The Experts below are selected from a list of 2460 Experts worldwide ranked by ideXlab platform
Armin Kohl - One of the best experts on this subject based on the ideXlab platform.
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Ocean mixed layer depth: A subsurface proxy of ocean‐atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
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Ocean mixed layer depth: A subsurface proxy of ocean-atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
Franco Reseghetti - One of the best experts on this subject based on the ideXlab platform.
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an algorithm for classifying unknown expendable bathythermograph xbt instruments based on existing metadata
Journal of Atmospheric and Oceanic Technology, 2018Co-Authors: Matthew D. Palmer, Shoichi Kizu, Franco Reseghetti, Timothy P Boyer, Rebecca Cowley, Toru Suzuki, Ann ThresherAbstract:AbstractTime-varying biases in expendable bathythermograph (XBT) instruments have emerged as a key uncertainty in estimates of historical ocean heat content variability and change. One of the chall...
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Assessment of Quality and Reliability of Measurements with XBT Sippican T5 and T5/20
Journal of Atmospheric and Oceanic Technology, 2018Co-Authors: Franco Reseghetti, Lijing Cheng, Mireno Borghini, Igor Yashayaev, Giancarlo Raiteri, Jiang ZhuAbstract:AbstractThe T5 expendable Bathythermographs reach the greatest depth within the current XBT family. Since the early 1970s, in several areas they have been providing a significant part of available ...
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How Well Can We Correct Systematic Errors in Historical XBT Data
Journal of Atmospheric and Oceanic Technology, 2018Co-Authors: Lijing Cheng, Viktor Gouretski, Franco Reseghetti, Timothy P Boyer, Rebecca Cowley, Hao Luo, John P. Abraham, Jiang ZhuAbstract:AbstractBiases have been identified in historical expendable bathythermograph (XBT) datasets, which are one of the major sources of uncertainty in the ocean subsurface database. More than 10 correc...
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A New Method of Calculating Ocean Temperatures Using Expendable Bathythermographs
Energy and Environment Research, 2011Co-Authors: John P. Abraham, Franco Reseghetti, John M Gorman, Kevin E. Trenberth, W. J. MinkowyczAbstract:A newly developed method is proposed to simplify the measurement of ocean temperatures and heat content. That method, which makes use of expendable bathythermograph probes (XBTs), is able to account for variations in the probes such as weight, size, drop height, and wire length. Additionally, this new method accounts for variations in the conditions of the drop region, such as ocean temperature and salinity. The method requires the determination of the drag coefficient which corresponds to the probe’s travel through water. This coefficient is introduced into a dynamic equation in which the position of the probe is calculated at a sequence of time steps. The calculated depths are matched with corresponding local temperatures to enable a determination of ocean heat content. The method outlined here avoids the reliance upon experimental correlations which are traditionally used for ocean-temperature measurements. To validate the method, it was applied to two calibrated XBT experiments. It is shown that the new method provides results that are virtually identical with results obtained from industry-standard techniques, and it is possible that the method can be applied to historical archives.
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on depth and temperature biases in bathythermograph data development of a new correction scheme based on analysis of a global ocean database
Deep Sea Research Part I: Oceanographic Research Papers, 2010Co-Authors: Viktor Gouretski, Franco ReseghettiAbstract:Abstract The World Ocean Database 2005 as of May 2009 is used to estimate temperature and sample depth biases of expendable (XBT) and mechanical (MBT) Bathythermographs by comparing bathythermograph temperature profiles with more accurate bottle and conductivity/temperature/depth (CTD) data. It is shown that the application of depth corrections estimated earlier from side-by-side XBT/CTD inter-comparisons, without accounting for a pure thermal bias, leads to even larger disagreement with the CTD and bottle reference temperatures. Our calculations give evidence for a depth-variable XBT fall-rate correction with the manufacturer-derived depth being underestimated in the upper 200 m and overestimated below this depth. These results are in agreement with side-by-side inter-comparisons and direct fall-rate estimates. Correcting XBT sample depths by a multiplicative factor which is constant with depth does not allow an effective elimination of the total temperature bias throughout the whole water column. The analysis further suggests a dependence of the fall rate on the water temperature which was reported earlier in the literature. Comparison among different correction schemes implies a significant impact of systematic biases on the estimates of the global ocean heat content anomaly.
K Lorbacher - One of the best experts on this subject based on the ideXlab platform.
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Ocean mixed layer depth: A subsurface proxy of ocean‐atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
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Ocean mixed layer depth: A subsurface proxy of ocean-atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
Pearn P Niiler - One of the best experts on this subject based on the ideXlab platform.
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Ocean mixed layer depth: A subsurface proxy of ocean‐atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
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Ocean mixed layer depth: A subsurface proxy of ocean-atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
Dietmar Dommenget - One of the best experts on this subject based on the ideXlab platform.
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Ocean mixed layer depth: A subsurface proxy of ocean‐atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
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Ocean mixed layer depth: A subsurface proxy of ocean-atmosphere variability
Journal of Geophysical Research, 2006Co-Authors: K Lorbacher, Dietmar Dommenget, Pearn P Niiler, Armin KohlAbstract:A new criterion, based on the shallowest extreme curvature of near surface layer density or temperature profiles, is established for demarking the mixed layer depth, h mix. Using historical global hydrographic profile data, including conductivity-temperature-depth and expendable bathythermograph data obtained during World Ocean Circulation Experiment, its seasonal variability and monthly to interannual anomalies are computed. Unlike the more commonly used Δ criterion, the new criterion is able to deal with both different vertical resolutions of the data set and a large variety of observed stratification profiles. For about two thirds of the profiles our algorithm produces an h mix/c that is more reliable than the one of the Δ criterion. The uncertainty for h mix/c is ±5 m for high- (
