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Full-Text Articles in Meteorology

Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer, Eric Jensen Dec 2014

Distributions Of Ice Supersaturation And Ice Crystals From Airborne Observations In Relation To Upper Tropospheric Dynamical Boundaries, Minghui Diao, Jorgen Jensen, Laura Pan, Cameron Homeyer, Shawn Honomichl, James Bresch, Aaron Bansemer, Eric Jensen

Faculty Publications, Meteorology and Climate Science

Cirrus clouds are one of the largest sources of uncertainties in predicting future climate. Ice nucleation and ice crystal growth inside cirrus clouds require ice supersaturation (ISS). Previously, remote sensing observations have shown that the locations of cirrus clouds’ cloud top height are highly correlated with the thermal tropopause height (Pan and Munchak, 2011). However, it is unclear if the initial conditions of cirrus clouds – ice supersaturated region (ISSRs) – have similar features in the extratropical upper troposphere and lower stratosphere (UT/LS). In fact, the dynamical processes and conditions that contribute to ISS formation from the microscale (~100 m) …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget

Faculty Publications, Meteorology and Climate Science

The optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) time windows containing significant ranking sequences in U.S. climate division temperature data. The simplicity of the ORR procedure’s output—a time series’ most significant nonoverlapping periods of high or low rankings—makes it possible to graphically identify common temporal breakpoints and spatial patterns of IMD variability in the analyses of 102 climate division temperature series. This approach is also applied to annual Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) climate indices, a Northern Hemisphere annual temperature (NHT) series, and divisional annual and seasonal temperature data during …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero

Faculty Publications, Meteorology and Climate Science

In Part I of this paper, the optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) regimes in U.S. climate division temperature data during 1896–2012. Here, the method is used to test for annual and seasonal precipitation regimes during that same period. Water-year mean streamflow rankings at 125 U.S. Hydro-Climatic Data Network gauge stations are also evaluated during 1939–2011. The precipitation and streamflow regimes identified are compared with ORR-derived regimes in the Pacific decadal oscillation (PDO), the Atlantic multidecadal oscillation (AMO), and indices derived from gridded SST anomaly (SSTA) analysis data. Using a graphic display approach …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part I: Temperature, Eugene C. Cordero, Steven A. Mauget

Eugene C. Cordero

The optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) time windows containing significant ranking sequences in U.S. climate division temperature data. The simplicity of the ORR procedure’s output—a time series’ most significant nonoverlapping periods of high or low rankings—makes it possible to graphically identify common temporal breakpoints and spatial patterns of IMD variability in the analyses of 102 climate division temperature series. This approach is also applied to annual Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) climate indices, a Northern Hemisphere annual temperature (NHT) series, and divisional annual and seasonal temperature data during …


Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero Dec 2014

Optimal Ranking Regime Analysis Of Intra- To Multidecadal U.S. Climate Variability. Part Ii: Precipitation And Streamflow, Steven A. Mauget, Eugene C. Cordero

Eugene C. Cordero

In Part I of this paper, the optimal ranking regime (ORR) method was used to identify intradecadal to multidecadal (IMD) regimes in U.S. climate division temperature data during 1896–2012. Here, the method is used to test for annual and seasonal precipitation regimes during that same period. Water-year mean streamflow rankings at 125 U.S. Hydro-Climatic Data Network gauge stations are also evaluated during 1939–2011. The precipitation and streamflow regimes identified are compared with ORR-derived regimes in the Pacific decadal oscillation (PDO), the Atlantic multidecadal oscillation (AMO), and indices derived from gridded SST anomaly (SSTA) analysis data. Using a graphic display approach …


Hemispheric Comparison Of Cirrus Cloud Evolution Using In Situ Measurements In Hiaper Pole-To-Pole Observations, Minghui Diao, Mark Zondlo, Andrew Heymsfield, Stuart Beaton Jul 2014

Hemispheric Comparison Of Cirrus Cloud Evolution Using In Situ Measurements In Hiaper Pole-To-Pole Observations, Minghui Diao, Mark Zondlo, Andrew Heymsfield, Stuart Beaton

Faculty Publications, Meteorology and Climate Science

The radiative forcing of cirrus clouds is highly sensitive to their microphysical properties as well as their evolution. However, there are very limited observations and analyses on the cirrus cloud formation and evolution with both microscale resolution and global scale coverage. The lack of such observations limits the overall comparison of cirrus cloud evolution between the two hemispheres. In fact, the previous hemispheric comparisons of cirrus cloud microphysics using in situ observations were only based on the sampling over two locations at 55°N and 55°S (Ovarlez et al., 2002; Gayet et al., 2004). Here we use a more comprehensive aircraft-based …


Metr 12: Global Warming Course Redesign, Eugene Cordero Apr 2014

Metr 12: Global Warming Course Redesign, Eugene Cordero

Innovative Teaching – Course Redesign Project Posters 2014

Poster summarizing course redesign activities for METR 12: Global Warming.


Metr 060 & 061: Introduction To Meteorology Course Redesign, Alison Bridger Apr 2014

Metr 060 & 061: Introduction To Meteorology Course Redesign, Alison Bridger

Innovative Teaching – Course Redesign Project Posters 2014

Poster summarizing course redesign activities for METR 060 & 061: Introduction to Meteorology.


