Understanding global environmental processes and their regional linkages has heightened the importance of full, open, and timely access to earth system science data and strong international scientific collaborations. To that end, the Unidata Program at the University Corporation for Atmospheric Research has a growing portfolio of international outreach activities, conducted in close collaboration with academic, research and operational institutions on several continents. The overarching goals of Unidata's international activities include:

• democratization of access-to and use-of data that describe the dynamic earth system • building capacity and empowering geoscientists and educators worldwide • strengthening international science partnerships for exchanging knowledge and expertise • effectuating sustainable cultural changes that recognize the benefits of data sharing, and • building regional and global communities around specific geoscientific themes.

Great strides have been made in establishing the underpinnings of a worldwide data sharing network. To date, over 160 institutions of higher education in North, Central and South America, the Caribbean, Asia, and Europe are participating in Unidata's innovative data sharing effort. The Internet Data Distribution (IDD) system, which was originally developed for sharing mostly atmospheric science data among U.S. institutions, has now been extended beyond North American borders into a system of interconnected regional data networks encompassing Latin America, the Caribbean, Antarctica, Asia, and most recently Europe. The adoption of the IDD concept has been so successful that Brazil now ranks only behind the United States in the number of institutions participating in their own regionally customized and managed data sharing network called the IDD-Brazil. Another noteworthy data distribution network, Antarctic IDD, is leveraging the IDD system for the benefit of the Antarctic meteorological research community. The availability of observations from polar areas is especially crucial for documenting the nature and extent of climate change, for those are the very regions that are projected to experience the most significant warming in climate simulations and as such most vulnerable from an Earth system science perspective.

The democratizing and transformative effects of access to data in atmospheric science education and research cannot be overstated. After all, a critical component of successful scientific inquiry includes learning how to collect, process, analyze, and integrate data from myriad sources, and geoscience education is uniquely suited in making science relevant by drawing connections between the dynamic Earth system and societal impacts. Continued collaborations that emerge from such data sharing efforts will result in greater understanding of a range of geoscientific problems including advances in climate change and hydrologic sciences, and weather and El Nino predictions. Moreover, they will provide a richer analysis of the evolving state of the planet. An overview of Unidata's international data sharing activities that are resulting in an organic expansion of the Unidata community and increased partnership for sharing knowledge and experience will be presented.

Great strides have been made in establishing the underpinnings of a worldwide data sharing network. To date, over 160 institutions of higher education in North, Central and South America, the Caribbean, Asia, and Europe are participating in Unidata's innovative data sharing effort. The Internet Data Distribution system, which was originally developed for data sharing amongst U.S. institutions, has now been extended beyond North American borders into a system of interconnected regional data networks spanning Latin America, the Caribbean, the Antarctica, and other continents. The adoption of the IDD concept has been so successful that Brazil now ranks only behind the United States in the number of participating sites in their own regionally customized and managed data sharing network called IDD-Brazil. Another noteworthy data distribution network, Antarctic IDD, is also leveraging the IDD system, primarily for the benefit of the Antarctic meteorological community. The availability of observations from polar areas is especially crucial for documenting the nature and extent of climate change, for those are the very regions that are projected to experience the most significant warming in climate simulations and as such most vulnerable from an Earth system science perspective.

The democratizing and transformative effects of access to data on atmospheric science education and research cannot be overstated. After all, a critical component of successful scientific inquiry includes learning how to collect, process, analyze, and integrate data from myriad sources, and geoscience education is uniquely suited in making science relevant by drawing connections between the dynamic Earth system and societal impacts. Continued collaborations resulting from such data sharing efforts will result in greater understanding of a range of geoscientific problems, which include advances in climate change and hydrologic sciences, and weather and El Nino predictions. Moreover, they will provide a richer analysis of the evolving state of the planet. An overview of Unidata's international data sharing activities that are resulting in an organic expansion of the Unidata community and increased partnership for sharing knowledge and experience will be presented.