1.NSIDC官网:https://nsidc.org/data
2.Earthdata Search:https://search.earthdata.nasa.gov/search/
3.OpenAltimetry:https://openaltimetry.org/

4.用python下载：

import icepyx as ipx
import os
import shutil
%matplotlib inline

short_name = 'ATL08'
spatial_extent = 'D:/' #输入感兴趣区
date_range = ['2020-12-26','2020-12-31'] #确定数据下载的时间段

region_a = ipx.Query(short_name, spatial_extent, date_range, \
   start_time='00:00:00', end_time='23:59:59', version='004')

#In addition to viewing the stored object information shown above (e.g. dataset, start and end date and time, version, etc.), we can also request summary information about the dataset itself or confirm that we have manually specified the latest version.
region_a.dataset_summary_info()
print(region_a.latest_version())

#bulid and view the parameters that will be submitted in our query
region_a.CMRparams

#search for available granules and provide basic summary info about them
region_a.avail_granules()

#Earthdata login
earthdata_uid = '' #账户名称
email = ''#邮箱
region_a.earthdata_login(earthdata_uid, email) #输入密码和账号登录

print(region_a.reqparams)
region_a.subsetparams()
region_a._geom_filepath

region_a.order_granules()
path = 'D:/' #保存路径
region_a.download_granules(path)

update 2021-06-02.

补充：可以查看icesat2 publications
https://icesat-2.gsfc.nasa.gov/publications

update 2021-06-23