No reason for me to post this, but I had to collect it so may as well share it.
Extracted from fifteen bom websites such as:
http://www.bom.gov.au/climate/current/month/aus/archive/202010.summary.shtml
http://www.bom.gov.au/climate/current/annual/aus/2020/data/map-rain-decile-year.png?popup
Charts for October each year. 2021 ro 2014
Charts for full year. 2020 to 2014
thanks
Very much above average sounds about right for this village this year.
mollwollfumble said:
No reason for me to post this, but I had to collect it so may as well share it.Extracted from fifteen bom websites such as:
http://www.bom.gov.au/climate/current/month/aus/archive/202010.summary.shtml
http://www.bom.gov.au/climate/current/annual/aus/2020/data/map-rain-decile-year.png?popup
Charts for October each year. 2021 ro 2014
Charts for full year. 2020 to 2014
“…of droughts and flooding rains…”
It appears to have been droughty and 2020 broke the drought.
From the first link:
“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
buffy said:
mollwollfumble said:
No reason for me to post this, but I had to collect it so may as well share it.Extracted from fifteen bom websites such as:
http://www.bom.gov.au/climate/current/month/aus/archive/202010.summary.shtml
http://www.bom.gov.au/climate/current/annual/aus/2020/data/map-rain-decile-year.png?popup
Charts for October each year. 2021 ro 2014
Charts for full year. 2020 to 2014
“…of droughts and flooding rains…”
It appears to have been droughty and 2020 broke the drought.
Well yes. For my area there was a low rainfall period of 19 years between 1991 and 2010 with three wet years between 2010 and 2020. 2020 and 2021 have been better years than average.
buffy said:
From the first link:“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
http://www.bom.gov.au/climate/cdo/about/about-stats.shtml#normals
poikilotherm said:
buffy said:
From the first link:“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
http://www.bom.gov.au/climate/cdo/about/about-stats.shtml#normals
Thank you. I didn’t find that.
buffy said:
poikilotherm said:
buffy said:
From the first link:“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
http://www.bom.gov.au/climate/cdo/about/about-stats.shtml#normals
Thank you. I didn’t find that.
Ditto.
roughbarked said:
buffy said:
poikilotherm said:http://www.bom.gov.au/climate/cdo/about/about-stats.shtml#normals
Thank you. I didn’t find that.
Ditto.
“Statistics calculated over standard periods (commonly a 30 year interval) are often called climate normals, and are generally used as reference values for comparative purposes. The period is long enough to include the majority of typical year to year variations in the climate, but no so long that it is significantly influenced by longer-term changes in climate. In Australia, the current reference climate normal is generated over the 30-year period 1 January 1961 to 31 December 1990.”
30 years is good for temperatures. But for rainfall a much longer length of time would be needed to cover year to year variations. For cyclones, 150 years is nowhere near long enough, which is why numerical simulations are needed to extend the available period of observations for cyclones.
mollwollfumble said:
roughbarked said:
buffy said:Thank you. I didn’t find that.
Ditto.
“Statistics calculated over standard periods (commonly a 30 year interval) are often called climate normals, and are generally used as reference values for comparative purposes. The period is long enough to include the majority of typical year to year variations in the climate, but no so long that it is significantly influenced by longer-term changes in climate. In Australia, the current reference climate normal is generated over the 30-year period 1 January 1961 to 31 December 1990.”
30 years is good for temperatures. But for rainfall a much longer length of time would be needed to cover year to year variations. For cyclones, 150 years is nowhere near long enough, which is why numerical simulations are needed to extend the available period of observations for cyclones.
So the numbers you put up for rainfall, being from a 30 year block, are questionable?
buffy said:
mollwollfumble said:
roughbarked said:Ditto.
“Statistics calculated over standard periods (commonly a 30 year interval) are often called climate normals, and are generally used as reference values for comparative purposes. The period is long enough to include the majority of typical year to year variations in the climate, but no so long that it is significantly influenced by longer-term changes in climate. In Australia, the current reference climate normal is generated over the 30-year period 1 January 1961 to 31 December 1990.”
30 years is good for temperatures. But for rainfall a much longer length of time would be needed to cover year to year variations. For cyclones, 150 years is nowhere near long enough, which is why numerical simulations are needed to extend the available period of observations for cyclones.
So the numbers you put up for rainfall, being from a 30 year block, are questionable?
