Factors that control the emergence of green turtle hatchlings from the nest

1993 ◽  
Vol 20 (3) ◽  
pp. 345 ◽  
Author(s):  
E Gyuris
Keyword(s):  
Temperature Gradient ◽  
Temporal Distribution ◽  
Sea Turtle ◽  
Absolute Temperature ◽  
Temperature Profiles ◽  
Sand Column ◽  
Sand Surface ◽  
Sand Temperature ◽  
Threshold Temperatures ◽  
Per Se

Sea turtle hatchlings typically emerge at night and temperature has often been suggested as controlling the timing of emergence. Models based on threshold temperatures, above which hatchling activity is inhibited, are not fully compatible with the observed temporal distribution of emergence. This study reports on the temporal pattern of hatchling emergence and associated sand temperature profiles and tidal regimes at Heron I., in the southern Great Barrier Reef, Australia. A new model is proposed on the basis of sand temperature gradients instead of the absolute temperature of the sand surface. The excellent fit between the temperature gradient model and the observed pattern of emergence suggests that it is the temperature gradient in the top 10cm of the sand column rather than an absolute temperature per se that turtle hatchlings use to time their emergence.

scholarly journals Potential feminization of Red Sea turtle hatchlings as indicated by in situ sand temperature profiles

2020 ◽  
Vol 2 (10) ◽  
Author(s):  
Lyndsey K. Tanabe ◽  
Joanne Ellis ◽  
Islam Elsadek ◽  
Michael L. Berumen
Keyword(s):  
Red Sea ◽  
Sea Turtle ◽  
Temperature Profiles ◽  
Sand Temperature

Temperature in the external auditory meatus as an index of central temperature changes

1964 ◽  
Vol 19 (5) ◽  
pp. 1032-1034 ◽  
Author(s):  
K. E. Cooper ◽  
W. I. Cranston ◽  
E. S. Snell
Keyword(s):  
Temperature Gradient ◽  
Temperature Regulation ◽  
External Auditory Meatus ◽  
Absolute Temperature ◽  
Central Temperature ◽  
Temperature Changes ◽  
Vasomotor Responses ◽  
Temperature Levels

The temperature of the wall of the external auditory meatus has been investigated. Changes in ear temperature reflect changes of sublingual temperature quite accurately and are well correlated with cutaneous vasomotor responses induced by body heating. The temperature of the external auditory meatus is little affected by reflex vasomotor changes. It is easily measured without discomfort or danger and provides a valid indication of temperature changes at the central receptors. There is a considerable temperature gradient down the wall of the meatus so that absolute temperature levels are probably not of value. ear temperature in man; central temperature regulation in man Submitted on February 24, 1964

scholarly journals STEAD: A high-resolution daily gridded temperature dataset for Spain

2019 ◽  
Author(s):  
Roberto Serrano-Notivoli ◽  
Santiago Beguería ◽  
Martín De Luis
Keyword(s):  
Quality Control ◽  
Spatial Resolution ◽  
Minimum Temperature ◽  
Grid Point ◽  
Temporal Distribution ◽  
Original Data ◽  
Accurate Estimate ◽  
Absolute Temperature ◽  
Data Series ◽  
Absolute Maximum

Abstract. Using the full total of available 5520 observatories covering the whole territory of Spain, a daily gridded maximum and minimum temperature was built covering a period from 1901 to 2014 in peninsular Spain and 1971–2014 in Balearic and Canary Islands. A comprehensive quality control was applied to the original data and the gaps were filled on each day and location independently. Using the filled data series, a grid of 5 × 5 km spatial resolution was created by estimating daily temperatures and their corresponding uncertainties at each grid point. Four daily temperature indices were calculated to describe the spatial distribution of absolute maximum and minimum temperature, number of frost days and number of summer days in Spain. The southern plateau showed the maximum values of maximum absolute temperature and summer days, while the minimum absolute temperature and frost days reached their maximums at northern plateau. The use of all the available information, the complete quality control and the high spatial resolution of the grid allowed for an accurate estimate of temperature that represents a precise spatial and temporal distribution of daily temperatures in Spain. STEAD dataset is publicly available at http://dx.doi.org/10.20350/digitalCSIC/8622.

Study on Radial Temperature Distribution of Aluminum Dispersed Nuclear Fuels: U3O8-Al, U3Si2-Al, and UN-Al

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Jayangani I. Ranasinghe ◽  
Ericmoore Jossou ◽  
Linu Malakkal ◽  
Barbara Szpunar ◽  
Jerzy A. Szpunar
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Steady State ◽  
Temperature Gradient ◽  
Heat Conduction Equation ◽  
Conduction Equation ◽  
Temperature Profiles ◽  
Nuclear Fuels ◽  
State Heat ◽  
Steady State Heat

