Local mais quente de Portugal ? 50°C é possível ?

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

They can write all they like but this is nonsens.

Não são eles que escrevem o que querem.
O trabalho deles é baseado em dados variados inclusive a partir de abrigos meteorológicos. Poder haver quem concorde ou quem discorde, mas a versão oficial é a deles. Se alguém quiser provar que os dados deles estão errados, terá que argumentar com estudos sérios feitos durante décadas.

It really is. Look at Cordoba Aeropuerto, at 90 m height placed well inland. It has an average maximum temperature of 34,5 C (summer average). Now there may be places that are just a little warmer, but not much. This is supported by Amareleja. I don't know where that one finishes up but I would be quite surprised if this station, at 175 m would be warmer than Cordoba. I think it will be cooler, about 1 C or so although I never witnessed that the last years.
So let us go down 175 m. We then come to a place that is nowhere to be found in the Iberian peninsula more than 50-100 km from the coast. Unless it is still influenced by the sea. Add 1,75 C (suggesting in dry air you on average reach 1 C/100m). Now 1.75 C added is really an upper limit. You go from 34,5 + 1,75= 36,2C. Well below 37,4 C.
In all fairness: Cordoba sits near the sweetspot for high temperatures in Iberia. It could be eclipsed, but you need to be in the south (850 hPa temperatures being higher on average) and you need to be inlandand you need to be low. In Portugal this means in the places I pointed you to,possible directly in the valley south of Amareleja or just south of Ficalho. Those places are about as low and may be a bit better sheltered than Cordoba. 37,4 is ou of the question, even 37,4 as the average max for one month is out of the question.
BTW: in the book "o ritmo climatico e a paisagem) that I have here the go no higher than 35 C for the maximum temperature of the warmest month....This seems more logical than 37+, let alone 37+ as a daytime max average for the whole summer. This would mean Tmax C. of the warmest month of 39 C or so...Totally unrealistic.

Deve haver alguma confusão.
Primeiro não se pode só usar 2 ou 3 factores e espetá-los no papel para fazer uma média. Neste caso usou a continentalidade e a altitude... Mas os dados do IM contam com estudos feitos em variados locais e aí teremos que ter em conta outros factores, como tipo de solo, relevo circundante ( isto também é MUITO importante), dados de abrigos meteorológicos na zona, ventos predominantes, etc...
Além de que esse valor de 37,4 é indicado para o Tejo interior, não para o Guadiana. São regiões MUITO encaixadas e com características locais muito próprias. Não se pode pegar em exemplos isolados, como o de Córdoba, que fica a centenas de kms de distância ( e nem sabemos que relevo local tem, ventos predominantes, etc...) e tentar comparar, para então decidir se está certo ou errado.
Nestas circunstâncias as coisas têm que ser vistas à escala local.
Eu não percebo qual é a diferença de acreditar que possam fazer médias para o mês mais quente de 38,5ºc, 39ºc ou 40ºc, quando vai dar praticamente ao mesmo...
As médias do IM, não são fixas, foram propostas como valores bastante aproximados.

Correct, but I wrote 2003-2010. Looked it up many times.

Não , você disse que eram de 2010. O que disse em relação a 2003 é que tem verificado não haver grandes diferenças entre Sevilha, Córdoba e Lameirões desde aí até hoje, ( como disse « mais ou menos»...)
E se tiver esses dados ( 2003-2010) gostaria de os ver.
Seria muito interessante.

In itself, yes. But if you can compare to nearby who do have a long record you can get a very good indication. 10 years is enough to come close to 0,2 or 0,3 C of deviation from the real climatic average. If you know the deviations of the other,longer stations you know somehting about the deviations of the station with the shorter record. In The Netherlands this is done with many stations if they move them to a place nearby..

Sim, concordo, é sem dúvida uma aproximação à média climática, embora por vezes não chegue, dadas as particularidades de uma região.

Oke, we can agree to disagree. Would like to know what area would be warmer and why...

Isto é só um forum.
E a conversa até está interessante.
A resposta foi dada mais acima, caro JS.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

Reasons to have clear doubts.

a) Taking 1 C/100 m of temperature rise is the highest value and it is obtained in dry air.
b) continentality in Portugal rise with 2,37 C/100 km inland (Lautensach)
c) lattide: temperatures rise with each 0,6 K/100 km move to the south.

a) We read this about Portugal:
" A elaboração das figuras 84 e 93 por J. Ventura leou-o naturalmente a tentar apreciar a variação regional do gradiente verticaldas temperaturas maximas e minimas. A analise grafica empirica das temperaturas registradas nas poucas estaçães existentes em cada região , em função da respectiva altitude, permitiu traçar uma recta de regressão, que exprime o correspondente gradiente regional medio. Os valores adoptados para o desenho dos mapas indicam-se a seguir. Em relação a temperatura minima media do mes mais frio, o gradiente medio e cerca de 0,4/100m tanto do NO como no Portugal interior e meridional; aumenta ate 0,5/100m na faixa de transição, que se extende da região de Lisboa ate Tras-os-Montes ocidental. Em relação as temperaturas meximas medias do mes mais quente, o gradiente e, em toda parte, muito superior, crescendo de cerca de 0,6/100m no Noroeste ate 0,9/100m e mesmo 1,0 C/100m nas regiões interiores."

So this is explicitly divided and the maximum of 1,0C/100 is not some sort of average. It is the maximum that can be found in the interior of continental Portugal as a daytime maximum average in summer.

b) is the special one specifically calculated or Portugal. Now Portugal is not 100% uniform, so we may expect some differences. Still we we can use it and look how well it does

c) lattide: temperatures rise with each 0,6 K/100 km move to the south.

So I take some examples form stations of which I know (more less) what the climatic averages are, how they are situated and look what comparison we get when we compare to various stations across country.

I take W to NW wind as the dominant winddirection in summer and calculate an average distance to the sea for both.

Beja - Amareleja
has a tmax media of 32,8 in july or august.

Beja: altitude 230 m, 59 km more to the coast, 10 km to the south.

0,4*1 K= 0,4K (height difference)
0,59*2,37= 1,39K (continentality)
0,1*-0,6 = -0,06 K (lattitude difference)

We come to: 32,8+0,4+1,31-0,06= 34,53 Tmax. To me this an absolute maximum, as the 1,0K is an absolute maximum in dry air.

What I found for Amareleja (1961-1990 data I believe) is 34,3 C. Pretty close.

Braganca to Beja:
4,7* -1K= -4,7K (470 m height difference)
0.9* 2,37= +2,37 K (100km more inland)
4,0* 0,6= -2,4 (400 km more to the north)

We come to -4.7+2,37 -2,4= -4,67 K. So Braganca would have an average daytime max of 32,8 -4,67 K= 28,13 C

I found 28,5C as the average max. So we come pretty close again. Mind you that local influenes (not climatological but not well maintained, sheltered stations) may and will have an effect. Many examples are available.

