Guy Brasseur ESSL Director

Director's Message

The Earth and Sun Systems Laboratory (ESSL) was established in October 2004 to develop an ambitious research program and to address some of the complex scientific questions that are directly related to major environmental challenges the world is facing. The overall objective of the Laboratory is to perform fundamental studies of the dynamics of the Earth and Sun Systems across spatial and temporal scales, and to assess how natural forcing processes and human-driven perturbations affect the evolution of the Earth’s Systems and ultimately the habitability of our planet.

By performing an integrated study of the Earth and Sun Systems and the changes occurring in these systems, ESSL will provide key knowledge needed to develop a sustainable future for humankind. Specifically, the Laboratory will study the fundamental processes that determine the evolution of the Earth and Sun Systems, develop the tools needed to observe and analyze these processes, and to predict their evolution. This requires a full understanding of the processes that determine the variations in the Sun’s radiative energy, of the mechanisms that determine the effects of solar radiation on the Earth’s environment as well as of the interactions that exist between the physical, biological and chemical processes in the coupled atmosphere, land and ocean system. The ultimate goal is to acquire the fundamental knowledge necessary to respond to global and regional environmental changes and to help societies to develop a sustainable future.

	The Earth system includes the atmosphere, ocean, land surface, cryosphere and the human system. Complex interactions take place within each compartment, and also between them. Transport of mass, momentum and energy within the Earth system are driven by the energy provided by the Sun. A challenge for ESSL is to understand the processes that contribute to the dynamics of the Earth and Sun systems, and to predict the complex evolution of this system across timescales. Figure provided by M. Andreae, MPI-Chemistry, Germany. High resolution figure
	The Community Climate System Model was used to simulate the ice sheet during the last Interglacial period. The figure shows (left) the summer surface temperature change for the last interglacial period 130,000 years ago compared to present-day as derived by CCSM and from observational data. The figure (right) shows the ice sheet topography for the same period. These results suggest that summer warming of the Arctic of 4-5C led to a significant melting of the Greenland ice sheet and a complete melting of most of the other Arctic glaciers. Summer temperature anomalies in the Arctic may be as warm or warmer as 130,000 years ago by 2100 having implications for future sea level (Otto-Bleisner and CAPE Last Interglacial Project Members, 2006) High resolution figure
	ESSL scientists have examined the evolution of Arctic summer sea ice in seven projections from the Community Climate System Model and find that abrupt reductions are a common feature of these 21st century simulations. These events have decreasing September ice extent trends that are typically four times larger than comparable observed trends. In the most dramatic event, shown here, the ice cover goes from conditions similar to observed to essentially September ice free conditions in a decade. For more information click here. High resolution figure
	Meteorological driftsonde has been launched in Western Africa as part of the AMMA (African Multi-disciplinary Analysis) field experiment and of the THORPEX (The Observing System Research and Predictability Experiment) Program. The purpose of this experiment conducted as a collaboration between CNES (the French Space Agency), CNRS and NCAR (with NOAA funding) was to advance understanding and improve prediction of the genesis of tropical cyclones and to understand the impact of dry Saharan Air on tropical convection (a stringent test of the convective parameterization schemes used in weather and climate models). The figure shows observations of the temperature and humidity profiles on 11 September 2006 near tropical cyclone Gordon. High resolution figure

A physically based-model of the solar magnetic field and meridional circulation developed by Dikpati, de Toma & Gilman, predicts that solar cycle 24 will be 30-50% larger than cycle 23.>. High resolution figure
The WRF model predicts successfully the trajectory of Hurricane Ernesto between August 29 and September 2, 2006 along the east coast of the United States. High resolution figure
The objective of this project was to characterize the extent, persistence, and potential impacts of the air pollution produced in the urban region of Mexico City on the surrounding areas. A field campaign that took place 1-29 March 2006 involved 60 participating institutions including 38 universities. It provided a unique opportunity for international cooperation and training of local students. The figure shows the pollution cloud observed by the NASA/UND DC-8 aircraft above Mexico City. The NCAR C-130 was also part of this field campaign. High resolution figure
In order to better simulate the role of the tropics in the climate system, ESSL scientists have nested a version of the Weather Research and Forecast (WRF) model into the global Community Climate System Model (CCSM). The figure shows a simulation of the development of tropical cyclones. The seasonal evolution of the number of cyclones simulated by the regional model is in very good agreement with the observed climatology. High resolution figure

The Earth and Sun Systems laboratory (ESSL) includes 4 scientific Divisions (the Atmospheric Chemistry Division (ACD), the Climate and Global Dynamics Division (CGD), the High Altitude Observatory (HAO), and the Mesoscale and Microscale Meteorology Division (MMM)) as well as the newly created Institute for Integrative and Multidisciplinary Earth Studies (TIIMES).

As you will notice from the different detailed web pages that constitute the 2006 Annual Report, ESSL scientists accomplished a lot of exciting science in the last year. A major discovery of the research has been the development of a new methodology to predict the future solar cycle.

The establishment of a program focusing on space weather is another exciting initiative. The Community Climate System Model (CCSM version 3) has been used to successfully reproduce the evolution of climate since the pre-industrial era, and to provide projections of the climate during the next 100 years, based on possible greenhouse gas emissions scenarios. This work represents a major contribution of NCAR to the Intergovernmental Panel of Climate Change (IPCC). Many ESSL scientists have contributed as lead or contributing authors to the preparation of the fourth IPCC assessment report.

The development of the Weather and Research Forecast Model (WRF) has continued; this model is now used in different countries as a community tool by a large number of researchers in academic institutions and by operational weather forecast centers. This model was used, for example, to successfully forecast the trajectory of Katrina before it landed in New Orleans in September 2005. In March 2006, ESSL contributed to a large field campaign in Mexico City (MIRAGE/MILAGRO), whose purpose was to characterize the chemical/physical transformations and the ultimate fate of pollutants exported from large urban areas, and to assess the current and future impacts of these exported pollutants on regional and global air quality, ecosystems, and climate.

TllMES was created to conduct and promote Earth science research across disciplines. The Institute promotes interactions for new and current initiatives associated with multidisciplinary Earth studies to be fostered, grown, and integrated. Beside managing cross-divisional Projects with large university participation, including the Biogeosciences initiative, the project on Water Across Scales, the Upper Troposphere/Lower Stratosphere initiative, and THORPEX, an international program aimed at improving weather forecasts, TIIMES hosted three very interesting summer meetings in Boulder on (1) gravity waves, (2) tropical convection and the weather-climate interface, and (3) water and biogeochemical cycles, respectively.

ESSL has, of course, great plans for the future. These include the development together with other Laboratories of a flexible modular Earth System modeling framework to address integrative scientific questions. In particular, the development of version 4 of the CCSM by the end of 2008 in preparation for the Intergovernmental Panel on Climate Change- Assessment Report 5 (IPCC AR5) is on the agenda of the Laboratory. Another important priority is the development of a Nested Regional Climate Model (NRCM) to study the seamless transition between weather and climate processes. Implementation of field observations, addressing interdisciplinary questions, including the interactions between dynamical, chemical, radiative and microphysical processes in the upper troposphere and lower stratosphere and the interactions between the continental biosphere, the water system, the carbon cycle, aerosols and cloud microphysics are also important priorities for the next 3 years. Research will conducted to increase our understanding of the global water cycle, to improve weather forecasts, including hurricane predictions, to observe, analyze and predict chemical weather at all scales, to better assess the impact of urban development on regional and global air quality, and to better predict the effects of space weather on the Earth System.

Guy P. Brasseur
Associate Director
NCAR Earth and Sun Systems Laboratory