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Post by sigurdur on Jan 29, 2018 16:22:02 GMT
Average daily temperature of 30 days should give you a monthly average?
OR, do you add ALL the hourly readings for the 30 days and then find the average?
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Post by nautonnier on Jan 29, 2018 17:08:37 GMT
Average daily temperature of 30 days should give you a monthly average? OR, do you add ALL the hourly readings for the 30 days and then find the average? The addition of maximum temperature and minimum temperature and dividing by two - is an arithmetic mean of an intensive variable (a nonsense). It has no relation to the average energy content of the atmosphere at the point of observation. The arguments about 'time of observation' are a spurious smoke screen' Temperature is the wrong metric for energy content, which is what 'global warming' [cough] is meant to be about 'trapping' heat. But as air has a variable 'specific heat' - enthalpy - dependent on the relative humidity temperature should not be used. As I have said several times air at 75DegF with 100% humidity say in Louisiana had twice the amount of energy in KiloJoules per Kilogram as air at 100DegF at close to zero humidity in say Death Valley. Averaging these intensive values together makes zero sense. So what should happen is for each observation point the heat content should be calculated on an hourly basis using RH and Temperature to calculate the enthalpy, providing KiloJoules per Kilogram. Then those values can be averaged to provide the average heat content of the atmosphere at that observation point. If this was to be done there would be a huge change in the values. It is probable that small drops in humidity are what have caused the increase in temperature - nothing to do with heat content at all. Temperature is totally wrong as a metric for atmospheric heat content.
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Post by missouriboy on Jan 29, 2018 17:47:20 GMT
Average daily temperature of 30 days should give you a monthly average? OR, do you add ALL the hourly readings for the 30 days and then find the average? The addition of maximum temperature and minimum temperature and dividing by two - is an arithmetic mean of an intensive variable (a nonsense). It has no relation to the average energy content of the atmosphere at the point of observation. The arguments about 'time of observation' are a spurious smoke screen' Temperature is the wrong metric for energy content, which is what 'global warming' [cough] is meant to be about 'trapping' heat. But as air has a variable 'specific heat' - enthalpy - dependent on the relative humidity temperature should not be used. As I have said several times air at 75DegF with 100% humidity say in Louisiana had twice the amount of energy in KiloJoules per Kilogram as air at 100DegF at close to zero humidity in say Death Valley. Averaging these intensive values together makes zero sense. So what should happen is for each observation point the heat content should be calculated on an hourly basis using RH and Temperature to calculate the enthalpy, providing KiloJoules per Kilogram. Then those values can be averaged to provide the average heat content of the atmosphere at that observation point. If this was to be done there would be a huge change in the values. It is probable that small drops in humidity are what have caused the increase in temperature - nothing to do with heat content at all. Temperature is totally wrong as a metric for atmospheric heat content. While I might agree, none of the available data sets contain relative humidity. If it is collected, it does not appear to be readily available. Looks like another grant request.
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Post by sigurdur on Jan 29, 2018 18:03:47 GMT
Average daily temperature of 30 days should give you a monthly average? OR, do you add ALL the hourly readings for the 30 days and then find the average? The addition of maximum temperature and minimum temperature and dividing by two - is an arithmetic mean of an intensive variable (a nonsense). It has no relation to the average energy content of the atmosphere at the point of observation. The arguments about 'time of observation' are a spurious smoke screen' Temperature is the wrong metric for energy content, which is what 'global warming' [cough] is meant to be about 'trapping' heat. But as air has a variable 'specific heat' - enthalpy - dependent on the relative humidity temperature should not be used. As I have said several times air at 75DegF with 100% humidity say in Louisiana had twice the amount of energy in KiloJoules per Kilogram as air at 100DegF at close to zero humidity in say Death Valley. Averaging these intensive values together makes zero sense. So what should happen is for each observation point the heat content should be calculated on an hourly basis using RH and Temperature to calculate the enthalpy, providing KiloJoules per Kilogram. Then those values can be averaged to provide the average heat content of the atmosphere at that observation point. If this was to be done there would be a huge change in the values. It is probable that small drops in humidity are what have caused the increase in temperature - nothing to do with heat content at all. Temperature is totally wrong as a metric for atmospheric heat content. Agreed
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Post by missouriboy on Jan 29, 2018 18:09:39 GMT
Average daily temperature of 30 days should give you a monthly average? OR, do you add ALL the hourly readings for the 30 days and then find the average? Probably number one. Unless there is some systematic skewing of the hourly distribution, it seems unlikely that the average of the sum of the hours would differ significantly from the average of the sum of the days. Probably fodder for some esoteric dissertation.