Braganca- Mirandela (data from 1961-1990)

450m lower, 50km less inland 30km to the south

We get +4,5 -1,19 +0,18 = +3,49.

28,5+3,49= 31,99 C for Mirandela.....1961-1990= 31,8. So we come very close again.

Mirandela is situated in the valley of the river Tua.

We can look at Portalegre-Beja.

350* -1 K= -3,5 K (580 m versus 230 m)
0,4* 2,37= 0,95 (40 km more inland)
1,3* 0,6 = -0,78 K (130 km to the north)

-3,5+0,95-0,78= - 3,33 K

32,8 -3,33K = 29,47 C. The real temperature is 29,8 C (1991-1990 average).


Compared to Rio Tejo.

Beja-Alvega. Tmax jul 32,8 and 32,1. Beja 20 km further inland, 170m less height and 180 km to the south.

1,70* 1,0= 1,7
0,20* -2,37 = -0.47
1,80*-0,6 = -1.08

Alvega should be 0,15 K warmer. It is 0,7 K cooler Difference 0,85K.



So inalmost all cases, we come very close. A reason for the difference between Alvega and Beja is that I think I should add more emphasis on the NW wind as it dominates more than the SW wind. In that case, Beja becomes more inland than Alvega.It will have very little difference compared to other stations.

When we look north of the Douro, we can say it is in general more enclosed than southern district which could add to some more continentality than the southern regions even with NW wind. Same is true for areas se to Castel Branco.

However: even so we see that the comparison still fits the bill very we calculate things for Mirandela, which is just 100-150 m higher than the Douro valley.

Now with this calculation, you can take a virtual point anywhere in Portugal at 0 metres and calculate how warm it will become. You will never reach the values of 37 C as an average summertmax temp and if 34,3 o Amareleja is now may 35 C (1971-2000 average) at 0 metres you can add 1 C.

I will do some more calculations with other stations.

Finally: the average juli temp of 2010 (tmediadas maximas) in Amareleja reached 38,0 C, ex aecquo with Cordoba.

 

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

Reasons to have clear doubts.

a) Taking 1 C/100 m of temperature rise is the highest value and it is obtained in dry air.
b) continentality in Portugal rise with 2,37 C/100 km inland (Lautensach)
c) lattide: temperatures rise with each 0,6 K/100 km move to the south.

a) We read this about Portugal:
" A elaboração das figuras 84 e 93 por J. Ventura leou-o naturalmente a tentar apreciar a variação regional do gradiente verticaldas temperaturas maximas e minimas. A analise grafica empirica das temperaturas registradas nas poucas estaçães existentes em cada região , em função da respectiva altitude, permitiu traçar uma recta de regressão, que exprime o correspondente gradiente regional medio. Os valores adoptados para o desenho dos mapas indicam-se a seguir. Em relação a temperatura minima media do mes mais frio, o gradiente medio e cerca de 0,4/100m tanto do NO como no Portugal interior e meridional; aumenta ate 0,5/100m na faixa de transição, que se extende da região de Lisboa ate Tras-os-Montes ocidental. Em relação as temperaturas meximas medias do mes mais quente, o gradiente e, em toda parte, muito superior, crescendo de cerca de 0,6/100m no Noroeste ate 0,9/100m e mesmo 1,0 C/100m nas regiões interiores."

So this is explicitly divided and the maximum of 1,0C/100 is not some sort of average. It is the maximum that can be found in the interior of continental Portugal as a daytime maximum average in summer.

b) is the special one specifically calculated or Portugal. Now Portugal is not 100% uniform, so we may expect some differences. Still we we can use it and look how well it does

c) lattide: temperatures rise with each 0,6 K/100 km move to the south.

So I take some examples form stations of which I know (more less) what the climatic averages are, how they are situated and look what comparison we get when we compare to various stations across country.

I take W to NW wind as the dominant winddirection in summer and calculate an average distance to the sea for both.

Beja - Amareleja
has a tmax media of 32,8 in july or august.

Beja: altitude 230 m, 59 km more to the coast, 10 km to the south.

0,4*1 K= 0,4K (height difference)
0,59*2,37= 1,39K (continentality)
0,1*-0,6 = -0,06 K (lattitude difference)

We come to: 32,8+0,4+1,31-0,06= 34,53 Tmax. To me this an absolute maximum, as the 1,0K is an absolute maximum in dry air.

What I found for Amareleja (1961-1990 data I believe) is 34,3 C. Pretty close.

Braganca to Beja:
4,7* -1K= -4,7K (470 m height difference)
0.9* 2,37= +2,37 K (100km more inland)
4,0* 0,6= -2,4 (400 km more to the north)

We come to -4.7+2,37 -2,4= -4,67 K. So Braganca would have an average daytime max of 32,8 -4,67 K= 28,13 C

I found 28,5C as the average max. So we come pretty close again. Mind you that local influenes (not climatological but not well maintained, sheltered stations) may and will have an effect. Many examples are available.

Braganca- Mirandela (data from 1961-1990)

450m lower, 50km less inland 30km to the south

We get +4,5 -1,19 +0,18 = +3,49.

28,5+3,49= 31,99 C for Mirandela.....1961-1990= 31,8. So we come very close again.

Mirandela is situated in the valley of the river Tua.

We can look at Portalegre-Beja.

350* -1 K= -3,5 K (580 m versus 230 m)
0,4* 2,37= 0,95 (40 km more inland)
1,3* 0,6 = -0,78 K (130 km to the north)

-3,5+0,95-0,78= - 3,33 K

32,8 -3,33K = 29,47 C. The real temperature is 29,8 C (1991-1990 average).


Compared to Rio Tejo.

Beja-Alvega. Tmax jul 32,8 and 32,1. Beja 20 km further inland, 170m less height and 180 km to the south.

1,70* 1,0= 1,7
0,20* -2,37 = -0.47
1,80*-0,6 = -1.08

Alvega should be 0,15 K warmer. It is 0,7 K cooler Difference 0,85K.



So inalmost all cases, we come very close. A reason for the difference between Alvega and Beja is that I think I should add more emphasis on the NW wind as it dominates more than the SW wind. In that case, Beja becomes more inland than Alvega.It will have very little difference compared to other stations.

When we look north of the Douro, we can say it is in general more enclosed than southern district which could add to some more continentality than the southern regions even with NW wind. Same is true for areas se to Castel Branco.

However: even so we see that the comparison still fits the bill very we calculate things for Mirandela, which is just 100-150 m higher than the Douro valley.

Now with this calculation, you can take a virtual point anywhere in Portugal at 0 metres and calculate how warm it will become. You will never reach the values of 37 C as an average summertmax temp and if 34,3 o Amareleja is now may 35 C (1971-2000 average) at 0 metres you can add 1 C.

I will do some more calculations with other stations.

Finally: the average juli temp of 2010 (tmediadas maximas) in Amareleja reached 38,0 C, ex aecquo with Cordoba.

