Climate classification - Atmosphere, Weather and Climate - page 421

windchill equivalent of -25°C. A windchill of -30°C
denotes a high risk of frostbite and corresponds to a
heat loss of approximately 1600 W m -2 . Nomograms to
determine windchill have been proposed as well as other
formulae that include the protective effect of clothing.
Heat discomfort is assessed from measurements of
air temperature and relative humidity. The US National
Weather Service uses a heat index based on a measure
of apparent temperature developed by R.G. Steadman
for normally clothed individuals. The value of apparent
temperature in the shade (TAPP) is approximately:

Climatology 7(4), Laboratory of Climatology,

Centerton, NJ.
Chang, J-H. (1959) An evaluation of the 1948
Thornthwaite classification. Ann. Assn. Amer. Geog .
49, 24-30.
Dixon, J. C. and Prior, M. J. (1987) Wind-chill indices - a
review. Met. Mag . 116, 1-17.
Essenwanger, O. (2001) Classification of climates. In
General Climatology, Vol.1C. World Survey of
Climatology , Elsevier, Amsterdam, pp. 1-102.
Flohn, H. (1950) Neue Anschauungen über die allgemeine
Zirkulation der Atmosphäre und ihre klimatische
Bedeutung. Erdkunde 4, 141-62.
Flohn, H. (1957) Zur Frage der Einteilung der Klimazonen.
Erdkunde 11, 161-75.
Gentilli, J. (1958) A Geography of Climate , University of
Western Australia Press, pp. 120-66.
Gregory, S. (1954) Climatic classification and climatic
change. Erdkunde 8, 246-52.
Kraus, H. and Alkhalaf, A. (1995) Characteristic surface
energy budgets for different climate types. Internat. J.
Climatol . 15, 275-84.
Lauer, W., Rafiqpoor, M. D. and Frankenberg, P. (1996)
Die Klimate der Erde. Eine Klassifikation auf öko-
physiologicher Grundlage auf der realen Vegetation.
Erdkunde 50(4), 275-300.
Lohmann, U. et al . (1993) The Köppen climate classi-
fication as a diagnostic tool for general circulation
models. Climate Res . 3, 277-94.
Mather, J. R. (1985) The water budget and the distribution
of climates, vegetation and soils. Publications in
Climatology 38(2), Center for Climatic Research,
University of Delaware, Newark (36pp.)
Olgyay, V. (1963) Design with Climate: Bioclimatic
Approach to Architectural Regionalism , Princeton
University Press, Princeton, NJ (190pp.)
Oliver, J. E. (1970) A genetic approach to climatic
classification. Ann. Assn. Amer. Geog . 60, 615-37.
(Commentary, see 61, 815-20.)
Oliver, J. E. and Wilson, L. (1987) Climatic classification.
In J. E. Oliver and R. W. Fairbridge (eds) The
Encyclopedia of Climatology , Van Nostrand Reinhold,
New York, pp. 231-6.
Rees, W. G. (1993) New wind-chill nomogram. Polar Rec .
29(170), 229-34.
Salmoud, J. and Smith, C.G. (1996) Back to basics: world
climatic types. Weather 51: 11-18.
Sanderson, M.E. (1999) The classification of climates from
Pythagoras to Koeppen. Bull. Amer. Met. Soc . 669-73.
Smith, G. L. et al . (2002) Surface radiation budget and
climate classification. J. Climate 15(10), 1175-88.
Steadman, R. G. (1984) A universal scale of apparent
temperature. J. Clim. Appl. Met . 23(12), 1674-87.

TAPP = - 2.7 1.04 T A 2.0e - 0.65 V 10

where TA = midday temperature (°C), e = vapour
pressure (mb), V 10 = 10 m wind speed (m s -1 ). Warnings
are issued in the United States when the apparent tem-
perature reaches 40.5°C for more than three hours/day
on two consecutive days.
Another approach measures the thermal insulation
provided by clothing. One 'clo' unit maintains a seated/
resting person comfortable in surroundings of 21°C,
relative humidity below 50 per cent and air movement
of 10 cm s -1 . For example, the clo values of represen-
tative clothing are: tropical wear ≤0.25, light summer
clothes 0.5, typical male/female day wear 1.0, winter
wear with hat and overcoat 2.0 to 2.5, woollen winter
sportswear 3.0, and polar clothing 3.6 to 4.5. The clo
units correlate closely with windchill and inversely with
the heat index. A bioclimatic classification that incor-
porates estimates of comfort using temperature, relative
humidity, sunshine and wind speed data has been
proposed for the United States by W. H. Terjung (1966).

FURTHER READING

Bailey, H. P. (1960) A method for determining the temper-
ateness of climate. Geografiska Annaler 42, 1-16.
Budyko, M. I. (1956) The Heat Balance of the Earth's
Surface (trans. N. I. Stepanova), US Weather Bureau,
Washington, DC.
Budyko, M. I. (1974) Climate and Life (trans. D. H. Miller),
Academic Press, New York (508pp.)
Buettner, K. J. (1962) Human aspects of bioclimatological
classification. In Tromp, S. W. and Weihe, W. H. (eds)
Biometeorology , Pergamon, Oxford and London, pp.
128-40.
Carter, D. B. (1954) Climates of Africa and India according
to Thornthwaite's 1948 classification. Publications in