The understanding of the radial distribution of temperature in a fuel pellet, under normal operation and accident conditions, is important for a safe operation of a nuclear reactor. Therefore, in this study, we have solved the steady-state heat conduction equation, to analyze the temperature profiles of a 12 mm diameter cylindrical dispersed nuclear fuels of U3O8-Al, U3Si2-Al, and UN-Al operating at 597 °C. Moreover, we have also derived the thermal conductivity correlations as a function of temperature for U3Si2, uranium mononitride (UN), and Al. To evaluate the thermal conductivity correlations of U3Si2, UN, and Al, we have used density functional theory (DFT) as incorporated in the Quantum ESPRESSO (QE) along with other codes such as Phonopy, ShengBTE, EPW (electron-phonon coupling adopting Wannier functions), and BoltzTraP (Boltzmann transport properties). However, for U3O8, we utilized the thermal conductivity correlation proposed by Pillai et al. Furthermore, the effective thermal conductivity of dispersed fuels with 5, 10, 15, 30, and 50 vol %, respectively of dispersed fuel particle densities over the temperature range of 27–627 °C was evaluated by Bruggman model. Additionally, the temperature profiles and temperature gradient profiles of the dispersed fuels were evaluated by solving the steady-state heat conduction equation by using Maple code. This study not only predicts a reduction in the centerline temperature and temperature gradient in dispersed fuels but also reveals the maximum concentration of fissile material (U3O8, U3Si2, and UN) that can be incorporated in the Al matrix without the centerline melting. Furthermore, these predictions enable the experimental scientists in selecting an appropriate dispersion fuel with a lower risk of fuel melting and fuel cracking.

Spatio‐temporal distribution of sea turtle strandings and factors contributing to their mortality in south‐eastern Brazil

2019 ◽  
Vol 30 (2) ◽  
pp. 331-350 ◽  
Author(s):  
Alicia Bertoloto Tagliolatto ◽  
Daphne Wrobel Goldberg ◽  
Matthew H. Godfrey ◽  
Cassiano Monteiro‐Neto
Keyword(s):  
Temporal Distribution ◽  
Sea Turtle ◽  
South Eastern ◽  
Eastern Brazil ◽  
Spatio Temporal

scholarly journals Response of the longwave radiation over melting snow and ice to atmospheric warming

1997 ◽  
Vol 43 (143) ◽  
pp. 66-70 ◽  
Author(s):  
Antoon Meesters ◽  
Michiel van den Broeke
Keyword(s):  
Numerical Simulation ◽  
Large Scale ◽  
Longwave Radiation ◽  
Surface Melting ◽  
Absolute Temperature ◽  
Scale Model ◽  
Fourth Power ◽  
Temperature Profiles ◽  
Melting Snow ◽  
Meso Scale

AbstractParameterizing the incoming longwave radiationL↓ in terms of the fourth power of the absolute temperature at the reference height is used in glaciology for several purposes. In this paper, the validity of this kind of parameterization is investigated for the Greenland ice sheer, both by observations and by numerical simulation with a meso-scale model, It is found that such a parameterization severely underestimates the increase ofL↓ in response to large-scale warming in an area where surface melting is important. This is explained by the systematic influence that is exerted on the shape of the temperature profiles by surface melting.

Estimating past and present sex ratios of sea turtles in Suriname

1996 ◽  
Vol 74 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Matthew H. Godfrey ◽  
N. Mrosovsky ◽  
R. Barreto
Keyword(s):  
Sea Turtles ◽  
Sex Ratios ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Green Turtles ◽  
Sand Temperature ◽  
Turtle Conservation ◽  
Sea Turtle Conservation

Leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles in Suriname lay eggs over several months of the year. During this nesting season, changes in rainfall produce changes in sand temperature, which in turn influence the sexual differentiation of incubating sea turtle embryos. The overall sex ratio of leatherback and green sea turtle hatchlings produced at Matapica beach in Suriname was investigated. Estimates of the sex ratios of these turtles in 1993 (green turtles 63.8% female, leatherbacks 69.4% female) were roughly 10% more female-biased than those from an earlier study in 1982. For both species, a significant negative relationship was found between monthly rainfall and monthly sex ratios. Using this relationship and data on rainfall in the past, it was possible to estimate overall sex ratios for an additional 12 years. These estimates varied considerably among different years, ranging from 20 to 90% female in the case of green turtles. Nevertheless, males tended to be produced primarily in April and May, while some females were produced in all months. Such seasonal patterns of production of turtles of different sexes have implications for sea turtle conservation programs that involve manipulating or harvesting eggs.

scholarly journals An Aperture Synthesis Survey of the Galactic Plane

1974 ◽  
Vol 27 (5) ◽  
pp. 687 ◽  
Author(s):  
BB Jones ◽  
EA Finlay
Keyword(s):  
Brightness Temperature ◽  
Supernova Remnants ◽  
Galactic Plane ◽  
Absolute Temperature ◽  
Temperature Profiles ◽  
Contour Maps ◽  
Average Value ◽  
Low Surface Brightness ◽  
Carina Nebula ◽  
The Galaxy