A tua opinião é interessante, mas faltam variados factores: como vegetação local, tipo de solos, corpos de água presentes, orientação do relevo circundante ( em relação a por exemplo corpos de água presentes,ao Norte, aos ventos predominantes, etc,etc,etc...), precipitação média anual, níveis ombrotérmicos ( ver mapa já colocado aqui no forum), níveis de insolação, afloramentos rochosos, tipos de rochas predominantes,quantidade de superfície reflectora de radiação solar,etc,etc,etc...
E novamente reafirmo que sem ter em conta esses factores e outros tantos mais, não se pode pegar em exemplos de Mirandela, Beja, Moura, Bragança,etc..., para se tomar uma conclusão sobre os valores nas zonas mais quentes...
Para já, a melhor versão que temos sobre o tema é a do IM.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

A tua opinião é interessante, mas faltam variados factores: como vegetação local, tipo de solos, corpos de água presentes, orientação do relevo circundante ( em relação a por exemplo corpos de água presentes,ao Norte, aos ventos predominantes, etc,etc,etc...), precipitação média anual, níveis ombrotérmicos ( ver mapa já colocado aqui no forum), níveis de insolação, afloramentos rochosos, tipos de rochas predominantes,quantidade de superfície reflectora de radiação solar,etc,etc,etc...
E novamente reafirmo que sem ter em conta esses factores e outros tantos mais, não se pode pegar em exemplos de Mirandela, Beja, Moura, Bragança,etc..., para se tomar uma conclusão sobre os valores nas zonas mais quentes...
Para já, a melhor versão que temos sobre o tema é a do IM.

Well, we can stop thinking of course and always say that. It ends all discussions. We can do the calculus ourselves and see where we come up with.

There are several reasons why I have little faith in this extrapolation for local climates.

First of all: I have exactly ths situation in The Netherlands where they portray my minimum temperature at 8,0 C. This is based on Vlissingen KNMI 10 km to the SW. My weatherstation consistently shows it is 1,4 K cooler over the last 13 years. Finally, another recent KNMI station 17 km to my east in a virtually identical situation to mine shows the same figures. So the extrapolation in the KNMI 2001 atlas (1971-2000 meteorological data) got horribly wrong. Horribly, as the bandwidth over here is 2,7 C for the whole country and there are no hills at all. And still they got it wrong.

Now why I did not trust them (IM) prior to my calculations? Because in nearby Spain we find stations that are situated further inland and at a lower altitude that do not even come near those values. Not even close. You can argue that may be some valleys in Portugal are a bit warmer. But 34,5 C in Cordoba or 37,5 somewhere in Portugal is not "a bit". It is a huge difference.

Why your remarks in this message are not substantiated if you ask me by the IM maps, that show 37,4 C near Braganca (in a valley) and 37,5 near Rosmanhinhal is because of this:
- If other factors than altitude, continentality and lattitude are of importance, why do we find all hotspots on the IM cards in the most continental and low lying areas?? If other factors, which are clearly not related to any of these factors, would have a big influence, we would not have seen such homogeneous temperature rise the further you go inland as long as you remain at the lowest altitudes.
Clearly, the IM based itself on altitude and continentality at least dominantly. Just like me.

- Green cover etc: if it has an influence, something is wrong with the station. It does not represent a climatic influence, but a difference based on a site anomaly. The WMO guidelines are clear: you measure on short grass, with no trees within a 200m radius and nothing above 50 cm in 100 m radius.
If you do so, you introduce errors.

- If other factors would be so influential, large errors would show up in my calculations. They clearly do not. And I have used data from valleys (Mirandela, Amareleja, Alvega and added Pinhão) as well as other, higher locations. But this does not influence the correctness of the calculations. Below I have added some other stations, form Spain. Still, no large error is found.

- Looking at you remarks about precipitation and solar influences: these are taken into account by the 1,0K/100 metres. 1,0 K is reached under sunny conditions and in very dry air. In essence, a fohnlike situation and it is supposed, in that calculation that this is constistently so throughout the month of july. So in ideal conditions. You can't get it more ideal.

- The only factor that has margin for some error are my calculations about the wind direction and thus continentallity. Which for some reason just gets wrong where there are no stations?

Pinhão....140 km from the sea at 80 m above sealevel. Compared to Mirandela.
continentality: 0,17*2,37= -0,4K (it is 17 km more inland than Mirandela)
latitude: 30* 0,6= 0,18 K (30 km south of Mirandela)
Altitude= 250-80= 1,7*1= 1,7K (80 lower than Mirandela)

So I'd expect a Tmediadasmaximas of 1,5+31,8= 33,3 C.

Now I found a value of 33,5 C as the tmaxdas medias and found it on this site...I found this AFTER my calculation above BTW. So 0,2 C deviation. Great!

And now from Pinhão to the valley SE of Cerejais. It is 50 km more inland, 70m higher and at the same lattitude.
2,37*0,5=1,19K warmer
0,7*1,0=0,7K cooler

This valley is therefore 0,5K warmer. Mind you, it takes 180 km in The Netherlands to reach that difference!
So the lower part of that valley is 34,0 C. I think it is really hot, but still cooler than Amareleja and Moura, but not by much. The valley right south of Amareleja is 100 m high, so they "enjoy" 35,2 C heath in july btw....very nice...I cannot find any part in Portugal warmer than that.

People really need to explain why 50km more inland would lead to a temperature rise of about 5,5 C!!!!! In order to get at an average summertemperature of 37,5 C. Remember: 33,5 C is the average maximum temperature for july in Pinhão, not for the whole summer. Average summer temperature in Pinhão will be about 32 C. So 5,5 C over 50km.....you take this serious?

I remind you again: 1,0 C K is a maximum for a 100 meter drop in latitude. So may be it is 0,6 K. Doesn't help much, we come to 34,3 C.


Sevilla B.A- Cordoba Aeropuerto: Difference in juli 1,6 C.

altitude: 91-87=m= -0,04K
continentality= 100 km= 1* 2,37= 2,37
Lattitude= 70*0,6= -0,42

Difference= 2,37-0,42-0,04K= 1,91 K....Adds up quite well again. Missed it by 0,31 C.

Badajoz Tal.- Caceres= 34,3-33,0 = 1,3 K difference
altitude: 185-405=220m= 2,2
continentality: 0,35*2,37= -0,83
latitude: 60* 0,6= 0,36

Badajoz should be 1,73K warmer. It is 1,3 K. Missed it by 0,43 K.

A last one, to get more to the interior parts of the Tejo:
Castelo Branco-Beja 31,8 -32,8= 1,0 K
altitude: 1,4*1= 1,4K
continentality:0,42*2,37= - 1,0K
Latitude: 2.1*0,6= 1,22K

So we end up with: 1,66K. The difference here is 0,66 K less than expected. Castelo Branco probably has a higher continentality because of higher mountains to the NW and again the 1,0 K per 100m is a maximum. Still. we are 0,66 K wrong.

Now I would like to know what unknown factor leads to a 5,5 C rise over 50 km with a rise in height of 80 m...

