Monthly. mean atmospheric data taken over the North Pacific during the period 1950-70 are used to investigate blocking ridge activity over the central ocean. The blocking ridge is observed to be a finiteamplitude, quasi-stationary long wave, most often centered over the North Pacific at 170W, superimposed upon the quasi-zonal mid-latitude westerlies. The dominant length scale is 7000 km, the same dimensions as the width of the mid-latitude ocean. The growth time scale is 1-2 weeks, with the duration of blocking activity rarely exceeding 2 months in any given year. The blocking activity is confined almost exclusively to the autumn/winter months, where block development is closely coupled with the sensible heat transfer from the underlying ocean (anomalously small heat transfer under the ridge and anomalously large heat transfer under the associated troughs). Year-to-year variability in blocking ridge activity is found to have a dominant time scale of approximately 5 years from 1950-70 and to be inversely correlated (-0.79) with the strength of the autumn/winter mean mid-latitude westerlies (the mean formed using months not containing blocking activity). Further analysis shows that both blocking ridge activity and the strength of the westerly winds fluctuate together with the Southern Oscillation over this time period. These space/time scale considerations suggest that this regional blocking activity owes its existence to the marine environment. To test this idea, appeal is made to some theoretical work by Haltiner, where the baroclinic instability process was modified by sensible heat transfer from the ocean to the atmosphere. Haltiner found that for normal winter values of the background flow, the otherwise stable stationary long wave became unstable when sensible heat transfer was allowed. The wavelength for the unstable stationary wave was 7000-8000 km with a growth time scale of approximately 2 weeks. The scales are similar to that of blocking ridge activity over the North Pacific. In addition to good scale agreement with observations, Haltiner's theory is able to explain both the seasonal and year-to-year variability in blocking activity in terms of corresponding fluctuations in sensible heat transfer and the strength of the mean westerly winds.

This paper seeks to examine the extent to which technological advances can enhance inter-organizational information sharing in disaster relief. Our case is the Virtual OSOCC (On-Site Operations Coordination Centre) which is a part of the Global Disaster Alert and Coordination System (GDACS) under the United Nations Office for Coordination of Humanitarian Affairs (UN OCHA). The online platform, which has been developing for more than a decade, provides a unique insight into coordination behaviour among disaster management agencies and individual actors. We build our study on the analysis of a complete database of user interaction including more than 20,000 users and 11,000 comments spread across approximately 300 disaster events. Controlling for types and severities of the events, location-specific vulnerabilities, and the overall trends, we find that the introduction of new features have led to increases in user activity. We supplement the data-driven approach with evidence from semi-structured interviews with administrators and key users, as well as a survey among all users specifically designed to capture and assess the elements highlighted by both interviews and data analysis.

Space applications have evolved to play a significant role in disaster relief by providing services including remote sensing imagery for mitigation and disaster damage assessments; satellite communication to provide access to medical services; positioning, navigation, and timing services; and data sharing. Common issues identified in past disaster response and relief efforts include lack of communication, delayed ordering of actions (eg, evacuations), and low levels of preparedness by authorities during and after disasters. We briefly summarize the Space for Health (S4H) Team Project, which was prepared during the Space Studies Program 2014 within the International Space University. The S4H Project aimed to improve the way space assets and experiences are used in support of public health during disaster relief efforts. We recommend an integrated solution based on nano-satellites or a balloon communication system, mobile self-contained relief units, portable medical scanning devices, and micro-unmanned vehicles that could revolutionize disaster relief and disrupt different markets. The recommended new system of coordination and communication using space assets to support public health during disaster relief efforts is feasible. Nevertheless, further actions should be taken by governments and organizations in collaboration with the private sector to design, test, and implement this system.

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