Brian Goodman

Volcanic Activity and Climatic Changes

Radiocarbon dates of volcanic activity suggest variations that appear to be related to climatic changes. Historical eruption records also show variations on the scale of years to centuries. These records can be combined with simple climatic models to estimate the impact of various volcanic activity levels. From this analysis it appears that climatic prediction in the range of 2 years to many decades requires broad-scale volcanic activity prediction. Statistical analysis of the volcanic record suggests that some predictability is possible.

Effects of estrogen replacement therapy on the circadian rhythms of serum cortisol and body temperature in postmenopausal women

Estrogen replacement therapy (ERT) seems to enhance longevity in women. Both gender and aging have been shown to influence the regulation of circadian rhythms, yet little is known about the effect of ERT on circadian regulation. The aim of this study was to determine the effects of ERT (oral conjugated estrogen: Premarin, 0.625 mg) for 6-8 weeks on circadian serum cortisol by continuous blood sampling every 15 min for 24 h with simultaneous measurements of body temperature in six healthy postmenopausal women (range, 54-61 years). The results are presented as median values (range in quartiles). The circadian amplitude of cortisol increased during ERT from 20.20 (18.35, 23.61) to 25.97 (24.94, 27.74) microg/dL (p = 0.016), whereas the timing of nocturnal nadir and morning acrophase did not differ significantly. ERT lowered the 24-h body temperature from 37.03 degrees C (36.95 degrees C, 37.07 degrees C) to 36.90 degrees C (36.77 degrees C, 36.97 degrees C) (p = 0.038), but did not alter the peak and trough body temperatures significantly. These findings are noteworthy because the increased circadian amplitude of serum cortisol during ERT contrasts with the reduction in circadian amplitude seen with normal aging. The reduction in body temperature confirms the regulatory effect of ERT in thermoregulation and has implications regarding the correlation between basal metabolic rate and life span.

Milankovitch and global ice volume simulation

SummaryThe wastage and accumulation rates of the global ice sheets are taken to be climatic parameters, responding to astronomical forcing, and the global ice volume to be the integral of the difference of these two rates. The particular form of the climatic response function is that it is proportional to the seasonality of irradiance totals. Taking the Fourier series of the ten major periodicities longer than ten millenia in the Berger formulation of the Milankovitch concept as the forcing function, analytical integration yields a time series that correlates about 0.51 with the ice volume reconstruction from oxygen isotopes for the past half million years, and matches the maxima and minima optimally. The integration process resolves part of the previous difficulty of ice volume spectra with too much power in the lowest frequencies.ZusammenfassungDie Verlust- und Aufspeicherraten der globalen Eisdecke werden als klimatische Parameter angenommen, welche auf astronomische Einwirkung reagieren und das globale Eisvolumen als das Integral der Differenz dieser beiden Raten. Die spezielle Form der klimatischen Wirkfunktion ist so, daß sie proportional zur jahreszeitlich bedingten gesamten Strahlung ist. Nimmt man die Fourierreihe der zehn wichtigsten Perioden mit länger als zehn Jahrtausenden in der Bergerformulierung des Milankovitchkonzeptes als die bestimmende Funktion an, so ergibt die analytische Integration eine Zeitreihe, welche mit etwa 0,51 mit der Rekonstruktion des Eisvolumens aus den Sauerstoffisotopen der vergangenen halben Million Jahre korreliert und die Maxima und Minima optimal trifft. Das Integrationsverfahren löst Teile der frühen Schwierigkeit bei Eisvolumenspektren, die zu großes Gewicht auf die niedrigsten Frequenzen legten.

Characterizing motivational styles of professionals who work on interdisciplinary healthcare teams

Relationship Awareness Theory is based on the premise that there is a purpose or motive behind all behavior. The Strength Deployment Inventory (SDI) was designed to help individuals identify their motives in relating to others under two kinds of conditions; when everything is going well in their relationships and when they are in conflict with others. The authors administered the SDI over a ten year period to 516 health professionals and advanced level trainees who worked or trained on interdisciplinary healthcare teams. Individual motivation styles were analyzed by discipline, and formal leadership role. One teams pattern was analyzed over time. The predominant motivational style of respondents was altruistic/nurturing under normal conditions and analytic/ autonomizing under conflict conditions. Nurses and social workers were most similar under normal conditions and nurses and physicians were most similar under conflict conditions. There were differences for both conditions between formal leaders and th...

Model simulations of ACTH pulsatility.

Using high intensity venous sampling (1-2 min integrated intervals) we have observed rapid (< 10 min) large amplitude (up to 80 pg/ml) fluctuations in plasma ACTH concentrations in addition to variations at longer time scales. We developed a mathematical model to assess whether plausible physiological explanations could account for our observations and compared model simulations with time series from two human subjects. Three key features enabled the model to accurately simulate the observed time series. 1) The pattern of instantaneous secretory events comprising a pulse followed a Poisson process during baseline activity and rapidly shifted to a step function pattern during a pulsatile episode. 2) The fraction of secreted ACTH shunted between a fast and slow clearance mechanism varied biphasically between baseline and pulsatile states. 3) A brief rate-sensitive suppression of secretion was invoked when secretory rates increased above a threshold amount.

4-D techniques for evaluation of atmospheric model forecasts

Evaluating model performance is difficult in light of the amount of data which is output that is to be compared to an analysis for verification. Examining 2-D plots of many different parameters at several levels is tedious. This information must then be mentally integrated in an attempt to understand where problems may exist. The use of 4-D displays can greatly aid in evaluations by presenting the output of the model as a volume instead of 2-D slices. A capability for 4-D displays of meteorological data is being developed at the Space Science and Engineering Center. The Man-computer Interactive Data Access System (McIDAS) is used for all aspects of the analysis: this includes acquiring data, running the model, storing the output and displaying the results. A version of the Australian Regional Analysis and Forecast Modules were applied to the eastern portion of the USA and adjacent Atlantic Ocean. This assimilation system is being used to analyze intensive observing periods during the GALE (Genesis of Atlantic Lows Experiment) field experiment.

A satellite‐based estimate of evapotranspiration over Amazonia

Abstract If rainfall, storage and flux divergence are known, evapotranspiration can be estimated as the residual in a budget of atmospheric moisture. We describe a new approach to moisture‐budget estimates of Amazon evapotranspiration. Synoptic observations (and numerical model analyses from the U.S. National Meteorological Center) are combined with wind, humidity and rain information retrieved from radiances measured by the Geostationary Operational Environmental Satellite (GOES). Rainfall is inferred from the thermal infrared channel of the Visible and Infrared Spin Scan Radiometer (VISSR). Humidity is retrieved from the VISSR Atmospheric Sounder (VAS). Winds are inferred from both VISSR and VAS images, using visible, thermal infrared and water vapor bands. Satellite and station or model information is merged by means of a recursive filter. The GOES‐budget approach was tested over a three‐day period from May 1987. Our estimate of evapotranspiration over the basin, 9 mm/d, is unrealistically large. A sen...