Finally: I'd say a place like Montoro to Andujar is very enclosed, low lying and more continental. There is another factor of importance and I truely wonder if the IM has taken it into account. That is the one of lattitude. If we look at Amareleja, it is 360 km south of Cerejais. It simply means that you have to overcome 3.6*0,6= 2,18 C aswell, solely based on the lattitude difference.

I have learned a lot during this discussion, never did this calculation before and found a lot of data. So thanks anyways!

 

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

Well, we can stop thinking of course and always say that. It ends all discussions. We can do the calculus ourselves and see where we come up with. !

Os cálculos já foram feitos. Mas obrigado por dar a sua opinião.

There are several reasons why I have little faith in this extrapolation for local climates.!

Esta extrapolação foi feita não só com cálculos, mas com trabalho de campo feito no local. Não é propriamente fazer matemática baseada em teorias.

Now why I did not trust them prior to my calculations. Because in nearby Spain we find stations that are situated further inland and at a lower altitude that do not even come near those values. Not even close. You an argue that may be some valleys in Portugal are a bit warmer. But 34,5 C in Cordoba or 37,5 somewhere in Portugal is not "a bit".!

Sinceramente não estou em condições de comparar ambas, porque não tenho conhecimentos profundos sobre ambas. Também nunca fiz trabalho de campo nesses locais.
Mas daria crédito aos profissionais que já o fizeram.

Why your remarks in this message are not substantiated if you ask me by the IM maps, that show 37,4 C near Braganca (in a valley) and 37,5 near Rosmaninhal is because of this:!

37,4 não são perto de Bragança, mas perto do Rosmaninhal e 37,5 ou mais são perto de Cerejais, embora existam mais vales com valores próximos ou iguais a 37,5ºc.

- If other factors than altitude, continentality and lattitude are of importance, why do we find all hotspots on the IM card in the most continental and low lying areas??!

Nem todos os locais baixos e no interior têm aqueles valores. Como se pode ver são zonas específicas que vão além de apenas serem baixas e continentais.

Clearly, the IM based itself on altitude and continentality at least dominantly.!

Sim, mas conjugam outros factores, não apenas esses...

I have learned a lot during this discussion, never did this calculation before and found a lot of data. So thanks anyways!

As suas críticas são interessantes, mas é difícil contrariar teoria e prática com apenas teoria.
Ainda bem que aprendeu, pois eu também aprendi consigo.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

It is not so difficult to answer this question. Do you think there is any logic to expect a 5,5 C temperature rise over 50 km, when one station is situated 140 km inland and the other is 190 km inland? And the one deeper inland is in fact at a higher alititude.

The calculations were done in my region as well., Even without any mountain or hill, just 10 km NE of a known KNMI station the got it 1,4 K wrong. In my situation, even 0,5K would be nothin short of a blunder. So to say that the calculations were done...? You yourself said that 7 years of climatic data are not enough to say anything substantial compared to a 30 year period. So what fieldwork are you talking about that in fact can do this as to have no discussion about it?

I think you either give way to much credit to someone with the title meteorologist or you rather want these numbers to be true for some reason. In all honesty I cannot imagine someone with knowledge of meteorology who, in this situation, thinks it is possible that you can get a 5,5 K temprise over such as short distance. You do not even seem to have a questionmark, which is beyond me as a critical meteorologist. There are no miracles in this world, certainly not in the scientific field. So everything has an explanation. These 37,4 or 37,5 as Tmax of the media even for one month (!) needs a miracle more than an explanation I think :-)

 

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

It is not so difficult to answer this question. Do you think there is any logic to expect a 5,5 C temperature rise over 50 km, when one station is situated 140 km inland and the other is 190 km inland? And the one deeper inland is in fact at a higher alititude.

The calculations were done in my region as well., Even without any mountain or hill, just 10 km NE of a known KNMI station the got it 1,4 K wrong. In my situation, even 0,5K would be nothin short of a blunder. So to say that the calculations were done...? You yourself said that 7 years of climatic data are not enough to say anything substantial compared to a 30 year period. So what fieldwork are you talking about that in fact can do this as to have no discussion about it?

I think you either give way to much credit to someone with the title meteorologist or you rather want these numbers to be true for some reason. In all honesty I cannot imagine someone with knowledge of meteorology who, in this situation, thinks it is possible that you can get a 5,5 K temprise over such as short distance. You do not even seem to have a questionmark, which is beyond me as a critical meteorologist. There are no miracles in this world, certainly not in the scientific field. So everything has an explanation. These 37,4 or 37,5 as Tmax of the media even for one month (!) needs a miracle more than an explanation I think :-)

Como já disse os resultados foram completados com dados provenientes de abrigos meteorológicos.
Já vi estações com valores mais elevados no verão e a altitudes maiores, que locais mais continentais e com menor altitude, tudo devido a diversos factores ( novamente ventos predominantes, relevo em redor, tipo de solo, etc, etc,etc...), embora claro que na maior parte das vezes, não seja assim. Dê uma olhada aos valores das localidades em torno de Córdoba, por exemplo e terá surpresas.
Penso que tenho todo o direito em favorecer o trabalho do IM sobre a sua teoria, não só pelo facto de serem profissionais, como por também conjugarem dados práticos com teóricos.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

Como já disse os resultados foram completados com dados provenientes de abrigos meteorológicos.
Já vi estações com valores mais elevados no verão e a altitudes maiores, que locais mais continentais e com menor altitude, tudo devido a diversos factores ( novamente ventos predominantes, relevo em redor, tipo de solo, etc, etc,etc...), embora claro que na maior parte das vezes, não seja assim. Dê uma olhada aos valores das localidades em torno de Córdoba, por exemplo e terá surpresas.
Penso que tenho todo o direito em favorecer o trabalho do IM sobre a sua teoria, não só pelo facto de serem profissionais, como por também conjugarem dados práticos com teóricos.

I use metstation data too, so it is not theory only. I do an interpolation, just like they did. And the theory is than checked against metstation data. So it is a theory tested against reality. And no large errors show up. They are in the order of a magnitude smaller than needed! That is 10 fold smaller.

Do you think they went up to every single valley in Portugal and hill side to come up with this map? For how long? How many people were involved and how many stations were used during this project? They do not have the people nor the money to do so. You would need hundreds of weatherstations, places which are in accord with WMO standards etc. The fact is that soil, vegetation etc simply has no big influence on your data, unless you plant trees right next to the station in which you introduce an error.
In some places this is not possible because the valley bottom consists of the river and it steeply rises. So how about a body of water influencing the temperature...

They just use theory as well to come up with that map, but there is much reason to doubt it to be correct.

Well, you are not thinking here I feel and this is no discussion. We can alsways say, in every field: specialist have calculated it so they are right. That is a discussionending phrase, not one that starts it.

But apart from my calculations, lets look at those maps. You know where to find them.

