cc: Eystein Jansen <eystein.jansenatXYZxyz.uib.no>
date: Sun, 2 Jan 2005 17:52:02 -0700
from: Jonathan Overpeck <jtoatXYZxyzrizona.edu>
subject: Re: [Wg1-ar4-ch06] IPCC last 2000 years data
to: Keith Briffa <k.briffaatXYZxyz.ac.uk>
Hi Keith - Thanks - hope your Christmas break is/was good. I'm in
the midst of the holiday too, and not likely able to spend too much
time on IPCC until just after the new year - thereafter, I'll be 100%
focused on it. However, given the importance of the section you're
working on, I'll try to give some helpful feedback... see BOLD
comments below. Many thanks for keeping things going - it sounds like
you're doing an excellent job.
Will you be around and able to help with the chapter during the first
two weeks of Jan? That would be great!
Thanks - see BELOW - Peck
>Peck and Eystein
>I have to break off now for the christmas period
>This is unavoidable. I am sending what I have now
>even though I am not at all happy with it.
>It is obviously only part way there. Getting the data
>to produce Figures and work out how to design them
>is going to be time very consuming
>and I will rely entirely on Tim here to do them
MY GUESS IS THAT YOUR FIGURES WILL BE AMONG THE MOST IMPORTANT OF THE
WHOLE AR4, SO THANKS FOR WORKING SO HARD ON THEM. SAY THANKS TO TIM
>- and the regional input
>stuff if wanted will need input from a number of people
>that I have not been able to contact (see later)
> The borehole discussion (contributed to by Henry Pollack) will need
>batting around and Henry (and Mike , who contributed
>a section on regional forced changes) will need to be kept
YES, VERY DELICATE I SUPPOSE. THE TRICK MIGHT BE TO LET THEM DISAGREE
WHERE THEY DO, BUT TO HIGHLIGHT WHERE THEY DO AGREE - EG THAT THE
LATE 20TH CENTURY IS WARMEST OF X YEARS. HAVE TO BALANCE OUT ED'S
LATEST TOO. BUT, YOU'RE MORE UP ON THIS THAN ANYONE, SO JUST LET ME
KNOW IF I CAN HELP - IF THINGS GET HAIRY WITH MIKE AND HENRY, I CAN
HELP - HAVE GOOD RELATIONSHIPS W/ BOTH.
>There will be loads to say on the simulated
>temperature histories and Tim will help here also
> - but much is unpublished or
>even unanalysed (hence Simon and Eduardo will need
>to contribute eventually).
LOOK FORWARD TO THIS - IT'S IMPORTANT. ACCORDING TO DAVID RIND,
JUDITH LEAN FEELS STRONGLY THAT THE SOLAR RECONS OF THE PAST
CENTURIES MAY BE COMPLETE BUNK. I'M TRYING TO GET THE INPUT SHE
PROVIDED AS LA TO THE RADIATION CHAPTER - SHE'S HAVING SOME SERIOUS
PERSONAL DISTRACTIONS NOW, BUT HOPE TO HAVE MORE TO SHARE WITH YOU
AND OTHERS SOON. I WOULD NOT WAIT BEFORE ENGAGING ALL THAT YOU THINK
ARE NEEDED TO DO A GOOD JOB. WHAT ABOUT CASPAR AMMAN TOO? HE HAS SOME
GOOD LONG RUNS AND INSIGHTS, BUT ISN'T TOO GOOD ABOUT PUBLISHING.
>The glacier bit at the end is what
>Olga sent and I have not had time to work through it.
