Dear Rolf,

The site was down last week for maintenance, but became available last
Wednesday. I had correspondence with them about some data that I downloaded
for Nicaragua in which the temperature minima were only about one degree
less than the temperature maxima. The explanation they gave is that the
POWER data are means of a 1 arc degree pixel. In the NIC case, most of the
pixel was over the sea, where the max and min vary little. Moreover, the
maxima were higher (about 29 deg) than I would have expected. But the MODIS
data show that the surface temperatures of the sea on the NIC Pacific coast
are indeed high. HOWEVER, the pixel size has important implications if you
are going to use these data in crop modeling. My guess would be, use the
temperature data at your peril, although if you are desperate, you could
obtain the mean elevation for the pixel from the DEM data and adjust the
POWER data for the actual elevation of your sites. Radiation data are
probably usable, but with a healthy dose of skepticism.

We could have answered this internally, but it might be useful to other
DSSATers.

Cheers.

Myles

Emeritus Scientist,
Centro Internacional de Agricultura Tropical CIAT,
Cali, Colombia.

On Mon, Oct 27, 2014 at 12:59 AM, Sommer, Rolf (CIAT-Kenya) <
[log in to unmask]> wrote:

> Dear all,
>
> from time to time I am using NASA POWER SSE daily time step weather data
> from
>
> [log in to unmask]" target="_blank">http:[log in to unmask]
> .
>
> It seems, however, that for the last days that page is unavailable.
>
> Would anybody know whether this is temporarily or whether the service has
> been discontinued.
>
> Best regards,
> Rolf
>
> Dr. Rolf Sommer, Senior Scientist Soil Health and Climate Change,
> International Center for Tropical Agriculture (CIAT),
> ICIPE Duduville Campus, Kasarani, P.O. Box 823-00621, Nairobi, Kenya.
> Tel: +254 20 863 2811
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> Research (CGIAR).
>