Let us take two points: One is the Douro valley. Just SE of Bragança (may be 10-20 km or so) , I see a reddish brown spickle indicating at least a summertime average maximumtemperature of somewhere between 35-37,5 C. It is impossible to tell, but 35 C seems the lower limit. Do you know how high this valley is actually situated? 480 meter. So that is 220 m lower than Bragança. Now even if I take 35,0 C as the value calculated there, the introduced rise over there is from 27,0 in Bragança to 35,0 C 220 m lower and 15 km away. That is a 8 C rise. That is four times the number we see in heavy fohn situations! And I am being modest. I took the lowest possible value. So 4 C rise per 100 m you go down..

Lets look at the Guadiana river, which gives us a better result as it is much easier to judge those maps. The reddishbrown spot indicates 35,0 C, according to you these are average summertime maxima. And it does occur east of Elvas so we end up just a few km short of Badajoz. Now how warm does Badajoz, with a perfect station in operation there for more than 30 years, get? It gets up to 30,5 june, 34,3 in july and 34,0 in august. This gives us the total of 32,9 C as a summer average (1971-2000 data, INM). That is 2,1 degrees lower than the IM calculations. So for some strange reason, if you just cross the Spanish border and go further inland without gaining any altitude to speak of, the temperature suddenly reverses its constant upward trend and goes down again...No sign of any drop on the Portuguese side and near Elvas the valley has broadened up quite nicely, so it is not that we have a very narrow valley over there that suddenly becomes much wider. No, looking at google earth we see the valley is already 4-8 kilometers wide.

Apart form my own calculations which do not take into account the findings of the IM maps, even when we use the maps it is almost sure they are wrong.

Of course anybody can believe what they want. I feel that saying "the IM says so" is not much different than saying "it says so in the bible". Nothing wrong with that, but it leaves little room for discussion.

 

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

I use metstation data too, so it is not theory only. I do an interpolation, just like they did. And the theory is than checked against metstation data. So it is a theory tested against reality. And no large errors show up. They are in the order of a magnitude smaller than needed! That is 10 fold smaller.

Do you think they went up to every single valley in Portugal and hill side to come up with this map? For how long? How many people were involved and how many stations were used during this project? They do not have the people nor the money to do so. You would need hundreds of weatherstations, places which are in accord with WMO standards etc. The fact is that soil, vegetation etc simply has no big influence on your data, unless you plant trees right next to the station in which you introduce an error.
In some places this is not possible because the valley bottom consists of the river and it steeply rises. So how about a body of water influencing the temperature....

São boas questões para colocar aos autores do trabalho, que muito provavelmente tiveram em conta, esses e tantos outros factores.
Mas certamente não se sentaram a uma mesa a criticar o trabalho dos outros, sem nunca terem feito trabalho de campo no local.
Não se pode usar uma variável, por exemplo, para definir a influência da aridez ou dos solos na temperatura, sem saber o que há no local.
Parece-me um tanto ambíguo esse procedimento.

Well, you are not thinking here I feel and this is no discussion. We can alsways say, in every field: specialist have calculated it so they are right. That is a discussionending phrase, not one that starts it..

O que se disse é que existe uma aproximação da realidade.

But apart from my calculations, lets look at those maps. You know where to find them.

Let us take two points: One is the Douro valley. Just SE of Bragança (may be 10-20 km or so) , I see a reddish brown spickle indicating at least a summertime average maximumtemperature of somewhere between 35-37,5 C. It is impossible to tell, but 35 C seems the lower limit. Do you know how high this valley is actually situated? 480 meter. .

Gostaria de ver a evidência que está a 480 metros. Mas nem foi essa a zona de maior atenção, foi antes a que fica junto a Cerejais.

So that is 220 m lower than Bragança. Now even if I take 35,0 C as the value calculated there, the introduced rise over there is from 27,0 in Bragança to 35,0 C 220 m lower and 15 km away. That is a 8 C rise. That is four times the number we see in heavy fohn situations! And I am being modest. I took the lowest possible value. So 4 C rise per 100 m you go down...

O IM deu ênfase às zonas mais quentes, no Vale do Douro foi junto aos Cerejais.
Não junto a Bragança.
Claro que estes mapas podem conter erros, ninguém disse que estavam 100% correctos. As zonas mais quentes, foram as zonas alvo.
Em Saucelle, mesmo junto a Portugal, junto a um grande corpo de água ( Rio Douro) sem qualquer diferença de altitude em relação ao lado português e tão ou mais exposta a ventos, temos médias gerais superiores a 27ºc para os 2 meses mais quentes do ano.
Será esta a zona mais quente do Douro? Duvido muito.

Lets look at the Guadiana river, which gives us a better result as it is much easier to judge those maps. The reddishbrown spot indicates 35,0 C, according to you these are average summertime maxima. And it does occur east of Elvas so we end up just a few km short of Badajoz. Now how warm does Badajoz, with a perfect station in operation there for more than 30 years, get? It gets up to 30,5 june, 34,3 in july and 34,0 in august. This gives us the total of 32,9 C as a summer average (1971-2000 data, INM). That is 2,1 degrees lower than the IM calculations. So for some strange reason, if you just cross the Spanish border and go further inland without gaining any altitude to speak of, the temperature suddenly reverses its constant upward trend and goes down again...No sign of any drop on the Portuguese side and near Elvas the valley has broadened up quite nicely, so it is not that we have a very narrow valley over there that suddenly becomes much wider. No, looking at google earth we see the valley is already 4-8 kilometers wide..

Não, a zona mais quente no Guadiana é apresentada no trabalho, como estando junto a Serpa.
Até junto a Alcoutim, em Sanlucar de Guadiana a apenas 500 metros de distância do porto de Alcoutim, junto a um grande corpo de água ( Guadiana) temos locais acima dos 27ºc de média geral para os 2 meses mais quentes. Será esta a zona mais quente do Guadiana? Duvido muito.

Apart form my own calculations which do not take into account the findings of the IM maps, even when we use the maps it is almost sure they are wrong..

Em locais que eles procuraram obter mais resultados para este trabalho ( as zonas mais quentes), até acredito em alguma margem de erro como já disse, mas também não acho que estejam muito longe. E sinceramente não vi a apresentação de um trabalho melhor.

Of course anybody can believe what they want. I feel that saying "the IM says so" is not much different than saying "it says so in the bible". Nothing wrong with that, but it leaves little room for discussion.

Eu estou aberto à discussão, pois nunca disse que estes cálculos estavam 100% correctos até porque como já se disse, é impossível com os meios dispostos fazer avaliações para tanta área ao mesmo tempo.
O que disse é que relativamente às zonas mais quentes há uma boa aproximação da realidade.

PS: Um conselho sincero, leia o que já se disse sobre este assunto.
Como por exemplo, mais atrás, neste mesmo tópico.
Mas não se sinta nunca impedido de criticar ou apresentar novos pontos, desde que tenha algum conhecimento da relevância que isso tem.
Este trabalho do IM, serve sobretudo para identificar quais os locais com maior potencial calorífico e fazer aproximações.
O ideal mesmo é, como já disse, fazer medições no local ( evidentemente que o ideal seria durante um período de tempo climatológico).

