How would you change the climate classification? (normal, comparison, East)

[Bisfbath]

Originally Posted by Joe90

Wellington, Motueka and Auckland have average winter averages of 7C/13C, 2.8c/13.8c and 7.2C/15.1C

Copenhagen has -0.4C/3.8c.


You've indicated that winter growth is a significant feature that should be considered, but the notion that Copenhagen's winter is in anyway comparable to my climate, where an avocado, orange or passionfruit is a pretty standard garden plant producing fruit in the winters months, and lawns are mowed weekly during winter, would make a mockery of winter growth being considered significant

All the 10C rule does is create the falsehood that Copenhagen and Motueka have some sort of climatic kinship in winter, when none exists whatsoever - if you can't increase understanding by meddling with an established system, leave it alone.

The thing is I haven't said which side of the border I think Motueka belongs. I haven't placed it with Copenhagen. I am not familiar enough with it, and in any case I was trying to set out some equivalents of Koppen's top level categories (A, B, C etc) which are very large, not set exact thresholds like a 10C rule.

Here's a thought on winter plant growth. In southern England there is slow growth of grass and "weeds" over winter, but not of native trees and shrubs, which would certainly point to it being a winter dormancy climate for me.

[Bisfbath]

Originally Posted by Joe90

What I'm saying, is the existing classifications of Cfa or Cfb are fine as they are, as despite huge differences, they still subscribe to a broadly similar genetic model that provides some understanding to climates as diverse Auckland/Copenhagen climates, or NYC/Mckay

Splitting the Cfb group up so as to have Motueka distinct from Auckland or Wellington, but the same as Copenhagen , has no basis under the genetic model, or under a day to day weather model

Climates don't have genetics though - if they did, it would be straightforward to classify them at least in theory. All you would have to do is work out a family tree.

If you mean the physical mechanism for a climate, I can see that being useful but not necessarily the main factor. For example tropical rainforest climates are mainly found in the lowland equatorial regions near the ITCZ, but broadly similar climates can also be produced where the trade winds blow roughly at right angles to a coast and bring enough rain to a place that would otherwise have a distinct dry season, such as parts of the coasts of Hawaii, Brazil and Australia. Desert can produced by decending air near the tropics e.g. the Sahara, but also by rain shadows or cold ocean currents.

[Klimaforscher]

I know it's been quite some time since I posted here - farewell messages aren't allowed, so I couldn't really explain that I'd gotten what I needed from the forum and had become busy. But now that we're in the midst of this shutdown, I have browse occasionally and hoped that I could add something helpful to this thread.

Originally Posted by Joe90

genetics

Underlying causes do matter, but they aren't the only thing that matters:

The 10C rule creates a divide that doesn't exist, and only creates false understanding - Motueka is either more like Wellington or Auckland genetically, or it is more like Copenhagen. There is no middle ground.

10C is of immense predictive value - it's where plants grow. Yes, that value is somewhat rough, because different plants are more sensitive to different temperatures, but as a rule of thumb, average temps over 10C is a superb way of knowing when vegetation will be active. I have no use for climate systems that don't tell me how plants grow.

Originally Posted by wawa1992

Anyway the "arid" climate grouping needs to be removed, and the arid climates denoted by precipitation letters.

Really? I'll grant that Trewartha didn't like them either, but for the most part the B-climates occur geographically at the horse latitudes, right between A and C.

Originally Posted by Bisfbath

Climates don't have genetics though - if they did, it would be straightforward to classify them at least in theory. All you would have to do is work out a family tree.

If you mean the physical mechanism for a climate

Yes, that's what "genetics" means in this context, and often people use genetics even more narrowly, to mean "where the wind comes from." (This latter usage has always struck me as utterly daft, because the energy in the system comes from the sun, and the water from the oceans; air masses simply distribute the fundamentals of heat and precipitation across the planet. But hey, that's just me.)

