BEN # 174

Adolf Ceska aceska at CUE.BC.CA
Mon Oct 27 02:19:20 EST 1997


                                                   
BBBBB    EEEEEE   NN   N             ISSN 1188-603X
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BBBBB    EEEEE    NN N N             BOTANICAL
BB   B   EE       NN  NN             ELECTRONIC
BBBBB    EEEEEE   NN   N             NEWS

No. 174                              October 26, 1997

aceska at freenet.victoria.bc.ca        Victoria, B.C.
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 Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
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BOTANY BC - AS IT HAPPENED IN AUGUST 1997
From: Del Meidinger <Del.Meidinger at gems2.gov.bc.ca>

BOTANY  BC was held at Cathedral Park on the 1-2 August 1997. It
was well attended and the sessions,  both  inside  and  outside,
proved  to  be  excellent.  The  staff  of the Conservation Data
Centre, especially Jan Kirkby, did an  outstanding  job  of  or-
ganizing  the  program,  facilities,  and  tour  guides. It will
definitely live on in the memories of those who attended as  one
of the best BOTANY BC meetings.

The  official  program  began  with  an  evening  of interesting
presentations by staff of the CDC (although many of us were able
to fit in an afternoon hike and plant identification tour).  The
presentations  were well presented and received. Hans' slides of
plants of the Alps were incredible. The next day involved a long
hike along the ridge trail with George Douglas and  Hans  Roemer
pointing  out  the plants along the trail. The evening concluded
with one of the best Botany Boogie's ever (thanks to Andy  MacK-
innon and all others around the fire).

BOTANY  BC  is still the best botanical meeting in BC and it has
the added attraction of being every year! See you next  year  in
the Peace River area.


IS IT EL NINO OR PACIFIC DECADAL OSCILLATION ?
[This News Release was originally posted on ECOLOG-L.]

It  looks  like  El  Nino, it feels like El Nino, and if you are
watching fish stocks, reservoir levels or farm  production,  you
would say it is El Nino. But it isn't.

Researchers  at  the  University of Washington are describing in
two recent research papers what they call a decades-long climate
shift in the Pacific Ocean that seems to  explain  many  of  the
changing  environmental  patterns seen across North America, and
particularly in the Pacific Northwest, since the late 1970s.

The scientists are calling this climatic phenomenon the PDO, for
Pacific decadal oscillation. And, they say, its current positive
cycle helps to explain why U.S. West  Coast  ocean  temperatures
have been warmer than average, why winters have been wetter than
usual  in the South, and why Alaska salmon harvests have been at
historic highs, while there have been record declines along  the
West Coast.

El  Nino, it appears, is only one small -- albeit exaggerated --
phase  of  this  cycle,  says  David  Battisti,  UW  atmospheric
sciences  associate  professor, who was the first to show why El
Nino recurs on an average of every four years. He describes this
latest discovery as an index of sea-surface temperatures in  the
North  Pacific, "which my guess also involves the tropics." Says
Battisti: "This phenomenon explains much about what is happening
in regional climate change. And if we could predict the PDO,  we
would have much more reliable forecasts."

However,  says  Nate Mantua, a UW research associate, scientists
probably will not have the  ability  to  begin  making  accurate
forecasts  for  at  least  another  five years. A PDO prediction
system, he says, would allow long-term planning in such areas as
fisheries, water supplies, agriculture and energy production.

"The science right now is more like our understanding of El Nino
15 to 20 years ago," says Mantua. But when  a  PDO  forecast  is
developed,  he  says,  it  will  become  an important measure of
climate across North America.

The discovery of the PDO has  been  something  of  a  scientific
detective  story. Using high-speed computers, researchers combed
the past century's meteorological records to see if  they  could
spot  any  recurring  patterns of climate change. In more recent
decades, El Nino  quickly  emerged  as  the  dominant  recurring
pattern  of  year-to-year climate variability on the planet. But
when records were studied back to 1900, with the  focus  on  the
region  north  of  Hawaii in the Pacific basin, the PDO revealed
itself with positive and negative phases lasting from 10  to  30
years.

