Priority 2: Investigating the Interactions of the Atmosphere, the Broader Earth System and Human Society

Whereas in the past, meteorology and climatology were separate fields, be it only because of disparate At NCAR, researchers are investigating changes in the Earth's water cycle with an interdisciplinary research program that integrates climate, weather, and hydrological research. time (and length scales as well), it appears today that the two fields are strongly coupled, not only as the climate gives the boundaries for investigating the weather, but also because localized events can influence the larger climatological scales. The key activities which NCAR scientists focused on this year are related to the role of aerosols in climate and weather; the coupling of ecosystems, biochemistry and climate; climate change, climate variability and extreme weather such as hurricanes; interactions of the water cycle with climate and weather; the impacts of climate and weather on society and ecosystems; and finally megacities and the effects of urbanization.

FY 2006 Accomplishments

The first key activity, the role of aerosols in climate and weather, involves studies of aerosol formation, composition, and effects on the atmosphere including direct effects from absorption of radiation to indirect effects through influence on reflectivity and precipitation characteristics of clouds. NCAR scientists have made significant progress in understanding aerosols through research on the role of aerosols in climate and weather. See projects related to this priority.

NCAR research in the key activity, ecosystems, biochemistry and climate, seeks to understand the inner workings, coupling, and feedbacks between ecosystems, the biogeochemical cycles within those ecosystems, and the atmosphere. Each of these represents extremely complex systems, as are the interrelationships between them. NCAR scientists have made considerable progress in examining these systems and relationships through research on Ocean Acidification. See projects related to this priority.

Another key activity deals with climate change, climate variability and extreme weather. NCAR researchers look to better understand the interactions among these phenomena to attempt to improve our predictions of extreme events, and clarify the implications of climate change on society and natural and managed ecosystem. See projects related to this priority.

Many aspects of the Earth's water cycle need to be understood better as water plays such a crucial role in all of our lives. At NCAR, researchers are investigating the changes in the Earth's water cycle with an interdisciplinary research program that integrates climate, weather, and hydrological research. See projects related to this priority.

The impacts of climate and weather on society and ecosystems are a critical area of research related to the assessment of vulnerability and impacts and the development and evaluation of adaptation and mitigation strategies. See projects related to this priority.

The final key activity is megacities and the effects of urbanization. Specifically, this activity involves studies to understand the characteristics of pollution in a given megacity, what happens to that pollution as it is transported away from the city, and what effects the pollution has on regional and global scales. In FY 2006 NCAR scientists led and participated in the largest multi-agency international study of a megacity conducted to date. Megacities Impacts on Regional And Global Environments Mexico City case study (MIRAGE-Mex) was the NCAR led portion of the study and focused on pollution from Mexico City (See Highlight below). NCAR scientists also participated in another study of pollution sources and transport in Houston, Texas. Scientific results from these comprehensive studies will aid policy makers and air pollution regulatory agencies in determining strategies for dealing with pollution. See projects related to this priority.

Program Plan

The following are the FY 2007 NCAR plans for Strategic Priority #2.

Analyze laboratory and the Niwot Ridge field study measurements designed to investigate the role of biogenic emissions and their oxidation in aerosol nucleation and growth and on the composition of secondary organic aerosols.

Add more refined aerosol, and aerosol-cloud interactions to the MOZART and Community Atmosphere Model (CAM)-Chem models to improve projections of aerosol impacts on climate.

Collaborate with university investigators to plan and conduct the Airborne Carbon in the Mountains Experiment (ACME)07 campaign, whose goal is to understand carbon dynamics in montane forest regions by developing new methods for estimating carbon exchange at local to regional scales.

Continue moving towards more fully coupled representations of biogeochemical cycles in the Community Climate System Model (CCSM).

Expand the nest- Large Eddy Simulation (LES) study for more complex and realistic planetary boundary layers, and continue analyses of Rain in Cumulus Over the Ocean (RICO), The Dynamics and Chemistry of Marine Stratocumulus (DYCOMS), NASA African Monsoon Multidisciplinary Analysis (NAMMA), and Ocean Horizontal Array Turbulence Study (OHATS) data.

Integrate the relatively continuous, albeit nonlinear, effects of climate with the often abrupt or even discontinuous effects of land use and disturbance in an assimilation or model-data fusion approach.

Assess the factors that produce abrupt reductions in the future summer sea ice cover in the Polar Regions, and study how permafrost thaw will affect the carbon balance in the Arctic.

Analyze past real-time convection-resolving forecasts. Model enhancements that demonstrate the potential for forecast improvements will be incorporated in NCAR real-time forecast experiments and made available for both research and operational use.

Continue to improve our understanding the landfall of hurricanes. Improved forecasts of hurricane intensity change, and time-extensions of skillful track prediction are vital for evacuation strategies. Furthermore, accurate assessment of the uncertainty in hurricane forecasts is critical in a variety of economic sectors. Progress requires solving difficult problems such as the inner-core hurricane dynamics and how it affects intensity, quantifying the net enthalpy flux from the ocean in high-wind-speed conditions, and incorporation of a variety of remotely sensed data into model initial conditions. The purpose of NCAR research in hurricane simulations is to create the next generation hurricane-prediction system, and a community hurricane-prediction model that can be used for process and predictability studies.

NCAR will implement a new program, which has the goal of providing early warning of potential impacts from Earth system changes, which are increasingly viewed as important to human health, the global economy, and ecosystems. The Biosphere-atmosphere Exchange of Aerosols within Cloud, Carbon and Hydrologic cycles, including Organics & Nitrogen (BEACHON) program will improve the predictive skill associated with Earth system behavior over a time scale of months to a decade by explicitly coupling water, energy and biogeochemical cycles in a multi-scale modeling framework.

Oceans play a key role in the Earth's climate system. To improve our understanding of the climate, we will study how the oceans initiate and modify climate variability, improve our understanding of key ocean processes and to represent this understanding in climate models such as CCSM, develop nested regional coastal ocean models for climate and marine ecosystem studies, and use high resolution global ocean simulations to investigate the role of ocean mesoscale eddies in climate.

On the following pages, we report on some of the highlights related to this priority.