scholarly journals Seasonal Change in Distribution and Heat Coma Temperature of Oceanic Skaters, Halobates (Insecta, Heteroptera: Gerridae)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 133 ◽  
Author(s):  
Tetsuo Harada ◽  
Mitsuru Nakajo ◽  
Takahiro Furuki ◽  
Noritomo Umamoto ◽  
Masatoshi Moku ◽  
...  
Keyword(s):  
Population Density ◽  
Temperature Limit ◽  
Temperature Tolerance ◽  
Temperature Acclimation ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Lower Temperature Limit ◽  
The Pacific ◽  
Lower Temperature

A series of studies were conducted during two cruises between Tokyo and Honolulu in September 2010 and from February to March 2012. The aims of the studies were to (1) compare the distribution of three species of Halobates oceanic skaters, H. germanus, H. micans, and H. sericeus, with respect to their temperature limits; (2) identify the lower temperature limit of H. sericeus, the species that displays the widest distribution range (40°N–35°S) latitude; and (3) test the hypothesis that H. sericeus can change their temperature tolerance to adapt to seasonal changes in sea surface temperatures. The heat coma temperature (HCT) was measured during the two cruises and the values were compared between the two populations of H. sericeus. The species collected in September 2010 were H. germanus, H. micans, and H. sericeus. H. sericeus was dominant, occupying more than 90% of the collecting sites. H. germanus and H. micans were collected in the northern and western part of the cruise track (29–34°N, 141–151°E), and not in the southern and eastern part. The population density of these two species was 9000–150,000/km2 in the first cruise, which took place in summer. On the other hand, H. sericeus was collected throughout the cruise track during that cruise. The population density of H. sericeus was relatively high, at 4000–310,000/km2, in the southern and eastern part of the cruise track (19–29°N, 152°E–165°W). In February and March 2012, only H. sericeus was collected at a density of 17,000–80,000/km2 and only in the eastern and southern part, at 25°–28°N, 169°E–178°W. No Halobates oceanic skaters were found in the western or northern part (30°N and further north, 159°E and further west) during that cruise. The lower limit for the inhabitation of sea surface temperatures appeared to be 27.8 °C or slightly lower for H. germanus and H. micans, but was 22.1 °C or slightly lower for H. sericeus. H. sericeus specimens, mostly adults, that had been collected during the two cruises were used in heat coma experiments. Summer specimens showed significantly higher heat coma temperatures (HCTs) than the winter specimens. This difference in HCTs may be the result of relatively long term temperature acclimation in the summer or winter for the adults that inhabit the temperate and subtropical areas along the cruise tracks between Tokyo and Honolulu in the Pacific Ocean. This temperature plasticity of H. sericeus may be related to the wider latitude area inhabited by this species (main range: 40°N–25°S).

The reconstruction of sea surface temperatures in the Pacific Ocean of 18,000 B.P.

1980 ◽  
Vol 5 ◽  
pp. 215-247 ◽  
Author(s):  
T.C. Moore ◽  
L.H. Burckle ◽  
K. Geitzenauer ◽  
B. Luz ◽  
A. Molina-Cruz ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
The Pacific ◽  
The Pacific Ocean

scholarly journals Douglas-fir radial growth in interior British Columbia can be linked to long-term oscillations in Pacific and Atlantic sea surface temperatures

2017 ◽  
Vol 47 (3) ◽  
pp. 371-381 ◽  
Author(s):  
Yueh-Hsin Lo ◽  
Juan A. Blanco ◽  
Biing T. Guan
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Tree Ring ◽  
Low Frequency ◽  
Growth Index ◽  
Sea Surface ◽  
Diameter Growth ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
The Pacific

A major problem in modern dendrochronology is that the methods traditionally used for linking tree-ring growth data to climate records are not well suited to reconstructing low-frequency climatic variations. In this study, we explored the alternative ensemble empirical mode decomposition (EEMD) to detrend tree-ring records and extract climate signals without removing low-frequency information. Tree cores of Pseudotsuga menziesii var. glauca (Mayr.) Franco were examined in a semi-arid forest in southern interior British Columbia, western Canada. Ring width data were decomposed into five oscillatory components (intrinsic mode functions, IMFs) of increasingly longer periodicities. IMF 1 was considered white noise, IMF 2 was used to create the first diameter growth index (DGI-1), and IMF 3 and IMF 4 were combined to create the second diameter growth index (DGI-2), whereas IMF 5 and the residual term together were considered as the trend term. The highest significant cross-correlations between DGI-1 and the NAOAugust, NIÑO12May, and PDOJanuary indices were found at 1-year lags. DGI-2 had positive and persistent correlations with NAOJune and PDOMay at 0- to 3-year lags and with NAOMay at 2- and 3-year lags. Our results indicate that periods of slow growth in the tree-ring record matched periods of drought in the North American Pacific Northwest. Such water-limiting conditions are likely caused by oscillatory patterns in the Pacific Ocean sea surface temperatures that influence precipitation in the Pacific Northwest. These drought events are likely exacerbated by changes in winter precipitation (snowpack) related to oscillations of the Atlantic Ocean sea surface temperatures, highlighting the ecological effects of both oceans on terrestrial ecosystems. Such relationships could not be easily found by traditional tree-ring analyses that remove some of the low-frequency signal, and therefore, we suggest EEMD as an additional tool to establishing tree growth – climate relationships.