I'LL READ - SHOULD WE ASK FOR SOMEONE ELSE TO LOOK AT IT - LIKE
LONNIE. I CAN'T SAY UNTIL I READ (AND I'M VERY SORRY I DON'T HAVE
READING TIME NOW), BUT WE WANT ALL THE IMPORTANT (SENSATIVE) PARTS OF
OUR CHAPTER TO BE AS STRONG AS POSSIBLE. HARD TO IMAGINE NOT HAVING
LONNIE'S INPUT - BUT I'LL RESERVE JUDGEMENT UNTIL I READ. ON THE
OTHER HAND, BETTER FOR YOU TO SEEK OUT HELP AND SECOND OPINIONS AS
SOON AS YOU CAN GIVEN THE SHORT AMOUNT OF TIME LEFT (MID JAN) BEFORE
WE HAVE TO HAND THINGS IN.
>You two need to give some direction as to how
>much you wish to have explicitly looking at the mass of
>NAO?AO reconstructions , ditto ENSO or PDO and all the
>simulations of these - but at this stage not sure where in overall
>plan all this going.
I THINK THESE "MODES" OF CLIMATE VARIABILITY AND THEIR POSSIBLE
INFLUENCES (E.G., ENSO CHANGES ON N. AMERICAN DROUGHT) NEED TO BE
CONSIDERED FOR SURE. IF THE DATA ARE INCONCLUSIVE, WE SHOULD SAY SO,
BUT IF THE DATA SAY THAT THE ENSO SYSTEM HAS CHANGED SYSTEMATICALLY,
THEN WE NEED TO ACCESS THAT TOO. TALKING TO JULIE, SHE AGREES THAT
THE EVIDENCE FOR CHANGE IN BOTH THE TROPICAL PACIFIC, THE TROPICAL
INDIAN OCEAN, AND RESULTING DROUGHT IMPACTS ARE ALL SIGNIFICANT OR AT
LEAST WORTHY OF CAREFUL ASSESSMENT.
PERHAPS THE BEST GAME PLAN WOULD BE TO QUICKLY ASSESS AND OUTLINE THE
MAIN POINTS FOR EACH:
- ENSO AND TROPICAL PACIFIC OCEAN (JULIE AND PECK)
- TROPICAL INDIAN OCEAN (JULIE AND PECK)
----- (BOTTOM LINE ON BOTH THE ABOVE IS THAT UNPRECIDENTED CHANGES
APPEAR TO BE TAKING PLACE, AND THAT THESE CHANGES DO SEEM TO MAKE
SENSE IN THE CONTEXT OF GW. MOREOVER, THEY DO SEEM TO BE INFLUENCING
DROUGHT OVER N. AMERICA AND N. AFRICA - CAN'T SAY WITH GREAT
CONFIDENCE THAT THE DROUGHTS ARE CAUSED, OR EXTENDED, OR DEEPENED BY
GW, BUT IT IS SUGGESTIVE. JULIE AND I CAN SAY MORE.)
- TROPICAL ATLANTIC (PECK AND JULIE - EYSTEIN - DO YOU KNOW MUCH ON
THIS TOPIC?) - RECENT CHANGE DOESN'T SEEM TO BE ANYTHING OUT OF
NORMAL RANGE OF VARIABILITY).
- NORTH ATLANTIC/NAO/AO (KEITH, ED, EYSTEIN??) WHAT'S THE STORY???
- PDO - WHO? MALCOLM? ED? (KEITH CAN YOU LEAD) - I SUSPECT THAT THE
STORY IS INCONCLUSIVE??? WHAT DO YOU THINK???
- ASIAN MONSOON (PECK AND RAMESH) - THERE IS SOME EVIDENCE THAT THE
MONSOON IS STREGTHENING (WIND STRESS OVER ARABIAN SEA) AND THAT THE
DRIER MARGINS OF THE S. ASIAN MONSOON ARE GETTING WETTER, WHEREAS
OTHER AREAS OF S. (INDIAN) MONSOON PPT ARE NOT CHANGING. DATA ON E.
ASIAN MONSOON APPEAR TO BE LESS CLEAR.