 

[belem]

Através dos cálculos que o JS usa diga-me qual é a média das máximas para o mês mais quente e para os 3 meses mais quentes para esta localidade de Córdoba ( Puente Genil).
Informações sobre o local:

Latitude: 37º 21´N
Longitude: 004º 43´N

Altitude 200 metros.

Já que falou em Montoro, que valores dá para esse local?

Seria interessante compará-os por exemplo com a estação Córdoba- Aeroporto entre outras.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

São boas questões para colocar aos autores do trabalho, que muito provavelmente tiveram em conta, esses e tantos outros factores.
Mas certamente não se sentaram a uma mesa a criticar o trabalho dos outros, sem nunca terem feito trabalho de campo no local.
Não se pode usar uma variável, por exemplo, para definir a influência da aridez ou dos solos na temperatura, sem saber o que há no local.
Parece-me um tanto ambíguo esse procedimento.

I am not critising their work, I don't know much about how they did it. I do have good reasons, using calculations specified for Portugal based on rsearch done in Portugal, to doubt it. It is always awkward when people start saying things about having to be in the area to knwo what you are talking about. That is true if data are missing. It is correct if I say that I am to 0,2 K exact. I can't be because the factors you told me about (especially soil type) does have an influence. It will add up to a couple of tens of a degree.
It is easy to introduce systemic errors, I have always thought about these in the Netherladsn: the less wind there is, there more unventilated screens start to warm up because to get detouched from the surrounding air. You do not want to measure how warm the "abrigo" can get, you want to measure the ambient temperature. Now at the coast there is more wind in general than further inland. So this error, which can account for several degrees, is much more likely to occur inland than near the coast. You end up measuring a bigger difference because of systemic errors rather than the real difference between two places. This is most apparent in days with high radiation (summer!). You can correct this by using a ventilator. It should not blow too hard, because then it introduces moist onto the sensor (Campell ventilators do this) which makes yiou measures wetbulb temperatures..ie: too low...

Just an example of an systemic error. another one is of course directly linked to this one: it is sheltered weatherstations. First of all they introduce a more stable aircolumn, which warms up more easily and second of all they introduce the error described above, because of less wind...

Now this I do not know for any station. Luckily, the warmest stations are situated inland so the wind will play a much smaller factor in almost all stations.
But if you start to measure in very sheltered valleys and you do not take precautions, you'll introduce a false higher temperature.

So, on a side note. If someone really wants to measure differences yoiu need to use a ventilator that is solardriven and that start blow with 3m/s-1 wind speed. And you need to use these screens everywhere.

Gostaria de ver a evidência que está a 480 metros. Mas nem foi essa a zona de maior atenção, foi antes a que fica junto a Cerejais.

No, that area is portrayed to be cooler, yellow to be exact. It is the small valley just souteast of Braganca that reaches these temperatures. There are others also, that is correct. But not the one of (I believe) the Rio Tua and certainly not the one SE of Cerejais.

O IM deu ênfase às zonas mais quentes, no Vale do Douro foi junto aos Cerejais.
Não junto a Bragança.

May be in words, but those maps you canfind here in this topic clearly paint another picture.

Claro que estes mapas podem conter erros, ninguém disse que estavam 100% correctos. As zonas mais quentes, foram as zonas alvo.
Em Saucelle, mesmo junto a Portugal, junto a um grande corpo de água ( Rio Douro) sem qualquer diferença de altitude em relação ao lado português e tão ou mais exposta a ventos, temos médias gerais superiores a 27ºc para os 2 meses mais quentes do ano.
Será esta a zona mais quente do Douro? Duvido muito.

Don't know. Average temp. do not have a 1:1 correlation with daytime max temperatures. Look at Amareleja. Tmedia in julho= 25,0. In Sevilla, it is 27,2.
At day, these two generally have similar temperatures. Within 1 C from onanother for sure. So the minimum in Sevilla is clearly higher and it is. I'd say this has to be the case in the Douro valley also. If we look at Pinhão it has an july average temp of 25,8 C. MAxtemp= 33,5. That is clearly lower than Amareleja (at least 1 C). SO again: minimumtemp is a couple of degrees higher higher in Pinhão (3 C most likely).
In short: amareleja behaves more continental than the valleys of teh Guadalquivir and the Douro.

Não, a zona mais quente no Guadiana é apresentada no trabalho, como estando junto a Serpa.
Até junto a Alcoutim, em Sanlucar de Guadiana a apenas 500 metros de distância do porto de Alcoutim, junto a um grande corpo de água ( Guadiana) temos locais acima dos 27ºc de média geral para os 2 meses mais quentes. Será esta a zona mais quente do Guadiana? Duvido muito.

This is of little interest actually, but I wonder if we are in fact looking at the same maps. It are those maps you find in this thread which focus on Tras-os-montes and Guadiana basin specifically. It is of no interest for finding errors in the IM calculations. Because it is clear they calculate 35,0 C over there, while Badajoz, just 17 km to the east is 2,1 K lower. Same latitude, lattitude and in a valley that is 5-8 km wide in Portugal and Spain in that area.

Em locais que eles procuraram obter mais resultados para este trabalho ( as zonas mais quentes), até acredito em alguma margem de erro como já disse, mas também não acho que estejam muito longe. E sinceramente não vi a apresentação de um trabalho melhor.

This work is not tested. The fact that professors do these things is no guarantee. If you want to test it first we need to know the methodology. Second it should be reviewed by the peerreviewing system. If we canot do the first and there is no second, this work is not tested or to be tested it all.

This still does not discount in any way my crude calculations, which simply should come up with large errors if it is in correct. I emphasise that in not a single case this is happens. The crude calculations take into account the most important factors and are specified for the Portugese circumstances.

The case of Badajoz and their calculations is an easy one. You do not need rocketscience to see that they are totally off there. This case is another sign things do not add up. My cacluations, without being arrogant, do.

I also repeat that we need a margin of error that is about 10 fold the margin found in my calculations to come to those figures in this IM research.

Another nail at the coffin is that in my Portugese book, another calculation is made based on metstations over the coarse of 11 years. They come no higher than 35 C near Serpa Moura and south of Amareleja. They do not reach 35 C anywhere in the tejo valley. They come to 35 C just east of Pinhão. Unfortunately, the map is too small to see the isotherms in that valley. But I am sure 35 C is hit in a small area.

This is for the warmest month, not the summer in total. WHich still indicates temperatures in the order of 33 C. It is btw exactly the number they write down for the hottest places in Alentejo. Now this value is corroborated by the BAdajoz value of 32,9 C. Amareleja will be warmer and the valley also. I think 33,5 is possible there.

My calculations show similar values in the deeper valley near Idanha (Se of Castelo Branco) and somewhat lower values 50 km east of Pinhão.

