Record Sun for Invercargill January 2008

[sthguy]

Keep your hair on R Wood. I'm glad your time is valuable. {Your last sentence frankly mystifies me }
You don't have time to perform a study as I suggested - I don't - so what? Damn good science project for some 7th former I'd suggest.

But...!

On what basis to you conclude that the last 11 months sunshine is 'somewhat doubtful'?
Since when did it become good science to use a proxy quote New Zealand flow anomaly unquote to measure a variable at a site, when site measurements of that variable are avaliable?

30 minutes a day is not nothing - but cloud cover is by it's very nature chaotic. Also, lets not forget that evaluation of suncards is subjective. Very easy for variations in interpretation between different people. Is that little ALMOST circular burn 0.1hr or did the sun only shine for a minute or two? and there might be 10 of those on the windy days. What about that tiny wee marks here and there 01, 0.2, 0.3hr long. So weak - perhaps its really wasn't bright sunshine? Perhaps there was a period of conservative evaluation followed by a change of personnel with more generous evaluations?

Yes I am contructing a case that there has been a lot of westerlies {at Invercargill, irrespective of the flow in Auckland, Wellington, Christchurch} in the current la nina phase. To elaborate:

Start, Jan 2007, end, March 2008.
Average = Mean monthly frequency of wind direction at Invercargill, includes all SW - W and NW
Actual = frequency of daily strongest wind direction at Invercargill, includes all SW - W and NW

Average Actual
Jan 48 71%
Feb 45 71%
Mar 43 71%
Apr 41 63%
May 39 77%
Jun 36 53%
Jul 32 23%
Aug 40 71%
Sep 45 57%
Oct 49 74%
Nov 51 100%
Dec 40 65%
Jan 48 71%
Feb 45 52%
Mar 43 77%

[RWood]

Keep your hair on R Wood. I'm glad your time is valuable. {Your last sentence frankly mystifies me }
You don't have time to perform a study as I suggested - I don't - so what? Damn good science project for some 7th former I'd suggest.

But...!

On what basis to you conclude that the last 11 months sunshine is 'somewhat doubtful'?
Since when did it become good science to use a proxy quote New Zealand flow anomaly unquote to measure a variable at a site, when site measurements of that variable are avaliable?

(1) Not just the last 11 months. I already said that something changed about the mid-90s. If the change is partly or wholly climatological, no qualitative or quantative evidence has been presented at this point. Whether the old values might have been a bit low/conservative or the new ones a bit high, is not clear. I am well aware of the many ways in which readings can vary with observer and other effects. It is regrettable that the site notes on NIWA's CliFlo contain virtually nothing for the period 1939-1994. "doubtful" does not necessarily mean wrong, simply that more investigation and data is needed. I remind you of the flags against the 1992-2005 data. What is clear is that the two do not go very well together. Conversion to EWS instrumentation is slowly occurring (and incidentally the EWS records also being kept at Invercargill show lower values than do the manual ones except in the winter months, a kind of pattern that has been observed in other conversion exercises here and overseas). I might add that I have a good track record of anticipating the changes resulting in readings at various locations made after (1) Conversion to EWS (or resumption of manual readings after a break) and/or (2) Resiting of equipment or the whole station, simply because of familiarity with the records and the fairly obvious anomalous changes (or unnaturally long unidirectional trends) that I could see in the records.

30 minutes a day is not nothing - but cloud cover is by it's very nature chaotic. Also, lets not forget that evaluation of suncards is subjective. Very easy for variations in interpretation between different people. Is that little ALMOST circular burn 0.1hr or did the sun only shine for a minute or two? and there might be 10 of those on the windy days. What about that tiny wee marks here and there 01, 0.2, 0.3hr long. So weak - perhaps its really wasn't bright sunshine? Perhaps there was a period of conservative evaluation followed by a change of personnel with more generous evaluations?

