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Articles of interest to the ENSO community
gleaned from publications or submitted by readers.
- El Niño Affects California Fisheries
- Get a WiF of This
- ENSO, Hail and Insurance
- North Atlantic Oscillation
- New NESDIS Data Sets
- New Fisheries Science Book
- Australia: Eye of the Storm
- ENSO CLIPER
- Time for a Look Back?
- Extreme Climate Events Program in Vietnam
- El Niño Impact Study Results Available Soon
- Ocean Envoys
- Poem by Mary Voice
- ? Point / Counterpoint ?
El Niño Affects California Fisheries
In the September 15 issue of Geophysical Research Letters, Mati Kahru and Greg Mitchell use satellite-derived time series in the California Current system to show that the 1997-98 El Niño event was associated with a two-fold increase in the extent of mesotrophic waters off Baja California. This El Niño is also associated with a reduction of eutrophic areas in the California Current System and of mesotrophic areas off Southern California, due possibly to the reduction in upwelling of cold, nutrient-rich waters. The authors argue that one of El Niño's effects on the California Current ecosystem is a more uniform distribution of phytoplankton, thus reducing the occurrence of high-concentration patches of phytoplankton that may be necessary for the production and survival of zooplankton and larval fish. (Some of the data for this article was gathered by the SeaWiFS project.)
Kahru, M. and B.G. Mitchell, 2000: Influence of the 1997-98 El Niño on the surface chlorophyll in the California Current. Geophysical Research Letters, 27(18), 2937-2940.
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Get a WiF of This
The SeaWiFS (Sea-Viewing Wide Field-of-View Sensor) project is part of NASA's Earth Science Enterprise that intends to provide data on ocean color to the earth science community. Subtle changes in ocean color indicate various types and number of marine phytoplankton that are affected by ENSO variations. SeaWiFS was launched in August 1997 to examine oceanic factors that affect global change and to assess the role of the oceans in the global carbon cycle over a five-year period. Satellite data are sent to the Goddard Space Flight Center (GSFC) EOS Data and Information System (EOSDIS) Distributed Active Archive Center (DAAC), which archives and distributes SeaWiFS data to the scientific community. For more information on the project, contact the SeaWiFS Project, Code 970.2, NASA Goddard Space Flight Center, Greenbelt, MD 20771 USA; tel: 1-301-286-9676 or visit the Web site at seawifs.gsfc.nasa.gov/SEAWIFS.html
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ENSO, Hail and Insurance
The Natural Hazards Research Centre (NHRC) at Macquarie University in Sydney, Australia, utilized its extensive natural peril data bases for the development of a probabilistic hail loss model for major metropolitan areas in eastern Australia. By incorporating into the model results of earlier NHRC research on ENSO, the simulations of annual hail loss aggregates can be driven by two different types of annual hailstorm frequency modes (experimental and optional), each of them relating to a different type of the annual Southern Oscillation Index (SOI) cycle. High annual hailstorm numbers in Australia tend to be reached during years marked by positive values of a multifactor index, which correspond to rising values of the SOI up to November, and falling SOI values thereafter. (It should be noted that the index correlates well with the frequency of hail events but does not show any relationship with the severity of the events; i.e., the amount of damage.) The purpose of this ENSO feature is to inform the end users of the loss model (e.g., the insurance industry sector) to the various types of ENSO-related climatic variability and to highlight their potential impacts on annually aggregated loss profiles. For more information, contact Ivan Kuhnel at ikuhnel@laurel.ocs.mq.edu.au or visit the NHRC Web site at www.es.mq.edu.au/NHRC/ or see the following articles:
Leigh, R., and I. Kuhnel, 2000: Hailstorm loss modeling and risk assessment in the Sydney region, Australia. Natural Hazards (in press).
Kuhnel, I., 1998: The use of a multifactor Southern Oscillation Index for the estimation of annual hailstorm frequencies in the Sydney area. International Journal of Climatology, 18, 841-858.