Eu estou aberto à discussão, pois nunca disse que estes cálculos estavam 100% correctos até porque como já se disse, é impossível com os meios dispostos fazer avaliações para tanta área ao mesmo tempo.
O que disse é que relativamente às zonas mais quentes há uma boa aproximação da realidade.

it is, but it depends on what you fiond acceptable or not. If we were to discuss variations of 1 C than my calculations will not suffice. Luckily, physics depends on certain laws. In this case, lattitude, height and continentallity are the decisive factors. Others are not. Not for a calculation within a 1 K certainty. In general, you could say that a 0,5 K error is possible. We are arguing about 5-6 and locally 8 C differences. It is not too difficult to calculate that these are bordering impossible.

PS: Um conselho sincero, leia o que já se disse sobre este assunto.
Como por exemplo, mais atrás, neste mesmo tópico.
Mas não se sinta nunca impedido de criticar ou apresentar novos pontos, desde que tenha algum conhecimento da relevância que isso tem.
Este trabalho do IM, serve sobretudo para identificar quais os locais com maior potencial calorífico e fazer aproximações.
O ideal mesmo é, como já disse, fazer medições no local ( evidentemente que o ideal seria durante um período de tempo climatológico).

I did already, that is where I found those maps and the 33,5C Tmax data from Pinhã.
BTW: I am not saying you are not open to discussion, I am saying that such a remark closes it. In short: I find the remark itself not helpfull. Yet I would like you to think about this if you have the knowledge (no offense, but not everybody does have it). Do not reitterate the work of IM and add the fact that "I don't know". As far as I know, there is currently no way to tell if this work is done with rigorous research or not. So we cannot say how good or bad it is from that perspective.

I restate that there are ways to calculate values, to check these calculations by comparing those with realdata and to check how well you are doing. For the figures we like to find, we see that throughout Portugal and western Spain the calculations are good enough to discount large errors.
Other work does not show these high values at all.
Badajoz stations how much lower temperatures than calculated just a few KM west of it in identical situation.

In short: there is very good reason to doubt it.

I would like you to pick some of my remarks and compare it. Most of all: how about the 2,1 K difference between badajoz and the IM data?
How abnout the fact that my calculations are virtually spot on and are well within 1 K of the real metstation data? What is your specific answer to this matter?

 

[J.S.]

Através dos cálculos que o JS usa diga-me qual é a média das máximas para o mês mais quente e para os 3 meses mais quentes para esta localidade de Córdoba ( Puente Genil).
Informações sobre o local:

Latitude: 37º 21´N
Longitude: 004º 43´N

Altitude 200 metros.

Já que falou em Montoro, que valores dá para esse local?

Seria interessante compará-os por exemplo com a estação Córdoba- Aeroporto entre outras.

Montoro ou Andujar. Sim. Mas atenção: sei que em Espanha ha algumas estações que estão ma ubicadas. Eu soube isto sobre alguns lugares em Huelva, onde hobbyistas sempre diziam que eu fui uma lastima...Mas ao fim, este estação fui ma ubicada..Outras pessoas "confecem" isto...Ficou na cidade sobre terre arena.....
Outras problemas: Xativa e Cazorla..Mas oke...primeiro quero ver as dados de Montoro e Andujar.

 

[belem]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

I am not critising their work, I don't know much about how they did it. I do have good reasons, using calculations specified for Portugal based on rsearch done in Portugal, to doubt it. It is always awkward when people start saying things about having to be in the area to knwo what you are talking about. That is true if data are missing. It is correct if I say that I am to 0,2 K exact. I can't be because the factors you told me about (especially soil type) does have an influence. It will add up to a couple of tens of a degree.?

Certamente que há variantes que se calhar nem eu nem o JS sabe.
O JS tem a sua opinião, o IM e eu temos a nossa.
O limite é esse.

Don't know. Average temp. do not have a 1:1 correlation with daytime max temperatures. Look at Amareleja. Tmedia in julho= 25,0. In Sevilla, it is 27,2.
At day, these two generally have similar temperatures. Within 1 C from onanother for sure. So the minimum in Sevilla is clearly higher and it is. I'd say this has to be the case in the Douro valley also. If we look at Pinhão it has an july average temp of 25,8 C. MAxtemp= 33,5. That is clearly lower than Amareleja (at least 1 C). SO again: minimumtemp is a couple of degrees higher higher in Pinhão (3 C most likely).
In short: amareleja behaves more continental than the valleys of teh Guadalquivir and the Douro.

Já sabemos que nem sempre há correlação, mas o que se sabe sobre as mínimas das regiões mais quentes do Douro, Tejo ou Guadiana?
Não quer lançar um palpite? Eu duvido muito mesmo, que seja tão baixas como as da Amareleja.

This is of little interest actually, but I wonder if we are in fact looking at the same maps. It are those maps you find in this thread which focus on Tras-os-montes and Guadiana basin specifically. It is of no interest for finding errors in the IM calculations. Because it is clear they calculate 35,0 C over there, while Badajoz, just 17 km to the east is 2,1 K lower. Same latitude, lattitude and in a valley that is 5-8 km wide in Portugal and Spain in that area.

Encontrar erros é interessante, mas estamos a falar das zonas mais quentes.

This work is not tested. The fact that professors do these things is no guarantee. If you want to test it first we need to know the methodology. Second it should be reviewed by the peerreviewing system. If we canot do the first and there is no second, this work is not tested or to be tested it all.
This still does not discount in any way my crude calculations, which simply should come up with large errors if it is in correct. I emphasise that in not a single case this is happens. The crude calculations take into account the most important factors and are specified for the Portugese circumstances.
The case of Badajoz and their calculations is an easy one. You do not need rocketscience to see that they are totally off there. This case is another sign things do not add up. My cacluations, without being arrogant, do.
I also repeat that we need a margin of error that is about 10 fold the margin found in my calculations to come to those figures in this IM research.
Another nail at the coffin is that in my Portugese book, another calculation is made based on metstations over the coarse of 11 years. They come no higher than 35 C near Serpa Moura and south of Amareleja. They do not reach 35 C anywhere in the tejo valley. They come to 35 C just east of Pinhão. Unfortunately, the map is too small to see the isotherms in that valley. But I am sure 35 C is hit in a small area.

Essa publicação é de que ano e quais são os autores?
O trabalho do IM é de 2002.
Não existe nenhuma evidência que demonstre que no Tejo não se atinjam médias de 35ºc, só com dados climatológicos é que seria possível confirmar qual o trabalho é que está correcto.
O trabalho do IM é avançado com uma possibilidade não como uma certeza.

If we were to discuss variations of 1 C than my calculations will not suffice. Luckily, physics depends on certain laws. In this case, lattitude, height and continentallity are the decisive factors. Others are not. Not for a calculation within a 1 K certainty. In general, you could say that a 0,5 K error is possible. We are arguing about 5-6 and locally 8 C differences. It is not too difficult to calculate that these are bordering impossible.