With  a few interruptions, researchers found that since 1977 the
PDO has been in a positive phase with cool air in the  Southeas-
tern U.S., and a tendency to dry weather over the Columbia Basin
and the Great Lakes. In the Northwest, winters have been largely
warm  and  dry,  water  levels have been down because there have
been fewer storms than normal, and snow packs have been low.  In
the  previous  negative  phase  of the PDO, lasting from 1947 to
1976, the Northwest's water  supplies  were  an  average  of  20
percent  higher  than between the 1920s and the 1940s, with more
precipitation and higher snow packs.

Evidence also suggests that many populations of  Pacific  salmon
are  influenced by changes in marine climate. This could explain
why in the last negative phase of the PDO,  when  coastal  ocean
temperatures  were cooler, coho and chinook salmon were in abun-
dance off the coasts of Washington, Oregon and  California,  but
Alaska's  stocks  were greatly depleted. Since the 1970s, warmer
coastal waters have reversed these conditions. However,  the  UW
researchers say, the present positive phase of the PDO should be
expected  to  reverse  within  a decade, at which time favorable
ocean conditions should return for West Coast salmon.

Many of these climate changes  are  felt  across  North  America
because  of  wave patterns -- like ripples in a stream -- in the
atmosphere, which is directly affected by changes of temperature
in Pacific Ocean currents. But the  phenomenon  is  particularly
evident  in the Northwest because of a feature in the wind field
called the Aleutian  low,  which  directs  atmospheric  patterns
across the region.

One  of  the puzzles of the PDO, says Mantua, is whether it acts
as a restraint on El Nino, or whether it is a long-term response
to the phenomenon. Mantua says he prefers the argument that  the
PDO  is  a slower change in the climate system of the oceans and
atmosphere over the entire Pacific basin which influences how El
Nino develops.

One frustrating aspect of attempting to forecast the PDO is that
it develops over such a long period that a negative or  a  posi-
tive  phase can have passed before researchers even discover it.
"We can recognize the phenomenon, but we can't  say  what  phase
we're  in  at the time," says Battisti. "But that's only because
we don't yet fully understand it. After all, it has only been in
recent years that we've recognized it even exists."

To find out what the PDO forecast could be for your region, call
Battisti at  (206) 543-2019 --- <david at atmos.washington.edu>, or 
call Mantua at (206) 616-5347 --- <mantua at atmos.washington.edu>.

Mantua,  N.J.  and  S.R.  Hare, Y. Zhang, J.M. Wallace, and R.C.
   Francis. 1997. A  Pacific  interdecadal  climate  oscillation
   with  impacts  on salmon production. Bulletin of the American
   Meteorological Society 78(6): 1069-1079.
   Full article is accessible at:
   http://www.atmos.washington.edu/~mantua/abst.PDO.html
Zhang, Y., J.M.  Wallace  and  D.S.  Battisti.  1997.  ENSO-like
   Decade-to-Century  Scale Variability: 1900-93. J. Climate 10:
   1004-1020.
   The abstract is at:
   http://www.atmos.washington.edu/misc/zhang.html
Note: See also Steven Hare's bibliography page at:
   http://www.iphc.washington.edu:80/PAGES/IPHC/Staff/hare/html
        /decadal/decadal.html [this should be all on one line]


GOOD NEWS FROM THE CANADA MUSEUM OF NATURE
From: Irwin Brodo <ibrodo at mus-nature.ca> originally posted on
         lichens-l at hawaii.edu [abbreviated]

I am happy to report that the Canadian Museum of Nature has just
signed  a contract with Yale University Press for the production
of "Lichens of North America," and as  a  result,  I  have  been
given  permission  to  resume work on the book. Many of you will
recall that the work was halted, first in early October 1996 and
then, after I was given  the  go-ahead  in  November,  again  in
December pending the signing of the contract.

[BEN  #  148 (November 2, 1996) paid some attention to this mat-
ter. - AC]
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