Yes I am contructing a case that there has been a lot of westerlies {at Invercargill, irrespective of the flow in Auckland, Wellington, Christchurch} in the current la nina phase. To elaborate:

Start, Jan 2007, end, March 2008.
Average = Mean monthly frequency of wind direction at Invercargill, includes all SW - W and NW
Actual = frequency of daily strongest wind direction at Invercargill, includes all SW - W and NW

Average Actual
Jan 48 71%
Feb 45 71%
Mar 43 71%
Apr 41 63%
May 39 77%
Jun 36 53%
Jul 32 23%
Aug 40 71%
Sep 45 57%
Oct 49 74%
Nov 51 100%
Dec 40 65%
Jan 48 71%
Feb 45 52%
Mar 43 77%

(2)Those average frequencies do not look all that high to me, but in any event you have not provided a context of longterm records for comparison. Without that, little can be said. (I have however seen monthly reports in which SW frequencies alone have reached 52%, possibly more). Incidentally, the windrun values at the Aero AWS (which only date back to 1995) do not show anything special for the last 12-15 months.

(3) I will return to the nub of my original statement, which was simply this: the sunshine values observed during the La Nina summer (especially January) were exceptionally high, perhaps even in the context of the data from the mid-90s only. What will need to be looked at is whether the values remain relatively high when the circulations return to more typical westerly patterns. Thta's all the time I intend to expend on this. It's already been too much.

[janewaystv]

Sthguy - where exactly in S NZ do you reside? You seem to know a lot about Invercargill's weather. Interesting posts from both sides, I've learnt quite a bit more about "Invercargill's " climate .

[RWood]

As I have already (re)stated above it makes no difference to my central point what the local distribution of wind directions is, but purely for my own interest I picked a windy westerly month from 1983 and analysed the 3-hour wind direction values (0000, 0300, 0600, .. 2100) at Invercargill Aero. I expected there to be a significant diurnal variation even in such a month, and this is borne out. The westerly contribution is highest in 7 of the 8 cases and reaches some pretty high values during daylight hours. The distribution of % among quadrants (N, E, S, W, Calm) was:

0000 29 10 10 42 9
0300 35 3 3 39 20
0600 39 3 6 32 20
0900 26 0 6 58 10
1200 16 3 7 71 3
1500 19 0 16 65 0
1800 10 0 35 55 0
2100 16 13 16 52 3

In order to conclude anything about the local "westerliness" in recent months with respect to historical values a considerable amount of data would need to be examined.

[sthguy]

Hi R Wood

I never think we can expend too much energy chasing obscure features of weather and climate. It is too full of mysteries to give up.

Not just the last 11 months. I already said that something changed about the mid-90s. If the change is partly or wholly climatological, no qualitative or quantative evidence has been presented at this point.

Can you give evidence of the change? ie 'monthly totals are higher sincer the mid 1990's by x% on average compared to the previous x years'. You have stated this but present no evidence?

"doubtful" does not necessarily mean wrong, simply that more investigation and data is needed. I remind you of the flags against the 1992-2005 data.

Why is more investigation and data needed? Forget the EWS data. It is a red herring. Let's just concentrate on actual suncard readings. There are no flags against actual suncard readings. Actual suncard readings can be compared through the complete period of observation. Although as I point out, and you agree, evaluation of suncards is an subjective exercise and is subject to human error.

Whether the old values might have been a bit low/conservative or the new ones a bit high, is not clear

And never will be clear short of getting my diligent 7th former to go through them all carefully.

What is clear is that the two do not go very well together. Conversion to EWS instrumentation is slowly occurring.

Forget the EWS data !!

I might add that I have a good track record of anticipating the changes resulting in readings at various locations made after (1) Conversion to EWS (or resumption of manual readings after a break) and/or (2) Resiting of equipment or the whole station, simply because of familiarity with the records and the fairly obvious anomalous changes (or unnaturally long unidirectional trends) that I could see in the records.

Great. It is important to let NIWA know of any obvious anomalies.

Those average frequencies do not look all that high to me, but in any event you have not provided a context of longterm records for comparison. Without that, little can be said. (I have however seen monthly reports in which SW frequencies alone have reached 52%, possibly more). Incidentally, the windrun values at the Aero AWS (which only date back to 1995) do not show anything special for the last 12-15 months.

Windrun is irrelevant except as a rather coarse measure of overall wind strength. It does not indicate wind direction frequencies.
Context of long term records: Averages are from MetService Pub 115[15] 1984

(3) I will return to the nub of my original statement, which was simply this: the sunshine values observed during the La Nina summer (especially January) were exceptionally high, perhaps even in the context of the data from the mid-90s only. What will need to be looked at is whether the values remain relatively high when the circulations return to more typical westerly patterns.

