cc: "Klein Tank, Albert" , David Easterling , Jim Renwick date: Wed Apr 20 17:00:07 2005 from: Phil Jones subject: Re: 3.3 and 3.8 to: Kevin Trenberth Kevin, Although CA had record rains they occurred in bursts from October to March, as opposed to in a couple of months (Jan/Feb) as in the classic El Ninos. Need to make clear somewhere these extremes were very atypical. There was one year someone said it was like, but I can't recall which. It just goes to show that when we think we know something, Nature changes the deck. Any SST-based index is likely to be a permanent El Nino state with a little more warming, unless the base period is changed. Wouldn't one based on SOI be less susceptible. The paper may be relevant. Seems to conclude lots of things happening in the Arctic, but can't be explained by the AO (NAM) or the NAO. Cheers Phil At 16:38 20/04/2005, Kevin Trenberth wrote: Phil raises a good point I forgot: the need to briefly annotate the comments. On ENSO: The recommendations to NOAA was that the single best index: if you want to have just 1, is Nino 3.4. I agree with that. But it was also recommended that it should not be applied with a threshold such that once it crosses it is EN and if it doesn't cross it is not! In fact at least 2 indices are essential as we have documented, and we proposed the TNI: the trans Nino index which is the normalized difference between Nino 4 and Nino 1+2. Historically all nino regions have been strongly correlated, but with lags: before 1976 Nino 1+2 led N 3 and N 4 by several months. After 1976 Nino 3.4 led 1+2 by several months: a reversal in evolution, and some responses on the coast have been wimpy: we have seen that especially in last 2 events, so not much in 1+2 region at all. (One can argue that it relates to warming of oceans and esp Nino 4 region) This past year has been remarkable in US: the wimpy EN has nonetheless had major impacts with record rains in southwest (Arizona, CA, N Mexico) and drought in northwest (Washington, Idaho). On satellite mean OLR you can see visually the direct link from anomalous convection near or west of dateline to California, so I don't think there is much doubt of a causal link. But it is not really much of a classical EN even though conditions are quite anomalous. Need to deal with the different flavors of EN, as I have been saying for years. Nino 3.4 is related to the basin scale mean and relates best to anomalous tropical precip. TNI discriminates between Nino 4 and Nino 1+2 and allows evolution to be described: it is related to Nino 3.4 at leads or lags on average. Nino 4 has been very high and Nino 1+2 not, so TNI has played a major role over past year. The following are the relevant pubs. Trenberth, K. E., and D. P. Stepaniak, 2001: Indices of El Niņo evolution. J. Climate, 14, 16971701. Trenberth, K. E., D. P. Stepaniak and J. M. Caron, 2002: Interannual variations in the atmospheric heat budget. J. Geophys. Res., 107(D8), 4066, 10.1029/2000D000297 Trenberth, K. E., J. M. Caron, D. P. Stepaniak and S. Worley, 2002: Evolution of El Niņo Southern Oscillation and global atmospheric surface temperatures. J. Geophys. Res., 107(D8), 4065,10.1029/2000D000298. Kevin Phil Jones wrote: Dear All, I was going to reply an hour ago to your emails, but got so fed up with interruptions here that I went somewhere quiet to try and read Kevin's new 3.4.1. Latter is good and I'll transfer my comments tonight and send to Kevin tomorrow. What I was going to suggest was tracked changes but just of your sections and we merge them in Beijing - or I can do this if you send me them by May 5. Probably best if we just bring all to China. Important, though, in all you do, is to note in the reviews that you've responded to each comment in some way. So keep track there as well - remembering the two sets of comments from the LAs and the formal WG1 reviews. These responses can be brief - even just say done. Also we are supposed to get a few more reviews from WG1. When you're doing this Albert, it is best for almost all aspects of extremes to be in your section, so note potential overlaps. I looked through the BAMS review whilst in a hotel room one night a week or two ago and it does contain a lot of useful info and some other diagrams in addition to the hurricane one. We should discuss the ACE work in Beijing at some point. It would be good to have something on that. One thing - linking it to ENSO stirred a chord ! We need to decide on a definition of ENSO (Nino3.4, SOI or whatever) and what are El Nino and La Nina years. I'm not advocating anything - except that we don't use the stupid new NOAA definition ! It seems that only NOAA think we've had or are in an El Nino. If any chapter amongst all of IPCC should have a definitive index and or list of moderate/strong years it should be us. It should be a good one though - I'm sure you have one in something you've done Kevin, or there is one you prefer that we can update. Darwin SOI is fine with me, maybe we can add a list of the key years to the Table in 3.6. Cheers Phil At 15:34 20/04/2005, Kevin Trenberth wrote: Hi guys, I suggested earlier, that it is desirable if you can use track changes and come to Beijing with proposed revised text. I realize it will be a logistical nightmare trying to bring all the stuff together, but it is important to be able to compare with one another on the proposed changes and get agreement: sanity checks from at least one other person before changing text for the FOD. ie.we need to keep making progress, not two steps forward and one backwards, as part of it degrades. Great figures (can be new) will be much appreciated. As David knows, I have been working with David Levinson on a new figure on global aspects of hurricanes. I think that whole section is very imnportant yet the ZOD falls way short. But the 2004 BAMS climate review, coming out in June and which I sent around, has all the basic material to allow a much better and more balance view of this issue, and it requires someone spending the time to pull out the relevant material. I wonder if you, Albert can have a crack at that? I went through and marked up some areas. David also provided me with a global view of the ACE index. He is not comfortable enough with it to have it published, but it is interesting and can be discussed. The key aspects here are that ENSO perturbs the distribution of hurricanes in every basin. With EN there is a decrease in Nth Atlantic but marked increase in E N. Pacific and also W N Pacific. So the most active year globally on record is 1997 by far, and second is 1992, also an El Nino year. We have a lot of the ingredients on this in the Nth Atlantic sectiuon, but the others are weak. Once material is revised, we will integrate it in Beijing into a master copy. Bring your memory sticks. Kevin Klein Tank, Albert wrote: Phil, Yes, I have planned time to work on the comments before the meeting. Is it OK to use track changes and edit Kevin's FOD? And can I make changes everywhere in the chapter (which will give us multiple versions of Ch3 in Beijing) or only in certain sections? I also intended to make brief notes to the comments in the table that Kevin send and the table that was send to us by the TSU. Here again my question is: do we just go ahead and integrate everything in Beijing? Albert. -----Original Message----- From: David Easterling [[1]mailto:David.Easterling@noaa.gov] Sent: woensdag 20 april 2005 14:58 To: Phil Jones Cc: Klein Tank, Albert; Kevin Trenberth Subject: Re: 3.3 and 3.8 Phil, I will have some time to do revisions before the meeting. I was wondering just how far to go prior to the meeting. Dave Phil Jones wrote: Albert, Dave, Will either of you have much time to do any revisions of sections 3.3 and 3.8 before LA2? Have any of the other LAs contacted you about revisions? I've been discussing 3.2 with David, and Kevin has rewritten 3.4.1, so am wondering how your timetables are between now and LA2? Deciding in 3.3 on which precip series to show was the reason for sending the new data from GPCC. All alternate/revised diagrams will be vitally important in Beijing. David has sent me 3 for 3.2. Cheers Phil 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 [2]p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- -- **************** Kevin E. Trenberth e-mail: [3]trenbert@ucar.edu Climate Analysis Section, NCAR [4]www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303 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 [5]p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- -- **************** Kevin E. Trenberth e-mail: [6]trenbert@ucar.edu Climate Analysis Section, NCAR [7]www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303 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 ----------------------------------------------------------------------------