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There is a loyal (and maybe even stubborn) few today who still insist on using the old 1899 Koppan system….even when it is obvious that is has some wild errors in climate groupings. Trewartha created his climate classification system in the 1960’s – when there were far more observational tools available to base things on. Most climate scientists today known the Trewartha system is far more “real world” than the old Koppen system.
Except actual climatologists do use the Köppen system. Here's a published paper using it:
full text is behind a paywall behind check some of the references; several mention Köppen. This similar one isn't behind a paywall [slow loading times]
And from the references, whatever your views on global warming, I think all regulars might find an article titled Projected distributions of novel and disappearing climates by 2100 AD. intriguing.
This published paper uses the Trewartha "Köppen Trewartha" system:
continentality is a meausure of annual temperature swings, not whether a place has winter snowpack or not.
Yea, though the words "continental" is often used to describe a specific climate type. You can use an index of continental to describe how continental a climate is. From an old post of mine:
Quote:
Originally Posted by nei
Another point: This "index of continentality" map shows the Great Lakes creates a large moderating effect in the eastern part of the continent. Parts of New England are more continental than the Great Lakes region, but once you get past the longitude of Chicago, continentality increases rapidly. You can see a large bend in the map curves; perhaps winters in this region would be much more severe, though maybe sunnier without the Great Lakes.
Interestingly, the contrast between continentality at the coast vs inland at the latitude of Long Island or Philadelphia is higher than further north. Both locations have an index of 35, but inland it increases quickly to 40 and 45 by the longitude of Chicago. The contrast is even stronger at the latitude of the Carolinas; perhaps wavehunter007 might find a thread on that comparison interesting.
Anyhow here's the map:
the numbers are from this equation:
where the greek "phi" symbol is the latitude in degrees and T_range the difference in mean temperature between the warmest and coldest month in Celsius. Remember most calculators and computers expect the argument of sin to be in radians. Map is from the third page of this link:
Yea, though the words "continental" is often used to describe a specific climate type. You can use an index of continental to describe how continental a climate is. From an old post of mine:
Very fascinating map! I never saw it before.. I find it very interesting that Vancouver and Orlando have the same continentality factor of 15 and Tofino and Miami are about the same as 10
full text is behind a paywall behind check some of the references; several mention Köppen. This similar one isn't behind a paywall [slow loading times]
And from the references, whatever your views on global warming, I think all regulars might find an article titled Projected distributions of novel and disappearing climates by 2100 AD. intriguing.
This published paper uses the Trewartha "Köppen Trewartha" system:
Just because a few science writers make mention of the old Koppen system should not be used to say that it is what most climatologists use in the modern era.
I took many college courses in climate and most used the Trewartha system and text, making mention of how it is an update of the old Koppen system. The whole reason that Trewartha modified the old Koppen system was that there was such outcry at the massive flaws in the climate groupings (London and Seattle were grouped in the same climate as Brisbane and New Orleans for example!).
True (the last part) that Koppen is the father of climate classification and the Trewartha system is really just a modest reorganization of the climate groups. Trewartha really just split up middle latitude climates from one group (C) into 3 groups – E (Boreal)…..D (Temperate)…and C (Subtropical). The second letters are really far less important.
Quote:
Originally Posted by Hartfordd
And does Washington DC have a humid subtropical climate ?
No. A climate must have 8 or more months with a mean temp of 10 C (50 F) or higher. Washington DC has 7.
Quote:
Originally Posted by nei
Yea, though the words "continental" is often used to describe a specific climate type. You can use an index of continental to describe how continental a climate is. From an old post of mine:
That IS an interesting map....but it is by no means the only one: I have several world and USA maps that have a "Continental index" - each with some variation on this theme. However, like many data points, these maps have their flaws as well. Highly marine climates that see little heat or real cold "appear" to have the same index numbers as places at much lower latitudes. Also, locations on the margins of the mainland ( yet at much higher latitude), can have the same numbers as near tropical locations in the interior. Numeric averages allow a near tropical climate that has a few cool months ....and a very hot long summer.....to have a similar index as a coastal climate which has a luke warmer summers and cold winters. In the map you posted eastern Long Island and southeast Connecticut have the same rough index number as central Mexico....and parts of the PNW have similar numbers to north Florida - lol.
A "continental index is a land biased index, and often has little to do with genetically WHY a location might fall into the temperate or subtropical climate group (i.e . wind patterns, air masses, solar angle, ...etc).
Just because a few science writers make mention of the old Koppen system should not be used to say that it is what most climatologists use in the modern era.
My point was that it still seems to be referenced.
Quote:
True (the last part) that Koppen is the father of climate classification and the Trewartha system is really just a modest reorganization of the climate groups. Trewartha really just split up middle latitude climates from one group (C) into 3 groups – E (Boreal)…..D (Temperate)…and C (Subtropical). The second letters are really far less important.
That's why the one paper I found that did use the Trewartha system described it as the "Koppen-Trewartha".
Quote:
That IS an interesting map....but it is by no means the only one: I have several world and USA maps that have a "Continental index" - each with some variation on this theme. However, like many data points, these maps have their flaws as well. Highly marine climates that see little heat or real cold "appear" to have the same index numbers as places at much lower latitudes. Also, locations on the margins of the mainland ( yet at much higher latitude), can have the same numbers as near tropical locations in the interior. Numeric averages allow a near tropical climate that has a few cool months ....and a very hot long summer.....to have a similar index as a coastal climate which has a luke warmer summers and cold winters. In the map you posted eastern Long Island and southeast Connecticut have the same rough index number as central Mexico....and parts of the PNW have similar numbers to north Florida - lol.
These are all true, but how are those flaws? It's a continentaly map, not a temperature map. The last two seem reasonable results. The purpose of a continentality index isn't tell us anything about temperature, but its range. As to the bolded, I puzzled why they shouldn't have similar numbers. By definition, a marine climate is the opposite of continental. I think it was assumed that Torshavn, Faoere Islands would get the lowest numbers. The map probably works poorly for equatorial locations, as they don't really have obvious seasons based on temperature to begin, so it doesn't make sense to call an equatorial location "continental" based off of annual temperature range. It actually does a fairly good job at separating climates on the west side or east side of a continent except for lower latitudes. Though, in a way, it makes sense for Florida to get a lower number — it's surrounded by water on both sides.
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