Cluster Observation of Ion Outflow in Middle Altitude LLBL/Cusp from Different Origins
, Huigen Yang 1,*, Jicheng Sun 1, Zejun Hu 1, Jianjun Liu 1, Xiangcai Chen 1, Yongfu Wang 2, Jie Ren 2, Chao Yue 2, C. Philippe Escoubet 3, Qian Wang 4 and Qiugang Zong 1,2
Olugbenga Ogunmodimu
Round 1
Reviewer 1 Report
The paper's outline is fine and the presentation is generally good. However, the paper will be better with minor editing. For example, there are parts of the abstract that shows abbreviation before the real meanings (e.g. solar EUV emission2, authors should write EUV in full before abbreviating, (LLBL/cusp) Low Latitude 18 Boundary Layer of the cusp, should be the other way round etc)
In the introduction: The ionosphere is the ionized part of the upper atmosphere which is caused mainly etc
It would be better to say "The ionized part of the upper atmosphere (ionosphere) is caused mainly etc .
I advise that authors take the time to once again read through the entire manuscript for possible presentation problems. However, the paper highlighted important findings to further compliment previous findings from the Cluster spacecraft.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper used the observations from Cluster spacecraft to study particles dynamic processes in the Earth’s cusp region by analyzing the cusp ions energy dispersion, outflowing cold ions, Poynting flux in LLBL/cusp, and outflowing plasma temperature. They show very interesting results: providing a picture of fine-structured ions outflow 374 in the Earth’s LLBL/cusp region and finding the cold ion groups on LLBL/cusp were mainly composed of H+ and O+, and all the 354 cold ions flows were turning upward gradually when its flow entered the down flowing 355 H+ channel.
However, there are some concerns about the results that need clarifications before I finally recommend a publication. Also, there are many typos needed to be corrected and the writing are not consistent. I suggest the authors carefully check their MS.
Main:
The MS emphasized that the cold ion outflow in the LLBL/cusp may benefit from additional nonadiabatic acceleration in the same region. Why temperature rising of the particles experienced a non-adiabatic acceleration. I would expect a more detailed discussion on this.
The data details need to be presented.
In many places, (1) words using is not self-consistent, for example, down ward, downward, , down-ward. Please use one kind of description in one MS. I suggest using downward. (2) citations not consistent. (3) Most figures lack their summary titles.
Minors:
1） L14, “Ionospheric” should be “and ionospheric”
2） L16, “Cluster spacecraft C1” is “spacecraft Cluster C1”
3） L18: “Low Latitude 18 Boundary Layer (LLBL/cusp)” instead of “(LLBL/cusp) Low Latitude Boundary Layer”
4） L31, same as 1)
5） L33-35, I suggest adding some citations, for example:
Milan et al., Variations in the polar cap area during two substorm cycles. Ann. Geophys., 21(5), 1121–1140, 2003.
Lu et al, on the response of magnetosphere to the IMF turning from north to south, Earth and Planetary Physics, 3(1), 8-18, 2019.
6） Polar wind should be “polar wind”
7） L43, one of the essential issue
8） L50, change “results” to “and”
9） L57, 66, 69, 77, many citations are not consistent, for example, Slapak et al [25], Waara et al., [26]. Please follow the journal requirement, delete or add the comma after authors.
10） L57-62, this sentence is too long
11） L71, change reveal to revealed
12） L76，“. Jacobsen”should be “, Jacobsen”
13） L83, citation is not consistent with others
14） L86, delete the comma
15） L92, same as 3)
16） L97, delete “particularly” or change to “, particularly the 97 shocked solar wind penetration through the polar cusps”
17） L99-102, the authors need to provide the data details, specify what data is from which website.
18） L107, add (IMF) in their first appearance.
19） L109, add “in” after interested
20） Figure 1 and 2 titles: first describe the figure content, for example: Fig1. The solar wind parameters observed on 23 August 2004. a), …, b) …
21） L138, delete “very often”
22） L154, presented
23） L155, and found
24） L157, and these
25） L163, change Happening to occuring
26） L185, the most
27） L191-192, and Lee et al.
28） L194, delete “which”
29） Fig.5, lack a summary title
30） L210-212, what reasons cause the high energy ions would return from low 211 altitude to higher altitude in a short time or distance?
31） L225-226, the sentence needs a verb.
32） L241-242, change down-ward to downward
33） L275, add a citation after “cusp”
34） L299, raised
35） L301, why so sure about that temperature rising of the particles presents a nonadiabatic acceleration?
36） L375, Earth
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
