The paper is to depict the major structures of the Northern Hemispheric summer sealevel pressure (SLP), 500 hPa height (H 500) and 500 hPa ridge-and-trough (RAT) field during1951-1980. The 1960s’ jump was found in th...The paper is to depict the major structures of the Northern Hemispheric summer sealevel pressure (SLP), 500 hPa height (H 500) and 500 hPa ridge-and-trough (RAT) field during1951-1980. The 1960s’ jump was found in the major signal of each field as well as inthe series of many circulation parameters. The major part of the H 500 change was the heightlowering over the most of the Hemisphere during the 1960s, corresponding well to the sur-face temperature change. The SLP and RAT changed in a way similar to that of the rainfallchange, with regard to the southwest-to-northeast zonal structure in the geographical distri-butions of the major signals of all the three fields. The relationship between the changes ofsome circulation parameters and the regional rainfall is discussed.展开更多
利用全球导航卫星系统反射技术(Global Navigation Satellite System Reflection,GNSS-R)监测海平面高度变化成为目前的热点。针对目前主要基于单系统反演海平面高度变化的研究,通过分析采用信噪比测量海平面高度原理,以BRST测站为例,...利用全球导航卫星系统反射技术(Global Navigation Satellite System Reflection,GNSS-R)监测海平面高度变化成为目前的热点。针对目前主要基于单系统反演海平面高度变化的研究,通过分析采用信噪比测量海平面高度原理,以BRST测站为例,对比分析采用单系统GPS、GLONASS以及两者联合反演的效果。经理论分析和实验表明:①利用单系统GPS、GLONASS以及两者联合反演海平面高度,反演结果的相关系数r均达到0.89以上,但基于单系统的反演结果,其时间分辨率较低。②利用GPS+GLONASS联合反演不仅反演结果更加稳定、精确可靠,而且进一步提高了时间分辨率,更有利于海平面变化的连续监测。展开更多
The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of stud...The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of studies based on tide gauges observations and satellite altimetry measurements. This study focuses on trend estimates from 18 high-quality tide gauge stations along the Mediterranean Sea coast. The seasonal Mann-Kendall test was run at a 5% significance level for each of the 18 stations for the period of 1993-2015 (satellite altimetry era). The results of this test indicate that the trends for 17 stations were statistically significant and showed an increase (no significant trend was observed only at one station). The rates of sea level change for the 17 stations that exhibit significant trends, estimated using seasonal Sen's approach, range after correction for Vertical Land Motion (VLM) from 1.48 to 8.72 mm/a for the period 1993-2015. Furthermore, the magnitude of change at the location of each tide gauge station was estimated using the satellite altimetry measurements. Thus, the results obtained agree with those from the tide-gauge data analysis.展开更多
文摘The paper is to depict the major structures of the Northern Hemispheric summer sealevel pressure (SLP), 500 hPa height (H 500) and 500 hPa ridge-and-trough (RAT) field during1951-1980. The 1960s’ jump was found in the major signal of each field as well as inthe series of many circulation parameters. The major part of the H 500 change was the heightlowering over the most of the Hemisphere during the 1960s, corresponding well to the sur-face temperature change. The SLP and RAT changed in a way similar to that of the rainfallchange, with regard to the southwest-to-northeast zonal structure in the geographical distri-butions of the major signals of all the three fields. The relationship between the changes ofsome circulation parameters and the regional rainfall is discussed.
文摘利用全球导航卫星系统反射技术(Global Navigation Satellite System Reflection,GNSS-R)监测海平面高度变化成为目前的热点。针对目前主要基于单系统反演海平面高度变化的研究,通过分析采用信噪比测量海平面高度原理,以BRST测站为例,对比分析采用单系统GPS、GLONASS以及两者联合反演的效果。经理论分析和实验表明:①利用单系统GPS、GLONASS以及两者联合反演海平面高度,反演结果的相关系数r均达到0.89以上,但基于单系统的反演结果,其时间分辨率较低。②利用GPS+GLONASS联合反演不仅反演结果更加稳定、精确可靠,而且进一步提高了时间分辨率,更有利于海平面变化的连续监测。
文摘The impact of climate change on sea level has received a great deal of attention by scientists worldwide. In this context, the problem of sea levels on global and regional scales have been analyzed in a number of studies based on tide gauges observations and satellite altimetry measurements. This study focuses on trend estimates from 18 high-quality tide gauge stations along the Mediterranean Sea coast. The seasonal Mann-Kendall test was run at a 5% significance level for each of the 18 stations for the period of 1993-2015 (satellite altimetry era). The results of this test indicate that the trends for 17 stations were statistically significant and showed an increase (no significant trend was observed only at one station). The rates of sea level change for the 17 stations that exhibit significant trends, estimated using seasonal Sen's approach, range after correction for Vertical Land Motion (VLM) from 1.48 to 8.72 mm/a for the period 1993-2015. Furthermore, the magnitude of change at the location of each tide gauge station was estimated using the satellite altimetry measurements. Thus, the results obtained agree with those from the tide-gauge data analysis.
