Details

Autor(en) / Beteiligte

• Elbaum, Eilat
• Garfinkel, Chaim I.
• Adam, Ori
• Morin, Efrat
• Rostkier‐Edelstein, Dorita
• Dayan, Uri

Titel

Uncertainty in Projected Changes in Precipitation Minus Evaporation: Dominant Role of Dynamic Circulation Changes and Weak Role for Thermodynamic Changes

Ist Teil von

• Geophysical research letters, 2022-06, Vol.49 (12), p.n/a

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2022

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• End of century projections from Coupled Model Intercomparison Project (CMIP) models show a decrease in precipitation over subtropical oceans that often extends into surrounding land areas, but with substantial intermodel spread. Changes in precipitation are controlled by both thermodynamical and dynamical processes, though the importance of these processes for regional scales and for intermodel spread is not well understood. The contribution of dynamic and thermodynamic processes to the model spread in regional precipitation minus evaporation (P − E) is computed for 48 CMIP models. The intermodel spread is dominated essentially everywhere by the change of the dynamic term, including in most regions where thermodynamic changes drive the multi‐model mean response. The dominant role of dynamic changes is insensitive to zonal averaging which removes any influence of stationary wave changes, and is also evident in subtropical oceanic regions. Relatedly, intermodel spread in P − E is generally unrelated to climate sensitivity. Plain Language Summary Earth's hydroclimate will change in response to increased greenhouse gas concentrations. However, the physical process(es) whereby climate change leads to these hydroclimate change is still uncertain, especially on regional scales. Furthermore, models disagree as to the magnitude of these hydroclimate changes, and the causes of this intermodel spread are also not well understood. We demonstrate that uncertainty in future changes is driven almost everywhere by changes in the large scale winds, while the precise amount of warming simulated by a given model is largely irrelevant. This highlights that reducing uncertainty in future hydroclimate changes requires primarily narrowing uncertainties in the circulation response. Key Points Even in regions where thermodynamic changes drive the multi‐model mean hydrologic changes, dynamic changes drive uncertainty Dynamic changes more important for intermodel spread even after zonal averaging and even over subtropical oceans Narrowing climate sensitivity will not help constrain future hydroclimate changes in most regions