A new version of the European surface reanalysis&#160;UERRA-Land2 at 5.5km for the period 1961-2019
Authors: Bazile Eric , Verrelle Antoine , Glinton Michael , Le Moigne Patrick 
Published: June 2022

&lt;p&gt;&lt;span&gt;Within the UERRA project (2014-2017) a surface re-analysis at 5.5km &lt;/span&gt;&lt;span&gt;resolution &lt;/span&gt;&lt;span&gt;has been produced &lt;/span&gt;&lt;span&gt;over Europe &lt;/span&gt;&lt;span&gt;for the period 1961-2015 (&lt;/span&gt;UERRA D2.8 https://www.uerra.eu&lt;span&gt;)&lt;/span&gt;&lt;span&gt; with the so-called MESCAN-SURFEX system. &lt;/span&gt;&lt;span&gt;D&lt;/span&gt;&lt;span&gt;uring the &lt;/span&gt;&lt;span&gt;Copernicus Climate Change Service &lt;/span&gt;&lt;span&gt;C3S_322_lot1 contract &lt;/span&gt;&lt;span&gt;(2018-2021)&lt;/span&gt;&lt;span&gt;, &lt;/span&gt;&lt;span&gt;t&lt;/span&gt;&lt;span&gt;he period 2016-2019 has been &lt;/span&gt;&lt;span&gt;produced&lt;/span&gt;&lt;span&gt; with exactly the same system. &lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;Since the data are available on the C&lt;/span&gt;&lt;span&gt;limate &lt;/span&gt;&lt;span&gt;D&lt;/span&gt;&lt;span&gt;ata &lt;/span&gt;&lt;span&gt;S&lt;/span&gt;&lt;span&gt;tore&lt;/span&gt;&lt;span&gt;, &lt;/span&gt;&lt;span&gt;several impact studies or local comparisons have been published f&lt;/span&gt;&lt;span&gt;or &lt;/span&gt;&lt;span&gt;different type&lt;/span&gt;&lt;span&gt;s&lt;/span&gt;&lt;span&gt; of applications: precipitation s&lt;/span&gt;&lt;span&gt;tudies &lt;/span&gt;&lt;span&gt;(Bezak et al., 2020 &lt;/span&gt;&lt;span&gt;and 2021), temperature &lt;/span&gt;&lt;span&gt;studies &lt;/span&gt;&lt;span&gt;(&lt;/span&gt;&lt;span&gt;Chervenkov et al., 2021, Hofer and Horak, 2020&lt;/span&gt;&lt;span&gt;) &lt;/span&gt;&lt;span&gt;or&lt;/span&gt;&lt;span&gt; for snow indicators (&lt;/span&gt;&lt;span&gt;Morin et al., 2021). &lt;/span&gt;&lt;span&gt;U&lt;/span&gt;&lt;span&gt;ser feedback, &lt;/span&gt;&lt;span&gt;depending of the &lt;/span&gt;&lt;span&gt;variables and/&lt;/span&gt;&lt;span&gt;or &lt;/span&gt;&lt;span&gt;the &lt;/span&gt;&lt;span&gt;study &lt;/span&gt;&lt;span&gt;area, can be very positive or &lt;/span&gt;&lt;span&gt;highlight&lt;/span&gt;&lt;span&gt; some &lt;/span&gt;&lt;span&gt;questions&lt;/span&gt;&lt;span&gt; or &lt;/span&gt;&lt;span&gt;some &lt;/span&gt;&lt;span&gt;weaknes&lt;/span&gt;&lt;span&gt;ses &lt;/span&gt;&lt;span&gt;of&lt;/span&gt; &lt;span&gt;the &lt;/span&gt;&lt;span&gt;product&lt;/span&gt;&lt;span&gt;. In &lt;/span&gt;&lt;span&gt;May 2020, a user shows some &amp;#8220;&lt;/span&gt;&lt;span&gt;curious&amp;#8221; &lt;/span&gt;&lt;span&gt;trends for the temperature &lt;/span&gt;&lt;span&gt;of&lt;/span&gt;&lt;span&gt; 3 &lt;/span&gt;&lt;span&gt;European &lt;/span&gt;&lt;span&gt;cities (Budapest, Riga and Warsaw). After several months of investigation, the problem was &lt;/span&gt;&lt;span&gt;fixed&lt;/span&gt;&lt;span&gt; and it was decided to &lt;/span&gt;&lt;span&gt;re-run the surface analysis MESCAN and the off-line &lt;/span&gt;&lt;span&gt;land surface model &lt;/span&gt;&lt;span&gt;SURFEX &lt;/span&gt;&lt;span&gt;for the period 1961-2019 &lt;/span&gt;&lt;span&gt;to produce version 2 of this re-analysis, named&lt;/span&gt; &lt;span&gt;UERRA-Land2.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;span&gt;A&lt;/span&gt;&lt;span&gt;fter a brief description of the problem &lt;/span&gt;&lt;span&gt;discovered in May 2020&lt;/span&gt;&lt;span&gt;, the modification &lt;/span&gt;&lt;span&gt;of&lt;/span&gt;&lt;span&gt; the surface analysis will be &lt;/span&gt;&lt;span&gt;explained&lt;/span&gt;&lt;span&gt; and the &lt;/span&gt;&lt;span&gt;impact on several variables such as temperature and snow depth will be &lt;/span&gt;&lt;span&gt;presented&lt;/span&gt;&lt;span&gt;. &lt;/span&gt;&lt;span&gt;A comparison with ERA5-Land and the&lt;/span&gt; &lt;span&gt;added value &lt;/span&gt;&lt;span&gt;of &lt;/span&gt;&lt;span&gt;the &lt;/span&gt;&lt;span&gt;regional re-analysis &lt;/span&gt;&lt;span&gt;UERRA-Land2 &lt;/span&gt;&lt;span&gt;will be &lt;/span&gt;&lt;span&gt;discussed&lt;/span&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;T&lt;/span&gt;&lt;span&gt;he UERRA-Land2 dataset is now available &lt;/span&gt;&lt;span&gt;on demand &lt;/span&gt;&lt;span&gt;at M&amp;#233;t&amp;#233;o-France and &lt;/span&gt;&lt;span&gt;hopefully soon&lt;/span&gt;&lt;span&gt; on the Climate Data Store. &lt;/span&gt;&lt;/p&gt;