Mithat Cemal Kuntay

Taha Toros Arşivi, Dosya No: 232-Mithat Cemal Kuntay. Not: Gazetenin "Fıkram" köşesinde yayımlanmıştır.İstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Variability of diatom species populations: From days to years

Based on over 300,000 individual measurements, temporal and spatial variations in diatom abundances and related atmospheric and oceanic variables have been investigated for two locations near the coast of southern California. Time scale of periods investigated ranged from days to 10 years; variability over centuries can be reconstructed from climate records. The results of principal component analysis based on weekly averages indicated that eigenvectors at Scripps and Pt. Hueneme piers, nearly 200 km apart, were similar; removal of seasonal cycles (by calculating anomalies) did not significantly alter these eigenvectors. Principal components derived from matrices based on weekly averages of 20, 23, and 65 species of diatoms have significant inverse correlations with sea-surface temperature anomalies. Based on 3-month (seasonal) averages, the abundance of several species of diatoms respond to climatic fluctuations as defined by changes in sea-surface temperature, air temperature, sea level and alongshore wind stress

Temporal variations in diatom abundance off southern California in relation to surface temperature, air temperature and sea level

Temporal variations in diatom abundance off the southern California coast during the 1920- 1939 period can be explained by a combination of the changes in the circulation patterns of major water masses and variations associated with upwelling events. Monthly, tri-monthly, seasonal and yearly anomalies of diatom abundances have significant negative correlation with the anomalies of sea surface temperature, air temperature and sea level

Câteva consideratii teoretice privind conceptele de „substitut”, „anafor” si „proform”

This article regards the concepts of substitute, anaphora and proform. In literature, there frequently appears a theory that the terms previously named “considerably overlap”, but Romanian grammar draws no clear boundaries between these concepts. After the comparative analysis of the main definitions for the concepts of substitute, anaphora/ anaphoric and proforms, I found that the anaphors/ anaphoricals are a type of proforms and the proforms are a type of substitute, which proves that the target terms are not equivalent

The bone structure of some marine vertebrates

This paper deals with the bone structure of albacore, fin whale and deep-sea rat-tail. The major components of bone - ash, organic, fat and water content are expressed on a volumetric basis. It has been found that both rat-tail and whale bone tissue are highly mineralized and the mineralization occurs at the expense of water. The whale and albacore tissue densities were 1.856 grams/cm³ and 1.557 grams/cm³ respectively. Bone organ densities of whale, albacore and rat-tail were 1.161 grams/cm³, 1.423 grams/cm³ and 1.378 grams/cm³, respectively. The differences in bone structure with respect to physiological and environmental factors are also discussed

Listening to Students: Voices From the Inner City

What do students in Catholic schools view as important aspects of their unique form of education? They want a safe environment for learning, caring and concerned teachers, high expectations for learning, responsibility and respect in the school community, and a clear sense of how school relates to success in life. This article describes a study which clearly documents student perceptions and values

Sea surface temperature changes in the southern California borderlands during the last glacial-interglacial cycle

A variety of evidence suggests that average sea surface temperatures (SSTs) during the last glacial maximum in the California Borderlands region were significantly colder than during the Holocene. Planktonic foraminiferal δ18O evidence and average SST estimates derived by the modern analog technique indicate that temperatures were 6°-10°C cooler during the last glacial relative to the present. The glacial plankton assemblage is dominated by the planktonic foraminifer Neogloboquadrina pachyderma (sinistral coiling) and the coccolith Coccolithus pelagicus, both of which are currently restricted to subpolar regions of the North Pacific. The glacial-interglacial average SST change determined in this study is considerably larger than the 2°C change estimated by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981]. We propose that a strengthened California Current flow was associated with the advance of subpolar surface waters into the Borderlands region during the last glacial

Annual trend patterns of phytoplankton species abundance belie homogeneous taxonomical group responses to climate in the NE Atlantic upwelling

Phytoplankton is a sentinel of marine ecosystem change. Composed by many species with different life-history strategies, it rapidly responds to environment changes. An analysis of the abundance of 54 phytoplankton species in Galicia (NW Spain) between 1989 and 2008 to determine the main components of temporal variability in relation to climate and upwelling showed that most of this variability was stochastic, as seasonality and long term trends contributed to relatively small fractions of the series. In general, trends appeared as non linear, and species clustered in 4 groups according to the trend pattern but there was no defined pattern for diatoms, dinoflagellates or other groups. While, in general, total abundance increased, no clear trend was found for 23 species, 14 species decreased, 4 species increased during the early 1990s, and only 13 species showed a general increase through the series. In contrast, series of local environmental conditions (temperature, stratification, nutrients) and climate-related variables (atmospheric pressure indices, upwelling winds) showed a high fraction of their variability in deterministic seasonality and trends. As a result, each species responded independently to environmental and climate variability, measured by generalized additive models. Most species showed a positive relationship with nutrient concentrations but only a few showed a direct relationship with stratification and upwelling. Climate variables had only measurable effects on some species but no common response emerged. Because its adaptation to frequent disturbances, phytoplankton communities in upwelling ecosystems appear less sensitive to changes in regional climate than other communities characterized by short and well defined productive periods.Versión del editor1,953

Large scale patterns in vertical distribution and behavior of mesopelagic scattering layers

Recent studies suggest that previous estimates of mesopelagic biomasses are severely biased, with the new, higher estimates underlining the need to unveil behaviourally mediated coupling between shallow and deep ocean habitats. We analysed vertical distribution and diel vertical migration (DVM) of mesopelagic acoustic scattering layers (SLs) recorded at 38 kHz across oceanographic regimes encountered during the circumglobal Malaspina expedition. Mesopelagic SLs were observed in all areas covered, but vertical distributions and DVM patterns varied markedly. The distribution of mesopelagic backscatter was deepest in the southern Indian Ocean (weighted mean daytime depth: WMD 590 m) and shallowest at the oxygen minimum zone in the eastern Pacific (WMD 350 m). DVM was evident in all areas covered, on average ~50% of mesopelagic backscatter made daily excursions from mesopelagic depths to shallow waters. There were marked differences in migrating proportions between the regions, ranging from ~20% in the Indian Ocean to ~90% in the Eastern Pacific. Overall the data suggest strong spatial gradients in mesopelagic DVM patterns, with implied ecological and biogeochemical consequences. Our results suggest that parts of this spatial variability can be explained by horizontal patterns in physical-chemical properties of water masses, such as oxygen, temperature and turbidity.En prensa2,927