CW3E welcomes Dr. David Lavers

CW3E welcomes Dr. David Lavers

September 12, 2016

Dr. David Lavers has joined CW3E at the Scripps Institution of Oceanography to work on improving understanding and forecasting of hydrologic extremes in the western United States. David’s previous research has been in the area of hydrometeorology, with a particular focus on atmospheric rivers (ARs). His work has included studying the connection between ARs and extreme precipitation and flood events across Europe and the Central United States, and investigating how ARs may change in the future. He has previously held appointments at the European Centre for Medium-Range Weather Forecasts, the University of Iowa, Princeton University, and the University of Reading UK. His PhD on seasonal hydrological prediction, awarded in 2011, was undertaken at the Centre for Ecology and Hydrology (Wallingford) UK, and the University of Birmingham UK. Away from work David enjoys outdoor pursuits including hiking and cycling.

Mike Dettinger elected AGU Fellow

CW3E congratulates Mike Dettinger – 2014 AGU Fellow<

July 30, 2014

CW3E congratulates PI Dr. Michael Dettinger’s election to AGU’s 2014 class of Fellows. This honor is a compliment to Mike’s long career and is presented with the citation “For insightful and useful research in understanding how climate and weather affect the variability of hydrologic systems”. Only one in a thousand members is elected AGU Fellow each year so this is a prestigious achievement. CW3E PI and colleague Dr. Dan Cayan notes “Mike was among the first to explain how hydrologic variability is organized across continental to global scales. Mike’s contributions also include new insights about how longer period climate variation may affect shorter period hydrologic phenomena. Mike’s recent emphasis on understanding North Pacific storms, with close ties to Marty Ralph and colleagues, has produced a sharper image of how “atmospheric rivers” produce most of the floods along the West Coast and deliver a large portion of its water supply.”

CW3E welcomes Reuben Demirdjian

CW3E welcomes Reuben Demirdjian

June 24, 2014

CW3E is pleased to welcome Reuben Demirdjian. Reuben joins CW3E to pursue his doctoral degree at Scripps Institution of Oceanography. Reuben completed his undergraduate degree at UC Santa Barbara in physics. “I met Dr. Ralph at the Scripps Open House and was impressed with the group he is building and his enthusiasm for understanding the role atmospheric rivers play in the precipittion regime of California and the western US,” Reuben said. Reuben is getting a head start this summer learning tools, especially the WRF (Weather, Research and Forecasting) model, and use of dropsonde observations from research aircraft.

Publication Notice: Chemical properties of insoluble precipitation residue particles

CW3E Publication Notice

Chemical properties of insoluble precipitation residue particles

Jessie Creamean posing for a photo while clearing snow from the top of the NOAA trailer at Sugar Pine Dam after the storm on 2/25/11.

This article provides an in-depth analysis of resuspended residues from precipitation samples collected at a remote site in the Sierra Nevada Mountains in California during the 2009-2011 winter seasons. These residues may be used as a benchmark for classification of insoluble precipitation. Knowledge of the precipitation chemistry of insoluble residues coupled with meteorological and cloud microphysical measurements will ultimately improve our understanding of the link between aerosols, clouds, and precipitation.

This paper represents a significant milestone from the CalWater experiment, which is led by members of UCSD/Scripps’ new Centers on aerosols (CAICE) and extreme events (CW3E), as well as NOAA, DOE, NASA, USGS. It also highlights the multi-disciplinary research stimulated by CalWater, and the partnerships between key researchers across organizations. The lead author, Jessie Creamean, received her PhD in atmospheric chemistry from UCSD under Kim Prather using CalWater data, and is now bringing that expertise to a primarily meteorological group in NOAA as she pursues emerging topics in aerosol-precipitation interactions in collaboration with CW3E scientists.

A personal use copy of the article is available here.

