A5080866527- Climate variability and models
- Oceanographic and Atmospheric Processes
- Meteorological Phenomena and Simulations
- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Tropical and Extratropical Cyclones Research
- Atmospheric and Environmental Gas Dynamics
- Aeolian processes and effects
- Ocean Acidification Effects and Responses
- Marine and coastal ecosystems
- Ocean Waves and Remote Sensing
- Spacecraft and Cryogenic Technologies
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Geology and Paleoclimatology Research
- Nuclear Physics and Applications
- Geological and Geophysical Studies
- Geological Studies and Exploration
- Hydrology and Drought Analysis
- Magnetic confinement fusion research
- Geomagnetism and Paleomagnetism Studies
- Plant Surface Properties and Treatments
Oregon State University
2015-2024
National Oceanic and Atmospheric Administration
2022-2023
NOAA Physical Sciences Laboratory
2008-2022
Corvallis Environmental Center
2021
Cooperative Institute for Research in Environmental Sciences
2009
University of Colorado Boulder
2009
University of Hawaiʻi at Mānoa
2005-2008
NOAA Earth System Research Laboratory
2008
Pacific International Center for High Technology Research
2006-2008
University of Hawaii System
2006-2008
Abstract This paper investigates the mechanisms of convective cloud organization by precipitation‐driven cold pools over warm tropical Indian Ocean during 2011 Atmospheric Radiation Measurement (ARM) Madden‐Julian Oscillation (MJO) Investigation Experiment/Dynamics MJO (AMIE/DYNAMO) field campaign. A high‐resolution regional model simulation is performed using Weather Research and Forecasting transition from suppressed to active phases November MJO. The simulated pool lifetimes, spatial...
Abstract The Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) deployment at Graciosa Island Azores generated a 21-month (April 2009–December 2010) comprehensive dataset documenting clouds, aerosols, precipitation using Atmospheric Radiation Measurement Program (ARM) Mobile Facility (AMF). scientific aim of is to gain improved understanding interactions marine boundary layer. straddles between subtropics midlatitudes northeast Atlantic Ocean consequently experiences...
Abstract Warmer SST and more rain in the Northern Hemisphere are observed year-round tropical eastern Pacific with southerly wind crossing equator toward atmospheric heating. The southerlies minimal during boreal spring, when two precipitation maxima straddle equator. Fourteen atmosphere–ocean coupled GCMs from Coupled Model Intercomparison Project (CMIP3) one regional model evaluated against observations simple metrics that diagnose seasonal cycle meridional migration of warm rain....
Abstract Well-known problems trouble coupled general circulation models of the eastern Atlantic and Pacific Ocean basins. Model climates are significantly more symmetric about equator than is observed. sea surface temperatures biased warm south southeast equator, atmosphere too rainy within a band equator. Near-coastal equatorial SSTs warm, producing zonal SST gradient in opposite sign to that The U.S. Climate Variability Predictability Program (CLIVAR) Eastern Tropical Synthesis Working...
Abstract A depth-dependent boundary layer lapse rate was empirically deduced from 156 radiosondes released during six month-long research cruises to the southeast Pacific sampling a variety of stratocumulus conditions. The lapse-rate dependence on height is weak, decreasing best fit 7.6 7.2 K km−1 as deepens 800 m 2 km. Ship-based cloud-base heights up correspond well lifting condensation levels, indicating well-mixed conditions, with cloud bases >800 often 200–600 higher than levels....
The life cycles of three Madden–Julian oscillation (MJO) events were observed over the Indian Ocean as part Dynamics MJO (DYNAMO) experiment. During November 2011 near 0°, 80°E, site research vessel Roger Revelle, authors intense multiscale interactions within an convective envelope, including exchanges between synoptic, meso, convective, and turbulence scales in both atmosphere ocean complicated by a developing tropical cyclone. Embedded event, two bursts sustained westerly wind (>10 m s−1;...
Abstract Cold pools dominate the surface temperature variability observed over central Indian Ocean (0°, 80°E) for 2 months of research cruise observations in Dynamics Madden–Julian Oscillation (DYNAMO) experiment October–December 2011. pool fronts are identified by a rapid drop temperature. Air cold is slightly drier than boundary layer (BL). Consistent with previous studies, attain wet-bulb potential temperatures representative saturated downdrafts originating from lower midtroposphere....
Abstract. To advance the understanding of interplay among clouds, convection, and circulation, its role in climate change, Elucidating clouds–circulation coupling campaign (EUREC4A) Atlantic Tradewind Ocean–Atmosphere Mesoscale Interaction Campaign (ATOMIC) collected measurements western tropical during January February 2020. Upper-air radiosondes were launched regularly (usually 4-hourly) from a network consisting Barbados Cloud Observatory (BCO) four ships within 6–16∘ N, 51–60∘ W. From 8...
Abstract The tropical Pacific Ocean is a climatically important region, home to El Niño and the Southern Oscillation. simulation of its climate remains challenge for global coupled ocean–atmosphere models, which suffer large biases especially in reproducing observed meridional asymmetry across equator sea surface temperature (SST) rainfall. A basin ocean general circulation model with full-physics regional atmospheric study eastern processes. (ROAM) reproduces salient features climate,...
Abstract The midsummer drought (MSD) is a diminution in rainfall experienced during the middle of rainy season southern Mexico and Central America, as well adjacent Caribbean, Gulf Mexico, eastern Pacific seas. aim this paper to describe regional characteristics MSD propose some possible forcing mechanisms. Satellite situ data are used form composite evolution typical MSD, which highlights its coincidence with low-level anticyclone centered over associated easterly flow across America....
