Slashdot Mirror

← Back to Stories (view on slashdot.org)

Cities Influence Their Own Weather

Posted by jamie on from the low-pressure-tactics dept.

CalamityJones writes "In the 'Well, DUH!' department, this story from the AP shrieks 'Cities May Make Their Own Weather.' As if anyone with half a brain could possibly have missed this point." Not having a weather supercomputer to crunch the numbers, it wasn't quite that obvious to me, but then what do I know. Living in Michigan I'm used to the lake effect - if I lived east of some major asphalt, I guess I'd get the L.A. effect.

1 of 119 comments (clear)

  1. Urban heat islands, people. by GianfrancoZola · · Score: 5

    The built-up area of cities produces 'islands' of higher temperatures, for a number of reasons, among which are:

    Manmade materials like concrete, asphalt, bricks, etc. absorb solar energy much more readily than vegetation.

    Water almost completely runs off because there's so much concrete everywhere, instead of standing around and slowly evaporating. Evaporation can make a significant contribution to cooling.

    Waste heat from vehicles, residences, etc. doesn't help the situation.

    Urban heat islands are pretty well understood. You can get nice images of them--temperature contrasts, that is--from AVHRR (Advanced Very High Resolution Radiometer) remotely-sensed imagery.

    cf. W.B. Myer, "Urban heat island and urban health: Early American perspective", Professional Geographer 43, 1991, p. 38 if yer curious for a little more.

    Throw more heat up into moist summertime air and that's a good prescription for thunderstorms.