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North Atlantic Oscillation
One of the most prominent patterns of teleconnections is the North
Atlantic Oscillation (NAO). The NAO Index is defined as the anomalous
pressure difference between the Icelandic Low and the belt of high
pressure that extends across the subtropical Atlantic. Sir Gilbert Walker
first wrote about the oscillation in 1932. It affects the circulation of
seas at the margins of the North Atlantic Ocean. James Hurrell carried
out a study published in 1995 that showed that the NAO contributes to the
global warming that has been seen in the past few decades. Both the
positive and negative phases of the NAO are associated with basin-wide
changes in the intensity and location of the North Atlantic jet stream and
storm track, which in turn results in changes in temperature and
precipitation patterns often extending from eastern North America to
western and central Europe. Strong positive phases of the NAO tend to be
associated with above-normal temperatures in the eastern United States and
across northern Europe, and below-normal temperatures in Greenland,
southern Europe and the Middle East, as well as above-normal precipitation
in northern Europe and below-normal precipitation over southern and
central Europe. Opposite patterns of temperature and precipitation are
typically observed during strong negative phases of the NAO. (Graphic
courtesy of James Hurrell) For more information on the NAO, see the
collection of selected Web sites published
with this newsletter, as well as these articles:
Walker, G.T. and E.W. Bliss, 1932: Memoirs of the Royal Meteoological Society, 44, 53-65.
Hurrell, J.W., 1995: Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation. Science, 269, 676-79. (also available on line with updates: www.cgd.ucar.edu/cas/papers/science1995/sci.html)
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New NESDIS Data Sets
During 1999, NESDIS (National Environmental Satellite, Data, and Information Service) scientists received new paleoclimate data sets on the past variability of El Niño and drought and led field expeditions to collect new records from land and ocean sites. Scientists demonstrated that at least two major droughts in the past two millennia significantly exceeded the severity, length, and spatial extent of twentieth-century droughts. New data sets included a paleo record of the North Atlantic Oscillation derived from ice cores, the 15,000-year record of El Niño, and many other new time series. For more information, see www.ngdc.noaa.gov (from NESDIS Highlights of 1999, US Department of Commerce, NOAA/NESDIS, Washington, DC) or see the Web site at www.nesdis.noaa.gov
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New Fisheries Science Book
A little more than two years ago, P.J. Harrison and Tim Parsons convened a small group interested in applied fisheries oceanography to make presentations on various aspects of the state of knowledge in the field. The publication from this event has just been released and contains many novel ideas and observations on the state of ocean science, fisheries biology, and applied oceanography. It is available in paperback and can be ordered on line at www.blackwell-science.com/~cgilib/bookpage.bin?File=10012072 (Blackwell Science).
Parsons, T.R. and P.J. Harrison (Eds.), 2000: Fish Biology and Aquatic Resources. UK: Blackwell Science Ltd. 362 pp.
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Australia: Eye of the Storm
The Australian Broadcasting Company (ABC) is producing a four-part series about Australia's extreme climate variations, focusing particularly on the adaptation of plants and animals to climate extremes. Using satellite images and computer graphics, each program traces the development of one extreme climatic event. The four parts feature El Niño, La Niña, Monsoons, and weather of the Southern Ocean. The program will air in Australia's Storm Chasers in October 2000. The Web site is available at abc.net.au/storm and is in itself very informative.
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ENSO CLIPER
Chris Landsea of NOAA's Hurricane Research Division and John Knaff of the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University have written a guest editorial
for the WeatherZine on "How much 'skill' is there in forecasting El Niño?" The editorial describes the development of the ENSO CLImatology and PERsistent model (CLIPER) as a simple statistical tool that takes advantage of the climatology of past El Niño events, persistence, and contemporary trends. For more information on the ENSO CLIPER, contact Landsea at NOAA/AOML/Hurricane Research Division, 4301 Rickenbacker Causeway, Miami, FL 33149 USA; tel: 1-305-361-4357; fax: 1-305-361-4402; email: landsea@aoml.noaa.gov
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Time for a Look Back?
