All,

For those working in linking dynamic crop models with Circulation models (Global, Regional, Coupled, etc) for climate variability or climate change applications, I strongly recommend you to read the paper ‘Baigorria, G.A., Jones, J.J., Shin, D.W., Mishra, A., and J.J. O’Brien. 2007. Assessing uncertainties in crop models simulations using bias-corrected regional circulation model outputs. Climate Research, 34: 211-222.’. If you don’t have time, go directly to results and discussions related to Figure 4, about the importance of how timing of water stress during specific phenological phases can be more important than total amount of forecasted rainfall. This is related to the uncertainty during temporal downscaling from G/RCMs and our lack of capacity to forecast specific behavior of daily events beyond weather.

Regards,
Guillermo Baigorria
University of Florida

________________________________________
From: DSSAT - Crop Models and Applications [[log in to unmask]] On Behalf Of Stephen Welch [[log in to unmask]]
Sent: Saturday, May 02, 2009 8:15 PM
To: [log in to unmask]
Subject: Re: Calender issue for climate change study

All:

I've been curious about this, myself, given that the DSSAT models have been used in many climate change studies.  Whatever system is used, it should be one that gives good results for winter wheat.

Steve Welch
Dept of Agronomy
Kansas State University

----- Original Message -----
From: "jagan TNAU" <[log in to unmask]>
To: [log in to unmask]
Sent: Friday, May 1, 2009 11:20:13 PM GMT -06:00 US/Canada Central
Subject: Calender issue for climate change study

Dear DSSAT users,

We have plans to do yield estimation using future climate change scenario.
We have already downscaled  the GCM data using an RCM (PRECIS) for our
region. The climate change models use 30 days/month calender ie 360
days/year while DSSAT uses Gregorian calender. One option to overcome this
is to keep the 360 days as Julian days and the remaining 5/6 days can be
copied from the 360th day keeping the rainfall alone as ZERO.

Is there any other specific methodology available to convert the 360 days
calender to Gregorian calender. Kindly help us to proceed further.

--
With regards

Dr.R.Jagannathan
Professor and Head
Agro Climate Research Centre,
Tamil Nadu Agricultural University,
Coimbatore - 641 003 India

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