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• 1. [Article] Late Quaternary and Holocene Paleoecology of Interior Mesic Forests of Northern Idaho

  The mesic forests distributed within the Rocky Mountains of northern Idaho are unique because many species contained within the forest are separated from their main distribution along the Pacific Northwest ...

  Citation × Citation Citation Abstract Copy Title: Late Quaternary and Holocene Paleoecology of Interior Mesic Forests of Northern Idaho Author: Herring, Erin Year: 2014 The mesic forests distributed within the Rocky Mountains of northern Idaho are unique because many species contained within the forest are separated from their main distribution along the Pacific Northwest coast. It remains unclear whether most species within the inland disjunction survived the glacial periods of the Pleistocene, or whether they were more recently dispersed from coastal populations. To see if the dominant tree taxa of the mesic forests today could have persisted in a refugium south of the large ice sheets, four sediment cores were used to reconstruct the vegetation and climate history of the region. A nearly continuous record of pollen and sediment composition (biogenic silica and inorganic and organic matter) over the last ca. 120,000 years provides evidence of a dynamic ecosystem. Over a long timescale, the slow shifts in vegetation are attributed to the changes in climate. During the last interglacial period, the region was warmer and drier with a Pinus dominated mixed conifer forest. Approximately 71,000 years ago, a Pseudotsuga/Larix forest became established in the area as a response to the increased available moisture. As climate cooled and glaciers expanded the Pinus and Picea forest was the dominant vegetation type until ca. 40,000 years ago. The environment during the Last Glacial Maximum (LGM) was so harsh that no vegetation record was recorded. After the LGM, climate warmed, enabling a Pinus and Picea forest to establish and persist until the Holocene. The mesic taxa that dominate the modern forests did not arrive in northern Idaho until the mid- to late-Holocene. The recent arrival of the dominant tree species, Thuja plicata and Tsuga mertensiana, suggests that they likely did not persist in a refugium during the last glaciation. Instead, these species recently dispersed from coastal populations, but expansion into their interior distributions was likely limited by both climate and species competition in already established forests. During the late-Quaternary, the deposition of thick tephra layers (>20 cm) from the eruptions of Glacier Peak (ca. 13,400 years ago) and Mt. Mazama (ca. 7,600 years ago) also facilitated an abrupt and persistent change in vegetation in northern Idaho. Title: Late Quaternary and Holocene Paleoecology of Interior Mesic Forests of Northern Idaho Author: Herring, Erin Year: 2014 The mesic forests distributed within the Rocky Mountains of northern Idaho are unique because many species contained within the forest are separated from their main distribution along the Pacific Northwest coast. It remains unclear whether most species within the inland disjunction survived the glacial periods of the Pleistocene, or whether they were more recently dispersed from coastal populations. To see if the dominant tree taxa of the mesic forests today could have persisted in a refugium south of the large ice sheets, four sediment cores were used to reconstruct the vegetation and climate history of the region. A nearly continuous record of pollen and sediment composition (biogenic silica and inorganic and organic matter) over the last ca. 120,000 years provides evidence of a dynamic ecosystem. Over a long timescale, the slow shifts in vegetation are attributed to the changes in climate. During the last interglacial period, the region was warmer and drier with a Pinus dominated mixed conifer forest. Approximately 71,000 years ago, a Pseudotsuga/Larix forest became established in the area as a response to the increased available moisture. As climate cooled and glaciers expanded the Pinus and Picea forest was the dominant vegetation type until ca. 40,000 years ago. The environment during the Last Glacial Maximum (LGM) was so harsh that no vegetation record was recorded. After the LGM, climate warmed, enabling a Pinus and Picea forest to establish and persist until the Holocene. The mesic taxa that dominate the modern forests did not arrive in northern Idaho until the mid- to late-Holocene. The recent arrival of the dominant tree species, Thuja plicata and Tsuga mertensiana, suggests that they likely did not persist in a refugium during the last glaciation. Instead, these species recently dispersed from coastal populations, but expansion into their interior distributions was likely limited by both climate and species competition in already established forests. During the late-Quaternary, the deposition of thick tephra layers (>20 cm) from the eruptions of Glacier Peak (ca. 13,400 years ago) and Mt. Mazama (ca. 7,600 years ago) also facilitated an abrupt and persistent change in vegetation in northern Idaho. Close

• 2. [Article] Glacier Status and Contribution to Streamflow in the Olympic Mountains, USA

  The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are -¹ (1900–80) ...

