A cold phase of the East Pacific triggers new phytoplankton blooms in San Francisco Bay. Cloern, James E.; Jassby, Alan D.; Thompson, Janet K. & Hieb, Kathryn A..
http://dx.doi.org/10.1073/pnas.0706151104 DOI: 10.1073/pnas.0706151104
Ecological observations sustained over decades often reveal abrupt changes in biological communities that signal altered ecosystem states. We report a large shift in the biological communities of San Francisco Bay, first detected as increasing phytoplankton biomass and occurrences of new seasonal blooms that began in 1999. This phytoplankton increase is paradoxical because it occurred in an era of decreasing wastewater nutrient inputs and reduced nitrogen and phosphorus concentrations, contrary to the guiding paradigm that algal biomass in estuaries increases in proportion to nutrient inputs from their watersheds. Coincidental changes included sharp declines in the abundance of bivalve mollusks, the key phytoplankton consumers in this estuary, and record high abundances of several bivalve predators: Bay shrimp, English sole, and Dungeness crab. The phytoplankton increase is consistent with a trophic cascade resulting from heightened predation on bivalves and suppression of their filtration control on phytoplankton growth. These community changes in San Francisco Bay across three trophic levels followed a state change in the California Current System characterized by increased upwelling intensity, amplified primary production, and strengthened southerly flows. These diagnostic features of the East Pacific "cold phase" lead to strong recruitment and immigration of juvenile flatfish and crustaceans into estuaries where they feed and develop. This study, built from three decades of observation, reveals a previously unrecognized mechanism of ocean-estuary connectivity. Interdecadal oceanic regime changes can propagate into estuaries, altering their community structure and efficiency of transforming land-derived nutrients into algal biomass.
Analysis of rainwater samples: comparison of single particle residues with ambient particle chemistry from the northeast Pacific and Indian oceans. Holecek, J.C.; Spencer, M.T. & Prather, K.A..
Journal of Geophysical Research:
http://dx.doi.org/10.1029/2006JD008269 DOI: 10.1029/2006JD008269
Individual particles produced from atomized rainwater samples collected in California and the Indian Ocean were analyzed with an aerosol time-of-flight mass spectrometer (ATOFMS) to investigate the chemical composition of the individual rain residue particles. Insoluble residue particle types were determined on the basis of a comparison of the rainwater particle mass spectra with ambient particle spectra. Major particle types found in rainwater include dust, organic carbon with sodium, aromatic organic carbon, vegetative detritus, and an internally mixed sea salt and elemental carbon class. A unique internally mixed sea salt-elemental carbon particle type was detected in both the ambient and rainwater samples, suggesting this particle type was most likely formed by cloud processing occurring during long-range transport. The presence of this particle type in remote marine locations has important climate ramifications as it is anticipated it will be strongly absorbing on the basis of the combination of an absor ng particle (elemental carbon) mixed with a high refractive index material (sea salt). Most of the particle types detected in rainwater were detected in the ambient particles with the exception of a unique aromatic particle type detected in rainwater samples from both locations. The presence of the aromatic type coupled with the absence of biomass particles in the rainwater samples leads to the hypothesis the aromatic components were originally associated with atmospheric biomass burning particles. The ubiquitous presence of this aromatic type in rainwater samples highlights the potential importance of biomass burning and/or humic-like substances (HULIS) compounds in cloud formation and rain processes.
As part of the West Coast Regional Carbon Sequestration Partnership (WESTCARB), the California Geological Survey (CGS) conducted an assessment of geologic carbon sequestration potential in California. An inventory of sedimentary basins was screened for preliminary suitability for carbon sequestration. Criteria included porous and permeable strata, seals, and depth sufficient for critical state carbon dioxide (CO2) injection. Of 104 basins inventoried, 27 met the criteria for further assessment. Petrophysical and fluid data from oil and gas reservoirs was used to characterize both saline aquifers and hydrocarbon reservoirs. Where available, well log or geophysical information was used to prepare basin-wide maps showing depth-to-basement and gross sand distribution. California's Cenozoic marine basins were determined to possess the most potential for geologic sequestration. These basins contain thick sedimentary sections, multiple saline aquifers and oil and gas reservoirs, widespread shale seals, and significant petrophysical data from oil and gas operations. Potential sequestration areas include the San Joaquin, Sacramento, Ventura, Los Angeles, and Eel River basins, followed by the smaller Salinas, La Honda, Cuyama, Livermore, Orinda, and Sonoma marine basins. California's terrestrial basins are generally too shallow for carbon sequestration. However, the Salton Trough and several smaller basins may offer opportunities for localized carbon sequestration._x000B__x000B_
A precipitation-dominated, mid-latitude glacier system: Mount Shasta, California. Howat, Ian; Tulaczyk, Slawek; Rhodes, Philip; Israel, Kevin & Snyder, Mark.