This period between ENSO events gives us a chance to look back at previous research on ENSO and learn from it. A good place to begin is an informative Web site on "Effects of El Niño on Streamflow, Lake Level, and Landslide Potential" by Richard Reynolds, Michael Dettinger, Daniel Cayan, Doyle Stephens, Lynn Highland and Raymond Wilson of the US Geological Survey. See geochange.er.usgs.gov/sw/changes/natural/elnino/
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Extreme Climate Events Program in Vietnam
The Asian Disaster Preparedness Center (ADPC), in collaboration with NOAA, has undertaken a project on the impacts of extreme climate events such as El Niño in Vietnam. A report based on the input of experts constituted the background paper for the National Consultation Workshop held in May 2000. The initiative successfully brought together the climate science community and users of climate information. A Climate Forecast Producers and Users Workshop will be held in September 2000 on receipt of a wet season forecast. Another workshop will be held in March 2001 to evaluate the experiences of the September 2000 forecast and application, and to use the dry season forecast for resource management. Based on the experience of the two workshops, a work plan will be formulated to further institutionalize climate forecast and application systems in Vietnam. For more information, contact the ADPC, Asian Institute of Technology, PO Box 4, Klong Luang,
Pathumthani 12120, Thailand; email: adpc@ait.ac.th (from Asian Disaster Management News)
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El Niño Impact Study Results Available Soon
The major findings from a 19-month, 16-country study focused on improving
early warning mechanisms and general preparedness for extreme El Niño-related climate events are to be released soon. The project, "Reducing the Impact of Environmental Emergencies through Early Warning and Preparedness: The Case of the 1997-98 El Niño", is funded by the UN Foundation for International Partnerships. It is implemented by the UN Environment Programme (UNEP) in collaboration with the National Center for Atmospheric Research (NCAR, USA), the UN University (UNU), World Meteorological Organization (WMO) and the International Strategy for Disaster Reduction (ISDR). Participating country study teams are from Bangladesh, China, Costa Rica, Cuba, Ecuador,
Ethiopia, Fiji, Indonesia, Kenya, Mozambique, Panama, Papua New Guinea, Paraguay, Peru, the Philippines and Vietnam.
The study findings are focused on lessons for governments, international agencies, scientific community, NGOs, popular media, and general public. The summary of these lessons will be released at the end of October under the auspices of the UN University at the UN Headquarters in New York. The summary and detailed country reports will become available through the project Web site: ccb.ucar.edu/un/ in December. For more information, please contact Michael Glantz, Principal Investigator, ESIG/NCAR, PO Box 3000, Boulder, CO USA 80307; tel: 1-303-497-8119; fax: 1-303-497-8125; email: glantz@ucar.edu
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Ocean Envoys
NASA's Jet Propulsion Laboratory is offering to provide materials to lecturers for formal and informal educational presentations and to the general public. The program is Ocean Envoys and is an international effort; however, all materials are in English. Educational and informational CD-ROMs about El Niño and physical oceanography, posters, lithographs, Powerpoint presentations, activities, bookmarks, stickers, etc. are offered. If you are interested in this program and becoming an Ocean Envoy, please contact Tom Nolan, Lead Outreach Coordinator at tom.nolan@jpl.nasa.gov or go to the Web site at topex-www.jpl.nasa.gov
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Poem by Mary Voice
The Bureau of Meteorology in Australia has a Christmas party Olympic Games (yes, we are besotted with the Olympics here in Australia at present), with 6 teams competing. The teams have names indicating extraordinary sporting prowess, such as Fog, Blizzard, Sunshine and Cloud. Such stunning events as best Christmas decoration with a weather theme, fastest person to trash the old Budget and Program document, count the lightning strikes on the lightning strike map, weather trivia quiz, and team Christmas carol are delivered at the party. Last year, one event was a poem with a weather theme (plagiarism allowed). Hence the penning of "El Niño." Apologies to Shakespeare!
— Mary Voice
(M.Voice@bom.gov.au)
El Niño
by Mary Voice
Niño, or not Niño; that is the question
Whether 'tis nobler in the mind to suffer
The swings and roundabouts of erratic climate,
Or to take arms against a sea of weather,
And by smoothing, damp them?
To seek the Signal;
Oh vain; perhaps by research to say we end
the heart-ache and the thousand natural shocks
That forecasters are heir to, 'tis a consummation
Devoutly to be wish'd
To research, to sleep,
To research: perchance to dream; aye, there's the rub;
For in that dream what insights may come
When we have shuffled off this operational toil,
Must give us pause.
For who would bear the whips and scorns of time,
The insolence of office and the spurts
That impatient users of the forecast makes.
Does conscience thus make cowards of us all;
And thus the forecaster of resolution
Is hindered by the niggling doubt in thought,
And forecasts of great pith and moment?
With this regard their currents turn awry,
And lose the name of action.
— Soft you now!
Oh foul El Niño or fair La Niña, in thy vagaries
Be all my sins remember'd.
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? Point / Counterpoint ?
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Trenberth, K.E. and T.J. Hoar, 1996: The 1990-1995 El Niño-Southern Oscillation event: Longest on record. Geophysical Research Letters, 23, 57-60.
Allan, R.J. and R.D. D'Arrigo, 1999: 'Persistent' ENSO sequences: How unusual was the 1990-1995 El Niño? The Holocene, 9(1), 101-118.
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