Quando sabemos quais as médias de certos locais ( como Badajoz ou Amareleja) é fácil fazer cálculos para que dêm certo e assim demonstremos que o que dizemos está certo. O problema é quando os locais têm particularidades climáticas e não sabemos quais as médias desse sítios.
A minha posição é mais humilde e concreta: só com medições em locais propícios é que saberemos o que lá se passa.

Montoro ou Andujar. Sim. Mas atenção: sei que em Espanha ha algumas estações que estão ma ubicadas. Eu soube isto sobre alguns lugares em Huelva, onde hobbyistas sempre diziam que eu fui uma lastima...Mas ao fim, este estação fui ma ubicada..Outras pessoas "confecem" isto...Ficou na cidade sobre terre arena.....
Outras problemas: Xativa e Cazorla..Mas oke...primeiro quero ver as dados de Montoro e Andujar.

Então não consegue usar os seus cálculos para esse lugares?
São todos em Córdoba ( distrito) e sempre pode usar os dados da cidade de Córdoba e fazer algumas interpolações.
Ou não dá?

I did already, that is where I found those maps and the 33,5C Tmax data from Pinhã.
BTW: I am not saying you are not open to discussion, I am saying that such a remark closes it. In short: I find the remark itself not helpfull. Yet I would like you to think about this if you have the knowledge (no offense, but not everybody does have it). Do not reitterate the work of IM and add the fact that "I don't know". As far as I know, there is currently no way to tell if this work is done with rigorous research or not. So we cannot say how good or bad it is from that perspective.

Eu já disse isso e gostaria que o JS também dissesse o mesmo em relação às limitações dos seus cálculos relativamente a locais que apresentam especificidades climáticas.

I restate that there are ways to calculate values, to check these calculations by comparing those with realdata and to check how well you are doing. For the figures we like to find, we see that throughout Portugal and western Spain the calculations are good enough to discount large errors.
Other work does not show these high values at all.
Badajoz stations how much lower temperatures than calculated just a few KM west of it in identical situation.
In short: there is very good reason to doubt it.
I would like you to pick some of my remarks and compare it. Most of all: how about the 2,1 K difference between badajoz and the IM data?
How abnout the fact that my calculations are virtually spot on and are well within 1 K of the real metstation data? What is your specific answer to this matter?

A minha resposta é a de que simplesmente seria interessante identificar quais os locais com maior potencial térmico e fazer medições. Eu ainda há 2 dias fiz trabalho de campo num local onde havia disparidades térmicas percorrendo apenas 8 metros, daí que acredito que certos locais, tenham particularidades climáticas e que não seja matemática básica que é usualmente aplicada a outros locais, que possa ser aplicada a todo o lugar sem ter em conta as características únicas de cada local. Só com dados medidos e concretos.

 

[belem]

Há uma coisa que o JS tem que ter em conta.
Se um local é o mais quente numa região inteira, este lugar não pode ser vulgar, nem pode receber metodologias teóricas aplicadas à maioria de outros sítios.
O mesmo se aplica ao lugar mais frio numa região inteira.
Moncorvo tem a mesma temperatura média que Beja nos 2 meses mais quentes do ano ( sensivelmente) e no entanto está muito mais alto e a uma latitude muito mais a norte (lá se vão duas das variáveis utilizadas...). Isto porque esta região não tem um comportamento normal em que se possam aplicar regras gerais e esperar resultados idênticos aos outros locais. Tem que ser feita uma abordagem à escala local e respeitar as suas características específicas.
É evidente que o Alto Douro, tem uma eficiência térmica estival acima do normal. Não se pode dizer que um local no Alto Douro há mesma distância do mar que um local no Interior do Alentejo, tenha o mesmo nível de continentalidade, pois o Alto Douro tem montanhas de mais de mil metros tanto a Norte como a Oeste, por exemplo, que o Alentejo não tem. Claro que também a Oeste, o litoral norte tem mais humidade e frescura, que o litoral alentejano, mas também logo pouco depois da costa, a influência marítima esbarra com montanhas que actuam com barreiras de condensação e como senão bastasse, o cortejo de montanhas não se fica por aí, indo praticamente até aos bordos da bacia do Alto Douro, multiplicando a aridez e a continentalidade, sobretudo no verão. As precipitações médias anuais atingem níveis baixíssimos nesta região, bem mais baixos até que no interior mais cálido e árido do Alentejo. Isso aliado ao facto de estar rodeado de montanhas, concentra ali níveis de calor bastante elevados.
É evidente que muito provavelmente existem fohen, ventos secos e quentes, aridez, irradiações a níveis que muitos de nós nem faz muito ideia, por isso parece-me mais prudente, incutir o debate sobre QUAIS os locais provavelmente mais quentes, para então poder fazer umas medições.

 

[J.S.]

Re: Evento «Onda de calor» 23 a 31 Julho 2010

Encontrar erros é interessante, mas estamos a falar das zonas mais quentes.

No, the discussion is now that you trust the IM more than my calculations. So I start to control them based on weatherstations nearby in homogenous areas. In the case of the Guadiana,. I found a second one that confirms my calculations even better. More on that later on.

You do not contradict the error of 2,1 K. Just to add Elvas here: I found out that Elvas IM is located at 208 m. It has a july maximum of 33,7 C. In general, it is 0,6 K cooler (!) than Badajoz. It is located at 23m higher and 20km less inland than Badajoz. 0,2*2,37K= 0,474 K cooler. 23 m higher= 0,23 K cooler. We come to 0,7K cooler. Lattitude is identical. 34,3-0,7=33,6. I miss it with 0,1 K....

Now: suppose this is true the whole summer (and it will be most likely). Than Elvas IM station at 208 m height enjoys an average summer temperature of 32,3 C (Badajoz 32,9 C - 0,6 K). The valley 5 km away is at 162m height at the absolute bottom. So it is 0,46 K warmer in ideal situations. This valley therefor is at 32,76 K +/- 0,1 K. It is 2,24 K cooler than the IM calculated.
May be it is 2K and may be it is 2,4 K. There is not much bandwidth there. IM simply got it horribly wrong.

That tells us something about checking their data, and how rigorous their calculations are. It happened over here to. Just juli: my station 14,1 C as minimum and Flushing 16,1 C. The regular 2K difference, corroborated by Wilhelminadorp KNMI. But KNMI doesn't notice. No, they say there is no difference at all in their Atlas. Fantastic calculations..

what is the rationale to believe that they will do fine in other areas, with less stations and with errors compared to my calculations that add up to 5,5 and 8 K...


Andujar and Montoro: 36,75 and 36,84 K as july average maxtemperatures. Guadalquivir is different from inland Portugal as there are no hills to the SW.
Andujar and Montoro differ, because there are some hills there. Anyway, I do not expect them to be much warmer than that. Ecija will be rather similar aswell: less inland, but lower lying.

And I stop right there, because you give no answers to questions and you start to direct your questionsmarks towards other people than me when you address me as "J.S.". I find that disrespectfull, addressing other people when we are in this discussion and have always directed questions to oneanothter and the questions you ask here are indeed directed to me.