http://dx.doi.org/10.1007/s00382-006-0178-9 DOI: 10.1007/s00382-006-0178-9
Temperature is often seen as the dominant control on inter-decadal glacier volume changes. However, despite regional warming over the past half-century, the glaciers of Mount Shasta have continued to expand following a contraction during a prolonged drought in the early twentieth century, indicating a greater sensitivity to precipitation than temperature. We use the 110 year record of fluctuations in Mount Shasta's glaciers and climate to calibrate numerical glacier models of the two largest glaciers. The reconstructed balance and volume histories show a much greater correlation to precipitation than temperature and significant correlation to oscillatory modes of Pacific Ocean climate. An approximately 20% increase in precipitation is needed for every 1C increase in temperature to maintain stability. Under continued historical trends, oscillations in climate modes and random variability will dominate inter-decadal variability in ice volume. Under the strong warming trend predicted by a regional climate model, the temperature trend will be the dominant forcing resulting in near total loss of Mount Shasta's glaciers by the end of the twenty-first century.
A pilot study was implemented to quantify impacts of rangeland management and reforestation of rangelands on net trace gas emissions and soil carbon sequestration as part of a study to assess potential carbon supply curves for afforestation of rangelands in Shasta County, California. This study utilizes spatially explicit GIS data on soils, climate, potential forest type, and current rangeland types and forest/rangeland management combined with two soil biogeochemical process models: Denitrification-Decomposition (DNDC) and Forest-DNDC. The study objectives were to (1) assess the impact of reforestation of rangelands in Shasta County on net trace gas emissions and soil carbon sequestration and (2) assess the impact of implementing more intensive grazing of range grasslands on soil carbon and trace gas emissions. Results from the analysis include: (1) predicted baseline carbon dynamics and greenhouse gas (GHG) emissions for existing rangelands in Shasta County, (2) the estimated impact of alternative rangeland management strategies (various grazing intensities) on soil carbon stocks and trace gas emissions, and (3) predicted impact of reforestation on soil carbon dynamics and GHG emissions across Shasta County. A complete GHG balance is compiled for Shasta County for the 50 years following afforestation and compared with baseline model results to map changes in net GHG balance. The study's results indicate that, in general, full accounting adjusted carbon sequestration potential in the county by less than 10 percent. The impact of soil carbon losses and trace gas emissions on the net GHG balance are modeled as percent offset of emissions, relative to carbon sequestered in woody biomass and forest floor, and vary spatially across forest types driven by difference in forest productivity and soil conditions. Impacts of fertilizer application and climate change on afforestation dynamics and effects of afforestation in local hydrology are also examined._x000B__x000B_
This study presents results from a long-term forecast of electricity consumption in California's residential sector to the year 2050. The model developed for this study's projections builds upon the California Energy Commission's (Energy Commission's) forecast results and historic input data for the period 1970 to 2015. These data are expanded upon using other sources, including long-term demographic forecasts, short-term bottom up energy-efficiency potential studies, econometric forecasts, and interviews with technologists on long-term emerging technology prospects. The focus of this work is on the interaction among key drivers of future electricity use, which includes population, energy efficiency, and end-use service demands. This study uses scenario analysis to address the major uncertainties associated with its long-term forecasting horizon. This study's results show that although energy efficiency improvements may continue to provide significant reductions in electricity consumption through 2050, aggregate consumption also is likely to continue increasing, due to increasing population and energy service demands. Only under one extremely aggressive and optimistic scenario is residential electricity consumption reduced by 2050 to today's level; however, this scenario requires reducing per capita consumption by almost 40 percent, which would be an unprecedented accomplishment, given historic efficiency achievements, consumer's current adoption preferences, and continually increasing demands for energy services. Continuation of existing efficiency programs and standards, along with new, more much more aggressive policies, and a major change in consumer preferences would likely be necessary to achieve such reductions.
