High and Dry – Probing Greenland’s Atmosphere and Clouds

ICECAPS1

– by Matthew Shupe (Cooperative Institute for Research in Environmental Studies)

High atop the Greenland Ice Sheet, cloudy skies portend warmer temperatures and higher winds.  These clouds alter the surface energy budget, diminish the strong near-surface atmospheric stability, and precipitate ice crystal to the surface.  Together these processes comprise the focus of the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at Summit (ICECAPS) project that has been underway at Summit, Greenland since summer 2010.  Exciting initial results are rolling out, providing the first detailed look at cloud and atmosphere properties and processes over the Greenland Ice Sheet.  The action observed by the extensive, ground-based instrument suite can be followed via daily imagery available at www.esrl.noaa.gov/psd/arctic/observatories/summit.

Playing key roles in the U.S. Arctic Observing Network (AON) and the International Arctic Systems for Observing the Atmosphere (IASOA) network, ICECAPS is a collaborative project between the Universities of Colorado, Idaho, and Wisconsin, with substantial support from the National Science Foundation, the National Oceanic and Atmospheric Administration, the Department of Energy, and Environment Canada.  Principle Investigators Von Walden (University of Idaho), Matthew Shupe (ESRL/CIRES), David Turner (NSSL), and Ralf Bennartz (University of Wisconsin) lead a large team of field technicians, engineers, graduate students, and collaborators as they endeavor to make year-round measurements of the atmosphere and clouds in the extreme Greenland Ice Sheet environment.  The instrument suite, housed in a movable facility, includes highly complementary observational perspectives from microwave and infrared radiometers, lidars, radar, ceilometer, sodar, precipitation sensor, and twice-daily radiosonde profiles (see Figure1).  These measurements can be jointly used to characterize the diurnal and seasonal variability of atmospheric structure, cloud microphysical and radiative properties, and precipitation.  ICECAPS provides a new and unique observational examination of these climatically-important aspects of the ice sheet environment and will offer important context for ongoing precipitation and surface energy budget measurements at the site.

At Summit, the atmosphere is extremely dry and cold with strong near-surface static stability predominating throughout the year, particularly in winter.  This low-level thermodynamic structure, coupled with frequent moisture inversions, conveys the importance of advection for local cloud and precipitation formation.  Cloud liquid water is observed in all months of the year, even in the particularly cold and dry winter, while annual cycle observations indicate the largest atmospheric moisture amounts, cloud water contents, and snowfall occur in summer and under southwesterly flow.  Atmospheric ice crystals, or diamond dust, readily form as advecting air masses cool over the ice sheet, leading to outstanding optical displays.  Surprisingly, many of the basic structural properties of clouds observed at Summit, and particularly the low-level stratiform clouds, are very similar to their counterparts in other Arctic regions in spite of the unique environment encountered on top of the ice sheet.  The ICECAPS observations and accompanying analyses will be used to improve the understanding of key cloud–atmosphere processes and the manner in which they interact with the GIS. Furthermore, they will facilitate model evaluation and development in this data-sparse but environmentally unique region.

Related Article:  Shupe, M. D., D. D. Turner, V. P. Walden, R. Bennartz, M. Cadeddu, B. Castellani, C. Cox, D. Hudak, M. Kulie, N. Miller, R. R. Neely III, W. Neff, and P. Rowe, 2013:  High and Dry:  New observations of tropospheric and cloud properties above the Greenland Ice Sheet.  Bull. Amer. Meteor. Soc., 94, 169-186, doi:10.1175/BAMS-D-11-00249.1.

 

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NSSL leverages new technologies in winter weather experiment

21Jan 2012
Dual-pol radar data of a winter precipitation event in New York.

NSSL and collaborators will leverage new technology including dual-polarized radar observations and a precipitation reporting mobile device app to improve forecasts of winter weather during February and March.

The experiment will evaluate the performance of new algorithms that use dual-polarized radar data and determine what new tools could be developed to improve detection of precipitation type and amount in winter storms.