In statistics, at least 30 data points are generally accepted as the minimum required for analysis…
furious said:
buffy said:
mollwollfumble said:“Statistics calculated over standard periods (commonly a 30 year interval) are often called climate normals, and are generally used as reference values for comparative purposes. The period is long enough to include the majority of typical year to year variations in the climate, but no so long that it is significantly influenced by longer-term changes in climate. In Australia, the current reference climate normal is generated over the 30-year period 1 January 1961 to 31 December 1990.”
30 years is good for temperatures. But for rainfall a much longer length of time would be needed to cover year to year variations. For cyclones, 150 years is nowhere near long enough, which is why numerical simulations are needed to extend the available period of observations for cyclones.
So the numbers you put up for rainfall, being from a 30 year block, are questionable?
In statistics, at least 30 data points are generally accepted as the minimum required for analysis…
But my point is that we have more than 30, so why not use them?
(Stats was not my favourite subject)
furious said:
buffy said:
mollwollfumble said:“Statistics calculated over standard periods (commonly a 30 year interval) are often called climate normals, and are generally used as reference values for comparative purposes. The period is long enough to include the majority of typical year to year variations in the climate, but no so long that it is significantly influenced by longer-term changes in climate. In Australia, the current reference climate normal is generated over the 30-year period 1 January 1961 to 31 December 1990.”
30 years is good for temperatures. But for rainfall a much longer length of time would be needed to cover year to year variations. For cyclones, 150 years is nowhere near long enough, which is why numerical simulations are needed to extend the available period of observations for cyclones.
So the numbers you put up for rainfall, being from a 30 year block, are questionable?
In statistics, at least 30 data points are generally accepted as the minimum required for analysis…
> So the numbers you put up for rainfall, being from a 30 year block, are questionable?
That’s my personal opinion. I can actually calculate how inaccurate they are, but I won’t do that now. At a guess, 30 years won’t pin down mean rainfall to within a 5% error. It wouldn’t give much better than a 10% error, which is plenty large enough to show up on the charts above.
> In statistics, at least 30 data points are generally accepted as the minimum required for analysis…
Far from it, it depends on the ratio of the mean to the standard deviation. If the standard deviation is much smaller than the mean then sometimes as few as 4 points are sufficient to define the mean. 5 points can suffice for either the slope or standard deviation, whichever has the biggest influence.
But for rainfall, the mean is only about two times the standard deviation, so a lot more points are needed.
That’s nonsense…
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
I’ve been asking the same question since the internet. They have never gone back earlier than 1959. Think it was 1911, when BOM started official records..
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
poikilotherm said:
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
It is probably because nobody has typed in the data yet.
poikilotherm said:
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
But, but, but…it seems pretty arbitrary to pick 1961 to 1990. They had the records from 1900 onwards when they picked that 30 year period.
roughbarked said:
poikilotherm said:
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
It is probably because nobody has typed in the data yet.
I think you will find it is online. So someone has.
buffy said:
poikilotherm said:
buffy said:
Still going back to why that specific 30 year period is used for the BOM baseline. It includes the wettest year on record, which was 1974, but it does not include the driest, 2019. But I still don’t really “get” why 1961 to 1990 is used as the period for comparison. There are records since 1900, according to the BOM. We have considerable computing power these days. Why not use all the records?
It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
But, but, but…it seems pretty arbitrary to pick 1961 to 1990. They had the records from 1900 onwards when they picked that 30 year period.
It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
Michael V said:
buffy said:
poikilotherm said:It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
But, but, but…it seems pretty arbitrary to pick 1961 to 1990. They had the records from 1900 onwards when they picked that 30 year period.
It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
I’ll go with that.
Michael V said:
buffy said:
poikilotherm said:It does change, it just hasn’t yet. Eg the USA use 1980 to 2010.
But, but, but…it seems pretty arbitrary to pick 1961 to 1990. They had the records from 1900 onwards when they picked that 30 year period.
It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
buffy said:
Michael V said:
buffy said:But, but, but…it seems pretty arbitrary to pick 1961 to 1990. They had the records from 1900 onwards when they picked that 30 year period.
It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
I have no idea. They’ve probably got their reasons, but in the absence of a statement about their arbitrary choice, my guesses are not worth anything.
Michael V said:
buffy said:
Michael V said:It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
I have no idea. They’ve probably got their reasons, but in the absence of a statement about their arbitrary choice, my guesses are not worth anything.
+1
furious said:
- Far from it, it depends on the ratio of the mean to the standard deviation. If the standard deviation is much smaller than the mean then sometimes as few as 4 points are sufficient to define the mean. 5 points can suffice for either the slope or standard deviation, whichever has the biggest influence.
