EKF400 version 2 is a monthly resolved paleo-reanalysis covering the period 1603 to 2003. Early instrumental temperature, surface pressure and precipitation (new in version 2) observations, temperature indices derived from historical documents and temperature and moisture sensitive tree-ring measurements (largely increased number in version 2) were assimilated into an atmospheric general circulation model ensemble using a Kalman filtering technique. This data set combines the advantage of traditional reconstruction methods of being as close as possible to observations with the advantage of climate models of being physically consistent and having 3-dimensional information about the global state of the atmosphere at 2x2 degree resolution for various variables and at all points in time.
While version 1 was using time-dependent covariances from the 30-member ensemble, version 2 uses a blended covariance matrix. It consists of 50% time-dependent and 50% climatological covariances. This leads to a better covariance estimation, not only between various locations in space but in between various variables, too.
Franke, Jörg; Valler, Veronika; Brugnara, Yuri; Brönnimann, Stefan (2020). Ensemble Kalman Fitting Paleo-Reanalysis Version 2 (EKF400_v2). World Data Center for Climate (WDCC) at DKRZ. https://doi.org/10.26050/WDCC/EKF400_v2.0
EKF400 version is an update of the first monthly resolved paleo-reanalysis covering the period 1603 to 2003. Early instrumental temperature, surface p...
Description
EKF400 version is an update of the first monthly resolved paleo-reanalysis covering the period 1603 to 2003. Early instrumental temperature, surface pressure and precipitation (new in version 2) observations, temperature indices derived from historical documents and temperature and moisture sensitive tree-ring proxies (largely increased number in version 2) were assimilated into an ensemble of atmospheric general circulation model (ECHAM 5.4) using a Kalman-filtering technique (Bhend et al, 2011). The additional assimilation of precipitation largely increases the skill of precipitation in the Paleo-Reanalysis since early instrumental observations exist. The largely increased proxy data set covers larger parts of the world, where tree-ring data exists and includes coral data.
While version 1 was using time-dependent covariances from the 30-member ensemble, version 2 uses a blended covariance matrix. It consists of 50% time-dependent and 50% climatological covariances. This leads to a better covariance estimation, not only between various locations in space but in between various variables, too.
EKF400 version 2 is a global data set with increased 2x2 degree resolution instead of 4x4 degree in version 1.
Due to the location of the majority of assimilated data, skill is highest in extratropical northern hemisphere land areas.
This data set should not be used south of 60ºS.
Skill is changing over time with the varying network of assimilated data.
FAIR
F-UJI result: total 66 %
Description
Summary: Findable: 6 of 7 level; Accessible: 2 of 3 level; Interoperable: 3 of 4 level; Reusable: 5 of 10 level
SQA - Scientific Quality Assurance 'approved by author'
Result Date
2020-07-28
Technical Quality Assurance (TQA)
TQA - Technical Quality Assurance 'approved by WDCC'
Description
1. Number of data sets is correct and > 0: passed; 2. Size of every data set is > 0: passed; 3. The data sets and corresponding metadata are accessible: passed; 4. The data sizes are controlled and correct: passed; 5. The temporal coverage description (metadata) is consistent to the data: passed; 6. The format is correct: passed; 7. Variable description and data are consistent: passed
Method
WDCC-TQA checklist
Method Description
Checks performed by WDCC. The list of TQA metrics are documented in the 'WDCC User Guide for Data Publication' Chapter 8.1.1
[1] DOIValler, Veronika; Franke, Jörg; Brugnara, Yuri; Brönnimann, Stefan. (2021). An updated global atmospheric paleo‐reanalysis covering the last 400 years. doi:10.1002/gdj3.121