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Post by nautonnier on Jan 29, 2018 18:23:00 GMT
The addition of maximum temperature and minimum temperature and dividing by two - is an arithmetic mean of an intensive variable (a nonsense). It has no relation to the average energy content of the atmosphere at the point of observation. The arguments about 'time of observation' are a spurious smoke screen' Temperature is the wrong metric for energy content, which is what 'global warming' [cough] is meant to be about 'trapping' heat. But as air has a variable 'specific heat' - enthalpy - dependent on the relative humidity temperature should not be used. As I have said several times air at 75DegF with 100% humidity say in Louisiana had twice the amount of energy in KiloJoules per Kilogram as air at 100DegF at close to zero humidity in say Death Valley. Averaging these intensive values together makes zero sense. So what should happen is for each observation point the heat content should be calculated on an hourly basis using RH and Temperature to calculate the enthalpy, providing KiloJoules per Kilogram. Then those values can be averaged to provide the average heat content of the atmosphere at that observation point. If this was to be done there would be a huge change in the values. It is probable that small drops in humidity are what have caused the increase in temperature - nothing to do with heat content at all. Temperature is totally wrong as a metric for atmospheric heat content. While I might agree, none of the available data sets contain relative humidity. If it is collected, it does not appear to be readily available. Looks like another grant request. Strangely, I had noticed that. I was looking at the USCRN with the idea that it might even be worth learning 'R' and having a go. Then I saw that RH was not recorded. Wet Bulb is a really important value in observations and not to have that available seemed strange. Unless, they don't want people to find out the enthalpy of course.
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Post by missouriboy on Jan 29, 2018 18:36:46 GMT
While I might agree, none of the available data sets contain relative humidity. If it is collected, it does not appear to be readily available. Looks like another grant request. Strangely, I had noticed that. I was looking at the USCRN with the idea that it might even be worth learning 'R' and having a go. Then I saw that RH was not recorded. Wet Bulb is a really important value in observations and not to have that available seemed strange. Unless, they don't want people to find out the enthalpy of course. Yes ... but don't underestimate good old bureaucratic laziness.
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Post by acidohm on Jan 29, 2018 18:55:21 GMT
The addition of maximum temperature and minimum temperature and dividing by two - is an arithmetic mean of an intensive variable (a nonsense). It has no relation to the average energy content of the atmosphere at the point of observation. The arguments about 'time of observation' are a spurious smoke screen' Temperature is the wrong metric for energy content, which is what 'global warming' [cough] is meant to be about 'trapping' heat. But as air has a variable 'specific heat' - enthalpy - dependent on the relative humidity temperature should not be used. As I have said several times air at 75DegF with 100% humidity say in Louisiana had twice the amount of energy in KiloJoules per Kilogram as air at 100DegF at close to zero humidity in say Death Valley. Averaging these intensive values together makes zero sense. So what should happen is for each observation point the heat content should be calculated on an hourly basis using RH and Temperature to calculate the enthalpy, providing KiloJoules per Kilogram. Then those values can be averaged to provide the average heat content of the atmosphere at that observation point. If this was to be done there would be a huge change in the values. It is probable that small drops in humidity are what have caused the increase in temperature - nothing to do with heat content at all. Temperature is totally wrong as a metric for atmospheric heat content. While I might agree, none of the available data sets contain relative humidity. If it is collected, it does not appear to be readily available. Looks like another grant request. iridl.ldeo.columbia.edu/SOURCES/.NOAA/.NCDC/.DAILY/.FSOD/Some sort of US humidity record here... Other records.. www.ncdc.noaa.gov/data-access/land-based-station-data/land-based-datasets
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Post by missouriboy on Jan 29, 2018 19:27:11 GMT
Good find Acid. So for the US looks possible if you had a GIS package, as the min and max relative humidity are in grid format. Would have to link to the point network for temp. Give me a couple hundred K and I'll do it. No guarantee of delivery date ... and limited number of stations. Indication of size of data set. This dataset has bytes (7.5692368E07 72.185867MB) of data in it, which should give you a rough idea of the size of any file that you ask for. For tabular data: you get an idea of mass. Partial Information Formats These files contain only some of the available metadata. Columnar Table A table with separate columns of numbers for each independent variable (i.e., grids) and for the data. This is an inefficient format, so you would have gotten a HUGE file for dataset of this size. This file will be approximately 908308464 bytes, with 3 columns of 75692372 numbers. 2-Dimensional Tab-Separated Tables Tab-separated-values (tsv) file with information about the independent variables (i.e., grids). The list to the left allows you to specify the format of the table. Note: The variable running across the top of the table (identifing columns) is listed first and the variable running down the side of the table (identifing rows) is listed second.