That’s nonsense…
Why is it?
The Rev Dodgson said:
furious said:
- Far from it, it depends on the ratio of the mean to the standard deviation. If the standard deviation is much smaller than the mean then sometimes as few as 4 points are sufficient to define the mean. 5 points can suffice for either the slope or standard deviation, whichever has the biggest influence.
That’s nonsense…
Why is it?
So you’re saying the 5 points tell you the stdev is much smaller than the mean and then no more is needed ¿
Michael V said:
buffy said:
Michael V said:It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
I have no idea. They’ve probably got their reasons, but in the absence of a statement about their arbitrary choice, my guesses are not worth anything.
Come now Michael, your guesses are worth just as much as mine.
Oh, wait a minute.
Anyway, my guess is that rainfall has long term (in human perspective) variations, so the figures are intended to compare the current 30 year period with a previous 30 year period.
Or something.
SCIENCE said:
The Rev Dodgson said:
furious said:
- Far from it, it depends on the ratio of the mean to the standard deviation. If the standard deviation is much smaller than the mean then sometimes as few as 4 points are sufficient to define the mean. 5 points can suffice for either the slope or standard deviation, whichever has the biggest influence.
That’s nonsense…
Why is it?
So you’re saying the 5 points tell you the stdev is much smaller than the mean and then no more is needed ¿
I’m assuming that question is addressed to Moll.
My only comment is that treating all observations as though they were part of a “normal distribution” results in invalid calculations and conclusions in very widespread ranges of human endeavours.
The Rev Dodgson said:
SCIENCE said:
The Rev Dodgson said:
Why is it?
So you’re saying the 5 points tell you the stdev is much smaller than the mean and then no more is needed ¿
I’m assuming that question is addressed to Moll.
My only comment is that treating all observations as though they were part of a “normal distribution” results in invalid calculations and conclusions in very widespread ranges of human endeavours.
when should statistics apply and when should exceptionalism apply
SCIENCE said:
The Rev Dodgson said:SCIENCE said:
So you’re saying the 5 points tell you the stdev is much smaller than the mean and then no more is needed ¿
I’m assuming that question is addressed to Moll.
My only comment is that treating all observations as though they were part of a “normal distribution” results in invalid calculations and conclusions in very widespread ranges of human endeavours.
when should statistics apply and when should exceptionalism apply
Properly applied statistics should always apply, but very rarely does.
I don’t know what you mean by exceptionalism.
buffy said:
From the first link:“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
this should be explained in the original research paper..
Arts said:
buffy said:
From the first link:“Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.”
Is there any reason this period is chosen for the averages? There is data before that and data after that. Shouldn’t your average be over the period for which data is available? Perhaps modified if some areas have shorter records.
this should be explained in the original research paper..
Can’t see where to view that.
How about this nypothesis?
We basically know the effects of climate change from the 60’s on. So maybe there isn’t much point worrying about that since we already have a yardstick?
Michael V said:
buffy said:
Michael V said:It is arbitrary. It’s supposed to be. It’s a “line in the sand”.
My guess about the choice of period: data quality.
But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
I have no idea. They’ve probably got their reasons, but in the absence of a statement about their arbitrary choice, my guesses are not worth anything.
any choice except the full set would be arbitrary. Too long a set might reduce the usefulness of the information being presented. It isn’t a climate set it is a trend set.
Bogsnorkler said:
Michael V said:
buffy said:But 30 years? Why not 50? We’ve got another 30 years since 1990 now. I suspect it might relate in some way to when there was a movement of a lot of weather stations out of towns to local airports. Hamilton records can’t really be properly compared to the early ones in the 1800s because the readings were taken at the Post Office from 1869 to 1983, and then they moved the equipment out to Hamilton airport, which is 10km out of town and often has different rainfall from in town. There was another station at the Hamilton Research Station, about 20km out of town on the other side from the airport, which operated from 1962 to 2000.
I have no idea. They’ve probably got their reasons, but in the absence of a statement about their arbitrary choice, my guesses are not worth anything.
any choice except the full set would be arbitrary. Too long a set might reduce the usefulness of the information being presented. It isn’t a climate set it is a trend set.
I’m definitely not a trend-setter.
https://www.theguardian.com/australia-news/2021/dec/13/highway-upgrades-near-queensland-nsw-border-affecting-floodplain-and-ecology-farmers-say