Are the modeled future temps Daily or Monthly Averages?

We are using the 30-year summary BCM modeled climate data together with the historic data in a graph (see attached), and we want to be sure we are getting the description right. We aren't sure whether to call the data "30-year average daily max temps" or "30-year averaged monthly max temps".

So we want to know if the modeled future max temperature data are averaged daily max temps or averaged monthly max temps. In the metadata on the Commons, it says:

Data variable name: Maximum monthly temperature
The maximum monthly temperature, from downscaled GCM

The modeled daily maximum and minimum are averaged to give daily average;
the maximum daily average in a calendar month becomes the monthly maximum;
this is averaged over a 30 year period to determine TMax for each month of the year, and for the water year.

In the informal metadata description by Jim Thorne (attached to the Commons record), it says in the table on page 2:

Variable name: Maximum Temperature, model input
Description: The maximum monthly temperature averaged annually

Attached Files: 
Lorrie Flint's picture

All the data is monthly. We average it into water years (oct-sep) then the averages of the various time frames are done on the water years.

Deanne DiPietro's picture

Saw this after I wrote the next one down. Thanks; I think I understand it now!

Deanne DiPietro, Conservation Biology Institute
deanne.dipietro@consbio.org

Deanne DiPietro's picture

Reading further, the Thorne paper says (page 18):

"This included downscaling the PRISM data from 4 km2 to 270 m2 grids, and doing the same for the four future scenarios. We then had month‐by‐month and year‐by‐year data for minimum temperature (Tmin), Maximum temperature (Tmax), and precipitation (PPT). These were used as inputs for running the BCM (see below, and Appendix A) to create the additional 11 hydrologic variables (see Appendix B). Finally, we summarized each variable for six 30‐year
time slices..."

We are using the Water Year Average Max Temp, which is made by taking the highest AVERAGE daily temp in a month as the "Max for the Month" and so we should be calling the water year average of those "Averaged Monthly Maximum Temp". Looking at the data, the water year max temps for our region are in the 70's F, so I guess they aren't the highs for the whole year but the average of the 12 monthly high temps.

Deanne DiPietro, Conservation Biology Institute
deanne.dipietro@consbio.org