  Citation × Citation Citation Abstract Copy Title: Glacier Status and Contribution to Streamflow in the Olympic Mountains, USA Author: Riedel, Jon L., Wilson, Steve, Baccus, William, Larrabee, Michael, Fudge, T.J., Fountain, Andrew G. Year: 2015 The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are -¹ (1900–80) to 0.54 km² a-¹ (1980–2009). Thinning rates on four of the largest glaciers averaged nearly 1ma-¹ from 1987 to 2010, resulting in estimated volume losses of 17–24%. Combined glacial snow, firn and ice melt in the Hoh watershed is in the range 63–79 ± 7 × 106m3, or 9–15% of total May–September streamflow. In the critical August–September period, the glacial fraction of total basin runoff increases to 18–30%, with one-third of the water directly from glacial ice (i.e. not snow and firn). Glaciers in the Elwha basin produce 12–15 ± 1.3 × 106m3 (2.5–4.0%), while those in the Dungeness basin contribute 2.5–3.1 ± 0.28 × 106m3 (3.0–3.8%). Title: Glacier Status and Contribution to Streamflow in the Olympic Mountains, USA Author: Riedel, Jon L., Wilson, Steve, Baccus, William, Larrabee, Michael, Fudge, T.J., Fountain, Andrew G. Year: 2015 The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are -¹ (1900–80) to 0.54 km² a-¹ (1980–2009). Thinning rates on four of the largest glaciers averaged nearly 1ma-¹ from 1987 to 2010, resulting in estimated volume losses of 17–24%. Combined glacial snow, firn and ice melt in the Hoh watershed is in the range 63–79 ± 7 × 106m3, or 9–15% of total May–September streamflow. In the critical August–September period, the glacial fraction of total basin runoff increases to 18–30%, with one-third of the water directly from glacial ice (i.e. not snow and firn). Glaciers in the Elwha basin produce 12–15 ± 1.3 × 106m3 (2.5–4.0%), while those in the Dungeness basin contribute 2.5–3.1 ± 0.28 × 106m3 (3.0–3.8%). Close

• 3. [Article] Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations

  Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses ...

  Citation × Citation Citation Abstract Copy Title: Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations Author: Izumi, Kenji Year: 2014 Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses of the earth environment to the climate and to evaluate how models work. This dissertation has two parts that each involve the development and application of approaches for data-model comparisons. In part 1, which is focused on the understanding of both past and future climatic changes/variations, I compare paleoclimate and historical simulations with future climate projections exploiting the fact that climate-model configurations are exactly the same in the paleo and future simulations in the Coupled Model Intercomparison Project Phase 5. In practice, I investigated large-scale temperature responses (land-ocean contrast, high-latitude amplification, and change in temperature seasonality) in paleo and future simulations, found broadly consistent relationships across the climate states, and validated the responses using modern observations and paleoclimate reconstructions. Furthermore, I examined the possibility that a small set of common mechanisms controls the large-scale temperature responses using a simple energy-balance model to decompose the temperature changes shown in warm and cold climate simulations and found that the clear-sky longwave downward radiation is a key control of the robust responses. In part 2, I applied the equilibrium terrestrial biosphere models, BIOME4 and BIOME5 (developed from BIOME4 herein), for reconstructing paleoclimate. I applied inverse modeling through the iterative forward-modeling (IMIFM) approach that uses the North American vegetation data to infer the mid-Holocene (MH, 6000 years ago) and the Last Glacial Maximum (LGM, 21,000 years ago) climates that control vegetation distributions. The IMIFM approach has the potential to provide more accurate quantitative climate estimates from pollen records than statistical approaches. Reconstructed North American MH and LGM climate anomaly patterns are coherent and consistent between variables and between BIOME4 and BIOME5, and these patterns are also consistent with previous data synthesis. This dissertation includes previously published and unpublished coauthored material. Title: Application of Paleoenvironmental Data for Testing Climate Models and Understanding Past and Future Climate Variations Author: Izumi, Kenji Year: 2014 Paleo data-model comparison is the process of comparing output from model simulations of past periods with paleoenvironmental data. It enables us to understand both the paleoclimate mechanism and responses of the earth environment to the climate and to evaluate how models work. This dissertation has two parts that each involve the development and application of approaches for data-model comparisons. In part 1, which is focused on the understanding of both past and future climatic changes/variations, I compare paleoclimate and historical simulations with future climate projections exploiting the fact that climate-model configurations are exactly the same in the paleo and future simulations in the Coupled Model Intercomparison Project Phase 5. In practice, I investigated large-scale temperature responses (land-ocean contrast, high-latitude amplification, and change in temperature seasonality) in paleo and future simulations, found broadly consistent relationships across the climate states, and validated the responses using modern observations and paleoclimate reconstructions. Furthermore, I examined the possibility that a small set of common mechanisms controls the large-scale temperature responses using a simple energy-balance model to decompose the temperature changes shown in warm and cold climate simulations and found that the clear-sky longwave downward radiation is a key control of the robust responses. In part 2, I applied the equilibrium terrestrial biosphere models, BIOME4 and BIOME5 (developed from BIOME4 herein), for reconstructing paleoclimate. I applied inverse modeling through the iterative forward-modeling (IMIFM) approach that uses the North American vegetation data to infer the mid-Holocene (MH, 6000 years ago) and the Last Glacial Maximum (LGM, 21,000 years ago) climates that control vegetation distributions. The IMIFM approach has the potential to provide more accurate quantitative climate estimates from pollen records than statistical approaches. Reconstructed North American MH and LGM climate anomaly patterns are coherent and consistent between variables and between BIOME4 and BIOME5, and these patterns are also consistent with previous data synthesis. This dissertation includes previously published and unpublished coauthored material. Close