scholarly journals High-Resolution Sea Surface Temperatures Derived from Landsat 8: A Study of Submesoscale Frontal Structures on the Pacific Shelf off the Hokkaido Coast, Japan

2020 ◽  
Vol 12 (20) ◽  
pp. 3326
Author(s):  
Hiroshi Kuroda ◽  
Yuko Toya
Keyword(s):  
Spatial Distribution ◽  
Ocean Model ◽  
Sea Surface ◽  
Basic Question ◽  
Landsat 8 ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
The Pacific ◽  
The Difference

Coastal and offshore waters are generally separated by a barrier or “ocean front” on the continental shelf. A basic question arises as to what the representative spatial scale across the front may be. To answer this question, we simply corrected skin sea surface temperatures (SSTs) estimated from Landsat 8 imagery with a resolution of 100 m using skin SSTs estimated from geostationary meteorological satellite Himawari 8 with a resolution of 2 km. We analyzed snapshot images of skin SSTs on 13 October 2016, when we performed a simultaneous ship survey. We focused in particular on submesoscale thermal fronts on the Pacific shelf off the southeastern coast of Hokkaido, Japan. The overall spatial distribution of skin SSTs was consistent between Landsat 8 and Himawari 8; however, the spatial distribution of horizontal gradients of skin SSTs differed greatly between the two datasets. Some parts of strong fronts on the order of 1 °C km−1 were underestimated with Himawari 8, mainly because of low resolution, whereas weak fronts on the order of 0.1 °C km−1 were obscured in the Landsat 8 imagery because the signal-to-noise ratios were low. The widths of the strong fronts were estimated to be 114–461 m via Landsat 8 imagery and 539–1050 m via in situ ship survey. The difference was probably attributable to the difference in measurement depth of the SST, i.e., about 10-μm skin layer by satellite and a few dozen centimeters below the sea surface by the in situ survey. Our results indicated that an ocean model with a grid size of no more than ≤100–200 m is essential for realistic simulation of the frontal structure on the shelf.

scholarly journals Interannual variability of the midsummer drought in Central America and the connection with sea surface temperatures

2016 ◽  
Vol 42 ◽  
pp. 35-50 ◽  
Author(s):  
Tito Maldonado ◽  
Anna Rutgersson ◽  
Eric Alfaro ◽  
Jorge Amador ◽  
Björn Claremar
Keyword(s):  
Central America ◽  
Negative Relationship ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Potential Predictability ◽  
The North ◽  
Surface Temperatures ◽  
Temporal Variables ◽  
The Pacific ◽  
The Caribbean

Abstract. The midsummer drought (MSD) in Central America is characterised in order to create annual indexes representing the timing of its phases (start, minimum and end), and other features relevant for MSD forecasting such as the intensity and the magnitude. The MSD intensity is defined as the minimum rainfall detected during the MSD, meanwhile the magnitude is the total precipitation divided by the total days between the start and end of the MSD. It is shown that the MSD extends along the Pacific coast, however, a similar MSD structure was detected also in two stations in the Caribbean side of Central America, located in Nicaragua. The MSD intensity and magnitude show a negative relationship with Niño 3.4 and a positive relationship with the Caribbean low-level jet (CLLJ) index, however for the Caribbean stations the results were not statistically significant, which is indicating that other processes might be modulating the precipitation during the MSD over the Caribbean coast. On the other hand, the temporal variables (start, minimum and end) show low and no significant correlations with the same indexes.The results from canonical correlation analysis (CCA) show good performance to study the MSD intensity and magnitude, however, for the temporal indexes the performance is not satisfactory due to the low skill to predict the MSD phases. Moreover, we find that CCA shows potential predictability of the MSD intensity and magnitude using sea surface temperatures (SST) with leading times of up to 3 months. Using CCA as diagnostic tool it is found that during June, an SST dipole pattern upon the neighbouring waters to Central America is the main variability mode controlling the inter-annual variability of the MSD features. However, there is also evidence that the regional waters are playing an important role in the annual modulation of the MSD features. The waters in the PDO vicinity might be also controlling the rainfall during the MSD, however, exerting an opposite effect at the north and south regions of Central America.

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