date: Thu Nov 11 11:00:42 2004 from: Phil Jones subject: RE: Easterling et al 97 Science paper on max and min temperature to: "H J Fowler" Hayley, Sounds more interesting now ! Do keep me informed as it will be very useful background for the Pune workshop and also for IPCC. I'm the co-ordinating lead author for the Atmospheric Observations chapter for AR4 - the next report due in 2007. We need to have papers out or in press by the end of 2005 for inclusion. For Pune, it would be useful to know the sources of the data but the paper should be sufficient for this. China has reasonably good data and it may be worth looking at the trends there. There are odd things going on there (some similar to yours) that can be explained by local pollution. A number of cities there have downward trends in sunshine and in cloudiness and this causes odd changes in max and min trends. I suspect that a lot of what is seen in Easterling et al around the world is real, it is just that DTR is a highly sensitive measure and it has a lot more variability than we are fully aware of from 30-50 yr records. Cheers Phil At 10:23 11/11/2004, you wrote: Cheers Phil Just realised that I said entirely the wrong thing in my last e-mail - the exciting thing that our research using observed data back 100 years in the Karakoram (Upper Indus) region Pakistan shows is an *increase* in DTR throughout the year, and particularly in the summer season. This is similar to trends in northern India - but I have not found evidence of an increase anywhere else - and the observations are certainly contrary to projections of GCMs for the region (projecting decreases in DTR, as has been observed elsewhere on the globe). We are trying to find an explanation for this. In summer months both max and min temps are falling, but min more than max - hence increasing DTR. Decreasing max may be explained by increased cloudiness (increasing trend in summer precip in last 40 years) but cannot also explain large decrease in min temps? In winter, we are seeing a more regular pattern with warming in max (large) but different changes in min dependent on location - generally mean temps show significant increases in winter though. It's all very interesting and - since in this region change in summer temperature and winter precip are significantly linked to summer runoff - could have implications for water management in the region. We hope to resubmit to J. Climate soon so I will forward a copy of the paper to you before we submit - would welcome any useful comments! Cheers Hayley ______________________________ Dr. Hayley Fowler Senior Research Associate Water Resource Systems Research Laboratory School of Civil Engineering and Geosciences Cassie Building University of Newcastle Newcastle upon Tyne NE1 7RU Tel: +44 (0)191 222 7113 Fax: +44 (0)191 222 6669 [1]http://www.staff.ncl.ac.uk/h.j.fowler/ -----Original Message----- From: Phil Jones [[2]mailto:p.jones@uea.ac.uk] Sent: 11 November 2004 10:11 To: H J Fowler Subject: Re: Easterling et al 97 Science paper on max and min temperature trends Hayley, Amazingly I've just managed to go on to the AAAS system and they have issues back this far and it didn't want any money. I think this might be as I have a subscription. I tried this several months ago and couldn't, so maybe they've relaxed their rules. Most places show decreases in DTR, but this isn't that strong in western Europe. There is also a paper by Frich et al. in 2002 in Climate Research - you should be able to get this from the journal's web page. CR is free. I'll be going to a workshop on extremes for S and SW Asia in Pune in Feb 05, so anything you find or will find will be useful. Workshop should bring people from the countries in the region with data to learn about homogeneity and extremes. People from Mongolia to Sri Lanka and Pakistan to China should come. This includes most of the 'stans' in what was the USSR and Afghanistan (if anyone from there comes). An earlier workshop was help in Turkey in October for countries between Iran and Turkey (Middle East not Africa but including the Ukraine and southern Russia, but omitting Israel). There should be a paper being prepared on this. I'm trying to get a copy of this for my Saudi student. A workshop is on this week in Guatemala for central America and one was held in South America. Malcolm Haylock from CRU has gone to both of these as he can get by in Spanish. His write up of the S. American one can be got from the link below. The aim of the workshops is similar, so a paper should appear from each and get reported on in the next IPCC Report. In case you are interested, the 1st draft of the Sth American rainfall paper is available at: [3]http://www.cru.uea.ac.uk/~malcolmh/publications/Maceio_Rainfall_draft1.p df Some interesting findings... Cheers Phil At 17:30 10/11/2004, you wrote: >Phil > >Do you have pdf version of the Easterling et al 97 Science paper (you >were a co-author) on Maximum and minimum temperature trends for the >globe. Any other papers you know of on max/min trends - esp. diurnal >range and esp. showing reductions in diurnal range rather than >increases! - would also be gratefully received! Doing some work on >temperature change in the karakoram over the past 100 years and it is >showing some surprising results. > >Cheers > >Hayley > >______________________________ >Dr. Hayley Fowler >Senior Research Associate >Water Resource Systems Research Laboratory >School of Civil Engineering and Geosciences >Cassie Building >University of Newcastle >Newcastle upon Tyne >NE1 7RU > >Tel: +44 (0)191 222 7113 >Fax: +44 (0)191 222 6669 [4]http://www.staff.ncl.ac.uk/h.j.fowler/ Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ------------------------------------------------------------------------ ---- Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------