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2009 Seminars at COLA
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Title: Hurricane Season Prediction Experiment with CFS
Speaker: Jae Schemm
Affiliation: NCEP/CPC
Date: January 21, 2009 at 2:00 p.m.
Title: The Impact of the Mean State onthe ENSO Simulation and Prediction
Speaker: Xiaohua Pan
Affiliation: AOES GMU / COLA
Date: January 23, 2008 at 11:00 a.m.
Abstract: Previous studies have shown that the structure of the tropical Pacific mean state, i.e., annual mean climatology, has a significant potential impact on the characteristics of the ENSO cycle. In this study, such impact is investigated quantitatively through a set of numerical experiments using the Climate Community System Model version3 (CCSM3), developed by the National Center for Atmospheric Research (NCAR). In a sensitivity experiment, an empirical time-independent heat flux correction over the tropical ocean is applied to the oceanic component of CCSM3. In comparison with the fully coupled control run, the annual mean SST and precipitation of the sensitivity run are more realistic: warm biases off the South America are significantly reduced. The double ITCZ problem in the control run is also eased. A major benefit of the improved annual mean state is a more realistic annual cycle of the SST and precipitation over the equatorial eastern Pacific and Nino3.4 regions (5°S-5°N, 170°W-120°W), which is associated with a reduction of the unrealistic semi-annual signals there. In addition, our results demonstrate that the model ENSO cycle is sensitive to these modifications of the mean state: ENSO variability is less regular and with longer period (but shorter than observed 4-year period) in the heat flux corrected simulation. However, ENSO events in the flux corrected run have weaker amplitude. In order to examine the impact of the mean state on the ENSO prediction, a series of 12-month hindcasts are performed using this coupled system with and without the heat flux correction. The initial conditions of the hindcasts are for the 1st of January and July of each year from 1982 to 1998. The predictive skills of the SST anomaly area-averaged in Nino3.4 region from flux corrected forecasts are slightly higher than those in control hindcasts in 7-9 lead months for the January and 9-11 lead months in the July hindcasts. However, the differences are not statistically significant even at the 90% level.
Title: Tropical Response to Greenhouse Forcing: Oceanic and Atmospheric Contribution
Speaker: Gabriel A. Vecchi
Affiliation: Geophysical Fluid Dynamics Laboratory, NOAA
Date: February 9, 2009 at 11:00 a.m.

The response of the tropics to increasing CO2 is a central topic in climate change research, as tropical climate onditions can have far-reaching effects and they set the background for changes in the character variations, such as those of El Niño. Theoretical and modeling understanding, and observational evidence for long-term changes to the tropical climate system will be highlighted. Changes in the oceanic circulation and thermal structure will be iscussed, as will changes in atmospheric circulation and precipitation patterns - including changes in the Hadley and Walker Circulations. The change to the tropical Pacific mean state to greenhouse warming is complex, controlled by both oceanic and atmospheric processes. In models with a simplified representation of atmospheric physics, feedbacks originating in the ocean drive the system to a “La Niña-like” state. In models with atmospheric general circulation components, thermodynamic constraints result in a reduction of the strength of the atmospheric overturning circulation – manifest primarily in the zonally-asymmetric (Walker) rather than zonal-mean (Hadley) component. In these models changes over the tropical Pacific Ocean resemble “El Niño-like” conditions, although the mechanisms are fundamentally different from those of El Niño, as are many of the impacts. Even though modeling studies can help reconcile aspects of the diverging theoretical understanding, a true reconciliation requires observational evidence. Observations of sea level pressure indicate that over the 20th Century the Pacific Walker circulation has weakened; however, differing reconstructions of historical SST are inadequate to distinguish between an increase or decrease in East-West SST gradient across the Pacific. We outline what we view as a way forward, with targeted reconstructions and paleo-proxy observations, to reconcile these diverging views. Implications of the modeled changes are also discussed.

Title: The relationships between Indo-Pacific SSTs and Asian summer Monsoons in the NCEP CFS
Speaker: Soo-Hyun Yoo
Affiliation: NCEP / Climate Prediction Center
Date: February 11, 2009 at 2:00 p.m.
Title: Forests, Climate, and National Measurement Systems: Bringing Carbon Sequestration into the UNFCCC
Speaker: Dr. D. James Baker

Director, Global Carbon Measurement Program, The William J. Clinton Foundation

Date: March 19, 2009 at 3:00 p.m.

