Earth science research

The analysis of ground-truth data from the boreal forest plots in the Superior National Forest, Minnesota, was completed. Development of statistical methods was completed for dimension analysis (equations to estimate the biomass of trees from measurements of diameter and height). The dimension-analysis equations were applied to the data obtained from ground-truth plots, to estimate the biomass. Classification and analyses of remote sensing images of the Superior National Forest were done as a test of the technique to determine forest biomass and ecological state by remote sensing. Data was archived on diskette and tape and transferred to UCSB to be used in subsequent research

The Geographic Distribution of Bowhead Whales, Balaena mysticetus, in the Bering, Chukchi, and Beaufort Seas: Evidence from Whaleship Records, 1849–1914

We have extracted, digitized, and analyzed information about bowhead whales, Balaena mysticetus, contained in records of whaling cruises that were undertaken in the Bering, Chukchi, and Beaufort Seas from 1849 to 1914. Our database consists of 65,000 days of observations which provide insights into whether this bowhead stock may comprise more than one population

Ten year change in forest succession and composition measured by remote sensing

Vegetation dynamics and changes in ecological patterns were measured by remote sensing over a 10 year period (1973 to 1983) for 148,406 landscape elements, covering more than 500 sq km in a protected forested wilderness. Quantitative measurements were made possible by methods to detect ecologically meaningful landscape units; these allowed measurement of ecological transition frequencies and calculation of expected recurrence times. Measured ecological transition frequencies reveal boreal forest wilderness as spatially heterogeneous and highly dynamic, with one-sixth of the area in clearings and early successional stages, consistent with recent postulates about the spatial and temporal patterns of natural ecosystems. Differences between managed forest areas and a protected wilderness allow assessment of different management regimes

Sea-Ice Distribution in the Bering and Chukchi Seas: Information from Historical Whaleships’ Logbooks and Journals

Satellite data have revealed dramatic losses of Northern Hemisphere sea ice since the end of the 1970s. To place these changes in a longer-term context, we draw on daily observations taken from logbooks and journals of whaling vessels cruising in the Bering and Chukchi seas to investigate sea-ice conditions in this region of the Arctic between 1850 and 1910. We compare these observations to sea-ice data from 1972 to 1982, which predate the majority of the recent changes and cover a period recognized as a relative maximum in recent Bering Sea ice extent. Records from May indicate that end-of-winter sea-ice extent in the Bering Sea during the mid 19th century closely resembled that in the 1972 – 82 data. However, the historical data reveal that sea ice was more extensive during summer, with the greatest difference occurring in July. This pattern indicates a later and more rapid seasonal retreat. These conclusions highlight the value of historical data, which we have far from exhausted in this study.Des données satellitaires révèlent que l’hémisphère nord a enregistré des pertes dramatiques de glaces de mer depuis la fin des années 1970. Afin de mettre ces changements dans un plus long contexte, nous nous appuyons sur les observations quotidiennes tirées de journaux et de carnets de bord de baleiniers ayant parcouru la mer de Béring et la mer des Tchouktches dans le but d’étudier les glaces de mer de cette région de l’Arctique entre les années 1850 et 1910. Nous comparons ces observations aux données sur les glaces de mer recueillies de 1972 à 1982 – soit avant que la plupart des récents changements n’aient été enregistrés – ce qui couvre une période reconnue comme un maximum relatif en matière d’étendue récente des glaces dans la mer de Béring. Les données enregistrées en mai laissent entrevoir que l’étendue des glaces de mer en fin d’hiver dans la mer de Béring au milieu du XIXe siècle ressemblait beaucoup à l’étendue des glaces dont témoignent les données prélevées entre 1972 et 1982. Cependant, les données historiques révèlent que les glaces de mer étaient plus considérables au cours de l’été, la plus grande différence se manifestant au mois de juillet. Cette tendance indique donc un retrait saisonnier plus tardif et plus rapide. Les conclusions mettent en évidence l’importance des données historiques, que nous sommes loin d’avoir épuisées dans le cadre de cette étude

Changing The Global Environment : Perspective on Human Involvement

xix,459 hal,;ill,;23 c

Global Warming: What It Is What Is Controversial About It and What We Might Do in Response to It

[No abstract

Global Warming: What It Is What Is Controversial About It and What We Might Do in Response to It

[No abstract