Comment on tc-2021-182

More context would be welcome, both on other possible glaciers among the “ More than 100 perennial snow patches “ in this region, and on comparison with other avalanche-fed glaciers and other glacierets / very small glaciers elsewhere. Can the feeding avalanche tracks be mapped? Are there cornices in winter, suggestive of wind drifting? Many aspects of the literature are well covered, but a number of other papers on glacierets or very small glaciers could be considered:

Some of these state that mass balances tend to vary from year to year, positive throughout or negative throughout, rather than between accumulation and ablation areas. Apart from the detailed corrections, and extending comparisons with avalanche-fed glacierets elsewhere, my main suggestion is to compare the (1.92 to 4.34) ratio of winter mass balance to local weq snowfall, with similar ratios for the other nine glaciers smaller than 0.11 km 2 in the Appendix (or consider similar ratios for balance amplitude).

DETAILS:
'likely' should usually be replaced by 'probably'.
Line 19 Why not 'very small avalanche-fed glaciers' ? 'Topographically controlled' is a broader class, including effects of aspect (shade) and shadow, and shelter from wind drifting snow off a plateau (not in this rugged part of the Japanese Alps !). 69 presumably end-winter: best to give a date for this, here.    Table 4: winter 5.63 to 12.72, summer 7.16 to 11.64.) Per glacier, summer balances vary up to 1.6 m, so are not exactly constant, just with much smaller variation than for winter.

'nearly constant' is an exaggeration. I would say 'is much less variable'
243 Add 'It is reassuring that balances are closely correlated between the five glaciers, over this time period (Figs. 9 and 10).' Table 3: seems like 'correction' should read 'corrected'. Caption should remind reader what the correction is for. (The text does not even mention correction, except for lines 111-114 on the DSM: is that relevant, or is the correction for emergence velocity?) 251-252. Yes, but it is more logical to say that standard deviations increase linearly with amplitudes. Fig.11 Not m ! Numbers on y axis are in mm, unless 000 is deleted throughout.

255-262
As emergence velocity has presumably been used above, should this section come earlier? More explanation of how it was used is needed. Fig. 11 provides an interesting comparison between regions, but is not the most relevant way of comparing mass balance data with the results in Japan. Clearly glacier size is important: the larger the glacier, the less important the topographic effects including avalanching and wind drifting of snow. As the Japanese glaciers are 0.11 km 2 or smaller, I suggest focussing on comparison with the small number of glaciers in the Appendix which are also of such tiny areas. I think there are nine: numbers 20, 21, 27, 51, 56, 74, 139, 151 and 180. One is in New Zealand, three in the Andes, four in the Alps and one in Apennines (Calderone is not in the Alps.) As the winter balances in Japan are 1.92 to 4.34 times the average direct snowfall (2.93 m), it would be useful to calculate similar ratios for the other very small glaciers. I think that would reveal that glaciers e.g. in the Urals have similar ratios, from what has been termed 'suralimentation' ('over-feeding'). That is , the Japanese glaciers are exceptional (practically 'outliers') in absolute terms, but probably not in amplitude relative to direct snowfall. (More accurate ratios could be calculated from annual snowfall values, rather than e.g. average snowfall at Tateyama Murododaira.)  325 It might be good to mention (somewhere) that (from the maps in Fig.3 and photos in Fig.2), the glaciers seem to receive avalanche snow throughout -not just at their upstream ends. Also, the evidence for some wind-drifting effect (despite the lack of plateaus or even rounded summits -the ridges are rugged) comes from the eastward component of aspect of all five glaciers.
336 'tend to have annual balances strongly …' 349 Yes, very probably, but by how much ?