Baker Perry 1, Richard Poremba 1, Anton Seimon 1,2, Daniel Martin 1, Ginger Kelly 1, and Alfredo...
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Baker Perry 1, Richard Poremba 1, Anton Seimon 1,2, Daniel Martin 1, Ginger Kelly 1, and Alfredo Tupayachi 3 1 Department of Geography and Planning, Appalachian
Baker Perry 1, Richard Poremba 1, Anton Seimon 1,2, Daniel
Martin 1, Ginger Kelly 1, and Alfredo Tupayachi 3 1 Department of
Geography and Planning, Appalachian State University 2 Climate
Change Institute, University of Maine, 3 Universidad Nacional de
San Antonio de Abd de Cusco 71 st Eastern Snow Conference Boone, NC
USA 5 June 2014 SNOWFALL EVENT CHARACTERISTICS IN THE CORDILLERA
VILCANOTA, PERU
Slide 2
Cordillera Vilcanota
Slide 3
Slide 4
Background and Significance Cordillera Vilcanota has been the
site of significant research focused on: Paleoclimatic
reconstructions from Quelccaya ice cores (e.g., Thompson et al.
1985, Seimon 2003, Thompson et al. 2006 ) Past glaciations and
climate-glacier interactions (e.g., Mark et al. 2002) Ecological
response to climate change (e.g., Seimon et al. 2007) Precipitation
variability is a fundamental influence on past and current changes
in the tropical Andes (Garreaud et al. 2003) Precipitation type,
amount, and timing controls surface albedo, which is critical to
glacier mass balance (e.g., Francou et al. 2003) Precipitation
processes play a dominant role in influencing stable oxygen isotope
ratios ( 18 O) preserved in snow/ice stratigraphy (e.g., Vuille et
al. 2008, Vimeux et al. 2009) However, considerable uncertainty
remains on the timing, precipitation type, and trajectories during
events
Slide 5
Descriptions of Central Andean Regional Precipitation Climatic
FeaturePrevious StudiesThis Study Precipitation diurnality Unimodal
daytime precipitation maximum Bimodal: broad nighttime maximum
peaking near midnight LST with secondary late-afternoon maximum
Precipitation character Exclusively deep, moist convection
Primarily stratiform (nighttime) with secondary deep moist
convection (daytime) Precipitating moisture trajectory E from
Amazon basin Primarily NW, but with 95 % tied to trajectories from
the Amazon basin Moisture source regions Amazon basin exclusively
Dominantly Amazon basin, but also 5% from Pacific Ocean
ENSO-related precipitation anomalies Negative anomalies with El
Nio; positive anomalies with La Nia Positive anomalies with El Nio;
negative anomalies with La Nia ?
Slide 6
Research Questions What are the predominant precipitation types
at ~ 5,000 m asl and how do they vary by season? Snow, graupel
(phati in Quechua), rain/snow mix, rain What is the daily timing of
snowfall events in the Cordillera Vilcanota? When is heavy snowfall
most likely to occur? What are the dominant wind directions and
antecedent upstream air trajectories associated with snowfall
events?
Slide 7
SENAMHI Stations: 2x Daily Observations 0000 and 1200 UTC Cusco
International Airport: Hourly Precip Observations Perry et al.