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Post by douglavers on Jan 29, 2018 20:02:53 GMT
To measure global average temperature as a proxy for telling whether our planet is warming or cooling is always going to be difficult.
I am sure pure temperature averages are used for sheer convenience, the satellite numbers being most comprehensive.
Do the latter numbers include humidity measurements?
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Post by acidohm on Jan 29, 2018 20:04:44 GMT
Good find Acid. So for the US looks possible if you had a GIS package, as the min and max relative humidity are in grid format. Would have to link to the point network for temp. Give me a couple hundred K and I'll do it. No guarantee of delivery date ... and limited number of stations. Indication of size of data set. This dataset has bytes (7.5692368E07 72.185867MB) of data in it, which should give you a rough idea of the size of any file that you ask for. For tabular data: you get an idea of mass. Partial Information Formats These files contain only some of the available metadata. Columnar Table A table with separate columns of numbers for each independent variable (i.e., grids) and for the data. This is an inefficient format, so you would have gotten a HUGE file for dataset of this size. This file will be approximately 908308464 bytes, with 3 columns of 75692372 numbers. 2-Dimensional Tab-Separated Tables Tab-separated-values (tsv) file with information about the independent variables (i.e., grids). The list to the left allows you to specify the format of the table. Note: The variable running across the top of the table (identifing columns) is listed first and the variable running down the side of the table (identifing rows) is listed second. Sounds like it sucks then!! I'm really unqualified to assess these, which is why I'm always so grateful when you turn numbers into graphics!! This maybe?? digital.nmla.metoffice.gov.uk/file/sdb%3AdigitalFile%7C07e86ee7-44b7-4e6c-85a9-8b648392f86d/
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Post by missouriboy on Jan 29, 2018 21:27:50 GMT
To measure global average temperature as a proxy for telling whether our planet is warming or cooling is always going to be difficult. I am sure pure temperature averages are used for sheer convenience, the satellite numbers being most comprehensive. Do the latter numbers include humidity measurements? Satellites have been measuring atmospheric water vapor since their inception with various interpretations of quality I assume. Getting them linked to land station records would still require overlay of a massive number of interpreted geo-referenced images. Probably already there as grids. The bureaucratic gears keep grinding. They keep those guys in dark dungeons where they can be controlled.
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Post by nautonnier on Jan 29, 2018 21:43:37 GMT
To measure global average temperature as a proxy for telling whether our planet is warming or cooling is always going to be difficult. I am sure pure temperature averages are used for sheer convenience, the satellite numbers being most comprehensive. Do the latter numbers include humidity measurements? Satellites have been measuring atmospheric water vapor since their inception with various interpretations of quality I assume. Getting them linked to land station records would still require overlay of a massive number of interpreted geo-referenced images. Probably already there as grids. The bureaucratic gears keep grinding. They keep those guys in dark dungeons where they can be controlled. Unfortunately, they then change their metric into 'useful' figures like Vertically Integrated Liquid
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Post by sigurdur on Jan 29, 2018 23:36:31 GMT
What I learned this afternoon, talking with the Assistant ND Climatologist.
1. Average daily temperature is the average of the high and the low for the day. I won't go into how far off that could/would make temperature, but let's say for starters it had better indicate at a minimum of 2 sigma. 2. Average monthly temperatures are the average of the averaged daily temperatures.
3. When one starts taking averages of averages.......does anyone really want to go there? The output isn't what one would consider accurate.
Offfffffffffta...............it addled me old brain!
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Post by mondeoman on Jan 30, 2018 22:46:11 GMT
Is that a 24 hour day or sunup to sundown?
The methodology is just so flawed, you’d fail 1st year physics if you suggested it for a classroom experiment.
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