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.

Long-term comparison of satellite and in-situ sea surface temperatures around the Korean Peninsula

2015 ◽  
Vol 50 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Myeong-Taek Kwak ◽  
Gwang-Ho Seo ◽  
Yang-Ki Cho ◽  
Bong-Guk Kim ◽  
Sung Hyup You ◽  
...  
Keyword(s):  
Korean Peninsula ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures

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 Do climate simulations from models forced by averaged sea surface temperatures represent actual dynamics?

1997 ◽  
Vol 4 (2) ◽  
pp. 93-100 ◽  
Author(s):  
P. J. Roebber ◽  
A. A. Tsonis ◽  
J. B. Elsner
Keyword(s):  
General Circulation ◽  
Climatic Variability ◽  
General Circulation Models ◽  
Ocean Model ◽  
Coupled Systems ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Fully Coupled ◽  
Low Order

Abstract. Recently atmospheric general circulation models (AGCMs) forced by observed sea surface temperatures (SSTs) have offered the possibility of studying climate variability over periods ranging from years to decades. Such models represent and alternative to fully coupled asynchronous atmosphere ocean models whose long term integration remains problematic. Here, the degree of the approximation represented by this approach is investigated from a conceptual point of view by comparing the dynamical properties of a low order coupled atmosphere-ocean model to those of the atmospheric component of the same model when forced with monthly values of SST derived from the fully coupled simulation. The low order modelling approach is undertaken with the expectation that it may reveal general principles concerning the dynamical behaviour of the forced versus coupled systems; it is not expected that such an approach will determine the details of these differences, for which higher order modelling studies will be required. We discover that even though attractor (global) averages may be similar, local dynamics and the resultant variability and predictability characteristics differ substantially. These results suggest that conclusions concerning regional climatic variability (in time as well as space) drawn from forced modelling approaches may be contaminated by an inherently unquantifiable error. It is therefore recommended that this possibility be carefully investigated using state-of-the-art coupled AGCMs.

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.

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