The Pacific sardine, Sardinops sagax, is a highly migratory coastal pelagic species that occurs from the tip of Baja California to the Gulf of Alaska and in the Gulf of California. We used fishery-independent egg surveys to characterize the relative amounts of sardine spawning habitat in the exclusive economic zones (EEZ5) of Mexico and the US during spring 2000-13. Most eggs were captured in the US EEZ from San Francisco to the Mexico-US border in all years sampled. A small fraction ranging from 0% to 10% of all eggs captured occurred in the Mexican EEZ, usually from Punta Eugenia north to the border. The abundance and distribution of eggs found in warmer waters between 15 degrees C to 18 degrees C off northern Baja California appear to be dependent on periods of more intense flow of the California Current, when sardine belonging to the northern subpopulation found in central and southern California extends southward into the nearshore area off Baja California. However, a small fraction of the southern subpopulation may also have spawned in coastal areas of the US-Mexican border during May in some years.

Climate and ocean ecosystem variability has been well recognized during the twentieth century but it is unclear if modern ocean biogeochemistry is susceptible to the large, abrupt shifts that characterized the Late Quaternary. Time series from marine sediments off Peru show an abrupt centennial-scale biogeochemical regime shift in the early nineteenth century, of much greater magnitude and duration than present day multi-decadal variability. A rapid expansion of the subsurface nutrient-rich, oxygen-depleted waters resulted in the present-day higher biological productivity, including pelagic fish. The shift was likely driven by a northward migration of the Intertropical Convergence Zone and the South Pacific Subtropical High to their present day locations, coupled with a strengthening of Walker circulation, towards the end of the Little Ice Age. These findings reveal the potential for large reorganizations in tropical Pacific climate with immediate effects on ocean biogeochemical cycling and ecosystem structure.

Sedimentological studies including X-ray digital analyses, mineralogy, inorganic contents, and organic geochemistry on cores of laminated sediments accumulated in the oxygen minimum zone of the central Peruvian margin reveal variable oceanographic and climate conditions during the last 500 yr. Coherent upcore variations in sedimentological and geochemical markers in box cores taken off Pisco (B0405-6) and Callao (B0405-13) indicate that variability in the climate proxies examined has regional significance. Most noteworthy is a large shift in proxies at ∼1820 AD, as determined by 210Pb and 14C radiometric dating. This shift is characterized by an increase in total organic carbon (TOC) in parallel with an abrupt increase in the enrichment factor for molybdenum Mo indicating a regional intensification of redox conditions, at least at the sediment water interface. In addition there was lower terrestrial input of quartz, feldspar and clays to the margin. Based on these results, we interpret that during several centuries prior to 1820, which corresponds to the little ice age (LIA), the northern Humboldt current region was less productive and experienced higher terrestrial input related to more humid conditions on the continent. These conditions were probably caused by a southward displacement of the inter-tropical convergence zone and the subtropical high pressure cell during the LIA. Since 1870, increases in TOC and terrigenous mineral fluxes suggest an increase of wind-driven upwelling and higher productivity. These conditions continued to intensify during the late 20th century, as shown by instrumental records of wind forcing.

High-resolution paleo-environmental and paleo-ecological archives in laminated sequences are present in selected areas from the upper continental Peruvian margin within the oxygen minimum zone. We present initial results of a multidisciplinary study (the PALEOPECES project) that aims to reconstruct environmental and ecosystem variability during the past 200 years from high-resolution records. We report chronology development, sediment structure, elemental, organic, and mineralogical compositions of a box core collected at 300 m depth off Pisco, central Peru. An average sedimentation rate of 2.2 mm y-1 was estimated from downcore excess 210Pb activities for the last 100-150 years. Extending this rate further downcore indicates that a slump located at 52 cm depth from the top of the core can be correlated with a large tsunami that struck the coast of central Peru in 1746. X-ray analyses reveal laminated structures composed of couplets of light and dark laminae. Observations under polarized microscope show that light laminae are dominated by more dense, detrital and terrigenous material, while dark laminae are less dense with greater concentrations of amorphous biogenic silica. Downcore variations in dry bulk density and X-ray radioscopy of gray level show similar patterns, including a major shift at 34 cm depth (ca. mid-nineteenth century). A finely laminated sequence, which may include annual varves, is present between 34 cm depth and the slump layer. Sediment characteristics of the sequence suggest increased seasonality of terrigenous versus biogenous sedimentation during the corresponding period. In addition to a mid-nineteenth century change and considerable multidecadal variability in TOC, there is a positive trend in the past 50 years. Mineralogical analyses from a Fourier Transformed Infrared Spectroscopy (FTIR) of the upper core covering the last 25 years, indicate higher concentrations of the mineral fraction (quartz, feldspar, kaolinite and illite) in layers including large El Niño events (1982-1983, 1986-1987 and 1997-1998), with the largest peak during the 1997-1998 episode. These results confirm that anoxic sediments off Pisco are suitable archives to investigate interannual and decadal changes in oceanographic conditions and climate of the northern Humboldt upwelling system.