2014, Int J Clim
Slide 8
Slide 9
Quelccaya Icecap Don Pedro Godfredo with Precipitation Gauge
(At Murmurani Alto 5,050 m asl) 10 cm diameter manual gauge August
2010
Slide 10
Sonic Snow Depth Parsivel Present Weather Temp & Relative
Humidity April 2012 Murmurani Alto (5,050 m)
Slide 11
RM Young 05103 Alpine Wind Sensor April 2012 Osjollo Anante
Icecap (5,540 m) Vaisala WXT 510 Multisensor with Sonic Wind,
Temperature, Relative Humidity, and Pressure
Slide 12
Snow and Graupel are the Primary Precipitation Types Rain is
Very Infrequent, Less than 4% of Hours
Slide 13
April 2012 Rapid Snow Ablation in Murmurani Alto
Slide 14
5.9 mm/event 68% of total =Stratiform? 3.3 mm/event 32% of
total =Convective? Night Day Sunrise Perry et al. 2014, Int J
Clim
Slide 15
73% of heavy events occur at night 59% of light events occur
during day Perry et al. 2014, Int J Clim
Slide 16
Night Day Sunrise
Slide 17
Composite Trajectory Clusters for All Events in Cusco,
2004-2010 Cluster 1 50% of events 4.7 mm/event Cluster 3 19% of
events 4.8 mm/event Cluster 6 5% of events 8.7 mm/event Cluster 2
14% of events 3.6 mm/event Cluster 4 5% of events 4.8 mm/event
Cluster 5 8% of events 3.3 mm/event 58% of precipitation events at
Cusco exhibit trajectories out of the NNW Infrequent, yet heavy 83%
of events are tied to weak low-level flow out of NNW, NE, and E
Perry et al. 2014, Int J Clim
Slide 18
Wind Speed and Direction During All Precipitation Events:
2012-2013 Wind Observations from Osjollo Anante Precipitation
Observations from Murmurani Alto
Slide 19
Wind Speed and Direction During DJF Precipitation Events:
2012-2013 Wind Observations from Osjollo Anante Precipitation
Observations from Murmurani Alto
Slide 20
Descriptions of Central Andean Regional Precipitation Climatic
FeaturePrevious StudiesThis Study Precipitation diurnality Unimodal
daytime precipitation maximum Bimodal: broad nighttime maximum
peaking near midnight LST with secondary late-afternoon maximum
Precipitation character Exclusively deep, moist convection
Primarily stratiform (nighttime) with secondary deep moist
convection (daytime) Precipitating moisture trajectory E from
Amazon basin Primarily NW, but with 95 % tied to trajectories from
the Amazon basin Moisture source regions Amazon basin exclusively
Dominantly Amazon basin, but also 5% from Pacific Ocean
ENSO-related precipitation anomalies Negative anomalies with El
Nio; positive anomalies with La Nia Positive anomalies with El Nio;
negative anomalies with La Nia (Not shown) Perry et al. 2014, Int J
Clim
Slide 21
Summary and Conclusions Precipitation primarily falls as snow
above 5,000 m, with graupel and heavily rimed snow crystals common.
Rain and mixed precipitation are rare, accounting for less than 5%
of total precipitation hours. How will these values change in
2014-2015, with the possibility of a major El Nio and an associated
elevated freezing level? There were a total of 281 events between
April 2012 and July 2013, with most of the heavy events occurring
at night. No hourly precipitation totals available, only present
weather. What are the meteorological mechanisms responsible for the
heavy nighttime stratiform precipitation? Most precipitation events
are associated with W and NW flow at Murmurani Alto and NW
trajectories at Cusco. In contrast to E flow as reported at other
sites in the Central Andes, including Quelccaya.
Slide 22
Paleoclimatic Implications Much of the inference from the
nearby Quelccaya ice core record presumes that the central Andean
precipitation meteorology is fairly well understood. Our findings
call that into question. A reconsideration of the climatological
inferences derived from Quelccaya (and possibly other tropical
Andean ice cores) may be needed. May result in improved
paleoclimatic understanding? Improved correlation with other
paleoclimatic proxy records?
Slide 23
Research Activities: July to November 2014 Install
precipitation monitoring stations on the Quelccaya Icecap and at
Chacaltaya (Cordillera Real), Bolivia. Recruit and train additional
citizen science precipitation observers in the Cordilleras
Vilcanota and Cordillera Real. Investigate the vertical structure
of precipitation with weather balloon releases and a
vertically-pointing radar. Categorize snow particle type and degree
of riming, which may provide insight to cloud microphysical
processes. Minder et al. (2012)
Slide 24
Acknowledgments Sandra Yuter, Doug Hardy, Nelson Quispe, Marcos
Andrade, Tracie Seimon, Jon Webb, Preston Sowell, Brooks Fisher,
Karina Yager, Charles Rodda, Skylar Haines, Nico Robles, Ben Boore,
Paul Carr, Dan Slayback, Don Pedro Godfredo, and Crispin family
Appalachian State University Board of Trustees International
Research Travel Grant (2009), Office of International Education and
Development (2010, 2012), Justin Brooks Fisher Foundation (2012),
College of Arts & Sciences (2012) NSF Grant AGS-1347179
(CAREER: Multiscale Investigations of Tropical Andean
Precipitation)Questions?