add info on EUREC4A-MIP warming deltas

how_to_eurec4a/eurec4a_mip.md

@@ -37,14 +37,30 @@ The boundary conditions and warming tendencies are provided on the DKRZ-SWIFT st
     ds = xr.concat([bc_cat(date=d).to_dask() for d in dates_of_interest], dim='time')
     ds.to_netcdf(f"EUREC4A-MIP_boundaryConditions_{experiment}.nc")
   ```
+
+  In addition to the boundary conditions already applied to the ERA5 simulations, the monthly mean climate deltas are also available separately. They are computed from the CMIP6 output of the GFDL-CM4 model {cite:p}`Held:2019` as the difference between the AMIP with patterned 4K SST increase experiment (AMIP-future 4K) and the AMIP historical (AMIP) simulation. Variables available are temperature, relative humidity, surface pressure, horizontal wind and sea and land surface temperature. These monthly mean climate deltas are available as two products.
+
+  - at original GFDL-CM4 resolution
+    ```python
+    delta_gfdl = cat.simulations.EUREC4A_MIP.warming.setup.boundary_conditions.deltas.GFDL_CM4.to_dask()
+    ```
+  - at ERA5 horizontal and vertical resolution (interpolated)
+    ```python
+    delta_era5 = cat.simulations.EUREC4A_MIP.warming.setup.boundary_conditions.deltas.ERA5.to_dask()
+    ```
+
   Instructions on how to install the mandatory packages can be found at the [EUREC⁴A Intake Catalog Repository](https://github.com/eurec4a/eurec4a-intake#usage)
 - from the browser interface 
   - [Boundary conditions Control](https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/CTRL_ERA5/)
   - [Boundary conditions Warming+4K](https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/PGW+4K/)
+  - [Boundary conditions Warming+4K Deltas on GFDL-CM4 grid](https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/DELTAS_ORI/)
+  - [Boundary conditions Warming+4K Deltas interpolated to ERA5 grid](https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/DELTAS_INT/)
 - or command line:
   ```bash
   wget -r -H -N --cut-dirs=3 --include-directories="/v1/" "https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/PGW+4K/?show_all"
   wget -r -H -N --cut-dirs=3 --include-directories="/v1/" "https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/CTRL_ERA5/?show_all"
+  wget -r -H -N --cut-dirs=3 --include-directories="/v1/" "https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/DELTAS_ORI/?show_all"
+  wget -r -H -N --cut-dirs=3 --include-directories="/v1/" "https://swiftbrowser.dkrz.de/public/dkrz_0913c8f3-e7b6-4f94-9221-06880d4ccfea/DELTAS_INT/?show_all"
   ```
 
 ## Further references

how_to_eurec4a/references.bib

@@ -201,4 +201,16 @@ @article{Bonyetal:2004
   pages = {71--86},
   issn = {1432-0894},
   doi = {10.1007/s00382-003-0369-6},
-}
+}
+
+@article{Held:2019,
+  title = {Structure and {{Performance}} of {{GFDL}}'s {{CM4}}.0 {{Climate Model}}},
+  author = {Held, I. M. and Guo, H. and Adcroft, A. and Dunne, J. P. and Horowitz, L. W. and Krasting, J. and Shevliakova, E. and Winton, M. and Zhao, M. and Bushuk, M. and Wittenberg, A. T. and Wyman, B. and Xiang, B. and Zhang, R. and Anderson, W. and Balaji, V. and Donner, L. and Dunne, K. and Durachta, J. and Gauthier, P. P. G. and Ginoux, P. and Golaz, J.-C. and Griffies, S. M. and Hallberg, R. and Harris, L. and Harrison, M. and Hurlin, W. and John, J. and Lin, P. and Lin, S.-J. and Malyshev, S. and Menzel, R. and Milly, P. C. D. and Ming, Y. and Naik, V. and Paynter, D. and Paulot, F. and Ramaswamy, V. and Reichl, B. and Robinson, T. and Rosati, A. and Seman, C. and Silvers, L. G. and Underwood, S. and Zadeh, N.},
+  year = {2019},
+  journal = {Journal of Advances in Modeling Earth Systems},
+  volume = {11},
+  number = {11},
+  pages = {3691--3727},
+  issn = {1942-2466},
+  doi = {10.1029/2019MS001829},
+}