(particle equivalent to 啊 after noun ending in -n)
sentence-final particle (abbr. for 呢啊[ne5 a5] or variant of 哪[na5])
(adverbial expression indicating that the attention of the subject of the verb is focused on what they are doing, not distracted by anything else)
just ...ing (and nothing else)
La Niña, equatorial climatic variation over the Eastern Pacific, as opposed to El Niño 厄爾尼諾|厄尔尼诺
For goodness sake!