- WEST AFRICAN MONSOON (PECK - ANYONE ELSE KNOW ANYTHING? - I HAVE
UNPUBLISHED DATA TO BE PUBLISHED - I PRAY - BEFORE END OF SUMMER -
DOES APPEAR THAT THE MONSOON IS STRENGTHENING IN CONCERT, BELIEVE IT
OR NOT, WITH THE S. ASIAN MONSOON - HAVE TO SEE HOW PEER-REVIEW OF
OUR NEW WEST AFRICAN RECORD DOES)
- RELATION OF THE ABOVE TO DROUGHT (NORTH AMERICAN AND AFRICAN -
JULIE AND PECK - SEE ABOVE - THERE IS EVIDENCE THAT "THE PERFECT
OCEAN FOR DROUGHT" IS A LATE 20TH CENTURY FEATURE DRIVEN BY GHGS)
> Do we really want a discussion on MWP
>and LIA per se ?
I THINK WE HAVE TO PROVIDE THE DEFINITIVE WORD ON THESE - ESPECIALLY
THE MWP AND THE LIKELIHOOD THAT MWP WARMTH IS AN ANALOG OR NOT FOR
LATE 20TH CENTURY WARMTH, AND THUS EVIDENCE THAT NATURAL PROCESSES
CAN EXPLAIN THE RECENT WARMTH (EVEN IF WE DON'T KNOW WHAT THOSE
PROCESSES WERE/ARE). HOW DOES THE RECENT WARMTH COMPARE TO MWP - BOTH
IN TIME AND SPACE (WAS IT GLOBALLY SYNCHRONOUS WARMTH??). WHAT ABOUT
FORCING. WE NEED TO HIT THIS ONE HEAD ON.
>The regional descriptions , including Southern Hemisphere
>could be infinite length and I suppose we should only discuss longest or
>pre assimilated information - but will need specific input here from
>if we are to do these regional (including precipitation ) sections .
>I know Julie and Ed , and presumably Eystein , will be the best people to ask.
>I am attaching the current text and placeholder ideas for Figures .
WE SHOULD FOCUS ON THE MOST COMPELLING, BUT BEWARE BEING CHARGED WITH
BIASES SUCH AS N HEM BIAS, ETC. WOULD BE GREAT TO WORK IN REGIONS TO
MWP VS RECENT DISCUSSION, FOR EXAMPLE. ALSO, SEE MY LIST ABOVE - ARE
THERE OTHER REGIONS THAT WE SHOULD CONSIDER - S. HEMISPHERE? RICARDO
CAN BE A BIG HELP HERE, ALSO ED NO DOUBT.
>Not feasible to work more on these until know wider priorities re space.
YOUR SECTION IS THE MOST, OR AT LEAST ONE OF THE MOST IMPORTANT OF
THE CHAPTER. I THINK WE CAN DEVOTE MORE SPACE IF NEEDED, AND ALSO CAN
BOIL THINGS DOWN ONCE WE HAVE IT ALL IN PERSPECTIVE.
>Have had bad experience with ENDNOTE - and Tom Melvin here will forward
>the biblio file later.
>I wanted to do more , but that is all I can manage til after Xmas
>Here is wishing you (and your loved ones) all the best
READING YOUR PROSE IS A TOP PRIOIRTY, AFTER SENDING THIS AND A COUPLE
OTHER "FEEDBACK" EMAILS. THANKS SO MUCH FOR WORKING SO HARD ON THIS,
AND FOR BEING PROACTIVE IN BRINGING IN THE OTHER EXPERTS THAT ARE
>Professor Keith Briffa,
>Climatic Research Unit
>University of East Anglia
>Norwich, NR4 7TJ, U.K.
>Attachment converted: Macintosh HD:ipccFAR-6-3-2-1Fig1.pdf (PDF
>Attachment converted: Macintosh HD:ipccFAR-6-3-2-1Fig3.pdf (PDF
>Attachment converted: Macintosh HD:IPCCFAR_6-3-2-1_ 22-12-04 .doc
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
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