2011 - Cooperative Institute for Research in Environmental Sciences ...

Climate Diagnostics Center
The mission of the Climate Diagnostics Center (CDC) is
to improve our understanding of global climate interactions
to improve regional climate predictions of direct relevance
to society. CDC‘s goal is to establish the causes of regional
climate variations around the globe on time scales of weeks
to millennia, by 1) developing and applying new diagnostic
techniques to global observations and model simulations;
2) developing new observational data sets and performing
new climate model integrations as needed for this purpose;
and 3) developing new techniques to diagnose and reduce
model errors.
Research disciplines include, but are not limited to, the
atmospheric sciences, oceanography, stochastic dynamics
and physics, remote sensing, numerical computational
methods, computer sciences, data management and complex
dynamical systems analysis. An integration of these
disciplines is required to transfer improvements in the
understanding of climate processes to improvements in the
models and methods used for climate predictions.
In 2010–2011, CDC published 23 peer-reviewed papers
on topics that included:
• The Twentieth Century Reanalysis (20CR) project, a
major international effort led by CDC and NOAA to
produce a comprehensive global atmospheric circulation
data set spanning the period 1871 to the present,
assimilating only surface pressure reports and using
observed monthly sea-surface temperatures and sea-ice
distributions as boundary conditions. The submission
of this paper was invited by a peer-reviewed journal
(QJRMS), a distinct honor.
• A demonstration (using the 20CR data set) that the
1918/19 El Niño event, which coincided with the
“Great Influenza Epidemic,” may have been much
stronger than previously thought.
• A critical evaluation of techniques for removing El
Niño–Southern Oscillation (ENSO) related variations
from the historical climate record to better isolate
climate change signals, and implementing a new technique
that suggests that the ENSO-related contribution
to 20th century warming may have been larger than
previously thought.
• Demonstrating the critical influence of the pattern of
tropical ocean warming on remote climate trends, and
also the inability of the climate models used in the Intergovernmental
Panel on Climate Change (IPCC) 2007
report to represent such patterns.
• Assessing the realism of the local and remote feedbacks
on tropical ocean temperatures in the IPCC models,
and showing that climate models are significantly deficient
in representing the remote feedbacks.
• Distinguishing the roles of natural and anthropogenically
forced decadal climate variability in the world’s
oceans.
• Determining the optimal tropical sea surface tempera-
64 CIRES Annual Report 2011
ture pattern for inducing North American drought
• Highlighting the sensitivity of global surface temperature
trend estimates to the choice of the time interval
used.
• Explicitly accounting for clouds in atmospheric data
assimilation.
• Documenting newly discovered features of the South
American monsoon system, including the 1970s climate
transition.
• Interannual ENSO variability forced through coupled
atmosphere-ocean feedback loops.
Additionally, CDC continued developing several observational
and atmospheric circulation data sets and forecast
products, and provided scientific input to international
programs. These efforts included:
ISTOCK
• Completing production of the 20CR data set for 1871
to the present, and making the data set widely available
through a web interface. For more, see: http://www.esrl
.noaa.gov/psd/data/gridded/data.20thC_Rean.html.
• Providing leadership in the international Global
Climate Observing System Surface-Pressure Working
Group, to promote the development of long-term, highquality
surface-pressure data sets.
• Providing leadership in the U.S. CLIVAR (Climate
Variability and Predictability) Working Group on
Decadal Predictability.
• Developing and releasing an experimental forecast
product (jointly with NOAA Earth System Research
Laboratory’s [ESRL] Physical Sciences Division) for
subseasonal tropical forecasts based on a coupled linear
inverse model of weekly tropical SSTs and outgoing longwave
radiation variations. For more, see: http://www.
cdc.noaa.gov/forecasts/clim/.