has actually been executed by the KNMI | The difference has a pretty even distributed noise around the zero line so comparison of current ''integral'' with observations from the past (for climatic studies) should be possible with statistical proof and a consolidation of past and current measurements has actually been executed by the KNMI <ref>[https://cdn.knmi.nl/system/data_center_publications/files/000/068/325/original/CNT.pdf?1495621137 The Construction of a Central Netherlands Temperature]</ref>. | ||
<references/> | |||
[[Category:CumulusUtils]] | [[Category:CumulusUtils]] | ||
