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21.
The influences of mesoscale eddies on variations of the Kuroshio path south of Japan have been investigated using time series
of the Kuroshio axis location and altimeter-derived sea surface height maps for a period of seven years from 1993 to 1999,
when the Kuroshio followed its non-large meander path. It was found that both the cyclonic and anticyclonic eddies may interact
with the Kuroshio and trigger short-term meanders of the Kuroshio path, although not all eddies that approached or collided
with the Kuroshio formed meanders. An anticyclonic eddy that revolves clockwise in a region south of Shikoku and Cape Shionomisaki
with a period of about 5–6 months was found to propagate westward along about 30°N and collide with the Kuroshio in the east
of Kyushu or south of Shikoku. This collision sometimes triggers meanders which propagate over the whole region south of Japan.
The eddy was advected downstream, generating a meander on the downstream side to the east of Cape Shionomisaki. After the
eddy passed Cape Shionomisaki, it detached from the Kuroshio and started to move westward again. Sometimes the eddy merges
with other anticyclonic eddies traveling from the east. Coalescence of cyclonic eddies, which are also generated in the Kuroshio
Extension region and propagate westward in the Kuroshio recirculation region south of Japan, into the Kuroshio in the east
of Kyushu, also triggers meanders which mainly propagate only in a region west of Cape Shionomisaki.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Purvee Joshi Sandip R. Oza Ujjwal K. Gupta Shailendra Saini D. Ram Rajak I. M. Bahuguna 《Marine Geodesy》2020,43(3):302-323
AbstractIntra and inter-annual variations in the sea ice thickness are highly sensitive indicators of climatic variations undergoing in the earth’s atmosphere and oceans. This paper describes the method of estimating sea ice thickness using radar waveforms data acquired by SARAL/Altika mission during its drifting orbit phase from July 2016 onwards yielding spatially dense data coverage. Based on statistical analysis of return echoes, classification of the surface has been carried out in three different types, viz. floe, lead and mixed. Time delay correction methods were suitably selected and implemented to make corrections in altimetric range measurements and thereby freeboard. By assuming hydrostatic equilibrium, freeboard data were converted into sea ice thickness. Results show that sea ice thickness varies from 4 to 5?m near ice shelves and 1 to 2.5?m in the marginal sea ice regions. Freeboard and sea ice thickness estimates were also validated using NASA’s Operation Ice Bridge (OIB) datasets. Freeboard measurements show very high correlation (0.97) having RMSE of 0.13. Overestimation of approximately 1–2?m observed in the sea ice thickness, which could be attributed to distance between AltiKa footprint and OIB locations. Moreover, sensitivity analysis shows that snow depth and snow density over sea ice play crucial role in the estimation of sea ice thickness. 相似文献
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J. Perbos P. Escudier F. Parisot G. Zaouche P. Vincent Y. Menard F. Manon G. Kunstmann D. Royer L. -L. Fu 《Marine Geodesy》2003,26(3):147-157
On 7 December 2001, Jason-1 was successfully launched by a Boeing Delta II rocket from the Vandenberg Air Force Base, California. The Jason-1 satellite will maintain the high accuracy altimeter service provided since 1992 by TOPEX/Poseidon (T/P), ensuring the continuity in observing and monitoring the Ocean Dynamics (intraseasonal to interannual changes, mean sea level, tides, etc.). Despite one-fourth the mass and power, the Jason-1 system has been designed to have basically the same performance as T/P, measuring sea surface topography at a centimetric level. This new CNES/NASA mission also provides near real-time data for sea state and ocean forecast. The first two months of the Jason-1 mission have been dedicated to the assessment of the overall system. The goals of this assessment phase were:
1. To assess the behavior of the spacecraft at the platform and payload levels (Jason-1 being the first program to call on the PROTEUS versatile multimission platform for Low and Medium Earth Orbit Missions developed in partnership between Alcatel Space and CNES);
2. To verify that platform performance requirements are met with respect to Jason-1 requirements;
3. To verify that payload instruments performance requirements evaluated at instrument level are met;
4. To assess the performance of the Jason-1 Ground System.
This article will display the main outputs of the assessment of the system. It will demonstrate that all the elements of the onboard and ground systems are within the specifications. Provision of data to the Jason-1 Science Working Team started at the end of March 2002. This is the goal of a six-month phase after closure of the initial assessment phase to derive the error budget of the system in terms of altimetry user products. 相似文献
1. To assess the behavior of the spacecraft at the platform and payload levels (Jason-1 being the first program to call on the PROTEUS versatile multimission platform for Low and Medium Earth Orbit Missions developed in partnership between Alcatel Space and CNES);
2. To verify that platform performance requirements are met with respect to Jason-1 requirements;
3. To verify that payload instruments performance requirements evaluated at instrument level are met;
4. To assess the performance of the Jason-1 Ground System.
This article will display the main outputs of the assessment of the system. It will demonstrate that all the elements of the onboard and ground systems are within the specifications. Provision of data to the Jason-1 Science Working Team started at the end of March 2002. This is the goal of a six-month phase after closure of the initial assessment phase to derive the error budget of the system in terms of altimetry user products. 相似文献
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1Introduction With the development and application of remotesensing technology, people fromthe international re-mote sensing community have realized the issue thatwe have immoderately emphasized characteristics ofvast volume data and great detail of remot… 相似文献
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The radiometers on board the satellites ERS-1, TOPEX/Poseidon, ERS-2, GFO, Jason-1, and Envisat measure brightness temperatures at two or three different frequencies to determine the total columnal water vapor content and wet tropospheric path delay, a major correction to the altimeter range measurements. In order to asses the long-term stability of the path delay, the radiometers are calibrated against vicarious cold and hot references, against each other, and against several atmospheric models. Four of these radiometers exhibit significant drifts in at least one of the channels, resulting in yet unmodeled errors in path delay of up to 1 mm/year, thus limiting the accuracy at which global sea level rise can be inferred from the altimeter range measurements. 相似文献
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