Can a climate record be extracted from giant sequoia tree rings?

Extreme low growth events in giant sequoia ring-width index series coincide with severe droughts in the San Joaquin drainage, on whose eastern flank the sequoia groves stand. Comparison with a network of 102 largely moisture-sensitive tree-ring chronologies from western North America suggests that this relationship has been stable for at least 380 years. The twentieth century is not unusual in the frequency of these events. We expect the growth record will soon be replicated for over 2000 years at two locations.

Tropical and subtropical moisture and southerly displaced North Pacific storm track: factors in the growth of late Quaternary lakes in the Mojave Desert

Historical flood events produced lakes in the Mojave River watershed in southeastern California and represent climatic conditions similar to those in the late Quaternary when perennial lakes formed in the Mojave Desert. Historical lakes are related to tropical and subtropical sources of moisture and an extreme southward shift of storm tracks. It is suggested that this atmospheric pattern occurred frequently during earlier periods with perennial lakes in the Mojave River drainage basin.

Simulation and diagnosis of large-scale atmospheric moisture and surface hydrology over North America

We describe a preliminary investigation into large-scale atmospheric and surface moisture variations over North America. We compare large-scale hydrologic budgets in the Los Alamos general circulation model (GCM) to observed precipitation and vertically integrated atmospheric moisture fluxes derived from the National Meteorological Center's operational analyses. THe GCM faithfully simulates the integrated flux divergence and P-E differences. However, the integrated moisture content is too low, and precipitation and evaporation are too high. The model produces summertime soil moisture dryness, which supports previous studies showing increased droughts under warmer conditions.

Real-time climate monitoring using an AVHRR-based vegetation index

A normalized difference vegetation index (NDVI) has been produced and archived on a 1° latitude by 1° longitude grid between 55°S and 75°N. The many sources of data errors in the NDVI include cloud contamination, scan angle biases, changes in solar zenith angle, and sensor degradation. Week-to-week variability, primarily caused by cloud contamination and scan angle biases, can be minimized by temporally filtering the data. Orbital drift and sensor degradation introduces interannual variability into the dataset. These trends make the usefulness of a long-term climatology uncertain and limit the usefulness of the NDVI. Elimination of these problems should produce an index that can be used for climate monitoring.

Weather index insurance: Lessons learned and best practices for Bangladesh

WorldFish and the International Centre for Climate Change and Development (ICCCAD) held a two-day workshop on the topic of Weather Index-Based Insurance: Lessons Learned and Best Practices for Bangladesh. Weather index insurance is based on a predefined weather event which when triggered ensures automatic payout to farmers who have taken out insurance. For example, the climatic trigger could be a predefined consecutive number of days where rainfall is below a set level or when the floodwater level reaches above a certain point. Index insurance has been operating for about 10 years in many countries but is still at an early stage in Bangladesh, where there are two schemes currently being piloted and three other projects being developed. The aim of the two-day workshop was twofold: to ascertain the present state of index insurance in Bangladesh and elsewhere, and to work together to identify ways forward.

Radiolarian flux in the Santa Barbara Basin as an index of climate variability

Annual radiolarian flux (1954-1986) extrapolated from varved Santa Barbara Basin sediments was compared to instrumental data to examine the effect of interannual climate variability. Paleo-reconstructions over large geographic areas or 10^3 years and longer typically rely on changes in species composition to signal environment or climate shifts. In the relatively short period studied, climate fluctuations were insufficient to significantly alter the assemblage, but there was considerable variability in the total flux of radiolarians. This variability, greatest on 5- to 25-year time scales, appears to be linked to regional climate variability. Total flux correlates to regional California sea surface temperature and the composite of sea level pressure over the Northern Hemisphere for years of high radiolarian flux resembles positive PNA circulation.

Multiple-proxy lacustrine record of moisture transport over western North America from 24,000 to 12,000 YBP, Lake Estancia, New Mexico [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Pluvial Lake Estancia in central New Mexico experienced large and rapid fluctuations in surface area and elevation during the build-up to and termination of the last glacial maximum (LGM). Due to continuous groundwater discharge, a minimum pool covering about 400 square kilometers was maintained in the central basin until about 12,000 years ago, ensuring a continuous depositional sequence even during low stands of the lake. ... The sensitive response to fluctuations in climate by several independent proxies at Estancia show that transport of Pacific moisture over western North America changed dramatically during the last Ice Age, perhaps comparable to the large and rapid changes in climate documented from high-latitude ice and North Atlantic marine sediments for the LCM and its transitions.

Some aspects on growth and condition index of Saccostrea cucullata (Born), Cerithium rubus (Desh) and Tellina angulata Gmelin from Bombay coast

Size variation, growth, condition index and spawning periodicities of three species of molluscs were studied for a period of 15 months from a polluted and a relatively clean marine habitat near Bombay, Maharashtra, India. Growth of Saccostrea cucullata was 1.2 times and of Cerithium rubus was 1.6 times higher in unpolluted habitat than the polluted water. Spawning was during premonsoon in S. cucullata, post monsoon in C. rubus and monsoon in Tellina angulata. Condition index and percentage edibility values were higher at less polluted stations.

