To download all objects using wget:

wget -r -H -N --cut-dirs=4 --include-directories="/v1/" "https://swiftbrowser.dkrz.de/public/dkrz_0262ea1f00e34439850f3f1d71817205/SIDFEx_index/observations/?show_all"

Name
127317.txt
139939.txt
145951.txt
204762.txt
210166.txt
300234010084660.txt
300234010307830.txt
300234011097770.txt
300234060430010.txt
300234060434550.txt
300234060436000.txt
300234060834110.txt
300234061872720.txt
300234062738010.txt
300234062880820.txt
300234062881810.txt
300234063803010.txt
300234063991680.txt
300234065495020.txt
300234065497190.txt
300234065498190.txt
300234065709990.txt
300234065801030.txt
300234065802030.txt
300234066030190.txt
300234066030330.txt
300234066031190.txt
300234066036110.txt
300234066084230.txt
300234066087220.txt
300234066089220.txt
300234066417330.txt
300234066711310.txt
300234066713470.txt
300234066830700.txt
300234066890230.txt
300234066890280.txt
300234066893240.txt
300234066896220.txt
300234067428260.txt
300234067509680.txt
300234067527540.txt
300234067527560.txt
300234067529520.txt
300234067700680.txt
300234067700760.txt
300234067939910.txt
300234068164710.txt
300234068312210.txt
300234068487020.txt
300234068764770.txt
300534060617370.txt
300534060710530.txt
300534061254970.txt
300534061512040.txt
300534062029520.txt
300534062171030.txt
300534062174040.txt
300534062175050.txt
300534062177020.txt
900120.txt
900121.txt
900126.txt
900128.txt
CENTRFLOE01.txt
FIXED84N120E.txt
FIXED84N140E.txt
FIXED85N130E.txt
FIXED86N120E.txt
FIXED86N140E.txt
FIXEDATW81p5N10E.txt
FIXEDATW81p5N15E.txt
FIXEDATW82p9N6p3W.txt
FIXEDEND68S51W.txt
FIXEDEND68S52W.txt
FIXEDEND68S53W.txt
FIXEDEND69S52W.txt
FIXEDENDCENTER.txt
POLARSTERN01.txt
POLARSTERN02.txt