The project described in Baseline Greenhouse Gas Emissions and Removals for Forest and Agricultural Lands in Arizona sought to quantify the baseline of changes in carbon stocks on forest and agricultural lands in Arizona for the 1990s. These baselines provide an estimate of the emissions and removals of greenhouse gases attributable to changes in the use and management of land and are useful for identifying where major opportunities could exist in Arizona for enhancing carbon stocks and/or reducing carbon sources to potentially reduce greenhouse gas emissions._x000B__x000B_The analysis revealed that forests were responsible for a net removal of carbon dioxide from the atmosphere of 0.9 million metric tons of carbon dioxide per year (MMTCO2/yr) between 1987 and 1997, and that agricultural lands were responsible for a net emission of 0.04 MMTCO2/yr. On non-federal lands emissions from forests caused by development were estimated at 0.0145-0.0152 MMTCO2/yr, and between 1990 and 1996 154,000 acres of forest and rangeland were burned by fires with an estimated emission of 0.47 MMTCO2eq/yr. Nitrous oxide (N2O) and methane (CH4) emissions (in CO2 eq) from agricultural lands are more than 100 times higher than carbon emission due to land-use change._x000B__x000B_
The project described in Baseline Greenhouse Gas Emissions and Removals for Forest and Agricultural Lands in Oregon sought to quantify the baseline of changes in carbon stocks on forest and agricultural lands in Oregon for the 1990s. These baselines provide an estimate of the emissions and removals of greenhouse gases attributable to changes in the use and management of land and are useful for identifying where major opportunities could exist in Oregon for enhancing carbon stocks and/or reducing carbon sources to potentially reduce greenhouse gas emissions._x000B__x000B_The analysis revealed that forests were responsible for a net removal of carbon dioxide from the atmosphere of 27 million metric tons of carbon dioxide per year between 1987 and 2003, and that agricultural lands were responsible for a net emission of 0.06 million metric tons of carbon dioxide per year. On non-federal lands, emissions from forests caused by development were estimated at 1.4-1.5 million metric tons of carbon dioxide per year, and between 1990 and 1996 (excluding 1994) 0.81 million acres of forest and rangeland were burned by fires, with an estimated emission of 1.03 million metric tons of carbon dioxide per year. Nitrous oxide and methane emissions (in carbon dioxide equivalents) from agricultural lands are more than 100 times higher than carbon emissions attributable to land use change._x000B__x000B_
The project described in Baseline Greenhouse Gas Emissions and Removals for Forest and Agricultural Lands in Washington sought to quantify the baseline of changes in carbon stocks on forest and agricultural lands in Washington for the 1990s. These baselines provide an estimate of the emissions and removals of greenhouse gases attributable to changes in the use and management of land and are useful for identifying where major opportunities could exist in Washington for enhancing carbon stocks and/or reducing carbon sources to potentially reduce greenhouse gas emissions._x000B__x000B_The analysis revealed that forests were responsible for a net emission of carbon dioxide from the atmosphere of 12 million metric tons of carbon dioxide per year (MMTCO2/yr) and that agricultural lands were responsible for a net emission of 0.05 MMTCO2/yr. On non-federal lands, emissions from forests caused by development were estimated at 6.5-7 MMTCO2/yr, and between 1990 and 1996 (excluding 1994) 0.18 million acres of forest and rangeland were burned by fires with an estimated emission of 0.18 MMTCO2 equivalents/yr. It should be noted that the study included periods of unusually low fire incidence in Washington state. Nitrous oxide (N2O) and methane (CH4) emissions (in CO2 equivalents) from agricultural lands are more than 70 times higher than carbon emission due to land use change._x000B__x000B__x000B__x000B_