{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,11]],"date-time":"2026-11-11T06:37:45Z","timestamp":1794379065280,"version":"4.9.0"},"reference-count":36,"publisher":"American Geophysical Union (AGU)","issue":"17","license":[{"start":{"date-parts":[[2007,9,5]],"date-time":"2007-09-05T00:00:00Z","timestamp":1188950400000},"content-version":"vor","delay-in-days":4,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Geophysical Research Letters"],"published-print":{"date-parts":[[2007,9]]},"abstract":"<jats:p><jats:italic>Cedrus atlantica<\/jats:italic> ring width data are used to reconstruct long\u2010term changes in the Palmer Drought Severity Index (PDSI) over the past 953 years in Morocco, NW Africa. The reconstruction captures the dry conditions since the 1980s well and places this extreme period within a millennium\u2010long context. PDSI values were above average for most of the 1450\u20131980 period, which let recent drought appear exceptional. However, our results also indicate that this pluvial episode of the past millennium was preceded by generally drier conditions back to 1049. Comparison of PDSI estimates with large\u2010scale pressure field reconstructions revealed steady synoptic patterns for drought conditions over the past 350 years. The long\u2010term changes from initially dry to pluvial to recent dry conditions are similar to PDSI trends reported from N America, and we suggest that they are related to long\u2010term temperature changes, potentially teleconnected with ENSO variability and forced by solar irradiance changes.<\/jats:p>","DOI":"10.1029\/2007gl030844","type":"journal-article","created":{"date-parts":[[2007,9,4]],"date-time":"2007-09-04T20:01:49Z","timestamp":1188936109000},"source":"Crossref","is-referenced-by-count":345,"title":["Long\u2010term drought severity variations in Morocco"],"prefix":"10.1029","volume":"34","author":[{"given":"Jan","family":"Esper","sequence":"first","affiliation":[{"name":"Swiss Federal Research Institute for Forest Snow and Landscape Research  Birmensdorf Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Frank","sequence":"additional","affiliation":[{"name":"Swiss Federal Research Institute for Forest Snow and Landscape Research  Birmensdorf Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ulf","family":"B\u00fcntgen","sequence":"additional","affiliation":[{"name":"Swiss Federal Research Institute for Forest Snow and Landscape Research  Birmensdorf Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Verstege","sequence":"additional","affiliation":[{"name":"Swiss Federal Research Institute for Forest Snow and Landscape Research  Birmensdorf Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00fcrg","family":"Luterbacher","sequence":"additional","affiliation":[{"name":"National Centre of Competence in Research on Climate (NCCR) and Institute of Geography University of Bern  Bern Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elena","family":"Xoplaki","sequence":"additional","affiliation":[{"name":"National Centre of Competence in Research on Climate (NCCR) and Institute of Geography University of Bern  Bern Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"13","published-online":{"date-parts":[[2007,9,5]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1029\/2000JD900617"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1175\/1520-0442(1999)012<2941:TUOTVI>2.0.CO;2"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1175\/JCLI3917.1"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/joc.3370150205"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature01779"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/joc.3370140404"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1175\/1520-0442(2002)015<1754:AWVMRO>2.0.CO;2"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1102586"},{"key":"e_1_2_6_10_1","first-page":"93","article-title":"North American drought: Reconstructions, causes and consequences","volume":"81","author":"Cook E. 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