Radiocarbon record of solar variability and Holocene climatic change in coastal southern California

EXTRACT (SEE PDF FOR FULL ABSTRACT): Pollen analysis and 5 radiocarbon dates for a 687-cm core provide a detailed chronology of environmental change for San Joaquin Marsh at the head of Newport Bay, Orange County, California. Sediment deposition kept pace with sea level rise during the mid-Holocene, but after 4500 years BP, sea water regularly reached the coring site, and salt marsh was the local vegetation. Brief periods of dominance by fresh-water vegetation 3800, 2800, 2300 and after 560 years BP correlate global cooling events and (except the 3800-year BP event) with carbon-14 production anomalies. The coincidence of climate change and carbon-14 anomalies support a causal connection with solar variability, but regardless of the causal mechanism(s) the delta-carbon-14 curves provide a chronology for global, high-frequency climatic change comparable to that of Milankovitch cyclicity for longer time scales.

Historical evidence of abrupt coastal climatic change in Southern California, 1790-1880

Historical sources of the late-18th and 19th centuries were searched for information on coastal weather conditions in Southern California. Relatively calm winters until 1828 were followed by unusually stormy winters from about 1829 to 1839. Later periods were again predominantly calm, with notable exceptions related to the ENSO events of 1845 and 1878. Following decreases through the stormy 1830s, sizes of kelp forests appear to have rebounded in the 1840s. ENSO occurrences and eruption of the volcano Cosiguina in 1835 are likely causes for changing wind patterns. Our results link the unique AD 1840 Macoma leptonoidea pelecypod shell layer in laminated Santa Barbara Basin sediment ("Macoma event") to abruptly changing oceanographic and weather patterns.

Evidence from the Pacific Northwest for solar modulation of climate and of northern ecosystems

EXTRACT (SEE PDF FOR FULL ABSTRACT): The 250-year net annual snow accumulation, or mass balance, time series derived from the Mt. Logan (Yukon) ice core has been spectrally analyzed and is found to contain a nominal 11-year waveform. The stable isotope time series contains a significant amount of power between 9 and 13 years, although this record is evidently not a straightforward proxy for air temperatures. The signal in the mass balance time series exhibits a close relationship with the sunspot cycle waveform and is, therefore, assumed to be related to it. Waveforms showing a high correlation with the solar cycle are found in other climate data in the region. ... Taken collectively, the data point to a link between solar variability, atmospheric variability, climate, and selected ecological dynamics in the Pacific Northwest, but other data, not presented, indicate these relationships may hold elsewhere. So far, the evidence is empirical; complete details of the physical mechanisms involved have yet to be synthesized in a satisfactory way.

Near and distant connection of atmospheric systems to ocean temperature change in the coastal California Current region

In studying hydrosphere, atmosphere, and biosphere interactions, it is useful to focus on specific subsystem processes and energy exchanges (forcing). Since subsystem scales range over ten orders of magnitude, it may be difficult to focus research on scales that will yield useful results in terms of establishing causal and predictive connections between more easily and less easily observed subsystems. In an effort to find pertinent scales, we have begun empirical investigations into relationships between atmospheric, oceanic, and biological systems having spatial scales exceeding 10^3 kilometers and temporal scales of six months or more.

Long-term and seasonal patterns in coastal temperature and salinity along the North American west coast

Numerous integrated time series have been assembled that suggest global temperature has been increasing steadily over the last century. ... However, superimposed on the long-term warming trends of these series are decadal-scale fluctuations, periods of slightly increasing and even decreasing temperature followed by rapid increases in temperature. ... In this pilot study, data for 1931-1990 from eight [western North America] coastal stations are examined to test the utility of a state-space statistical model (developed by Dr. Roy Mendelssohn, PFEG) in separating and describing seasonal patterns and long-term trends.

