Carpe Diem: A high-frequency ‘weather’-tology perspective on western U.S. summertime precipitation

Presenter Information

Simon WangFollow
Jon Meyer
Larry Hipps

Location

Logan Country Club

Streaming Media

Start Date

3-27-2017 4:25 PM

End Date

3-28-2017 4:30 PM

Description

Historically, much of what is currently known about many of Earth’s climate system processes and relationships have come via analysis conducted using data averaged into monthly or longer timescales. While analysis at these timescales has provided a wealth of extremely valuable and comprehensive information on the complexities of Earth’s climate system, the progress has come at the expense of the inclusion of high-frequency extrema and the many interactions occurring on daily (or shorter) timescales as well as the impact to high frequency extrema. Perhaps the most apparent victim from long-timescale averaging is the scientific understanding regarding how the biosphere (i.e. biodiversity, physiological stressors, growing conditions) responds to atmospheric conditions (e.g. temperature, humidity, wind) and hydrologic properties (e.g. streamflow and temperature, yearly hydrograph). Oftentimes, it is the high-frequency, short-term extreme events that dictate the biosphere, so in the case of climate prediction or climate change impact studies, the fidelity of analysis decreases as timescale increases. Here we present the case for why the timescales of the analysis need to match the timescales unique to an area’s climate. Attempting to improve on what is casually referred to as synoptic climatology, this study begins to probe the question of how daily phenomena (weather) can be quantified to increase the fidelity of climate analysis to better account for daily effects. Set over the western U.S., the focus for this study is the daily variability of the dominant summertime anticyclone circulation pattern and the associated synoptic and mesoscale processes responsible for the surges of monsoonal moisture (and precipitation). Deservedly so, this drought-susceptible region has received much scientific attention thanks to growing water resource demands and dwindling ground water reserves. Precipitation characteristics during this time result from a symphony of processes spanning diurnal to sub-seasonal timescales that together define the North American Monsoon (NAM). With an eye on increasing predictability of daily climate variability, the goal of this study is to use observation-based reanalysis data to (1) identify distinct regimes of daily atmospheric phenomena over the western U.S., and (2) investigate the relationship between these regimes and the various scales of their controlling factors. Thus, developing a climatology of daily weather events, or a ‘weather’-tology. Armed with new understanding of high-frequency climate variability beyond monthly timescales, this study has the potential to open the door to more robust and capable interdisciplinary applications of climate data—especially for future-climate studies.

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Mar 27th, 4:25 PM Mar 28th, 4:30 PM

Carpe Diem: A high-frequency ‘weather’-tology perspective on western U.S. summertime precipitation

Logan Country Club

Historically, much of what is currently known about many of Earth’s climate system processes and relationships have come via analysis conducted using data averaged into monthly or longer timescales. While analysis at these timescales has provided a wealth of extremely valuable and comprehensive information on the complexities of Earth’s climate system, the progress has come at the expense of the inclusion of high-frequency extrema and the many interactions occurring on daily (or shorter) timescales as well as the impact to high frequency extrema. Perhaps the most apparent victim from long-timescale averaging is the scientific understanding regarding how the biosphere (i.e. biodiversity, physiological stressors, growing conditions) responds to atmospheric conditions (e.g. temperature, humidity, wind) and hydrologic properties (e.g. streamflow and temperature, yearly hydrograph). Oftentimes, it is the high-frequency, short-term extreme events that dictate the biosphere, so in the case of climate prediction or climate change impact studies, the fidelity of analysis decreases as timescale increases. Here we present the case for why the timescales of the analysis need to match the timescales unique to an area’s climate. Attempting to improve on what is casually referred to as synoptic climatology, this study begins to probe the question of how daily phenomena (weather) can be quantified to increase the fidelity of climate analysis to better account for daily effects. Set over the western U.S., the focus for this study is the daily variability of the dominant summertime anticyclone circulation pattern and the associated synoptic and mesoscale processes responsible for the surges of monsoonal moisture (and precipitation). Deservedly so, this drought-susceptible region has received much scientific attention thanks to growing water resource demands and dwindling ground water reserves. Precipitation characteristics during this time result from a symphony of processes spanning diurnal to sub-seasonal timescales that together define the North American Monsoon (NAM). With an eye on increasing predictability of daily climate variability, the goal of this study is to use observation-based reanalysis data to (1) identify distinct regimes of daily atmospheric phenomena over the western U.S., and (2) investigate the relationship between these regimes and the various scales of their controlling factors. Thus, developing a climatology of daily weather events, or a ‘weather’-tology. Armed with new understanding of high-frequency climate variability beyond monthly timescales, this study has the potential to open the door to more robust and capable interdisciplinary applications of climate data—especially for future-climate studies.