Measurement of moisture in dry cured fish by infrared irradiation

Heating conditions have been standardised for measurement of moisture in dry cured fish using infrared irradiation source of 150w. Results obtained are comparable to those obtained from standard air oven method (drying to a constant weight at l02°c), the mean deviation being less than two units. The method works equally well for fresh fish muscle.

Studies on the gonadosomatic index and fecundity of chapila (Gudusia chapra Ham.)

The study was conducted in pond to determine the fecundity and gonadosomatic index of chapila, Gudusia chapra. The male fish was found to attain sexual maturity at 7.7 cm and 7.41 g and that of the female at 9.3 cm and 14.65 g by standard-length and body-weight respectively. The investigated fishes were found to be male and female at the ratio of 1:3 and generally female was found to be larger than male. The fish was found to spawn for several months with two spawning peaks, one in April and another in August as indicated by the peaks of gonadosomatic index and ova diameter. Fecundity of the fish ranged from 25,220 to 154,528 with an average value of 72,383 and was found to increase with the increase in length and weight of the fish. The relationships between fecundity and standard-length, body-weight, gonad-length and gonad weight of the fish were found to be linear and significant.

Effect of high and low cost brood feeds on gonado-somatic index and fecundity of freshwater prawn Macrobrachium rogenbergii de Man

Studies were conducted to observe the effects of different types of feeds on the gonado-somatic index (GSI) and fecundity of freshwater prawn Macrobrachium rogenbergii. Three different treatments (T1 T2 and T3) were designed with three types of feed as follows: (i) Saudi-Bangla Prawn feed 100% - T1 (ii) SaudiBangla prawn feed 50%+ local feed 50%- T2 and (iii) local feed 100%- T3. The results showed that the average value of gonado-somatic index (GSI) was 14.39, 14.35 and 14.36 and the average fecundity of M. rogenbergiiwas 99,741, 98,125 and 97,911 in T1 T2 and T3 respectively. No significant difference (p>00.5) was between gonado-somatic indices (GSI) and fecundities of M. rogenbergii among different feeding trails. The price of Saudi-Bangla prawn feed was very high (Tk. 23/kg) than the local feed (Tk. 14/kg). So, use of local feed was recommended for M. rogenbergii brood rearing.

Factors influencing the livelihood index and level of aspiration of fisherwomen

A study was conducted among fifty women fish vendors in Kancheepuram and Chennai districts to determine the factors influencing the livelihood index and level of aspiration. The independent variables such as annual income, scientific orientation, expenditure per year and savings per year were found to have highest factor loadings on livelihood index and level of aspiration of fisherwomen. Besides most of the fisherwomen had a high level (score of <50) of livelihood index and a high level (score greater than 13) of aspiration.

Development of intermediate moisture marinated fish product and its storage characteristics

An attempt was made to prepare an intermediate moisture (around 44% moisture) marinated (pH around 4) fish product. Fillets from Sciaenid fish (each fish weighing 70-80 gm) were dipped in a solution containing 7% acetic acid, 20% common salt and 1% propionic acid for 2 hours. After soaking, the soaked fillets were partially dried to about 44% moisture. Three effective hurdles like low pH (by using 7% acetic add and 1% propionic acid), low water activity (by using 20% salt and partially drying the fillets) and preservative (1% propionic add), were used to prepare a shelf-stable product at room temperature. The dried product was sprayed with 0.0 5% BHA in 50% alcohol and further dried for 10 minutes to remove added water and alcohol, thereby another hurdle (preservative) against fat oxidation. The product was packed in 300 gauge polythene bags and stored in transparent screw cap plastic jars. Fortnightly samples were drawn and subjected to biochemical, bacteriological and organoleptic evaluation to study its storage characteristics. The product was in good acceptable form up to 4 months at ambient temperature. The product needed one hour soaking in water with two changes of water in between to make it free from excess salt and acid smell.

Studies on equilibrium moisture content of canned prawn with particular reference to drained weight

Drained weight of canned prawn depends on moisture content of blanched meat and equilibrium moisture (EM) content of processed meat. The greater the difference between the two values the more is the fluctuation in drained weight. EM is a fixed value with particular reference to the species of prawn, which has been justified mathematically and by material balance of can contents before and after processing.

Studies on the influence of moisture and specific gravity on the strength properties of mango wood (Mangifera indica)

Influence of moisture and specific gravity on the strength of mango wood is discussed. The co-efficient of correlation between specific gravity and breaking strength was found to be non-significant. The relation of strength and moisture was found to be highly significant. The mean strength values indicated a reduction in strength when the moisture increased from 8.5 to 18.8%. However no appreciable difference in strength values could be observed when moisture increased above 37%. The strength-moisture relationship is a straight line, passing approximately through the fibre saturation point. By using the exponential formula, the breaking strength corresponding to any moisture level between zero and fibre saturation can be determined.