I can see that being useful but not necessarily the main factor. For example tropical rainforest climates are mainly found in the lowland equatorial regions near the ITCZ, but broadly similar climates can also be produced where the trade winds blow roughly at right angles to a coast and bring enough rain to a place that would otherwise have a distinct dry season, such as parts of the coasts of Hawaii, Brazil and Australia. Desert can produced by decending air near the tropics e.g. the Sahara, but also by rain shadows or cold ocean currents.

Yep. Sadly, this argument you made will likely not convince anyone, but it's obvious to me.

anything at the edge of a category is going to be more like something just over the border in a neighbouring category than it is like something in its own category's core... we categorize colours as "red", "orange", "yellow" etc. Now you could come along and say that we shouldn't divide "red" from "orange" because a very reddish orange is closer to red than a middle orange or a yellowish orange and therefore the category "orange" makes no sense.

You may already understand what I'm going to write here, but, with climate there is more to it than this. Indeed, there's more to it even with colors. The electromagnetic spectrum may be a simple, unidemensional thing describing an inverse relationship between the energy and wavelength of a photon, but when you study the spectrum, you'll quickly notice that

* Very long wavelengths are invisible
* Long wavelengths activate our red cones
* Midrange wavelengths activate our green comes
* Short wavelenths activate our blue cones, and
* Very short wavelengths are invisible again
* Very very short wavelengths can break atoms apart

So the effects of these wavelengths matter a great deal for us, and, as we're the ones talking about it, it's quite reasonable to break the spectrum into numerous qualitatively distinct bands. (It isn't so reasonable to break the red-green range into red/orange/yellow/green though; that division is indeed arbitrary.)

With climate, the situation is similar: in the tropics, horse latitudes, midlatitudes, and polar regions the prevailing wind blows in completely different directions - and that's just wind! Add the very natural boundary of 0C when water freezes and melts a 1atm, and the natural boundary of 10C when trees can/cannot grow, and then add a more complicated precipitation-vs-evaporation+transpiration boundary describing whether vegetation of any kind can thrive, and a truly beautiful complexity of objective climate types emerges.

So even though cities standing at the climactic boundaries will always be seen to blend two or three climates together, clear climactic types do remain to be discussed.

[Joe90]

Originally Posted by Klimaforscher

Underlying causes do matter, but they aren't the only thing that matters:

10C is of immense predictive value - it's where plants grow. Yes, that value is somewhat rough, because different plants are more sensitive to different temperatures, but as a rule of thumb, average temps over 10C is a superb way of knowing when vegetation will be active. I have no use for climate systems that don't tell me how plants grow.

They are the only thing that matter - all other information conveyed by classifications, is inferior to a standard wiki box containing annual stats in terms of furthering understanding of the climate of any place

Trewartha's 8 months > 10 is superior to a straight 10C imo. Living in an area that has 8 months>10C, but which is also adjacent to areas with less months above 10C as well as areas with 10C in all months, it seems obvious that the 8 month rule is the one at which the most fundamental changes in ecology/vegetation occur.

I can think of plenty of species that couldn't exist here if there were only 6 or 7 months above 10C, but between that and a flat 10C limit, I really can't think of any that fail to grow

[Joe90]

Originally Posted by Bisfbath

Climates don't have genetics though - if they did, it would be straightforward to classify them at least in theory. All you would have to do is work out a family tree.

If you mean the physical mechanism for a climate, I can see that being useful but not necessarily the main factor. For example tropical rainforest climates are mainly found in the lowland equatorial regions near the ITCZ, but broadly similar climates can also be produced where the trade winds blow roughly at right angles to a coast and bring enough rain to a place that would otherwise have a distinct dry season, such as parts of the coasts of Hawaii, Brazil and Australia. Desert can produced by decending air near the tropics e.g. the Sahara, but also by rain shadows or cold ocean currents.

Climates do have genetics, but rigid adherence to thresholds lessen understanding of them - in the case of Cfb climates, it's moderation in all seasons due to the proximity of large bodies of water. For deserts, it's lack of rainfall for whatever reason.

Originally Posted by Bisfbath

The thing is I haven't said which side of the border I think Motueka belongs. I haven't placed it with Copenhagen. I am not familiar enough with it, and in any case I was trying to set out some equivalents of Koppen's top level categories (A, B, C etc) which are very large, not set exact thresholds like a 10C rule.

