Difference between 晴れ晴れ and 晴々しい is?

Question

Im in research about structure and meaning of reduplicated word. I want to ask about the difference between 晴れ晴れ and 晴々しい is?

Answer 1

According to jiho.org here, they are difined as:

晴れ晴れ
earch for 晴ればれ
Adverb, Adverb taking the 'to' particle, Suru verb
1. bright; cheerful ​ Other forms
晴晴 【はればれ】、晴々 【はればれ】、晴ればれ 【はればれ】、晴{は}れ晴｛ばれ｝

晴れ晴れしい
I-adjective
1. clear; splendid; cheerful; bright (e.g. look) ​ Other forms
晴々しい 【はればれしい】

Difference:

1) 品詞が違う。
They have a different part of speech from each other.

2)「晴々しい」はそのまま形容詞として使えますが、「晴れ晴れ」はそのままでは使えず、「晴れ晴れとした」「晴れ晴れとする」のような形で使う。
"晴々しい" is an adjective and it could be used as it is, but "晴れ晴れ" cannot be used as it is, it is used in a form like "晴れ晴れとした" or "晴れ晴れとする".

3)「晴々しい」は、普段あまり使われない。clear; splendid; cheerful; bright のような意味で使っても聞き手には自然に聞こえない。
As the statistics show, "晴々しい" is not usually used so much. It doesn't sound natural, if you want to use it as an adjective meaning "clear; splendid; cheerful; bright".

Statistics

Examining them with a famous Japanese example sentence collection site here, the number of example sentences containing "晴々しい" + "晴れ晴れしい" being recorded is only one + three, while the number of that of "晴れ晴れ" is 70.

The only one sentence containing "晴々しい" is:
長老自身は、そのわきの床の上に座っています。息子のことを思うと、晴々しい席にいならぶ気にはなれないからでした。
The elder himself was sitting on the floor at the side of the seat. It was because he did not feel like sitting in such a brilliant and gorgeous row when he thought of his son.

---

EDIT

手許の国語辞典で２つの意味を調べると次のように書いてある。
A Japanese dictionary at hand defines their meaning as:

【晴れ晴れ】（副詞、自動詞スル）
①晴れ渡っているさま。 the appearance that it's lucid in the sky; that it's very clear in the sky; that there isn't a speck of cloud in the sky
例文：晴れ晴れとした天気 Example: very clear weather
②心配ごとがなく気分がすっきりしているさま。 the appearance of not having to worry and being feeling clearer 例文：晴れ晴れとした顔 Example: a bright/cheerful look

【晴れ晴れしい】（形容詞）
①空がよく晴れ渡っている。 very clear in the sky; not being any cloud in the sky
②心配ごともなく気分が良い。not having to worry and being feeling clearer
③はなやかである。 showy, brilliant, gorgeous, floral, bright
例文：晴れ晴れしい行列 Example: showy and gorgeous procession

国語辞典によると「晴れ晴れ」と「晴々しい」の基本的な違いは「晴々しい」の③の定義にあることが分かる。
According to the Japanese dictionary, it is understood that the substantial difference between "晴れ晴れ" and "晴々しい" is in the definition of ③ in "晴々しい".

①②の意味では、一般に「晴れ晴れした」ではなく、「晴れ晴れ」が「晴れ晴れとした」という形で使われている。
In the meaning of ① and ②, "晴れ晴れ" seems to be commonly used in the form of "晴れ晴れとした" in stead of "晴々しい" or "晴れ晴れしい".

一方、「晴れ晴れした」の③の意味は、日本語として余りその意味が定着しておらず、数少ない使用例を見ても③で定義された意味と少し違うニュアンスで使われているように感じる。前に挙げた資料に収録された各々の例について、どのような意味で使われているか見てみよう。
On the other hand, judging from a few examples, the meaning of ③ of "晴れ晴れしい" is not so much established as Japanese, and it seems to be used with a slightly different nuance than the meaning defined in ③.
Let's see in what meaning "晴れ晴れしい" is used in each of the example sentences listed in the said sentence collection.

Sentence Examination

note: The phrase in parenthesis is added to clarify the meaning of "晴れ晴れしい" as judged from the context.

• 長老自身は、そのわきの床の上に座っています。息子のことを思うと、(畏怖の念を起こさせる) 晴々しい席にいならぶ気にはなれないからでした。 note: いならぶ is 居並ぶ meaning to be/stand/sit in a row.
  The elder himself was sitting on the floor at the side of the seat. It was because he did not feel like sitting in such an (awe-inspiring) brilliant and gorgeous row when he thought of his son.

• ラジオは紅白歌合戦の中継を華やかに伝え始めた。家族そろって卓袱台｛ちゃぶだい｝につくと、(慶事にふさわしい) 晴れ晴れしい 母の手料理が卓上を埋めつくしていた。
  When I sat at table with my families, it was a groaning board with luxurious and colorful mom's home cooking (worthy on the auspicious day).

• 「桃夭」を、ここで紹介しましょう。日本語訳で読んでさえ、そのすばらしい、（躍動的な) 晴れ晴れしいリズムが、桃そのものの精のように、伝わってくるものです。
  Let me introduce "桃夭｛とうよう｝ Chinese classical dance Tao Yao" here. Even reading it in a Japanese translation, the showy, brillient, floral, graceful (and dynamic) rhythm will be delivered to you like a spirit of a peach itself.