Problems in estimating the response functions of natural climatic recording systems [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): High-resolution proxy records of climate, such as varves, ice cores, and tree-rings, provide the opportunity for reconstructing climate on a year-by-year basis. In order to do so it is necessary to approximate the complex nonlinear response function of the natural recording system using linear statistical models. Three problems with this approach were discussed, and possible solutions were suggested. Examples were given from a reconstruction of Santa Barbara precipitation based on tree-ring records from Santa Barbara County.

High-resolution natural recording systems: intercomparisons of the response to interannual climatic variability [abstract]

The goal of this work is to examine the properties of recording mechanisms which are common to continuously recording high-resolution natural systems in which climatic signals are imprinted and preserved as proxy records. These systems produce seasonal structures as an indirect response to climatic variability over the annual cycle. We compare the proxy records from four different high-resolution systems: the Quelccaya ice cap of the Peruvian Andes; composite tree ring growth from southern California and the southwestern United States; and the marine varve sedimentation systems in the Santa Barbara basin (off California, United States) and in the Gulf of California, Mexico. An important focus of this work is to indicate how the interannual climatic signal is recorded in a variety of different natural systems with vastly different recording mechanisms and widely separated in space. These high-resolution records are the products of natural processes which should be comparable, to some degree, to human-engineered systems developed to transmit and record physical quantities. We therefore present a simple analogy of a data recording system as a heuristic model to provide some unifying concepts with which we may better understand the formation of the records. This analogy assumes special significance when we consider that natural proxy records are the principal means to extend our knowledge of climatic variability into the past, beyond the limits of instrumentally recorded data.

On the trail of interannual variability in phytoplankton and climate [abstract and figures]

EXTRACT (SEE PDF FOR FULL ABSTRACT): A selective but nontheless real record of phytoplankton activity over the Santa Barbara Basin can be obtained from the underlying varved sediments. The phytoplankton groups preserved are: diatoms (frustrules and spores), silicoflagellates, dinoflagellates (cysts) and coccoliths.

Stratigraphy and chronology of Holocene marine sedment core from the California continental borderland and their paleoceanographic/paleoclimatic significance [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Paleomagnetic secular variation (PSV) records have been recovered from three marine sediment cores from Santa Catalina basin, California continental borderland, in order to more accurately date these late Quaternary sediments. ... The sedimentation rates derived from the time/depth curves suggest a constant rate of 20-25 cm/ky for the last 6700 years throughout Santa Catalina basin, and more variable rates (but constant within each core) of 13-86 cm/ky prior to 6700 ybp. The sedimentation rates prior to 6700 ybp are lowest in the southcentral portion of the basin and systematically increase toward the north end of the basin. These results suggest that 6700±300 ybp marks a major change in paleoceanographic processes within Santa Catalina basin.