scholarly journals Ground and satellite observations of low-latitude red auroras at the initial phase of magnetic storms

2013 ◽  
Vol 118 (1) ◽  
pp. 256-270 ◽  
Author(s):  
K. Shiokawa ◽  
Y. Miyoshi ◽  
P. C. Brandt ◽  
D. S. Evans ◽  
H. U. Frey ◽  
...  
2004 ◽  
Author(s):  
J. F. Fennell ◽  
J. B. Blake ◽  
R. Friedel ◽  
S. Kanekal

2007 ◽  
Vol 4 (3) ◽  
pp. 1877-1921 ◽  
Author(s):  
B. Schneider ◽  
L. Bopp ◽  
M. Gehlen ◽  
J. Segschneider ◽  
T. L. Frölicher ◽  
...  

Abstract. This study compares spatial and temporal variability in net primary productivity (PP) and particulate organic carbon (POC) export production (EP) from three different coupled climate carbon cycle models (IPSL, MPIM, NCAR) with observation-based estimates derived from satellite measurements of ocean colour and inverse modelling. Satellite observations of ocean colour have shown that temporal variability of PP on the global scale is largely dominated by the permanently stratified, low-latitude ocean (Behrenfeld et al., 2006)\\nocite{Behrenfeld06} with stronger stratification (higher SSTs) leading to negative PP anomalies and vice versa. Results from all three coupled models confirm the role of the low-latitude, permanently stratified ocean for global PP anomalies. Two of the models also reproduce the inverse relationship between stratification (SST) and PP, especially in the equatorial Pacific. With the help of the model results we are able to explain the chain of cause and effect leading from stratification (SST) through nutrient concentrations to PP and finally to EP. There are significant uncertainties in observational PP and especially EP. Our finding of a good agreement between independent estimates from coupled models and satellite observations provides increased confidence that such models can be used as a first basis to estimate the impact of future climate change on marine productivity and carbon export.


2013 ◽  
Vol 118 (6) ◽  
pp. 3866-3876 ◽  
Author(s):  
G. D. Earle ◽  
R. L. Davidson ◽  
R. A. Heelis ◽  
W. R. Coley ◽  
D. R. Weimer ◽  
...  
Keyword(s):  

Radio Science ◽  
1993 ◽  
Vol 28 (3) ◽  
pp. 389-400 ◽  
Author(s):  
D. R. Lakshmi ◽  
R. S. Dabas ◽  
B. C. N. Rao ◽  
B. M. Reddy

1994 ◽  
Vol 46 (3) ◽  
pp. 231-252 ◽  
Author(s):  
K. Shiokawa ◽  
K. Yumoto ◽  
Y. Tanaka ◽  
T. Oguti ◽  
Y. Kiyama
Keyword(s):  

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Yusuke Ebihara ◽  
Shinichi Watari ◽  
Sandeep Kumar

AbstractLarge-amplitude geomagnetically induced currents (GICs) are the natural consequences of the solar–terrestrial connection triggered by solar eruptions. The threat of severe damage of power grids due to the GICs is a major concern, in particular, at high latitudes, but is not well understood as for low-latitude power grids. The purpose of this study is to evaluate the lower limit of the GICs that could flow in the Japanese power grid against a Carrington-class severe magnetic storm. On the basis of the geomagnetic disturbances (GMDs) observed at Colaba, India, during the Carrington event in 1859, we calculated the geoelectric disturbances (GEDs) by a convolution theory, and calculated GICs flowing through transformers at 3 substations in the Japanese extra-high-voltage (500-kV) power grid by a linear combination of the GEDs. The estimated GEDs could reach ~ 2.5 V/km at Kakioka, and the GICs could reach, at least, 89 ± 30 A near the storm maximum. These values are several times larger than those estimated for the 13–14 March 1989 storm (in which power blackout occurred in Canada), and the 29–31 October 2003 storm (in which power blackout occurred in Sweden). The GICs estimated here are the lower limits, and there is a probability of stronger GICs at other substations. The method introduced here will be immediately applicable for benchmark evaluation of low-latitude GICs against the Carrington-class magnetic storms if one assumes electrical parameters, such as resistance of transmission lines, with sufficient accuracy.


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