Fixed-beam smart antennas are a simple but effective method to boost the downlink capacity of UMTS FDD. In this paper we compare the two possible strategies. Using a four element uniform linear antenna array, we find the optimum number of fixed beams per 120/spl deg/ sector dependent on the direction of departure (DoD) spread at the base station. For the first method we find the optimum number of beams to be four for low DoD spreads and two or three for large DoD spreads. For the second method the optimum number of beams per sector is seven for small DoD spreads and goes down to four or five beams per sector for large DoD spreads depending on base station spacing. By extensive system level simulations, we show, for 1 km inter base station distance, a capacity gain of more than 160% over a conventional 3-sectored reference system by both fixed beam methods.

Fish population variability and fisheries activities are closely linked to weather and climate dynamics. While weather at sea directly affects fishing, environmental variability determines the distribution, migration, and abundance of fish. Fishery science grew up during the last century by integrating knowledge from oceanography, fish biology, marine ecology, and fish population dynamics, largely focused on the great Northern Hemisphere fisheries. During this period, understanding and explaining interannual fish recruitment variability became a major focus for fisheries oceanographers. Yet, the close link between climate and fisheries is best illustrated by the effect of "unexpected" events-that is, nonseasonal, and sometimes catastrophic-on fish exploitation, such as those associated with the El Nino-Southern Oscillation (ENSO). The observation that fish populations fluctuate at decadal time scales and show patterns of synchrony while being geographically separated drew attention to oceanographic processes driven by low-frequency signals, as reflected by indices tracking large-scale climate patterns such as the Pacific decadal oscillation (PDO) and the North Atlantic Oscillation (NAO). This low-frequency variability was first observed in catch fluctuations of small pelagic fish (anchovies and sardines), but similar effects soon emerged for larger fish such as salmon, various groundfish species, and some tuna species. Today, the availability of long time series of observations combined with major scientific advances in sampling and modeling the oceans' ecosystems allows fisheries science to investigate processes generating variability in abundance, distribution, and dynamics of fish species at daily. decadal, and even centennial scales. These studies are central to the research program of Global Ocean Ecosystems Dynamics (GLOBEC). This review presents examples of relationships between climate variability and fisheries at these different time scales for species covering various marine ecosystems ranging from equatorial to subarctic regions. Some of the known mechanisms linking climate variability and exploited fish populations are described, as well as some leading hypotheses, and their implications for their management and for the modeling of their dynamics. It is concluded with recommendations for collaborative work between climatologists, oceanographers, and fisheries scientists to resolve some of the outstanding problems in the development of sustainable fisheries.

In an office building equipped with a thermally activated building component system (TABS) detailed in situ measurements have been performed. The measurements presented in this paper have been concentrated on the concrete core conditioning (CCC) system, which is used for heating and cooling the building. Plastic pipes with circulating water have been placed in the concrete slab. One coil of the thermally activated concrete slab has been measured in detail using 80 measurement points. The measurements include temperature measurements at different heights of the concrete slabs as well as in the suspended floor and in both adjacent rooms. Furthermore the supply and return water temperature, the volume flow for the coil as well as the heat flow at the surface of the concrete slab have been measured. The measurements have been analyzed in the frequency-domain with help of a Fourier-transform. The temperature measurements and the volume flow have been utilized to validate a FEM-program working in the frequency-domain and a simplified RC star network placed in the time-domain simulation environment TRNSYS. The simplified RC-network has been previously validated with help of the FEM-program working in frequency-domain. For the validation of the FEM-program the measured time series have been transformed into Fourier-series and then used as input to the FEM-program performing the calculation in frequency-domain.

In this paper the switched beam method is compared with beam pointing. Using extensive system simulations it is shown that both methods achieve a capacity gain over a 3-sectored reference system of more than 170%. As the capacity achieved with the two systems is nearly the same but the complexity of beam pointing is significantly higher, I conclude that switched beams are the appropriate method for boosting the downlink capacity of UMTS FDD.

To estimate ocean primary production at large space and time scales, it is necessary to use models combined with ocean-color satellite data. Detailed estimates of primary production are typically done at only a few representative stations. To get survey-scale estimates of primary production, one must introduce routinely measured Chlorophyll-a (Chl-a) into models. For best precision, models should be based on accurate parameterizations developed from optical and photosynthesis data collected in the region of interest. To develop regional model parameterizations 14C-bicarbonate was used to estimate in situ primary production and photosynthetic parameters (α*,Pm*, and Ek) derived from photosynthesis–irradiance (P–E) experiments from IMECOCAL cruises to the southern California Current during July and October 1998. The P–E experiments were done for samples collected from the 50% surface light depth for which we also determined particle and phytoplankton absorption coefficients (ap, aφ, and aφ*). Physical data collected during both surveys indicated that the 1997–1998 El Niño was abating during the summer of 1998, with a subsequent transition to the typical California Current circulation and coastal upwelling conditions. Phytoplankton chl-a and in situ primary production were elevated at coastal stations for both surveys, with the highest values during summer. Phytoplankton specific absorption coefficients in the blue peak (aφ*(440)) ranged from 0.02 to 0.11 m2 (mg Chl-a)−1 with largest values in offshore surface waters. In general aφ* was lower at depth compared to the surface. P–E samples were collected at the 50% light level that was usually in the surface mixed layer. Using α* and spectral absorption, we estimated maximum photosynthetic quantum yields (φmax; mol C/mol quanta). φmax values were lowest in offshore surface waters, with a total range of 0.01–0.07. Mean values of φmax for July and October were 0.011 and 0.022, respectively. In July Pm* was approximately double and α* was about 1.4 times the values for October. Since the P–E samples were generally within the upper mixed layer, these tendencies in the photosynthetic parameters are attributed to deeper mixing of this layer during October when the mean mixed layer for the photosynthesis stations was 35 m compared to a mean of 10 m in July. Application of a semi-analytical model using mean values of P–E parameters determined at the 50% light depth provided good agreement with 14C in situ estimates at the discrete 50% light depth and for the water-column integrated primary production.