Modeling North Pacific temperature and pressure changes from coastal tree-ring chronologies

Climate modeling using coastal tree-ring chronologies has yielded the first summer temperature reconstructions for coastal stations along the Gulf of Alaska and the Pacific Northwest. These land temperature reconstructions are strongly correlated with nearby sea surface temperatures, indicating large-scale ocean-atmospheric influences. Significant progress has also been made in modeling winter land temperatures and sea surface temperatures from coastal and shipboard stations. In addition to temperature, the pressure variability center over the central North Pacific Ocean (PAC), which is related to the strength and location of the Aleutian Low pressure system, could be extended using coastal tree rings.

Effects of interdecadal climate variability on the oceanic ecosystems of the northeast Pacific Ocean [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): It is increasingly apparent that a major reorganization of the Northeast Pacific biota transpired following a climatic "regime shift" in the mid-1970s. In this paper, we characterize the effects of interdecadal climate forcing on the oceanic ecosystems of the northeastern Pacific Ocean.

Interannual variability in the PFEG coastal upwelling indices

Numerous studies examine decadal-scale variability in basin-scale parameters in the Northern Pacific. Characterizing such interannual-to-interdecadal variability is essential to identifying long-term climate changes. The Pacific Fisheries Environmental Group (PFEG) coastal upwelling indices display variability on these time scales and may help explain the mechanisms responsible for such climate variability. ... In this study, examination of 49-year time series of monthly mean upwelling indices at the 15 PFEG-standard positions along the west coast of North America revealed variability on large spatial scales as well as temporal scales.

Decadal hydroclimatic variability in the western coastal United States: temporal and spatial variations in precipitation, streamflow, and lake level

EXTRACT (SEE PDF FOR FULL ABSTRACT): We have analyzed streamflow variations recorded at 15 USGS gauging stations in California during the past 90 years or so. The anomalies (departures from the 1960-1990 mean discharge) of streamflow on annual-to-decadal time scales are strongly correlated with precipitation anomalies in each drainage basin. ... Although causes of the decadal climate (precipitation) variability are not known with certainty, the use of streamflow records may help us understand the relative strengths of moisture sources and shift of the jet stream in atmospheric circulation.

Long-term response of Torrey pine to coastal climate: precipitation, temperature, and fog

EXTRACT (SEE PDF FOR FULL ABSTRACT): Torrey pine (Pinus torreyana Parry ex Carr.) has one of the most limited geographical ranges and population size in the Pinus genus; it is present only on Santa Rosa Island and on the coast between San Diego and Del Mar, where our research was conducted. A 168-year chronology (1827-1994) was developed using 28 increment cores extracted from 15 living and 2 dead stranding trees at Torrey Pines State Reserve, San Diego, California. ... The spatial correlation with western North America winter and spring precipitation, as well as with published tree-ring chronologies, indicates a connection with the American Southwest. Global correlation maps with winter sea level pressure and sea surface temperature are consistent with the hypothesis that San Diego precipitation is affected by a southerly displaced North Pacific storm track and by warmer water farther south, both leading to higher transport of lower latitude moisture.

Studies on the occurrence of coliforms and streptococci in coastal waters of Bombay

The distribution of coliforms and streptococci in Bombay coastal waters was investigated in order to determine the state of pollution in the area. Findings show the incidence of pollution to be of a recurring nature, primarily due to discharge of raw or improperly treated sewage; thus regular monitoring of the incidence of coliforms and streptococci is of importance in determining the public health safety of the beaches and coastal waters.

Nutrient Enhanced Coastal Ocean Productivity (NECOP). Data report: CTD and hydrographic data, R/V Pelican cruise, April 3-11, 1993

The Nutrient Enhanced Coastal Ocean Productivity (NECOP) Program is a component of NOAA's Coastal Ocean Program. The central hypothesis of this research is: Anthropogenic nutrient inputs have enhanced coastal ocean productivity with subsequent impacts on coastal ocean water quality, living resource yields, and the global marine carbon cycle. The initial study area for this program is the Mississippi/Atchafalaya River Outflow and adjacent Louisiana shelf region.