The group will assess a new technique that is a “first-guess” of precipitation type using dual-pol data and compare it to observations collected from the Precipitation Identification Near the Ground mobile app and the Severe Hazards Analysis and Verification Experiment phone calls. They plan to identify potential biases and regions of poor performance.

They will also look at quantitative precipitation estimation products that include dual-polarized information and compare them to current products to see if dual-polarized data improves the result.

The experiment is a collaboration between NSSL, the Storm Prediction Center, the Norman Weather Forecast Office, the National Weather Service Warning Decision Training Branch and the Radar Operations Center.

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Warn-on-Forecast Week!

Researchers and forecasters talk Warn-on-Forecast
Researchers and forecasters talk Warn-on-Forecast

The NOAA NSSL hosted the Technical Workshop on Numerical Guidance Support Warn-on-Forecast on Tuesday February 5.

The fourth annual Warn on Forecast and High Impact Weather Workshop followed on February 6-7.

Warn-on-Forecast http://www.nssl.noaa.gov/projects/wof/collaborators include NSSL and Earth System Research Laboratory, NOAA National Weather Service and Storm Prediction Center, The University of Oklahoma’s Center for the Analysis and Prediction of Storms, and Social Science Woven Into Meteorology.

These workshops give researchers an opportunity to present progress reports and to discuss plans for further research toward improvements in lead time for severe weather warnings.

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Recent significant papers released online

(OAR National Severe Storms Laboratory and Cooperative Institute for Mesoscale Meteorological Studies) Tornado path length forecasts from 2010 – 2011 using ensemble updraft helicity

Journal:  Weather and Forecasting (Early online release 1/14/13)

Authors:  Adam J. Clark, (CIMMS/NSSL) Jidong Gao,(NSSL) Patrick T. Marsh, (CIMMS/NSSL) Travis Smith, (CIMMS/NSSL) John S. Kain,(NSSL) James Correia, Jr., Ming Xue, and Fanyou Kong

Summary
This paper adds new data to previous research that diagnosed a strong relationship between the cumulative path lengths of simulated rotating storms (measured using a 3-dimensional object identification algorithm applied to forecast updraft helicity) and the cumulative path lengths of tornadoes. The new forecast examples are from three major 2011 tornado outbreaks – 16 and 27 April, and 24 May, as well as two forecast failure cases from June 2010. Finally, analysis updraft helicity from 27 April 2011 is computed using a three-dimensional variational data assimilation system to obtain 1.25 km grid-spacing analyses at 5-minute intervals and compared to forecast UH from individual SSEF members.

Important conclusions:   Forecast updraft helicity pathlengths during the spring could be a very skillfull predictor for the severity of tornado outbreaks as measured by total pathlengths.

Significance:  Efforts continue to find better ways to predict tornadoes and tornado outbreaks  Weather and Forecasting (Early online release 1/14/13)

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(OAR-National Severe Storms Laboratory) A Unified Flash Flood Database over the US

Journal:  Bulletin of the American Meteorological Society (early online release 1/25/13)

Authors:  Jonathan J. Gourley (NSSL), Yang Hong, Zachary L. Flamig (NSSL), Ami Arthur (NSSL/CIMMS), Robert Clark (NSSL/CIMMS), Martin Calianno, Isabelle Ruin, Terry Ortel, Michael E. Wieczorek, Pierre-Emmanuel Kirstetter (NSSL), Edward Clark, Witold F. Krajewski

Summary:  This study is the first of its kind to assemble, reprocess, describe, and disseminate a georeferenced US database providing a long-term, detailed characterization of flash flooding in terms of spatiotemporal behavior and specificity of impacts. The database is comprised of three primary sources: 1) the entire archive of automated discharge observations from the US Geological Survey that has been reprocessed to describe individual flooding events, 2) flash flooding reports collected by the National Weather Service from 2006-present, and 3) witness reports obtained directly from the public in the Severe Hazards Analysis and Verification Experiment during the summers 2008–2010.

