Amount‐weighted annual isotopic (δ18O) values are affected by the seasonality of precipitation: A sensitivity study

Year to year differences in the isotopes of precipitation (δ18O) are typically attributed to corresponding interannual changes in mean annual temperature. However, changes in the seasonal distribution of precipitation are one of the main complicating factors in interpreting year to year variability of isotopes of precipitation. Using a five year dataset with 73 sites across the United States, we investigate the influence of changes in seasonal distribution of precipitation on annually averaged δ18O. Based on these δ18O measurements, and using multi‐decadal records of variability of monthly precipitation amounts, we identify areas within the United States where records of isotopes in precipitation are susceptible to changes in the seasonal distribution of precipitation. For the three regions, Northern Great Plains, the Rocky Mountains, and the Southwest, seasonality effects could be misinterpreted as 1°C to 3°C temperature changes between years. These findings will improve and possibly change our interpretation of climate isotopic climate records and provide spatially explicit areas where classic interpretations require caution.

[1]  J. Welker,et al.  Spatial distribution and seasonal variation in 18O/16O of modern precipitation and river water across the conterminous USA , 2005 .

[2]  J. Welker,et al.  Arctic and North Atlantic Oscillation phase changes are recorded in the isotopes (δ18O and δ13C) of Cassiope tetragona plants , 2005 .

[3]  W. Broecker,et al.  The role of seasonality in abrupt climate change , 2005 .

[4]  David J. Smith,et al.  Is photoinhibition of zooxanthellae photosynthesis the primary cause of thermal bleaching in corals? , 2005 .

[5]  F. Hu,et al.  A biogenic-silica δ18O record of climatic change during the last glacial–interglacial transition in southwestern Alaska , 2003, Quaternary Research.

[6]  S. John,et al.  Comparison of oxygen isotope records from the GISP 2 and GRIP Greenland ice cores , 2002 .

[7]  P. D’Odorico,et al.  An Assessment of ENSO-Induced Patterns of Rainfall Erosivity in the Southwestern United States , 2001 .

[8]  J. Overpeck,et al.  Influence of mean climate change on climate variability from a 155-year tropical Pacific coral record , 2000, Nature.

[9]  J. Welker.  Isotopic (δ18O) characteristics of weekly precipitation collected across the USA : an initial analysis with application to water source studies , 2000 .

[10]  M. Heimann,et al.  Borehole versus isotope temperatures on Greenland: Seasonality does matter , 2000 .

[11]  J. Jouzel,et al.  The climate signal in the stable isotopes of snow from Summit, Greenland: Results of comparisons with modern climate observations , 1997 .

[12]  J. Jouzel,et al.  Seasonal precipitation timing and ice core records. , 1995, Science.

[13]  E. Mosley‐Thompson,et al.  Late Glacial Stage and Holocene Tropical Ice Core Records from Huascar�n, Peru , 1995, Science.

[14]  J. Lynch,et al.  Trends in precipitation chemistry in the United States: A national perspective, 1980–1992 , 1995 .

[15]  Sridhar Anandakrishnan,et al.  Temperature and accumulation at the Greenland Summit: Comparison of high‐resolution isotope profiles and satellite passive microwave brightness temperature trends , 1995 .

[16]  M. Stuiver,et al.  Seasonal precipitation timing and ice core records. , 1994, Science.

[17]  J. Jouzel,et al.  Comparison of oxygen isotope records from the GISP2 and GRIP Greenland ice cores , 1993, Nature.

[18]  Tyler B. Coplen,et al.  Continuous 500,000-Year Climate Record from Vein Calcite in Devils Hole, Nevada , 1992, Science.