Here's a thought on winter plant growth. In southern England there is slow growth of grass and "weeds" over winter, but not of native trees and shrubs, which would certainly point to it being a winter dormancy climate for me.

Mowing lawns is part of winter here, and while certainly not like spring, it's still active growth. All native species here produce steady growth during winter. There are introduced deciduous species that go dormant, but probably in a different manner to the UK - the oaks for example are still pretty much green, and will lose all their leaves in just a few days around late June.

[tenkier7]

Originally Posted by Joe90

What I'm saying, is the existing classifications of Cfa or Cfb are fine as they are, as despite huge differences, they still subscribe to a broadly similar genetic model that provides some understanding to climates as diverse Auckland/Copenhagen climates, or NYC/Mckay

Splitting the Cfb group up so as to have Motueka distinct from Auckland or Wellington, but the same as Copenhagen , has no basis under the genetic model, or under a day to day weather model

Fair enough. Reevaluating what's an actual basic meaning of subtropical. Subtropical could be considered: â‘  Individual geographic zone situated between the tropics and the temperate â‘¡Subtype within temperate which encompasses everywhere that isn't tropical or polar plus moisture. In this case, only Cfa and Csa are falling under while other C and D groups remain in the temperate. I know you're going to claim Motueka can grow numerous subtropical plants while New York is limited, however, I can see New York has an advantage of crops requiring higher growing degree days like rice. Humid Subtropical[Apple tree] and Oceanic[Vine] both got C[Fruit] in a big category though inevitable to say their mechanism of pressure/prevailing wind[cultivation] comes out quite different.

Originally Posted by Klimaforscher

10C is of immense predictive value - it's where plants grow. Yes, that value is somewhat rough, because different plants are more sensitive to different temperatures, but as a rule of thumb, average temps over 10C is a superb way of knowing when vegetation will be active. I have no use for climate systems that don't tell me how plants grow.

Right, I don't see a reason why 10°C is less important than 0°C to distinguish between temperate and continent. The former can take a guideline of certain insect life for risk level of tropical-sque environment influenced plague, brief check for either duration of the hibernation period in a deciduous tree and scale of seed species. One good example would be comparing planting cherries in the mainland Japan(Somei Yoshino) and Okinawa Islands(Prunus Campanulata), the southernmost border of Somei Yoshino is known the coldest month around 10°C. Meanwhile 0°C is useful for estimating the duration of ground frost.

[Joe90]

Originally Posted by tenkier7

Fair enough. Reevaluating what's an actual basic meaning of subtropical. Subtropical could be considered: â‘  Individual geographic zone situated between the tropics and the temperate â‘¡Subtype within temperate which encompasses everywhere that isn't tropical or polar plus moisture. In this case, only Cfa and Csa are falling under while other C and D groups remain in the temperate. I know you're going to claim Motueka can grow numerous subtropical plants while New York is limited, however, I can see New York has an advantage of crops requiring higher growing degree days like rice. Humid Subtropical[Apple tree] and Oceanic[vine] both got C[Fruit] in a big category though inevitable to say their mechanism of pressure/prevailing wind[cultivation] comes out quite different.

The key difference is Motueka can still grow rice, while NYC doesn't grow a huge array of crops that survive in Motueka.

Not sure what the point is regarding apples and vines, but vines in NYC would be limited to grapes and berries, and not crops like passionfruit.

[Bisfbath]

Originally Posted by Joe90

Climates do have genetics, but rigid adherence to thresholds lessen understanding of them - in the case of Cfb climates, it's moderation in all seasons due to the proximity of large bodies of water. For deserts, it's lack of rainfall for whatever reason.





Mowing lawns is part of winter here, and while certainly not like spring, it's still active growth. All native species here produce steady growth during winter. There are introduced deciduous species that go dormant, but probably in a different manner to the UK - the oaks for example are still pretty much green, and will lose all their leaves in just a few days around late June.