Certainly they were high, and about time too. The deep south has earned a few credits, looking at some of your stats . As I've already shown, Invercargill measured an anomously high westerly pattern for many months, compared to published long terms means up to 1984. In January westerlies occured over 71% of the month compared to an average of 48%. despite the strong la nina pattern. Despite the strong la nina pattern westerlies did not weaken or reduce below the monthly means for any significant length of time in Invercargill over spring and summer. The connection between la nina and a reduction in frequency and strength of westerly winds in Invercargill is not absolute.

Just caught your last interesting post, when I thought you'd given up

Ps I have corrected a multitude of spelling errors in this post. And deleted a sentence that didn't make sense to me even though I wrote it. Must be time for bed.

[sthguy]

Sthguy - where exactly in S NZ do you reside? You seem to know a lot about Invercargill's weather. Interesting posts from both sides, I've learnt quite a bit more about "Invercargill's " climate .

hi, janewaystv, thank you for asking, somewhat south, and further south somewhat. Mostly

I know just enough about the weather south of the border [Waitaki River of course!] to make sure I still get caught without a brolly from time to time

Have a lovely day

[RWood]

Hi R Wood

I never think we can expend too much energy chasing obscure features of weather and climate. It is too full of mysteries to give up.

Not just the last 11 months. I already said that something changed about the mid-90s. If the change is partly or wholly climatological, no qualitative or quantative evidence has been presented at this point.

Can you give evidence of the change? ie 'monthly totals are higher sincer the mid 1990's by x% on average compared to the previous x years'. You have stated this but present no evidence?

This will definitely be my last post on this subject. I am not going to bang around just because I'm asked to prove every single point because you take absolutely nothing I assert as read. That is simply insulting. I am not in the habit of making assertions about known and recorded numbers without knowing that I am correct, and I am simply not going to respond to your every whim. The average annual sunshine 1932-1993 was 1615 hours; the average 1994-2007 is 1746, much higher than for any comparable-length period in the past. In more detail:

1932-1993 182.4 160.4 139.2 104.1 86.0 71.8 91.2 120.0 136.6 161.2 174.6 187.9 1615.4
1994-2007 199.9 174.6 150.1 121.6 93.1 79.5 104.2 124.6 150.9 174.1 179.3 194.6 1746.5

And no, i am NOT going to upload graphs of the monthly and annual totals of the original data just to please you.
"doubtful" does not necessarily mean wrong, simply that more investigation and data is needed. I remind you of the flags against the 1992-2005 data.

Why is more investigation and data needed? Forget the EWS data. It is a red herring. Let's just concentrate on actual suncard readings. There are no flags against actual suncard readings. Actual suncard readings can be compared through the complete period of observation. Although as I point out, and you agree, evaluation of suncards is an objective exercise and is subject to human error.

The data for the period 1992-2005 is flagged, PERIOD. The EWS data can't be ignored all that readily. The vagaries of C/S recording including the general tendency to overread on partly cloudy bright summer days in particular is well documented.

Whether the old values might have been a bit low/conservative or the new ones a bit high, is not clear

And never will be clear short of getting my diligent 7th former to go through them all carefully.

What is clear is that the two do not go very well together. Conversion to EWS instrumentation is slowly occurring.

Forget the EWS data !!

I might add that I have a good track record of anticipating the changes resulting in readings at various locations made after (1) Conversion to EWS (or resumption of manual readings after a break) and/or (2) Resiting of equipment or the whole station, simply because of familiarity with the records and the fairly obvious anomalous changes (or unnaturally long unidirectional trends) that I could see in the records.

Great. It is important to let NIWA know of any obvious anomalies.

Those average frequencies do not look all that high to me, but in any event you have not provided a context of longterm records for comparison. Without that, little can be said. (I have however seen monthly reports in which SW frequencies alone have reached 52%, possibly more). Incidentally, the windrun values at the Aero AWS (which only date back to 1995) do not show anything special for the last 12-15 months.