CalWater-ACAPEX 2015 Planning Workshop

CalWater-ACAPEX 2015 Planning Workshop

Scripps Institution of Oceanography

La Jolla, California

CalWater 2 Co-Leads: Marty Ralph, Kim Prather, Dan Cayan (Scripps)

Organizing Committee: Chris Fairall (NOAA), Ruby Leung (PNNL), Andrew Martin (Scripps), Ryan Spackman (NOAA/STC)

CalWater2 – ACAPEX Observational Strategy Winter 2014-15

CalWater-2 took major steps from vision to reality on 22-24 April 2014 at Scripps Institution of Oceanography when roughly 40 key individuals (scientists, engineers, aircraft and ship managers, and students) met to plan for major field deployments in 2015. The following facilities are committed (or nearly so) to a field campaign between roughly 10 January and 10 March 2015:

  • DOE – G-1 aircraft
  • DOE AMF-2 ocean-atmosphere facility on the NOAA Research Vessel (ship) Ron Brown
  • NOAA G-IV aircraft
  • NOAA P-3 aircraft
  • ATOFMS mobile, land-based aerosol-sensor suite
  • EFREP hydrometeorological Mesonetwork in California

The DOE facilities are part of the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) experiment addressing (1) aerosol impacts on clouds and precipitation and (2) atmospheric rivers. The NOAA facilities were requested also based on the CalWater vision, with an emphasis on atmospheric-river science questions.

The workshop concluded with a plan for specific start and end dates for each facility, narrowed options for where to operate them, a plan for a field operations center (and a specific possible location), strategies for developing coordinated ship and aircraft operations, and plans for the forecasting capabilities needed to guide missions. In addition, the 12-member CalWater Core Scientific Steering Group met afterword and reviewed plans for 2016-2018 and strategies to advance the longer term Calwater Vision. The Steering Group committed to organizing two special sessions and a side meeting (for last minute coordinations of the 2015 CalWater and ACAPEX activities) at the Fall Meeting of AGU in December 2014, and a journal article describing the program. The proposed AGU sessions are:

  1. CalWater Theme 1: Cloud-Aerosol-Precipitation Interactions in California (Conveners: Daniel Rosenfeld, Kimberly Prather),
  2. Atmospheric Rivers: Observations, Dynamics, Modeling, Impacts and Applications (Conveners: Marty Ralph, Duane Waliser, Jason Cordeira).

The presentations from the Workshop are available here.

Workshop Sponsored by:

  • Scripps, Center for Western Weather and Water Extremes (CW3E)
  • Scripps Center for Aerosol Impacts on Climate and the Environment (CAICE)
  • Science and Technology Corporation (STC)

Workshop Sponsored by:Workshop Participants

Photo of most workshop participants at the CalWater 2015 – ACAPEX workshop at Scripps, April 2014.

CalWater2 Workshop Participants

CW3E welcomes Dr. Ryan Spackman

CW3E welcomes Dr. Ryan Spackman

February 12, 2014

CW3E is pleased to welcome Dr. Ryan Spackman! Ryan, an atmospheric chemist, will play a critical role bridging CW3E’s dynamics-focused capabilities with chemistry prowess. As deputy principal investigator for NASA Earth Venture and as a member of the CalWater 2 Core Scientific Steering Group, Ryan brings extensive expertise with airborne science campaign planning, execution and delivery of results. Ryan has a passion for observing the components of the water budget and using this data to evaluate weather and climate models. Graduating with a PhD from Harvard in 2004, Ryan continues to work with NOAA’s Earth System Research Laboratory and Science and Technology Corporation. Ryan’s abilities, enthusiasm and energy are superb additions to the CW3E group.

Likelihood of Drought Ending

Drought Recovery by end of Water Year?

New updates to these figures taking into account February rains, and estimates of rains thru mid March, are available.

Please see updated information including a full set of updated figures on Mike Dettinger’s page and on post from 21 March 2014

February 12, 2014

Drought Recovery Odds

CW3E researcher Mike Dettinger was interested in knowing the likelihood of California recovering from the drought by the end of the current water year on Sept 30, 2014. The method he came up with starts with the precipitation deficit from last water year (Oct 2012 – Sept 2013). Observed precipitation for Oct 2013 thru Jan 2014 was used to determine what has been added to this previous water year deficit, depicted in the above figure by the black squares. Here negative precipitation refers to the carryover deficit from the period extending back to October 2012.

Projections into the future of cumulative precipitation since Oct 2012 were computed by adding observed monthly precipitation from each year in the historical record, 1931-2013, or a total of 83 projections. For each future month (Feb-Sep 2014) the red dots in the above figure represent each of the 83 projections.

The example shown above is for the Sacramento Drainage region (CA Climate Division 2). For this region, only 2 of the 83 projections make it above the 75%-tile level by the end of Sept 2014. None of the projections show the 24-month cumulative precipitation reaching “normal” levels by the end of this water year.

New updates to these figures taking into account February rains, and estimates of rains thru mid March, are available here.

Visit the CW3E Drought Info Page to see projections for all seven of California’s climatic divisions.