Determination of global mean sea surface WHU2000 using multi-satellite altimetric data

2002 ◽  
Vol 47 (19) ◽  
pp. 1664
Author(s):  
Weiping JIANG
2002 ◽  
Vol 47 (19) ◽  
pp. 1664-1668 ◽  
Author(s):  
Weiping Jiang ◽  
Jiancheng Li ◽  
Zhengtao Wang

Author(s):  
Erin McClymont ◽  
Heather Ford ◽  
Sze Ling Ho ◽  
Julia Tindall ◽  
Alan Haywood ◽  
...  

<p>A range of future climate scenarios are projected for high atmospheric CO<sub>2</sub> concentrations, given uncertainties over future human actions as well as potential environmental and climatic feedbacks. The geological record offers an opportunity to understand climate system response to a range of forcings and feedbacks which operate over multiple temporal and spatial scales. Here, we examine a single interglacial during the late Pliocene (KM5c, ca. 3.205 +/- 0.01 Ma) when atmospheric CO<sub>2</sub> concentrations were higher than pre-industrial, but similar to today and to the lowest emission scenarios for this century. As orbital forcing and continental configurations were almost identical to today, we are able to focus on equilibrium climate system response to modern and near-future CO<sub>2</sub>. Using proxy data from 32 sites, we demonstrate that global mean sea-surface temperatures were warmer than pre-industrial, by ~2.3 ºC for the combined proxy data (foraminifera Mg/Ca and alkenones), or by ~3.2ºC (alkenones only). Compared to the pre-industrial, reduced meridional gradients and enhanced warming in the North Atlantic are consistently reconstructed. There is broad agreement between data and models at the global scale, with regional differences reflecting ocean circulation and/or proxy signals. An uneven distribution of proxy data in time and space does, however, add uncertainty to our anomaly calculations. The reconstructed global mean sea-surface temperature anomaly for KM5c is warmer than all but three of the PlioMIP2 model outputs, and the reconstructed North Atlantic data tend to align with the warmest KM5c model values.  Our results demonstrate that even under low CO<sub>2</sub> emission scenarios, surface ocean warming may be expected to exceed model projections, and will be accentuated in the higher latitudes.</p>


1992 ◽  
Vol 97 (B4) ◽  
pp. 4915 ◽  
Author(s):  
J. G. Marsh ◽  
C. J. Koblinsky ◽  
H. J. Zwally ◽  
A. C. Brenner ◽  
B. D. Beckley

2012 ◽  
Vol 5 (2) ◽  
pp. 523-533 ◽  
Author(s):  
Z. S. Zhang ◽  
K. Nisancioglu ◽  
M. Bentsen ◽  
J. Tjiputra ◽  
I. Bethke ◽  
...  

Abstract. The mid-Pliocene period (3.3 to 3.0 Ma) is known as a warm climate with atmospheric greenhouse gas levels similar to the present. As the climate at this time was in equilibrium with the greenhouse forcing, it is a valuable test case to better understand the long-term response to high levels of atmospheric greenhouse gases. In this study, we use the low resolution version of the Norwegian Earth System Model (NorESM-L) to simulate the pre-industrial and the mid-Pliocene climate. Comparison of the simulation with observations demonstrates that NorESM-L simulates a realistic pre-industrial climate. The simulated mid-Pliocene global mean surface air temperature is 16.7 °C, which is 3.2 °C warmer than the pre-industrial. The simulated mid-Pliocene global mean sea surface temperature is 19.1 °C, which is 2.0 °C warmer than the pre-industrial. The warming is relatively uniform globally, except for a strong amplification at high latitudes.


2014 ◽  
Vol 20 (2) ◽  
pp. 300-316 ◽  
Author(s):  
Henry Montecino Castro ◽  
Aharon Cuevas Cordero ◽  
Sílvio Rogério Correia de Freitas

Most aspects related to the horizontal component of the Geocentric Reference System for the Americas (SIRGAS) have been solved. However, in the case of the vertical component there are still aspects of definition, national realizations and continental unification still not accomplished. Chile is no exception; due to its particular geographic characteristics, a number of tide gauges (TG) had to be installed in the coast from which the leveling lines that compose the Chilean Vertical Network (CHVN) were established. This study explored the offsets of the CHVN by two different approaches; one geodetic and one oceanographic. In the first approach, the offsets were obtained in relation to the following Global Geopotential Models (GGM): the satellite-only model (unbiased) GO_CONS_gcf_2_tim_r3 derived from GOCE satellite mission; EGM2008 (combined-biased); and GOEGM08, combining information from the GO_CONS_gcf_2_tim_r3 in long wavelengths (n max~200) with the mean/short wavelengths of EGM2008 (n>200). In the oceanographic method, we used the CNES CLS 2011 Global Mean Sea surface and EIGEN_GRACE_5C GGM to obtain the values of MDT at the different TG. We also evaluated the CHVN in relation to different GGMs. The results showed consistency between the values obtained by the two methods at the TG of Valparaíso and Puerto Chacabuco. In terms of the evaluation of the GGM, GOEGM08 produced the best results.


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