Search Results - "Holappa, L"

The Polarity of IMF By Strongly Modulates Particle Precipitation During High‐Speed Streams by Laitinen, J., Holappa, L., Vanhamäki, H.

“…Recent studies have suggested that the interplanetary magnetic field (IMF) By ${B}_{y}$ component modulates particle precipitation during solstices, or periods…”
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Explicit IMF B y -Dependence of Energetic Protons and the Ring Current by Holappa, L, Buzulukova, N Y

“…The most important parameter driving the solar wind-magnetosphere interaction is the southward ( ) component of the interplanetary magnetic field (IMF). While…”
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Explicit IMF By-Dependence of Energetic Protons and the Ring Current by Holappa, L, Buzulukova, N Y

“…The most important parameter driving the solar wind-magnetosphere interaction is the southward (Bz) component of the interplanetary magnetic field (IMF). While…”
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Explicit IMF By Dependence in High‐Latitude Geomagnetic Activity by Holappa, L., Mursula, K.

“…The interaction of the solar wind with the Earth's magnetic field produces geomagnetic activity, which is critically dependent on the orientation of the…”
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A Combined Effect of the Earth's Magnetic Dipole Tilt and IMF By in Controlling Auroral Electron Precipitation by Laitinen, J., Holappa, L., Vanhamäki, H.

“…Auroral particle precipitation is usually assumed to be equally strong for both signs of the By component of the interplanetary magnetic field (IMF). This is…”
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Explicit IMF By Dependence in Geomagnetic Activity: Modulation of Precipitating Electrons by Holappa, L., Asikainen, T., Mursula, K.

“…The most important driver of geomagnetic activity is the north–south ( Bz) component of the interplanetary magnetic field (IMF), which dominates the solar…”
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BMP6/TAZ-Hippo signaling modulates angiogenesis and endothelial cell response to VEGF by Pulkkinen, H. H., Kiema, M., Lappalainen, J. P., Toropainen, A., Beter, M., Tirronen, A., Holappa, L., Niskanen, H., Kaikkonen, M. U., Ylä-Herttuala, S., Laakkonen, Johanna P.

“…The BMP/TGFβ-Smad, Notch and VEGF signaling guides formation of endothelial tip and stalk cells. However, the crosstalk of bone morphogenetic proteins (BMPs)…”
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A new method to estimate annual solar wind parameters and contributions of different solar wind structures to geomagnetic activity by Holappa, L., Mursula, K., Asikainen, T.

“…In this paper, we study two sets of local geomagnetic indices from 26 stations using the principal component and the independent component (IC) analysis…”
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Explicit IMF By‐Dependence in Geomagnetic Activity: Quantifying Ionospheric Electrodynamics by Holappa, L., Robinson, R. M., Pulkkinen, A., Asikainen, T., Mursula, K.

“…Geomagnetic activity is mainly driven by the southward (Bz) component of the interplanetary magnetic field (IMF), which dominates all solar wind coupling…”
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Seasonal solar wind speeds for the last 100 years: Unique coronal hole structures during the peak and demise of the Grand Modern Maximum by Mursula, K., Holappa, L., Lukianova, R.

“…Solar coronal holes are sources of high‐speed solar wind streams, which cause persistent geomagnetic activity especially at high latitudes. Here we estimate…”
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Annual fractions of high-speed streams from principal component analysis of local geomagnetic activity by Holappa, L., Mursula, K., Asikainen, T., Richardson, I. G.

“…We study the latitudinal distribution of geomagnetic activity in 1966–2009 with local geomagnetic activity indices at 26 magnetic observatories. Using the…”
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Explicit IMF By‐Effect Maximizes at Subauroral Latitudes (Dedicated to the Memory of Eigil Friis‐Christensen) by Holappa, L., Gopalswamy, N., Mursula, K.

“…The most important parameter in the coupling between solar wind and geomagnetic activity is the Bz‐component of the interplanetary magnetic field (IMF)…”
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Toward more reliable long‐term indices of geomagnetic activity: Correcting a new inhomogeneity problem in early geomagnetic data by Holappa, L., Mursula, K.

“…For the time before the space era, our knowledge of the centennial evolution of solar wind (SW) and interplanetary magnetic field (IMF) is based on proxies…”
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On Physico-Chemical and Technical Limits in Clean Steel Production by Holappa, L.

“…Great progresses in steel cleanliness have been attained during the last decades. In the measures of oxygen the lowest levels are approaching 5 ppm in Otot…”
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Average properties of geomagnetic storms in 1932-2009 by Yakovchouk, O. S., Mursula, K., Holappa, L., Veselovsky, I. S., Karinen, A.

“…We investigate the average properties of geomagnetic storms using the global and local Dxt indices at four Dst stations in 1932–2009. Imposing the condition of…”
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The effect of silicon, vanadium and nitrogen on the microstructure and hardness of air cooled medium carbon low alloy steels by Ollilainen, V., Kasprzak, W., Holappa, L.

“…This paper presents a comparison of structural investigations of four medium carbon low alloy steels: 38MnSi6, 38MnSiV5 and modifications with higher silicon…”
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Surface characterization and H2S-sensing potential of iron molybdate particles produced by supercritical solvothermal method and subsequent oxidation by KERSEN, Ü, HOLAPPA, L

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Uneven weighting of stations in the Dst index by Mursula, K., Holappa, L., Karinen, A.

“…We note in this paper that the average disturbances of the four Dst stations are systematically different and, therefore, the stations contribute to the Dst…”
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Explicit IMF B y Dependence in High‐Latitude Geomagnetic Activity by Holappa, L., Mursula, K.

“…Abstract The interaction of the solar wind with the Earth's magnetic field produces geomagnetic activity, which is critically dependent on the orientation of…”
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Ring current development during high speed streams by Jordanova, V.K., Matsui, H., Puhl-Quinn, P.A., Thomsen, M.F., Mursula, K., Holappa, L.

“…Episodes of southward ( B z < 0 ) interplanetary magnetic field (IMF) which lead to disturbed geomagnetic conditions are associated either with coronal mass…”
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