Development of a 2000 Meter Aircraft Expendable Bathythermograph

1984 ◽  
Author(s):  
Jeffrey S. Russell ◽  
Karen M. Leavitt
Keyword(s):  
Expendable Bathythermograph

Estimating Global Ocean Heat Content Changes in the Upper 1800 m since 1950 and the Influence of Climatology Choice*

2014 ◽  
Vol 27 (5) ◽  
pp. 1945-1957 ◽  
Author(s):  
John M. Lyman ◽  
Gregory C. Johnson
Keyword(s):  
Heat Content ◽  
Ocean Heat Content ◽  
Global Ocean ◽  
Ocean Temperature ◽  
Vertical Separation ◽  
Ocean Heat Uptake ◽  
Expendable Bathythermograph ◽  
Heat Uptake ◽  
The Mean

Abstract Ocean heat content anomalies are analyzed from 1950 to 2011 in five distinct depth layers (0–100, 100–300, 300–700, 700–900, and 900–1800 m). These layers correspond to historic increases in common maximum sampling depths of ocean temperature measurements with time, as different instruments—mechanical bathythermograph (MBT), shallow expendable bathythermograph (XBT), deep XBT, early sometimes shallower Argo profiling floats, and recent Argo floats capable of worldwide sampling to 2000 m—have come into widespread use. This vertical separation of maps allows computation of annual ocean heat content anomalies and their sampling uncertainties back to 1950 while taking account of in situ sampling advances and changing sampling patterns. The 0–100-m layer is measured over 50% of the globe annually starting in 1956, the 100–300-m layer starting in 1967, the 300–700-m layer starting in 1983, and the deepest two layers considered here starting in 2003 and 2004, during the implementation of Argo. Furthermore, global ocean heat uptake estimates since 1950 depend strongly on assumptions made concerning changes in undersampled or unsampled ocean regions. If unsampled areas are assumed to have zero anomalies and are included in the global integrals, the choice of climatological reference from which anomalies are estimated can strongly influence the global integral values and their trend: the sparser the sampling and the bigger the mean difference between climatological and actual values, the larger the influence.

scholarly journals Comparison of the fall rate and structure of recent T-7 XBT manufactured by Sippican and TSK

2010 ◽  
Vol 7 (5) ◽  
pp. 1811-1847 ◽  
Author(s):  
S. Kizu ◽  
C. Sukigara ◽  
K. Hanawa
Keyword(s):  
Quadratic Form ◽  
Water Entry ◽  
Rate Coefficients ◽  
Fall Rate ◽  
Current Standard ◽  
Expendable Bathythermograph ◽  
Structural Differences ◽  
Fall Rates ◽  
The Difference ◽  
Temperature Depth

Abstract. The fall rate of recent T-7 expendable bathythermograph (XBT) is evaluated based on a series of concurrent measurement with a calibrated Conductivity Temperature Depth profiler (CTD) in the sea east of Japan. An emphasis is placed on comparing the fall rates of T-7 produced by the two present manufacturers, the Lockheed Martin Sippican Inc., and the Tsurumi Seiki Co. Ltd., which have been believed to be identical but had never been compared directly. It is found that the two manufacturers' T-7 fall at rates different by about 3.5%. The Sippican T-7 falls slower than the current standard equation by Hanawa et al. (1995) gives by about 2.1%, and the TSK T-7 falls faster than it tells by about 1.4%. The fall-rate coefficients estimated based on the present sea test by applying the equation of traditional quadratic form, d(t)=at−bt2 where d is depth in meters and t is the time elapsed, since the water entry of the probe, in seconds, are a=6.553 and b=0.00221 for the LMS T-7, and a=6.803 and b=0.00242 for the TSK T-7. By detail examination of the probes, it is revealed that the two companies' T-7 have different total weight and many structural differences. Because the difference in the fall rate is about twice larger than the difference in weight (about 2%), it is inferred that those structural differences give sizable impact to the difference in their fall rates. Our results clearly show that the recent T-7 of the two companies needs to be discriminated.

scholarly journals Comparison of the fall rate and structure of recent T-7 XBT manufactured by Sippican and TSK

Ocean Science ◽  
2011 ◽  
Vol 7 (2) ◽  
pp. 231-244 ◽  
Author(s):  
S. Kizu ◽  
C. Sukigara ◽  
K. Hanawa
Keyword(s):  
Quadratic Form ◽  
Rate Equation ◽  
Total Weight ◽  
Rate Coefficients ◽  
Fall Rate ◽  
Expendable Bathythermograph ◽  
Structural Differences ◽  
Fall Rates ◽  
The Difference ◽  
Temperature Depth

Abstract. The fall rate of recent T-7 expendable bathythermograph (XBT; 760 m) is evaluated based on a series of concurrent measurement with a calibrated Conductivity Temperature Depth profiler (CTD) in the sea east of Japan. An emphasis is placed on comparing the fall rates of T-7 produced by the two present manufacturers, the Lockheed Martin Sippican Inc., and the Tsurumi Seiki Co. Ltd., which have been believed to be identical but had never been compared directly. It is found that the two manufacturers' T-7 fall at rates different by about 3.5%. The Sippican T-7 falls slower than given by the fall-rate equation (FRE) of Hanawa et al. (1995) by about 2.1%, and the TSK T-7 falls faster by about 1.4%. The fall-rate coefficients estimated based on the sea test by applying the equation of traditional quadratic form, d(t)=at−bt2 where d is depth in meters and t is the time elapsed, in seconds, are a=6.553 (m s−1) and b=0.00221 (m s−2) for the LMS T-7, and a=6.803 (m s−1) and b=0.00242 (m s−2) for the TSK T-7. By detail examination of the probes, we found that the two companies' T-7 have different total weight and many structural differences. Because the difference in the fall rate is about twice larger than the difference in weight (about 2%), it is inferred that the structural differences give sizable impact to the difference in their fall rates. Our results clearly show that the recent T-7 of the two companies needs to be discriminated.

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