Howard P. Hanson

Recent Great Lakes Ice Trends

Abstract Analysis of ice observations made by cooperative observers from shoreline stations reveals significant changes in the ice season on the North American Great Lakes over the past 35years. Although the dataset is highly inhomogeneous and year-to-year variability is also quite large, there is a statistically significant indication that the end of the ice season (as defined by the time at which ice departs from the observer stations in spring) has come increasingly early at a number of locations. The earlier ice departure is reflected in a somewhat earlier spring runoff through the St. Lawrence River over the same time period and correlates with increases in springtime temperatures at stations in the region. This example of a trend toward warmer, earlier springs in the upper Midwest is consistent with results from a number of other regional datasets. Because the ice observations began in the rnid-1950s, other analyses, including comparisons with modern satellite datasets, could provide a useful tool f...

The potential and promise of physics-based wildfire simulation

Abstract Wildfire — that is the unmanaged, uncontrolled burning of forests, brushlands, or grasslands with or without the presence of structures — is an increasing threat to society. We briefly review the extent of this threat, particularly its relationship to changes in the systems it threatens, and discuss its management. Recent developments in computer models of wildfire are reviewed and their application to several aspects of the wildfire threat are proposed in the context of a national resource. The requirements of an operational wildfire prediction center are discussed as a method to leverage existing and near-term capabilities into new tools to help mitigate the potential threat of this natural process.

Syndication of the earth system: the future of geoscience?

Abstract Current global change policy debate reverberates around the polarized extremes of civilization-level cooperation through treaties as a mitigation tactic, on the one hand, and a wait-and-see approach that may lead to a climatic tragedy of the commons, on the other. Meanwhile, energy technology research is rapidly generating a perception that it will be possible to tune the earth system via carbon sequestration and other types of biogeochemical engineering. The consequences of this potential for planetary management, based on provincial self-interest, include the transition of the earth sciences into a security industry involving proprietary scientific knowledge bases of biogeochemical cycling and the evolution of a climate-design brokerage dominated by military/industrial interests. As the dominant political powers perceive the potential for planetary engineering and consider implementation, the global economy will adjust to exploit new opportunities, perceptions of which will be determined by the quality of system simulations. The growth of a viable international climate-design community will profoundly influence the trajectory of the earth system by providing either the illusion or the reality of predictability. Although this process will be chaotic at first, the probability of stabilization will ultimately be enhanced because the vast resources of the military/industrial sector will become involved. These concepts are disturbingly familiar in that they acknowledge the pervasion of competition and conflict in human technological affairs. However, they are consistent with approaches used in thermodynamics, ecological energetics, behavioral evolution, economics, and interdisciplinary climate science to describe collectively the evolution of the earth system. This paper argues that the perception that the climate can be regulated inexpensively will create an economic driving force for international cartel-style management of the total earth system. That is, the earth system may well become syndicated by those with the resources to effect large-scale management.

Fueling Asian modernization

Abstract During upcoming industrialization, the human population of Asia will exert a strong influence on both the Pacific Rim environment and the total earth system. We review energy-use trajectories both likely and possible on the continent, taking the historical market penetration series as a framework. Today, the Peoples Republic of China is coal rich, but as its economy grows in the short term, fuel substitution from solid fossils will occur. Major automakers will exploit new niches in the Orient, adding petroleum to the mix of fuels and producing photochemical smog on the regional scale. Demand is rising in coastal cities for cleaner fuels such as natural gas, but they must be imported. Nuclear industries in India and China are small and expanding only slowly. The Tibetan plateau confers exceptional hydroelectric potential but peripheral concerns plague the big dams. Solar and hydrogen are decades from implementation even in Europe. Fossil resources are largely remote from the Asian consumer class. The disconnect feeds back into the design of new transportation networks. Since for the moment development lags, the option exists to view Asia as a crucible for the techniques of cogeneration, sequestration and pollutant recapture.

A Survey of Employment Opportunities in the Atmospheric Sciences, 1981–1991

Results from an analysis of 11 years of the AMS Employment Announcements newsletter are discussed. The strongest signals in the record of various job categories are the annual cycle in advertisements of tenure-track faculty positions and the interannual variations in the overall market, which are dominated by private-sector positions. On average, there are 23±9 new positions announced each month, with maxima in March and November and the minimum in July. The overall market grew throughout the mid-1980s, but has declined in recent years.

Subsurface mooring stability in the presence of vertical shear

Observations in the Florida Current reveal significant vertical shear that can occur on the scale of turbine rotors and that can reverse. Because ocean current turbines in the Florida Current will require anchored moorings, the dynamics of the moored systems in the presence of shear become a factor in design and operation. Here, a simple stability analysis shows that the case of negative shear (slow current near the surface) is dynamically unstable for moored turbine systems.

Radiative Destabilization in Clear-Sky Cooling Calculations

JANUARY 2002 AMERICAN METEOROLOGICAL SOCIETY | indzen et al. (2001, hereafter LCH) recently discussed observations of clouds and water vapor over the tropical oceans and concluded that the earth may exhibit an “adaptive infrared iris” effect, in which tropical cloudiness and uppertropospheric water vapor respond to changes of sea surface temperature in a manner to produce a negative feedback mechanism in the climate system. LCH also discussed preliminary results that suggest the current generation of global climate models does not exhibit the irislike behavior observed in the satellite datasets they examined, a deficiency that needs to be addressed. This comment provides one possible source of climate-model bias that could explain some of the differences noted by LCH. This bias is analogous to that which results from ignoring the differences between cloudy and clear-air column radiative transfer. It arises due to the steep water vapor gradients discussed by LCH. Because steep water vapor gradients are also observed in midlatitude synoptic systems (e.g., see just about any day’s image of the water vapor channel on the National Oceanic and Atmospheric Administration Geostationary Operational Environmental Satellite Web site, www.goes.noaa.gov) this is not a problem confined to calculations in the Tropics.