The present paper describes the Variability of American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study (VOCALS), an international research program focused on improved understanding and modeling southeastern Pacific (SEP) climate system diurnal to interannual time scales. In framework SEP climate, VOCALS has two fundamental objectives: 1) simulations by coupled atmosphere–ocean general circulation models (CGCMs), with emphasis reducing systematic errors in region; 2) estimates...
Abstract Dynamics of the Madden–Julian Oscillation (DYNAMO) and Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) observations reanalysis-based surface flux products are used to test theories atmosphere–ocean interaction that explain oscillation (MJO). Negative intraseasonal outgoing longwave radiation, indicating deep convective clouds, is in phase with increased wind stress, decreased solar heating, turbulent heat flux—mostly evaporation—from ocean...
Abstract. We evaluate a regional-scale simulation with the WRF-Chem model for VAMOS (Variability of American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx), which sampled Southeast Pacific's persistent stratocumulus deck. Evaluation VOCALS-REx ship-based and three aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL) dynamics cloud microphysics. compare local time series campaign-averaged longitudinal...
Abstract. The Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) took place from 7 January to 11 July 2020 in the tropical North between eastern edge of Barbados and 51∘ W, longitude Northwest Tropical Station (NTAS) mooring. Measurements were made gather information on shallow atmospheric convection, effects aerosols clouds ocean surface energy budget, mesoscale oceanic processes. Multiple platforms deployed during ATOMIC including NOAA RV Ronald H. Brown (RHB) (7...
In order to better understand the general problem of satellite cloud top height retrievals for low clouds, observations made by NOAA research vessels in stratocumulus region southeastern Pacific during cruises 2001 and 2003 2006 were matched with near‐coincident from Moderate Resolution Imaging Spectroradiometer (MODIS) Multiangle SpectroRadiometer (MISR) instruments on Terra satellite, along a limited set ISCCP 30‐km (DX) retrievals. The heights, determined pressures, found be biased high...
Abstract A new dataset synthesizes in situ and remote sensing observations from research ships deployed to the southeastern tropical Pacific stratocumulus region for 7 years boreal fall. Surface meteorology, turbulent radiative fluxes, aerosols, cloud properties, rawinsonde profiles were measured on nine ship transects along 20°S 75° 85°W. Fluxes at ocean surface are essential equilibrium SST. Solar radiation is only warming net heat flux, with 180–200 W m−2 The strongest cooling evaporation...
Abstract The diurnal cycle of marine stratocumulus in cloud-topped boundary layers is examined using ship-based meteorological data obtained during the 2008 Variability American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study Regional Experiment (VOCALS-REx). high temporal and spatial continuity ship data, as well 31-day sample size, allows transition degree coupling stratocumulus-topped layer to be resolved. amplitude variation was comparable magnitude longitudinal differences...
Abstract The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of Southern Ocean using Weather Research and Forecasting (WRF) Model U.S. Navy Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) atmospheric model. SST-induced assessed from eight simulations with different subgrid-scale vertical mixing parameterizations, validated Quick Scatterometer (QuikSCAT) winds satellite-based sea surface temperature (SST) observations on...
Abstract Multidecade global regressions of inversion strength, vertical velocity, and sea surface temperature (SST) on low cloud amount, from subdaily to multiyear time scales, refute the dominance seasonal strength marine variability. Multiday variance averaged over eastern Pacific Atlantic stratocumulus regions [5 × 10 −2 (cloud amount) 2 ] is twice 5 times larger than multimonth variance. The broad multiday band contains most (60%) variance, despite strong (annual) diurnal spectral peaks....
Abstract. In early 2020, an international team set out to investigate trade-wind cumulus clouds and their coupling the large-scale circulation through field campaign EUREC4A: ElUcidating RolE of Clouds-Circulation Coupling in ClimAte. Focused on western tropical Atlantic near Barbados, EUREC4A deployed a number innovative observational strategies, including large network water isotopic measurements collectively known as EUREC4A-iso, study shallow convective environment. The goal was...
Abstract. Dimethylsulfide (DMS) emitted from the ocean is a biogenic precursor gas for sulfur dioxide (SO2) and non-sea-salt sulfate aerosols (SO42−). During VAMOS-Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) in 2008, multiple instrumented platforms were deployed Southeastern Pacific (SEP) off coast of Chile Peru to study linkage between stratocumulus clouds. We present here observations NOAA Ship Ronald H. Brown NSF/NCAR C-130 aircraft along ~20° S (70° W) remote...
Abstract Widespread stratocumulus clouds were observed on nine transects from seven research cruises to the southeastern tropical Pacific Ocean along 20°S, 75°–85°W in October–November of 2001–08. The sample a unique combination synoptic and interannual variability affecting clouds; their ensemble diagnoses longitude–vertical sections atmosphere, diurnal cycles cloud properties drizzle statistics, effect surface radiation. Mean fraction was 0.88, 67% 10-min overhead observations overcast....
Abstract A near-large-eddy simulation approach with size-revolving (bin) microphysics is employed to evaluate the relative sensitivity of southeast Pacific marine boundary layer cloud properties thermodynamic and aerosol parameters. Simulations are based on a heavily drizzling system observed by NOAA ship Ronald H. Brown during Variability American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study—Regional Experiment (VOCALS-Rex) field campaign. suite numerical experiments examines...
Abstract The diurnal variability and the environmental conditions that support moisture resurgence of MJO events observed during Cooperative Indian Ocean Experiment on Intraseasonal Variability (CINDY)/DYNAMO campaign in October–December 2011 are investigated using situ observations cloud-resolving fully air–ocean–wave Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS). Spectral density wavelet analysis total precipitable water (TPW) constructed from DYNAMO soundings TRMM...