scholarly journals On the ability of statistical wind-wave models to capture the variability and long-term trends of the North Atlantic winter wave climate

2016 ◽  
Vol 103 ◽  
pp. 177-189 ◽  
Author(s):  
Adrián Martínez-Asensio ◽  
Marta Marcos ◽  
Michael N. Tsimplis ◽  
Gabriel Jordà ◽  
Xiangbo Feng ◽  
...  
2007 ◽  
Vol 7 (1) ◽  
pp. 93-126 ◽  
Author(s):  
K. Eleftheratos ◽  
C. S. Zerefos ◽  
P. Zanis ◽  
D. S. Balis ◽  
G. Tselioudis ◽  
...  

Abstract. The seasonal variability and the interannual variance explained by ENSO and NAO to cirrus cloud cover (CCC) are examined during the twenty-year period 1984–2004. CCC was found to be significantly correlated with vertical velocities and relative humidity from ECMWF/ERA40 in the tropics (correlations up to –0.7 and +0.7 at some locations, respectively) suggesting that variations in large-scale vertical winds and relative humidity fields can be the origin of up to half of the local variability in CCC over these regions. These correlations reflect mostly the seasonal cycle. Although the annual cycle is dominant in all latitudes and longitudes, peaking over the tropics and subtropics, its amplitude can be exceeded during strong El Nino/La Nina events. Over the eastern tropical Pacific Ocean the interannual variance of CCC which can be explained by ENSO is about 6.8% and it is ~2.3 times larger than the amplitude of the annual cycle. Natural long-term trends in the tropics are generally small (about –0.3% cloud cover per decade) and possible manmade trends in those regions are also small. The contributions of NAO and QBO to the variance of CCC in the tropics are also small. In the northern mid–latitudes, on the other hand, the effect of NAO is more significant and can be very important regionally. Over northern Europe and the eastern part of the North Atlantic Flight Corridor (NAFC) there is a small positive correlation between CCC and NAO index during the wintertime of about 0.3. In this region, the interannual variance of CCC explained by NAO is 2.6% and the amplitude of the annual cycle is 3.1%. Long-term trends over this region are about +1.6% cloud cover per decade and compare well with the observed manmade trends over congested air traffic regions in Europe and the North Atlantic as have been evidenced from earlier findings.


2007 ◽  
Vol 7 (10) ◽  
pp. 2631-2642 ◽  
Author(s):  
K. Eleftheratos ◽  
C. S. Zerefos ◽  
P. Zanis ◽  
D. S. Balis ◽  
G. Tselioudis ◽  
...  

Abstract. The seasonal variability and the interannual variance explained by ENSO and NAO to cirrus cloud cover (CCC) are examined during the twenty-year period 1984–2004. CCC was found to be significantly correlated with vertical velocities and relative humidity from ECMWF/ERA40 in the tropics (correlations up to −0.7 and +0.7 at some locations, respectively) suggesting that variations in large-scale vertical winds and relative humidity fields can be the origin of up to half of the local variability in CCC over these regions. These correlations reflect mostly the seasonal cycle. Although the annual cycle is dominant in all latitudes and longitudes, peaking over the tropics and subtropics, its amplitude can be exceeded during strong El Nino/La Nina events. Over the eastern tropical Pacific Ocean the interannual variance of CCC which can be explained by ENSO is about 6.8% and it is ~2.3 times larger than the amplitude of the annual cycle. Natural long-term trends in the tropics are generally small (about −0.3% cloud cover per decade) and possible manmade trends in those regions are also small. The contributions of NAO and QBO to the variance of CCC in the tropics are also small. In the northern mid-latitudes, on the other hand, the effect of NAO is more significant and can be very important regionally. Over northern Europe and the eastern part of the North Atlantic Flight Corridor (NAFC) there is a small positive correlation between CCC and NAO index during the wintertime of about 0.3. In this region, the interannual variance of CCC explained by NAO is 2.6% and the amplitude of the annual cycle is 3.1%. Long-term trends over this region are about +1.6% cloud cover per decade and compare well with the observed manmade trends over congested air traffic regions in Europe and the North Atlantic as have been evidenced from earlier findings.


Water ◽  
2012 ◽  
Vol 4 (1) ◽  
pp. 170-195 ◽  
Author(s):  
Sönke Dangendorf ◽  
Thomas Wahl ◽  
Hartmut Hein ◽  
Jürgen Jensen ◽  
Stephan Mai ◽  
...  

1997 ◽  
Vol 119 (3) ◽  
pp. 184-190 ◽  
Author(s):  
M. T. Pontes ◽  
S. Barstow ◽  
L. Bertotti ◽  
L. Cavaleri ◽  
H. Oliveira-Pires

In the last two decades the performance of numerical wind-wave models has improved considerably. Several models have been routinely producing good quality wave estimates globally since the mid-1980s. The verifications of wind-wave models have mainly focused on the evaluation of the error of the significant wave height Hs estimates. However, for wave energy purposes, the main parameters to be assessed are the wave power Pw and the mean (energy) period Te. Since Pw is proportional to Hs2 Tc, its expected error is much larger than for the single-wave parameters. This paper summarizes the intercomparison of two wind-wave models against buoy data in the North Atlantic and the Mediterranean Sea to select the most suitable one for the construction of an Atlas of the wave energy resource in European waters. A full verification in the two basins of the selected model—the WAM model implemented in the routine operation of the European Centre for Medium-Range Weather Forecasts—was then performed against buoy and satellite altimeter data. It was found that the WAM model accuracy is very good for offshore locations in the North Atlantic; but for the Mediterranean Sea the results are much less accurate, probably due to a lower quality of the input wind fields.


2018 ◽  
Vol 68 (11) ◽  
pp. 1593-1604 ◽  
Author(s):  
Margarita Markina ◽  
Alexander Gavrikov ◽  
Sergey Gulev ◽  
Bernard Barnier

Author(s):  
Robert H. Ellison

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.


2015 ◽  
Vol 12 (17) ◽  
pp. 15223-15244
Author(s):  
M. L. Breeden ◽  
G. A. McKinley

Abstract. The North Atlantic is the most intense region of ocean CO2 uptake. Here, we investigate multidecadal timescale variability of the partial pressure CO2 (pCO2) that is due to the natural carbon cycle using a regional model forced with realistic climate and pre-industrial atmospheric pCO2 for 1948–2009. Large-scale patterns of natural pCO2 variability are primarily associated with basin-averaged sea surface temperature (SST) that, in turn, is composed of two parts: the Atlantic Multidecadal Oscillation (AMO) and a long-term positive SST trend. The North Atlantic Oscillation (NAO) drives a secondary mode of variability. For the primary mode, positive AMO and the SST trend modify pCO2 with different mechanisms and spatial patterns. Warming with the positive AMO increases subpolar gyre pCO2, but there is also a significant reduction of dissolved inorganic carbon (DIC) due primarily to reduced vertical mixing. The net impact of positive AMO is to reduce pCO2 in the subpolar gyre. Through direct impacts on SST, the net impacts of positive AMO is to increase pCO2 in the subtropical gyre. From 1980 to present, long-term SST warming has amplified AMO impacts on pCO2.


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