Abstract
In this work, empirical relationships based on indices (AE, IL, and KP), an empirical model (Weimer-2005), coupled space weather models (BATS-R-US+CRCM/RCM), and combinative methods (using data from SuperDARN for electric field and OVATION PRIME+IRI combination for the conductances) are employed to investigate the Joule heating (JH) variability during two isolated substorms on 8 March 2008. The results are compared according to substorm phases, magnetic local time sectors, magnetic latitudes, role of electric fields, ionospheric conductances, and neutral wind. Qualitatively, all methods exhibit similar variations in the estimated JH rates. AE-dependent methods and the Weimer-2005 model show the highest JH rates. The response of AE to the elevated Epsilon levels is found to be delayed up to 50 min, whereas the onsets and variations in the other methods are concurrent with Epsilon. The combination of OVATION Prime+IRI and SuperDARN provides values close to the (Foster et al., 1983, https://doi.org/10.1029/JA088iA06p04885) suggesting that it is representative enough to use for estimating the JH. The OVATION Prime+IRI and SuperDARN method can provide JH at any point in the solar cycle based on dynamic solar wind input. BATSRUS/CRCM conductances and electric fields are higher than BATSRUS/RCM leading to 2.5 times as much JH as estimated by BATSRUS/RCM on average. Neutral winds are found to comprise an overall 15% of total JH with a maximum of 25% in dusk sector during the expansion phase. We discuss that W05 and AE-dependent methods overestimate the JH rates during the solar minimum since they are constructed using solar maximum data.
| Original language | English |
|---|---|
| Pages (from-to) | 987-1012 |
| Number of pages | 26 |
| Journal | Space Weather |
| Volume | 16 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Aug 2018 |
Bibliographical note
Publisher Copyright:©2018. American Geophysical Union. All Rights Reserved.
Funding
This work has been supported by the Turkish Scientific and Technological Council (TÜBİTAK), project 109Y058 and 113Y213, and 2214/International Doctoral Research Fellowship Programme. It is also partially supported by ITU-Research Fund (BAP). We thank the PIs of the instruments on ACE, and the producers and providers of the AE and Dst index, WDC, Kyoto. We are grateful to the producers of the OP model for making their model available online for all users. We thank the institutes who maintain the IMAGE Magnetometer Array: Tromsø Geophysical Observatory of UiT the Arctic University of Norway (Norway), Finnish Meteorological Institute (Finland), Institute of Geophysics Polish Academy of Sciences (Poland), GFZ German Research Centre for Geosciences (Germany), Geological Survey of Sweden (Sweden), Swedish Institute of Space Physics (Sweden), Sodankylä Geophysical Observatory of the University of Oulu (Finland), and Polar Geophysical Institute (Russia). The Virginia Tech authors acknowledge the support of NSF award AGS-0946900. They also acknowledge the support of national funding agencies of the United States, Canada, U.K., France, and Japan for the operation of SuperDARN radars in the northern hemisphere. This work was carried out using the SWMF/BATSRUS tools developed at The University of Michigan Center for Space Environment Modeling (CSEM) and made available through the NASA Community Coordinated Modeling Center (CCMC) through their public Runs on Request system (http://ccmc. gsfc.nasa.gov). The CCMC is a multia gency partnership between NASA, AFMC, AFOSR, AFRL, AFWA, NOAA, NSF, and ONR. We thank Yi-Jiun Su Caton for her proofreading of the first version of the manuscript and valuable comments in the text. Additionally, we thank both referees for their valuable and constructive comments that improved our paper. This work has been supported by the Turkish Scientific and Technological Council (T?B?TAK), project 109Y058 and 113Y213, and 2214/International Doctoral Research Fellowship Programme. It is also partially supported by ITU-Research Fund (BAP). We thank the PIs of the instruments on ACE, and the producers and providers of the AE and Dst index, WDC, Kyoto. We are grateful to the producers of the OP model for making their model available online for all users. We thank the institutes who maintain the IMAGE Magnetometer Array: Troms? Geophysical Observatory of UiT the Arctic University of Norway (Norway), Finnish Meteorological Institute (Finland), Institute of Geophysics Polish Academy of Sciences (Poland), GFZ German Research Centre for Geosciences (Germany), Geological Survey of Sweden (Sweden), Swedish Institute of Space Physics (Sweden), Sodankyl? Geophysical Observatory of the University of Oulu (Finland), and Polar Geophysical Institute (Russia). The Virginia Tech authors acknowledge the support of NSF award AGS-0946900. They also acknowledge the support of national funding agencies of the United States, Canada, U.K., France, and Japan for the operation of SuperDARN radars in the northern hemisphere. This work was carried out using the SWMF/BATSRUS tools developed at The University of Michigan Center for Space Environment Modeling (CSEM) and made available through the NASA Community Coordinated Modeling Center (CCMC) through their public Runs on Request system (http://ccmc.gsfc.nasa.gov). The CCMC is a multiagency partnership between NASA, AFMC, AFOSR, AFRL, AFWA, NOAA, NSF, and ONR. We thank Yi-Jiun Su Caton for her proofreading of the first version of the manuscript and valuable comments in the text. Additionally, we thank both referees for their valuable and constructive comments that improved our paper.
| Funders | Funder number |
|---|---|
| AFWA | |
| CCMC | |
| Finnish Meteorological Institute | |
| ITU-Research Fund | |
| Institute of Geophysics Polish Academy of Sciences | |
| Polar Geophysical Institute | |
| Swedish Institute of Space Physics | |
| Turkish Scientific and Technological Council | |
| National Science Foundation | AGS-0946900 |
| Office of Naval Research | |
| National Aeronautics and Space Administration | |
| Air Force Office of Scientific Research | |
| National Oceanic and Atmospheric Administration | |
| Air Force Materiel Command | |
| Air Force Research Laboratory | |
| Universitetet i Tromsø | |
| British Association for Psychopharmacology | |
| Sveriges Geologiska Undersökning | |
| Türkiye Bilimsel ve Teknolojik Araştırma Kurumu | 109Y058, 113Y213 |
| Oulun Yliopisto | |
| Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ |
Keywords
- conductance
- electric field
- empirical models
- Joule heating
- MHD models
- substorm