Physical processes, biotic processes and human activities all act to shape marine ecosystems. Future management of these valuable ecosystems requires an integrative approach that takes into account complicated organismal interactions, oceanographic processes that span large scales of time and space, and how anthropogenic effects interact with the natural environment. The temperate west coasts of North and South America represent a unique opportunity for comparison, as many of the same oceanographic processes, particularly upwelling, occur off both coasts. Additionally, a number of marine ecosystems in both areas have surprising parallels. Here we present an overview of the oceanographic processes that dominate the coastlines, and give examples of ecosystems and the effects that oceanography, human activities and their interaction have on the communitiesLos procesos físicos y biológicos y las actividades humanas determinan los ecosistemas marinos. El manejo futuro de estos valiosos ecosistemas requiere de una aproximación integrativa que considere las complejas interacciones entre individuos, los procesos oceanográficos que se desarrollan a gran escala espacial y temporal, y la interacción de los efectos antropogénicos con el medio ambiente. Las costas templadas del oeste de Norteamérica y Sudamérica representan una oportunidad única para efectuar comparaciones ya que muchos procesos oceanográficos, particularmente la surgencia costera, ocurren en ambas costas. Adicionalmente, numerosos ecosistemas marinos en ambas áreas presentan sorprendentes paralelos. La presente revisión ofrece una visión general de los procesos oceanográficos dominantes en ambas costas y ofrece ejemplos de ecosistemas y los efectos que la oceanografía, las actividades humanas y las interacciones entre individuos tienen sobre las comunidades marinas

In mobile communication systems using CDMA, common channels needed for proper network operation share the same resource as the dedicated channels for data transmission. However, the 3GPP standard does not specify the amount of transmit power for the common channels. So it is up to the network operator to assign appropriate transmit powers to the various common channels. We study the influence of the power assigned to the common channels on the achievable capacity in UMTS FDD systems that use beam switching. For a system with five beams per 120/spl deg/ sector, we show that a change of the common-channel power per beam by only 1 watt can boost capacity by about 70%.

We present a simple beam switching scheme to increase the downlink capacity of the UMTS FDD-mode. At the base station, this method only requires one additional transceiver chain, i.e. a separate one for each beam, a beamforming network and a uniform linear array. The mobiles need no changes at all. We analyze the performance of our method by means of system level simulations for different angular spreads. We found an increase in downlink capacity of more than 75% over a conventional 3-sectored system for small direction of departure spreads. Compared to a 6-sectored system our scheme gives a capacity gain of more than 25% for small direction of departure spreads.

This paper investigates the minimum network size for system simulations in UMTS FDD uplink that is required to yield reliable results of system performance, e.g. system capacity for multiservice operation. The yardstick for answering this question are the probability distributions of the interference at the base station as well as in the individual cells. These are found by studying various network configurations with a Monte Carlo simulation approach that keeps simulation time low. Published link-level results of required E-b/(N-o+I-o) serve as input to the simulator that handles multi-service scenarios with both speech and data users with different data rates of up to 384kbit/s. Soft Handover (SHO), transmit power control (TPC), variable antenna pattern at the BS and variable user distributions are included. A 19-site network turns out to be necessary and sufficient for single-site investigations. A 7-site network, though taking only 1/8 of simulation time, underestimates interference by several dB. Owing to its modular architecture, the simulator lends itself to any kind of system performance investigations in FDD uplink.

Examples are presented of inter-hemispheric comparison of instrumental climate and paleoclimate proxy records from the Americas for different temporal scales. Despite a certain symmetry of seasonal precipitation patterns along the PEP 1 transect, decadal variability of winter precipitation shows different characteristics in terms of amplitude and frequency in both the last 100 and last 1000 years. Such differences in variability are also seen in a comparison of time series of different El Niño/Southern Oscillation proxy records from North and South America, however, these differences do not appear to affect the spatial correlation with Pacific sea surface temperature patterns. Local and regional differences in response to climate change are even more pronounced for records with lower temporal resolution, and inter-hemispheric synchroneity may or may not be indicative of the same forcing. This aspect is illustrated in an inter-hemispheric comparison of the last 1000 years of glacier variability, and of the full- and lateglacial lake level history.