But moderation due to large bodies of water is a mechanism for producing a certain type of climate. Another would be altitude. Lack of rainfall isn't a mechanism but its effect - it's mechanism would be persistent descending air or a mountain range producing a rain shadow. It's interesting and important to understand mechanisms, but I think for classification purposes the effects are more important, eg the lack of rain in desert climates is a more important feature than the mechanism that produces the lack of rain.

I'm not arguing that Motueka should go in one category or another (though from the little I know of it, I would tend to group it in the C category I laid out), just that its similarity to nearby and similar places isn't in itself a good reason not to separate it from them.

Here's why your logic as I see it is obviously flawed. I could walk from Singapore to Dikson and with each step the climate would change only imperceptibly. Wherever along the route a line was drawn it would separate very similar climates. The logical conclusion of your line of reasoning would be that Singapore and Dikson must be in the same climate category! But obviously that would be absurd

[Joe90]

Originally Posted by Bisfbath

But moderation due to large bodies of water is a mechanism for producing a certain type of climate. Another would be altitude. Lack of rainfall isn't a mechanism but its effect - it's mechanism would be persistent descending air or a mountain range producing a rain shadow. It's interesting and important to understand mechanisms, but I think for classification purposes the effects are more important, eg the lack of rain in desert climates is a more important feature than the mechanism that produces the lack of rain.

I'm not arguing that Motueka should go in one category or another (though from the little I know of it, I would tend to group it in the C category I laid out), just that its similarity to nearby and similar places isn't in itself a good reason not to separate it from them.

Here's why your logic as I see it is obviously flawed. I could walk from Singapore to Dikson and with each step the climate would change only imperceptibly. Wherever along the route a line was drawn it would separate very similar climates. The logical conclusion of your line of reasoning would be that Singapore and Dikson must be in the same climate category! But obviously that would be absurd

When you say a certain type of climate, that doesn't mean anything in the real world - People from Denmark that come here, don't talk about familiarity of climate. The biggest effect of Koppen's classification schemes is to take general ideas about climates,and mold them to to strong stereotypes about climates, that may or may not be true.

I'm arguing that it doesn't matter what category Motueka is in, as long as it's defined by it's single most relevant climatic feature, which for Motueka, is moderation in all seasons and only minor (50%)seasonal rainfall distribution. For deserts, the single most relevant feature is lack of rainfall (for whatever reason) and that's the logical way to group.

Similarity of nearby climates (and for the same reason) is absolutely a reason not to separate them - classification is an attempt at science, and as such should not create artificial divisions that lessen understanding of any place's climate. Taking place A, which is a near copy of place B (and only 20 km away), and saying it's actually a climate that can be somehow found to be fundamentally actually more like place C (10000km away)even though it's 6C cooler, is leading people to conclusions that don't exist.

Not sure what your Singapore-Dikson example means, but why would you take a climate 20km from Singapore, and say it's actually a climate fundamentally more similar to Dikson?

[tenkier7]

Originally Posted by Joe90

The key difference is Motueka can still grow rice, while NYC doesn't grow a huge array of crops that survive in Motueka.

Not sure what the point is regarding apples and vines, but vines in NYC would be limited to grapes and berries, and not crops like passionfruit.

Motueka can breed the exact same kind of Oryza Sativa that's common in Cfa zones in East Asia and the Southeastern U.S.?
The given example classification to fruit comparison isn't linked to each other, just showing apple and grape both are fruit but growing different ways fundamentally.

Originally Posted by Joe90

Similarity of nearby climates (and for the same reason) is absolutely a reason not to separate them - classification is an attempt at science, and as such should not create artificial divisions that lessen understanding of any place's climate. Taking place A, which is a near copy of place B (and only 20 km away), and saying it's actually a climate that can be somehow found to be fundamentally actually more like place C (10000km away)even though it's 6C cooler, is leading people to conclusions that don't exist.

Not sure what your Singapore-Dikson example means, but why would you take a climate 20km from Singapore, and say it's actually a climate fundamentally more similar to Dikson?

If you were living in Hong Kong or Xi'an, sure you'd complain why Haikou or Beijing doesn't contain same letters. This is paradoxical what you saying.