Introduction of Climatic Characteristics

     The city of Bangalore is geographically located within the northern tropics, and is classified under the Koppen classification system as a tropical savanna climate (Aw) or more specifically a tropical wet and dry climate (As).  This classification is distinguished by two distinct periods, a relatively dry winter followed by a wet period over the summer and early fall.  The seasons of the city are thus defined by the amount of precipitation. The dry season is from December through February, followed by the summer season from March to to May, a monsoon season which experiences most of the overall rainfall occurs  from June to September, and finally the post monsoon season marked by a variable climate, which lasts from October to November .   This climate does differ from the regions directly to the north which tend to have a drier climate and are classified as subtropical steppes(Bsh), and to the south of the city which have a humid subtropical (Cwa). Combined these climates represent the entirety of the southern portion of the Indian sub-continent.  An area that generally experiences mild to warm weather and has a topography which is characterized by relatively flat plateaus,  the Bangalore metro area has elevations ranging between 720 and 962 meters.
     This blogs intent is to explore these climatic characteristics, how the regions geography plays a role in the development of these characteristics and how the cities recent population explosion factors in on as a precursor for potential anthropogenically induced climate change. (Source: 1,2,3,4)

Temperature Data

     The above graph and table illustrate the high, low, and average monthly temperature of Bangalore.  Due to the cities geographical location (which lies within the tropics and is positioned inland of the  Indian subcontinent) the temperature of the city is generally mild and relatively consistent. The sub-solar point of the earth occurs over the city twice a year, on March 25th and September 16th in 2012.(Source: 3,4,5)

Precipitation Data

     The above graph and table illustrate the average monthly precipitation and relative humidity of Bangalore.  The primary force driving the frequency and magnitude of rainfall events within the city is the monsoon season associated with the region. Often falsely describe as precipitation phenomenon, a monsoon event is actually global circulation event associated with winds.  Monsoons generate a pronounced pressure gradient that is formed from a differential in the surface heating properties of land (the massive Asian continent) in relation to water (the adjacent Indian Ocean), thus creating a significant seasonal variation.  In the case of the Indian subcontinent, which lies within the tropics, the intertropical convergence zone seasonally travels the entire expanse of the region. In the summer months this creates a high pressure system inland which draws moisture from the low pressure system in the Indian Ocean, resulting in heavy precipitation. The exact opposite holds true in the winter months, as the directional wind flow comes from the cold Asian continent bringing in dry high pressure systems over the city.  Exacerbating this situation is the positioning of the world's highest mountain range, the Himalayas, which promote orographic lift.  These factors combined create the produce the most noteworthy precipitation change on Earth. (Source 2,3,4,5)

GEEBIT

     The global equilibrium energy balance tinker toy (GEEBIT), is a spreadsheet device that uses built in computations that estimate the effects of earth's regulatory characteristics on the overall mean surface temperatures of the planet. Developed by NASA as an educational tool, the program considers such critical factors as planetary distance, albedo, and the greenhouse effect, all which can be manipulated to demonstrate the importance of planetary energy budgets. For example, the above spreadsheet shows earth's present energy balance which creates an average surface temperature of 15 C.  However if the average albedo of planet was raised by 0.10 to 0.406, the planetary surface temperature would drop to 4 C, conversely if the albedo was lowered by 0.10 to 0.206 it would rise to 24.8 C.  Another example is the greenhouse factor. An increase of 10% would take the planetary temperature from 15 C to 17.7 C, while a decrease would lower global surface temperatures to 12.1 C.  Of course these are all just estimations that cannot account for all of the potential positive feedback mechanisms which would occur.  Bangalore, like the world over, would see drastic changes in climate and weather, likely producing more variable and severe weather patterns, as well as an eventual overall biospheric change.   (Source: 6)

Bowen Ratio

     The bowen ratio is a mathematical formula used to determine the percentage of radiant heat that goes into either sensible heat or  the amount that go into latent heat.  Starting at a base of 1, where there is an equal distribution of available radiation between the two fluxs, is the amount which is near representative of  the  balance of the planet as a whole.  The ratio is lowered when more radiant heat is used for latent heat, resulting in moister conditions,  the opposite holds true when more of the energy goes toward sensible heat. The differences in the results of the ratio is determined by the available moisture content within the atmosphere as well as the amount of evapotranspiration occurring on the surface. Generally speaking more heat goes into latent heat around coastal areas (causing moister conditions), whereas continental regions tend to be drier, were more energy goes into sensible heat.  Bangalore's geographical position is influenced by both, depending on the season.   Bangalore likely has a ratio around or slightly above 1.2 in the winter months and early spring and around 0.45 from late spring until the late fall.  This discrepancy can be attributed to the influx of moisture during the monsoon seasons.  (4,7)

Water Conservation in Bangalore

Sources: 

1.  Indian Institute of Science, Centre for Ecological Sciences. (n.d.). Study Area: Bangalore. Retrieved March 07, 2012, from ces.iisc.ernet.in: http://ces.iisc.ernet.in/energy/wetlands/sarea.html

2.  Keller, E. A., & DeVecchio, D. E. (2012). Natural Hazards. Upper Saddle River: Pearson Prentice Hall.

3.  Lutgens, F. K., & Tarbuck, E. J. (2007). The Atmosphere: An introduction to meteorology. Upper Saddle River: Pearson Prentice Hall.

4.  McKnight, T. L., & Hess, D. (2008). Physical Geography: A landscape appreciation. Upper Saddle River: Pearson Prentice Hall.

5.  National Oceanic and Atmospheric Administration. (n.d.). Bangalore WMO:43295. Retrieved March 07, 2012, from dossier.ogp.noaa.gov: ftp://dossier.ogp.noaa.gov/GCOS/WMO-Normals/RA-II/IN/43295.TXT

6.  Petersen, C. (n.d.). Education: GEEBIT. Retrieved March 07, 2012, from GISS Institute on Climate and Planets: http://icp.giss.nasa.gov/education/geebitt/

7.  Ward, A. D., & Trimble, S. W. (2004). Environmental Hydrology. Boca Raton: CRC Press.