Andrew J Schwartz

• Doctorate in Atmospheric Science
• Director at University of California, Berkeley

Forests exert control on snowpack properties and processes through their modification of energy balance and micrometeorological conditions. Though forest disturbance by fire is increasing in frequency and severity in many warm regions containing seasonal snowpacks, increases are also expected in high latitude and altitude regions as a result of cli...

Forests modulate energy reaching the Earth’s surface. They can change energy balance fluxes, near-ground meteorological conditions, and seasonal snowpack properties in montane areas. Regions of forests cover are often collocated with areas of freshwater importance for ecosystem and anthropogenic uses. As such, alteration of forests in these regions...

Synoptic weather patterns are investigated for their impact on energy fluxes driving melt of a marginal snowpack in the Snowy Mountains, southeast Australia. K-means clustering applied to ECMWF ERA-Interim data identified common synoptic types and patterns that were then associated with in situ snowpack energy flux measurements. The analysis showed...

Atmospheric Rivers (ARs) are tropospheric corridors that provide ~90% of poleward water vapour transport. They are predicted to increase in frequency and intensity if global warming continues unabated. Here we present a case study of the first direct observations of the impact of AR rain-on-snow (RoS) events on the marginal snowpack of the Australi...

In the 21st century, warmer temperatures and changing atmospheric circulation will likely produce unprecedented changes in Western United States snowfall1–3, with impacts on the timing, amount, and spatial patterns of snowpack4–7. The ~900 snow pillow stations are indispensable to water resource management by measuring snow-water equivalent (SWE)8,...

Rain-on-snow (ROS) events are commonly linked to large historic floods in the United States. Projected increases in the frequency and magnitude of ROS multiply existing uncertainties and risks in operational decision making. Here, we introduce a framework for quality-controlling hourly soil moisture, precipitation, and temperature data to guide the...

In its current form, the Automated Surface Observing System (ASOS) provides automated precipitation type reports of rain, snow, and freezing rain. Unknown precipitation can also be reported when the system recognizes precipitation is occurring but cannot classify it. A new method has been developed that can reprocess the raw ASOS one-minute observa...

Abstract. Synoptic weather patterns are investigated for their impact on energy fluxes driving melt of a marginal snowpack in the Snowy Mountains, southeast Australia. K-means clustering applied to ECMWF ERA-Interim data identified common synoptic types and patterns that were then associated with in-situ snowpack energy flux measurements. The analy...

The National Center for Atmospheric Research (NCAR) developed an artificial snow-generation system designed to operate in a laboratory cold chamber for testing aircraft anti-icing fluids under controlled conditions. Flakes of ice are produced by shaving an ice cylinder with a rotating carbide bit; the resulting artificial snow is dispersed by turbu...

The Terminal Area Icing Weather Information for NextGen (TAIWIN) project, funded by the Federal Aviation Administration (FAA), has identified winter precipitation variability across the terminal area as a research area of interest. Winter precipitation variability has never been studied in-depth and different precipitation rates across the terminal...

The introduction of the Automated Surface Observing System (ASOS) in the late 1990’s and early 2000’s had significant impacts on the weather observational network across the United States. Many locations where humans had provided the weather observations (including present weather) were modified to either include ASOS with the human observers (refe...

In its current state, the Automated Surface Observing System (ASOS) operated primarily by the National Weather Service (NWS) and the Federal Aviation Administration (FAA) can only detect three precipitation types: rain, snow, and freezing rain. An algorithm was written for ASOS to detect freezing drizzle, but it was never accepted for formal implem...

Snow events can have significant impacts on human activities such as agriculture, business, transportation, and recreation. Aircraft de-icing and anti-icing procedures and the clearing of snow from airport runways and public roadways is paramount to safety when snow accumulation is occurring. In order to accurately predict and respond to snowfall a...

The Federal Aviation Administration (FAA) recently published a Notice of Proposed Rulemaking on certification of aircraft for operation in supercooled large drop (SLD) icing conditions with a final rule expected in 2014. One likely consequence of the rule is new limitations on takeoff andlanding in freezing drizzle and/or freezing rain conditions f...