The Dynamics of Earth’s Cusp in Response to the Interplanetary Shock
, Qiugang Zong 1,*, Suiyan Fu 1, Huigen Yang 2, Zejun Hu 2, Xiaoxin Zhang 3, Xuzhi Zhou 1, Chao Yue 1, Lynn Kistler 4, Patrick Daly 5, Elena Kronberg 6 and Robert Rankin 7
Yuri A. Omelchenko
Round 1
Reviewer 1 Report
The paper is devoted to the dynamics of the high altitude cusp in response to an IP shock arrival. Such studies are rare, since they require simultaneous direct measurements in several localized regions of the magnetosphere. In this study joint measurements onboard the ACE, THEMIS, and Cluster satellites showed that the triple crossings of the cusp is the result of three successive increases and decreases in the solar wind pressure behind the shock front. During each cusp crossing a strong electric field up to 40 mV/m and appearance of energetic O+, He+ and H+ ions with energies up to 1 MeV were registered. The authors explained the appearance of energetic ions, especially a high-energy O+ population, by impulsive acceleration by an electric field.
Overall I find this contribution is acceptable for publication after the following minor remarks have been corrected.
1. Fig. 4a: On the X-axis of the figure, label 102 is indicated twice.
2. Fig. S2a: The right boundary of the TOF window for He+ coincides with the left boundary of the TOF window for O+, while from the investigation of Fig. S1b, these channels are well separated.
Author Response
We appreciate the reviewer's comments. Our responses are shown in bold letters, together with the reviewer's comments in italics.
1.Fig. 4a:On the X-axis of the figure, label 102is indicated twice.
Reply: This error has been corrected on the X-axix of Fig. 4a.
2.Fig. S2a:The right boundary of theTOF window for He+ coincides with the left boundary of the TOF window for O+, while from the investigation of Fig. S1b, these channels are well separated.
Reply: The left boundary of the TOF window for O+ has been added in Fig. S2a.
Reviewer 2 Report
This is a very interesting article that discusses a new physical mechanism for heavy ion acceleration in Earth's cusp by impulsive electric fields generated by an interplanetary shock. The article is exceptionally well written and of significant interest to the space physics community. I have only two minor suggestions as follows:
Line 34: Please provide the expanded meaning of DMSP.
Line 35: "that merging" seems to be spurious. Should it be "where merging" instead?
Author Response
We appreciate the reviewer's comments. Our responses are shown in bold letters, together with the reviewer's comments in italics.
Line 34: Please provide the expanded meaning of DMSP.
Reply: The expanded meaning of DMSP has been added in Line 34.
Line 35: "that merging" seems to be spurious. Should it be "where merging" instead?
Reply: It has been corrected.