Important conclusions:  A major asset of the unified flash flood database is its collation of relevant information from a variety of sources that is now readily available to the community in common formats.

Significance:  It is anticipated that this database will be used for many diverse purposes such as evaluating tools to predict flash flooding, characterizing seasonal and regional trends, and improving understanding of dominant flood-producing processes.   Bulletin of the American Meteorological Society (early online release 1/25/13)

Authors:  Jonathan J. Gourley (NSSL), Yang Hong, Zachary L. Flamig (NSSL), Ami Arthur (NSSL/CIMMS), Robert Clark (NSSL/CIMMS), Martin Calianno, Isabelle Ruin, Terry Ortel, Michael E. Wieczorek, Pierre-Emmanuel Kirstetter (NSSL), Edward Clark, Witold F. Krajewski

Summary:  This study is the first of its kind to assemble, reprocess, describe, and disseminate a georeferenced US database providing a long-term, detailed characterization of flash flooding in terms of spatiotemporal behavior and specificity of impacts. The database is comprised of three primary sources: 1) the entire archive of automated discharge observations from the US Geological Survey that has been reprocessed to describe individual flooding events, 2) flash flooding reports collected by the National Weather Service from 2006-present, and 3) witness reports obtained directly from the public in the Severe Hazards Analysis and Verification Experiment during the summers 2008–2010.

Important conclusions:  A major asset of the unified flash flood database is its collation of relevant information from a variety of sources that is now readily available to the community in common formats.

Significance:  It is anticipated that this database will be used for many diverse purposes such as evaluating tools to predict flash flooding, characterizing seasonal and regional trends, and improving understanding of dominant flood-producing processes.

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NSSL unveils re-designed web presence

webpageThe NOAA National Severe Storms Laboratory has just launched a completely redesigned website to showcase NSSL’s leadership and success in severe weather research.

The site features new content and an improved, easy-to-use structure, taking advantage of current technology that makes updates simpler and also supports smartphones and tablets.  Heavy integration of photos and graphics help tell the NSSL story visually.

The NSSL website now features a rotating header that cycles through the most current research stories.  An easy to use navigation bar lists all main topics and subheadings without having to “mouse-over” them individually.  Content is organized by severe weather research topics and tools targeting both curious public visitors as well as scientists already familiar with NSSL’s work.

A comprehensive search engine points visitors to information quickly and there is now convenient access to fact sheets, multi-media and media resources.

On the footer of every page, visitors can connect to NSSL through social media where interesting pieces of news and photos are posted.

The most visited part of the NSSL site, the education section, now offers a short course in severe weather phenomena written for the generall public called “Severe Weather 101.” There is also a comprehensive list of FAQ’s on each topic, written from emails that are sent to NSSL.  Links to other weather resources, games and activities are featured for educators, students and visitors of all ages.

The NSSL web site is very popular, with more than 4,000 unique visitors every day. This is the first comprehensive update since 2005.

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NSSL Launches iPhone and Android Apps to collect precipitation reports from the public

Screenshot of the mPING app for iPhone

The NOAA National Severe Storms Laboratory (NSSL), in partnership with the University of Oklahoma and has launched an app where users can anonymously report precipitation from their iPhone or Android through the “mobile Precipitation Identification Near the Ground “mPING” app.  NSSL researchers will compare the reports with what radars detect and use the information to develop new radar and forecasting technologies and techniques to determine whether snow, rain, ice pellets, mixtures or hail is falling. NSSL hopes to build a valuable database of tens of thousands of observations from across the U.S.
The apps are available on iTunes or Google Play for use on both phones and tablets.

The reports can be viewed here in real-time:
http://www.nssl.noaa.gov/projects/ping/display/

Learn more at NSSL’s main PING page:  http://www.nssl.noaa.gov/projects/ping/

Link for iTunes mPING app

Link for Android app

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