Cloud-Scale Ice-Supersaturated Regions Spatially Correlate With High Water Vapor Heterogeneities, Minghui Diao, Mark Zondlo, Andrew Heymsfield, L. Avallone, M. Paige, Stuart Beaton, T. Campos, D. Rogers Mar 2014

Cloud-Scale Ice-Supersaturated Regions Spatially Correlate With High Water Vapor Heterogeneities, Minghui Diao, Mark Zondlo, Andrew Heymsfield, L. Avallone, M. Paige, Stuart Beaton, T. Campos, D. Rogers

Faculty Publications, Meteorology and Climate Science

Cirrus clouds have large yet uncertain impacts on Earth's climate. Ice supersaturation (ISS) – where the relative humidity with respect to ice (RHi) is greater than 100% – is the prerequisite condition of ice nucleation. Here we use 1 Hz (~230 m) in situ, aircraft-based observations from 87° N to 67° S to analyze the spatial characteristics of ice-supersaturated regions (ISSRs). The median length of 1-D horizontal ISSR segments is found to be very small (~1 km), which is 2 orders of magnitude smaller than previously reported. To understand the conditions of these small-scale ISSRs, we compare individual ISSRs with …


Prescribed Burning Of Logging Slash In The Boreal Forest Of Finland: Emissions And Effects On Meteorological Quantities And Soil Properties, A. Virkkula, J. Levula, T. Pohja, P. Aalto, P. Keronen, S. Schobesberger, Craig Clements, L. Pirjola, A. Kieloaho, L. Kulmala, H. Aaltonen, J. Patoskoski, J. Pumpanen, J. Rinne, T. Ruuskanen, M. Pihlatie, H. Mannien, V. Aaltonen, H. Junninen, T. Petaja, J. Backman, M. Dal Maso, T. Nieminen, T. Olsson, T. Grönholm, J. Aalto, T. Virtanen, M. Kajos, V. Kerminen, D. Shultz, J. Kukkonen, M. Sofiev, G. De Leeuw, J. Back, P. Hari, M. Kulmala Jan 2014

Prescribed Burning Of Logging Slash In The Boreal Forest Of Finland: Emissions And Effects On Meteorological Quantities And Soil Properties, A. Virkkula, J. Levula, T. Pohja, P. Aalto, P. Keronen, S. Schobesberger, Craig Clements, L. Pirjola, A. Kieloaho, L. Kulmala, H. Aaltonen, J. Patoskoski, J. Pumpanen, J. Rinne, T. Ruuskanen, M. Pihlatie, H. Mannien, V. Aaltonen, H. Junninen, T. Petaja, J. Backman, M. Dal Maso, T. Nieminen, T. Olsson, T. Grönholm, J. Aalto, T. Virtanen, M. Kajos, V. Kerminen, D. Shultz, J. Kukkonen, M. Sofiev, G. De Leeuw, J. Back, P. Hari, M. Kulmala

Faculty Publications, Meteorology and Climate Science

A prescribed fire experiment was conducted on 26 June 2009 in Hyytiälä, Finland, to study aerosol and trace gas emissions from prescribed fires of slash fuels and the effects of fire on soil properties in a controlled environment. A 0.8 ha forest near the SMEAR II measurement station (Station for Measuring Ecosystem-Atmosphere Relations) was cut clear; some tree trunks, all tree tops and branches were left on the ground and burned. The amount of burned organic material was ~46.8 tons (i.e., ~60 tons ha−1). The flaming phase lasted 2 h 15 min, the smoldering phase 3 h. Measurements were conducted …


Airborne Measurements Of Aerosols And Carbon Dioxide During A Prescribed Fire Experiment At A Boreal Forest Site, Aki Virkkula, Toivo Pohja, Pasi Aalto, Petri Keronen, Siegfried Schobesberger, Craig Clements, Tuukka Petäjä, Juha Nikmo, Markku Kulmala Jan 2014

Airborne Measurements Of Aerosols And Carbon Dioxide During A Prescribed Fire Experiment At A Boreal Forest Site, Aki Virkkula, Toivo Pohja, Pasi Aalto, Petri Keronen, Siegfried Schobesberger, Craig Clements, Tuukka Petäjä, Juha Nikmo, Markku Kulmala

Faculty Publications, Meteorology and Climate Science

During a prescribed fire experiment, CO2 and particle number concentrations, light scattering and absorption coefficients were measured from a Cessna 172 airplane. Peak number concentrations were (3 ± 1) x 106 cm–3 and they decreased faster than what can be explained by coagulation alone. The single-scattering albedo of particles grew from the values of 0.4 ± 0.1 closest to the emissions to the values of 0.8 ± 0.1 at the distance of 400 m from the emissions. The mean Ângström exponent of absorption, 1.70 ± 0.24, is in line with the published spectral absorption values of wood-smoke aerosol. The estimated …


Representation Of Ethiopian Wet Spells In Global And Nested Models, Mark Jury, Sen Chiao Jan 2014

Representation Of Ethiopian Wet Spells In Global And Nested Models, Mark Jury, Sen Chiao

Faculty Publications, Meteorology and Climate Science

Weather forecast and reanalysis models exhibit different performance in daily rainfall estimation over the Ethiopian highlands, 2000–2012, with ECMWF closer to observations than other models. Background is given to illustrate the Hadley circulation and easterly jets over Ethiopia, using sections on 37°E in July–August 2011. ECMWF reanalysis has a narrow band of rainfall >15 mm/day on 10°N, consistent with TRMM satellite estimates, associated with a steep gradient in meridional wind. MERRA and GFS models have a wider band of rainfall and weaker gradients in meridional winds. The contrasting background states influence a nested WRF model simulation of heavy rain in …