PMEL Programs and Plans
Accomplishments in FY 97 and Plans for FY 98
Figure. Hindcast of 1982-1983 El Nino.
Thermal Modeling and Analysis Project
Scientific Accomplishments in FY 97
This year saw excellent progress in TMAP studies in support of NOAA's
Seasonal to Interannual Mission. We published on the surface expression
of El Nino over the globe, on the space-time structure of Westerly Wind Events
over the tropical Pacific and on the extent to which the behavior of El Nino
events has or has not been different during the 1990s. We also developed a
new index for the identification and quantification of El Nino periods, the
Bjerknes ENSO Index (BEI), based on the common features of the events between
1946 and 1992 (see Harrison and Larkin, 1998 (hot link). Harrison and Larkin
(1997a) (hot link) described in detail the sea level pressure patterns
associated with the climatological seasonal cycle and with El Nino periods.
The most statistically significant SLP signals were not those associated with
the Southern Oscillation, but instead were in the eastern equatorial Pacific
and in the western central North Pacific. Harrison and Larkin (1997b) (hot
link) examined 150 years of Darwin, Australia SLP data (a proxy for the
Southern Oscillation Index meaure of El Nino conditions) and found that the
behavior of recent decades has been within historical statistical variability;
there appears to be no need to invoke global warming or other climate changes
to account for recent behavior. Harrison and Vecchi (1997) (hot link) published
an extensive study of the space and time scales of Westerly Wind Events in the
tropical Pacific. These events are much more common before and during El Nino
periods, but their detailed role(s) in the onset and maintenance of El Nino
remains unclear. McDermott, Harrison and Larkin (1997) evaluated the extent to
which different global surface wind analyses differ from each other, over the
past ten years; they found very few regions of the globe where monthly mean
anomalies are as well known as desired. It appears that more and better
surface wind information is needed, as well as new data assimilation
proceedures to make use of these data, to improve the operational wind
products. Supercomputer studies of the seasonal cycle and of El Nino periods
were carried out using the NOAA Tropical Pacific Ocean Model, and various
studies are being written up for publication during FY98.
Our work in support of NOAA's Decadal to Centennial Mission included
publication of a one-degree resolution global ocean experiment that describes
the ability of our present models to exhibit all of the ocean ventillation
pathways that are known to exist. PMEL CFC data were key to the success of
this study (see Craig et al, 1998) (hot link). A survey of some of the
sampling issues for measuring ocean surface carbon flux in the subpolar North
Pacific will appear soon. Simple model studies of the tropical Pacific food
web and its effects on primary production and the ocean carbonate system
continue. The Harrison and Larkin (1997b) paper also addresses Dec-Cen issues
in El Nino.
Data Systems Accomplishments FY 97
The past year has been one of major advancements in TMAP's data
systems -- the
Ferret analysis and visualization program and the Live Access
Server. The Ferret program continues to enjoy wide-spread and
growing acceptance throughout the ocean research community. Over 1000
copies of the program were downloaded via the Internet during the past
year. The program is used within PMEL across the spectrum of research
activities.
Ferret was significantly enhanced through the addition of 1) a very
flexible curvilinear graphics framework, which allows any map
projection to be realized directly from its projection equations;
2) a sweeping generalization of the concept of a Ferret "function" so
that functions can now return self-describing results that are
shape-modified relative to their arguments (e.g. EOFs, objective
analysis, etc.); 3) a robust framework for user-written FORTRAN, C,
or C++ analyses to appear inside of Ferret as shape-changing
functions. These changes represent a quantum leap in the flexibility
of the analyses that Ferret can perform.
The Live Access Server (LAS) may be thought of as a World Wide Web
interface to the Ferret program. Work on LAS has been funded
principally by the NOAA ESDIM and HPCC programs. LAS
servers at PMEL have been receiving approximately 120 thousand "Web
hits" per month, representing the delivery of about 10 thousand data
products (plots and data files). Inside of PMEL LAS is increasingly
used as the simplest and fastest means to gain access to gridded
referance data fields. Work on LAS during the past year has focussed
on making the server portable, configurable and accessible through
distributed object technology (CORBA and JAVA/RMI). Through these
enhancements users of LAS will be able to create networks of
collaborative sister servers allowing, for example, modelers at
distributed locations to share and compare results.
TMAP is also a core developer in the NOAAServer project -- working
on distributed object approaches to unifying NOAA's data holdings; on
metadata quality and metadata search strategies; and on developing low
bandwidth interfaces for modem-connected NOAAServer access. TMAP's
work to create portable, configurable Web servers will form the basis
of a NOAAServer "reference data server" -- a portable data server to
ease the process of bringing CORBA connectivity into NOAA facilities.
Thermal Modeling and Anaylsis Project
Scienfific Plans for FY 98
- Publish summary of statistically significant US Weather anomalies associated
with ENSO periods and their robustness.
- Publish summary of the tropical Pacific SST, SST anomaly and thermocline
depth anomalies associated with Westerly Wind Events since 1985.
- Complete ocean modeling studies of the mechanisms likely responsible for the
onset of the 1997 El Nino event.
- Prepare ocean model results on the variability of SST and currents in the
eastern tropical Pacific, with emphasis on the ocean observing system
appropriate to the EPIC field program under PACS
- Participate in the PMEL/UW-APL/NRL/NESDIS/SIO National Ocean Partnership
Program project on "Monitoring the North Pacific for improved Ocean, Weather
and Climate Forecasts".
- Participate as US member of the GOOS/GCOS "Ocean Observations Panel for
Climate" and "Atmospheric Observations Panel for Climate" committees, working
to advance NOAA's mission in climate observations.
- Continue, if resources permit, observing system studies in support of the
evolution of the ENSO Observing System and the PIRATA field program, of the
development of the CLIVAR-Pacific Basin-Extended Climate Studies program and of
the planning of a North Pacific observing system.
Data Systems Plans FY 98
- Develop the foundation of a library of Ferret "external functions" by
incorporating legacy codes for EOFs, FFTs, and objective analysis.
- Expand the list of LAS-served data sets to 27 gigabytes of gridded
reference data sets.
- Expand LAS functionality to enable full Ferret data analysis and fusion
in the Web environment.
- Continue participation in the NOAAServer project contributing to
the development of a CORBA-enabled NOAAServer "version 2"
- Develop a framework for easy 3D visualization of Ferret variables using
third party visualization tools such as the public domain "Vis5D" viewer.
- Develop Ferret external funtions to perform precision diagnostic analysis
of heat and momentum budgets from history files generated by the Modular
Ocean Model (MOM II).
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