The results of a survey already published have been used to construct contour maps and ruled surface diagrams of the brightness temperature at 29�9 MHz near the galactic plane between I = 225� and 30�. The angular resolution was 0�� 8 at the zenith, and the range of zenith angles involved was � 30�. Restoration of the background was achieved with the aid of a low resolution filled-aperture survey carried out by others. The brightness temperature scale was calibrated absolutely. The optical depth of the Galaxy in directions within 40� of latitude from the centre has been estimated by a method which relies only on the shapes of brightness temperature profiles and not on absolute temperature calibrations. If an electron temperature is assumed, r.m.s. electron densities can be deduced. The average value of the disc emissivity at 29�9 MHz and the value of its spectral index have been calculated from brightness temperature profiles observed at a number of different frequencies, calibrations being required for these purposes. About 29 discrete absorption regions have been observed and identified with optically observed HII regions, and the fact that these are all nearer than 4 kpc permits a choice between kinematic distances in two cases. The Carina nebula and RCW 108 lend themselves to the measurement of local emissivities, and values of these together with their implications have already been published. A number of previously unlisted nonthermal sources have been observed, many of which are objects of low surface brightness and probably are supernova remnants.

Measurements on, and Modelling of Diffusive and Advective Radon Transport in Soil

1994 ◽  
Vol 56 (1-4) ◽  
pp. 167-170 ◽  
Author(s):  
E.R. van der Graaf ◽  
G.A.A. Witteman ◽  
W.H. van der Spoel ◽  
C.E. Andersen ◽  
R.J. de Meijer
Keyword(s):  
Radon Concentration ◽  
Air Flow ◽  
Concentration Profiles ◽  
Sand Column ◽  
Steel Vessel ◽  
Sand Surface ◽  
Stainless Steel Vessel ◽  
Laboratory Facility ◽  
Flow Equilibrium ◽  
Flow Through

Abstract Results are presented of measurements on radon transport in soil under controlled conditions with a laboratory facility consisting of a stainless steel vessel (height and diameter 2 m) filled with a uniform column of sand. At several depths under the sand surface, probes are radically inserted into the vessel to measure the radon concentration in the soil gas. To study advective radon transport a perforated circular box is placed in the sand close to the bottom of the vessel. By pressurising this box, an air flow through the sand column is induced. Radon concentration profiles were measured without an air flow as a function of time, and for several values of the air flow, equilibrium radon concentration profiles were measured.

scholarly journals Influence of ENSO and MJO on the zonal structure of tropical tropopause inversion layer using high-resolution temperature profiles retrieved from COSMIC GPS Radio Occultation

2019 ◽  
Vol 19 (10) ◽  
pp. 6985-7000
Author(s):  
◽  
Toshitaka Tsuda ◽  
Masatomo Fujiwara
Keyword(s):  
Temperature Gradient ◽  
Radio Occultation ◽  
Deep Convection ◽  
Inversion Layer ◽  
Temperature Profiles ◽  
Convective Activity ◽  
Zonal Structure ◽  
Gps Radio Occultation ◽  
The Mean ◽  
The Tropics

Abstract. Using COSMIC GPS Radio Occultation (RO) observations from January 2007 to December 2016, we retrieved temperature profiles with the height resolution of about 0.1 km in the upper troposphere and lower stratosphere (UTLS). We investigated the distribution of static stability (N2) and the zonal structure of the tropopause inversion layer (TIL) in the tropics, where a large change in the temperature gradient occurs associated with sharp variations in N2. We show the variations in the mean N2 profiles in coordinates relative to the cold-point tropopause (CPT). A very thin (<1 km) layer is found with average maximum N2 in the range of 11.0–12.0×10-4 s−2. The mean and standard deviation of TIL sharpness, defined as the difference between the maximum N2 (max⁡N2) and minimum N2 (min⁡N2) within ±1 km of the CPT, is (10.5±3.7)×10-4 s−2. The max⁡N2 is typically located within 0.5 km above CPT. We focused on the variation in TIL sharpness in two longitude regions, 90–150∘ E (Maritime Continent; MC) and 170–230∘ E (Pacific Ocean; PO), with different land–sea distribution. Seasonal variations in TIL sharpness and thickness were related to the deep convective activity represented by low outgoing longwave radiation (OLR) during the Australian and Asian monsoons. The deviation from the mean sharpness (sharpness anomaly) was out of phase with the OLR anomaly in both the MC and PO. The correlation between the sharpness anomaly over the MC and PO and the sea surface temperature (SST) Niño 3.4 index was −0.66 and +0.88, respectively. During La Niña (SST Niño 3.4 <-0.5 K) in the MC and El Niño (SST Niño 3.4 >+0.5 K) in the PO, warmer SSTs in the MC and PO produce more active deep convection that tends to force the air upward to the tropopause layer and increase the temperature gradient there. The intraseasonal variation in sharpness anomaly during slow and fast episodes of the Madden–Julian Oscillation (MJO) demonstrates that eastward propagation of the positive sharpness anomaly is associated with organized deep convection. Deep convection during MJO will tend to decrease N2 below CPT and increase N2 above CPT, thus enlarging the TIL sharpness. Convective activity in the tropics is a major control on variations in tropopause sharpness at intraseasonal to interannual timescales.

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