Windrun is irrelevant except as a rather coarse measure of overall wind strength. It does not indicate wind direction frequencies.
Context of long term records: Averages are from MetService Pub 115[15] 1984

Yes, but the windruns over the period I quoted vary quite considerably and there is little doubt that the westerly quadrant does make by far the largest contribution to the values. The 2007 values were below the period average in several cases, especially December (large scale anomaly was anticyclonic with more NE), but above in October and well above in May (not surprising in either case). The values for Jan-March 2008 were nothing special.
(3) I will return to the nub of my original statement, which was simply this: the sunshine values observed during the La Nina summer (especially January) were exceptionally high, perhaps even in the context of the data from the mid-90s only. What will need to be looked at is whether the values remain relatively high when the circulations return to more typical westerly patterns.

Certainly they were high, and about time too. The deep south has earned a few credits, looking at some of your stats . As I've already shown, Invercargill measured an anomously high westerly pattern for many months, compared to published long terms means up to 1984. In January westerlies occured over 71% of the month compared to an average of 48%. despite the strong la nina pattern. Despite the strong la nina pattern westerlies did not weaken or reduce below the monthly means for any significant length of time in Invercargill over spring and summer. The connection between la nina and a reduction in frequency and strength of westerly winds in Invercargill is not absolute.

You have not specified what times of day your averages relate to, or whether they are averaged over several different times. Once again, see the comments about local flows below.

[/b]Just caught your last interesting post, when I thought you'd given up
it makes no difference to my central point what the local distribution of wind directions is

In the deep south the local distribution of wind directions is dependant on synoptic events. I'm not sure, but you might be trying to tell me westerlies can occur locally in Invercargill when the large scale synoptic situation has pressure gradients that should bring wind from other directions? Westerlies only occur with low pressure to the south and high to the north. Irrespective of la nia/el nino.

Local anomalies when compared to large-scale flow can occur for a variety of reasons. I would suggest that Invercargill Aero may well respond to its relative closeness to the sea in a way that probably exaggerates the westerly components, and the diurnal variations in the post earlier might support this notion. I suspect that a site 20 or 30km further inland would give a different distribution. But let me cut to something more obvious to make the point - Wellington windflows. Anyone who understands the climate here - thousands who live here don't, and a few are so ignorant they can't clearly identify which of the two major directions is occurring on an "averagely" windy day.
To nearly all it is just "northerly" and "southerly", especially in the parts where topography narrows the bands even further. With that bald kind of observation on its own nothing is said about the large-scale flow (and the recent, present or forthcoming weather) unless the local elements are looked at much more closely. Years ago a local observer who recognised this defined about 5 categories in each of the two groups. The scheme works well.

That's it - you're welcome to continue your conversation with rainfan, or if you like arguing for its own sake (trolling, in other words), try and bait Gary Roberts into responding about something.

[sthguy]

Oh dear. What a post !!

Can you give evidence of the change? ie 'monthly totals are higher sincer the mid 1990's by x% on average compared to the previous x years'. You have stated this but present no evidence?

This will definitely be my last post on this subject. I am not going to bang around just because I'm asked to prove every single point because you take absolutely nothing I assert as read. That is simply insulting. I am not in the habit of making assertions about known and recorded numbers without knowing that I am correct, and I am simply not going to respond to your every whim. The average annual sunshine 1932-1993 was 1615 hours; the average 1994-2007 is 1746, much higher than for any comparable-length period in the past. In more detail:

1932-1993 182.4 160.4 139.2 104.1 86.0 71.8 91.2 120.0 136.6 161.2 174.6 187.9 1615.4
1994-2007 199.9 174.6 150.1 121.6 93.1 79.5 104.2 124.6 150.9 174.1 179.3 194.6 1746.5

I'm quite sorry you interpet every request for data as insulting. I didn't mean to damage your fragile ego.

And no, i am NOT going to upload graphs of the monthly and annual totals of the original data just to please you.

I didn't ask you to!!!

Trying to conflate Wellington's unique geographical location with Invercargill does nothing to enhance your points in my humble opinion.

That's it - you're welcome to continue your conversation with rainfan, or if you like arguing for its own sake (trolling, in other words), try and bait Gary Roberts into responding about something.

A staggering comment to make. You are clearly a person who never likes their views contested.

[Willoughby]

Time to wrap this thread up now guys. I think both opinions have been well noted now.