Close to twenty percent of global carbon emissions can be traced to deforestation in the tropics. By preserving forests(BS1)(BS2), reforesting marginal lands(BS3), and improving agricultural practices, carbon sequestration can be enhanced and carbon emissions reduced. Hence the United Nations Framework Convention on Climate Change (UNFCCC) has taken on the issues of Reducing Emissions from Deforestation and Forest Degradation (REDD) in developing countries and incorporating changes in carbon storage and emissions from Agriculture, Forestry, and Other Land Use (AFOLU) in intergovernmental agreements. Previous negotiations on the inclusion of forests for climate mitigation in developing countries have been held back for many reasons including technical challenges of monitoring carbon stocks with high certainty, and issues of leakage, additionality, and permanence (BS4). Moreover, despite much effort to date by national and international organizations, the requisite national and global information to underpin such agreements and financial markets is lacking. Some useful lessons can be learned from a onsideration of the information delivery of weather forecasts and services to the public as a model for forest carbon accounting systems. The responsibility and roles of all the institutions involved - from national governments and various international organizations and agreements to foundations, non-governmental organizations, universities, and the private sector, are similar. The comparison of how weather forecasts and other services are developed and delivered to users may help in defining the issues to be addressed in forest carbon accounting. In this talk I will outline what is needed to establish national forest carbon accounting systems that will provide estimates of forest carbon storage and emissions information with a high degree of certainty

Title: The intraseasonal oscillation of the Indian summer monsoon: Air-sea interactions and high-resolution modeling
Speaker: Nicholas Klingaman
Affiliation: National Centre for Atmospheric Science--Climate Department of Meteorology, University of Reading
Date: March 20 , 2009 at 11:00 a.m.
Title: Future climate change projections from multiple climate models: Consensus, uncertainties and what all that may mean for impact models
Speaker: Claudia Tebaldi
Affiliation: Climate Central
Date: April 1, 2009 at 11:00 a.m.
Title: Towards the Theory of the NAO
Speaker: MIchael Ghil
Affiliation: Ecole Normale Supérieure, Paris, and Univ. of California at Los Angeles
Date: April 9, 2009 at 3:00 p.m.
Title: Ocean state estimation in the Southern Ocean Gas exchange experiment region using 4DVar
Speaker: Suneet Dwivedi
Affiliation: Dept of Earth and Planetary Sciences, JHU
Date: May 19, 2009 at 3:00 p.m.
Title: Interdecadal Variability of Climate from Regional China and Global Scale
Speaker: Dr. Weihong Qian
Affiliation: Dept of Atmospheric Sciences, Peking UNiversity
Date: August 27, 2009 at 11:00 a.m.
Title: Physical Identification of East Asian Subtropical Monsoon and Global Monsoon System
Speaker: Dr. Weihong Qian
Affiliation: Dept of Atmospheric Sciences, Peking University
Date: August 28, 2009 at 11:00 a.m.
Title: Global Climate Change and Sahel Rainfall
Speaker: Dr. Michela Biasutti
Affiliation: LDEO, Columbia University
Date: September 18, 2009 at 11:00 a.m.
Title: Latent heating, radiative heating, and the large-scale tropical circulation
Speaker: Courtney Schumacher
Affiliation: Dept of Atmospheric Sciences, Texan A&M University
Date: September 11, 2009 at 3:00 p.m.
Title: Overview of NICAM: Global cloud-resolving simulations and physics schemes
Speaker: Masaki Satoh
Affiliation: Center for Climate System Research, the University of Tokyo/RIGC, JAMSTEC
Date: October 21, 2009 at 11:00 a.m.
Title: Physical Identification of East Asian Subtropical Monsoon and Global Monsoon System
Speaker: Hirofumi Tomita
Affiliation: Research Institute for Global Change, JAMSTEC
Date: October 21, 2009 at 3:00 p.m.
Title: NICAM Overview
Speaker: Kodoma
Affiliation: JAMSTEC
Date: October 22, 2009 at 11:00 a.m.
Title: Climate Computing in Times of CMIP5: Experiences, Plans and Perspectives at MPI für Meteorologie
Speaker: Reinhard Budich
Affiliation: The Max-Planck-Institut für Meteorologie, Hamburg, Germany
Date: November 23, 2009 at 11:00 a.m.
Title: Dynamics and Impacts of Fine-Scale Climate Change
Speaker: Noah Diffenbaugh
Affiliation: Department of Environmental Earth System Science, Stanford University Center Fellow, Woods Institute for the Environment
Date: November 23, 2009 at 3:30 p.m.
Title: The Role of Mesoscale Eddies in the Rectification of the Southern Ocean Response to Climate Change
Speaker: Dr. Ricchardo Farneti
Affiliation: AOS program at Princeton University
Date: November 24, 2009 at 11:00 a.m.
Title: Simulation and Assimilation of Denmark Strait Overflow
Speaker: Tom Haine
Affiliation: Johns Hopkins University
Date: December 4, 2009 at 2:00 p.m.