Re: [Phys-l] climate and temperature

[John Denker <jsd@av8n.com>]

On 04/23/2011 02:04 PM, Woolf, Lawrence wrote:
> -----Original Message----- From: Anthony Lapinski Sent: Saturday,
> April 23, 2011 1:53 PM Subject: Re: [Phys-l] Thermal mass
>
> The last phrase is not true. The hottest days are about a month after
> the summer solstice, and the coldest days are about a month after the
> winter solstice. This "thermal lagging" is due to the large mass of
> the Earth and the time it takes it to cool/warm. 
> ========================================================================
>
>
> This is visually apparent by looking at the 2 graphs in the bottom
> half of the seasons poster that plot average daily solar insolation
> and average daily temperature vs. month.
>
> <http://www.sci-ed-ga.org/modules/materialscience/color/images/SeasonsPoster.jpg>

All of that is wildly oversimplified.  What's true for one locale
is not true for another (even within the northern temperate zone).
The answer depends on longitude as well as latitude.

Consider the comparison:

In NYC the hottest temperatures are in late July, about a month after
the solstice, as suggested above.
    http://www.climatestations.com/images/stories/new-york/lagtemps.gif

However, in SF the hottest temperatures are in mid September, almost
three months -- an entire season -- after the solstice.
    http://www.climatestations.com/images/stories/san-francisco/sftempf.gif

There is an obvious physical explanation for the dissimilarity.