Aaqib Iqbal Deccan School of Planning & Architecture Climatology Project on tropical climate
Climate is a measure of the average pattern of variation in temperature , humidity , atmospheric pressure , wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time. Climate is different from weather , in that weather only describes the short-term conditions of these variables in a given region A region's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere . The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents. Climates can be classified according to the average and the typical ranges of different variables, most commonly temperature and precipitation. Climate
Worldwide climate classifications
A tropical climate is a climate in the tropical region. In the Köppen climate classification it is a non- arid climate in which all twelve months have mean temperatures of at least 18 °C (64 °F). Tropical temperature remains relatively constant throughout the year and seasonal variations are dominated by precipitation . Tropical Climates are those climates where heat is dominant problem where the greater part of year buildings serve to keep cool for occupants room rather than warm. Tropical Climate
The Basis of classification is given by 3 atmospheric factors which dominantly influence human comfort – air , temperate & humidity The Tropical regions of earth are divided into 3 major climatic zones & three sub groups Warm Humid equatorial climate Hot Dry Desert (or) semi desert climate Composite or monsoon climate Classification
These climates are found in belt near equator extending to about 15ºN & s. Logos,Dar-es-Salam,Colombo,Singapore etc are examples of this climate. There is very less seasonal variation throughout the year .Periods of more or less rain & occurrence of gusty winds & electric storms Air Temperature – Shades reaches a max during the day of between 27 & 32ºc but occasionally it may exceed. The mean minimum varies from 21º & 27ºc Humidity – Rh(Relative humidity remains high at about 75 % for most of the time but it may vary from 55 to almost 100 % . Vapor pressure is steady from 2500 to 3000 N/m2 Warm humid climate
Locations of warm humid climates
Precipitation – High through out the year. Annual rainfall can vary from2000 to 5000 mm & may exceed 500 mm . Sky Condition – Fairly cloudy throughout the year . Cloud cover varies between 60 & 90 % .Skies are usually bright . Solar Radiation – is partly reflected & partly scattered by cloud blanket but strong radiation can cause painful sky glare Wind Velocities – are typically low, calm periods are forewent but strong winds can occur during rainfall Vegetation : Grown quickly due to frequent rains & high temperature & it is difficult to control the red or brown laterite soils are generally poor for agriculture . Special Characteristics – High humidity accelerates mould & algal growth rusting & rotting .Organic buildings materials tend to decay rapidly Mosquitoes and other insects abound .The thunder storms are accompanied by frequent air – to air electrical discharges
These climates occur in two belts at latitudes between approximately 15 & 30ºnorth & south of the equator . Example's : Assuan Baghdad,Alice springs & phoenix Two marked seasons occur :a hot & a somewhat cooler period Air Temperature : DBT in shade rises quickly after sunrise to day time mean maximum temperature ranged from 27 to 32ºc . Night time mean minima between 24 & 30ºc in hot season & between 10 & 18º in cool season .The diurnal range is very great 17 to 22º Humidity : RH varies from 10 to 55 % as wet depression is large (rapid evaporation) .Vapor pressure is normally between 750 & 1500 N /m2 Hot DRY DESERT CLIMATE
Locations of Hot DRY DESERT CLIMATE
Precipitation : Slight & variable throughout the year, from 50 to 155 mm per annum ,Flash storms may occur over limited areas but some regions may not have rains for several years . Sky Conditions : Normally Clear .Clouds are few due to low humidity of the air . The sky is usually dark blue , with a luminance of 700 to 2500 cd/m2 & further darkened dust or sand storms may occur Solar Radiation : Direct & strong during the day , but the absence of cloud permits easy release of hear stored during day time Winds : are usually local .Heating of air over hot ground cause a temperature inversion Vegetation : is sparse & difficult to maintain humidity . The soil is usually dusty & very dry. Soils dries quickly after rain & would generally be fertile if irrigated
These climates usually occur in large land masses near tropics of cancer & Capricorn which are sufficiently far from equator to experience seasonal changes in solar radiation & wind direction Examples : Lahore ,Mandalay, New Delhi Two seasons occur normally .Approximately 2/3rds of the year is hot dry & other third is warm humid. Localities further north & south often have a third season but described as cool dry Air temperature : in shade as follows COMPOSITE OR MONSOON CLIMATE Seasons Hot Dry Warm Humid Cool Dry Day time 32 -43ºc 27-32ºc Upton 27ºc Night time 21-27ºc 24-27ºc 4-10ºc Diurnal mean range 11-22ºc 3-6 11-22ºc
Locations of COMPOSITE OR MONSOON CLIMATE
Humidity i.e. RH : Is low throughout the dry periods at 20 to 55 % with a vapor pressure of 1300 to 1600 N/m2.Durin wet period it rises to 55 to 95 % Precipitation : Monsoon rains are intense & continued for a long time occasionally 25 to 38 mm can fall in an hour. Annual rainfall varies from 500 to 1300 mm with 200 to 250 mm wettest month. There Is little rain during dry seasons Sky conditions :Markedly vary with the seasons .The sky is heavily overcast & dull during monsoons & clear with dark blue color in dry seasons Solar Radiation : Alternated between conditions found in warm humid & hot dry desert climates Winds : are hot & dusty during dry period .Monsoon winds are fairly strong & steady
Vegetation : Hot dry region has brown & red barren ground which changes rapidly with the rain .Plants grow quickly. There is a risk of soil erosion during monsoon Special Characteristics : Seasonal changes in relative humidity cause rapid weakening of building materials .Dust & Sand storms may occur