Quantifying the Land–Atmosphere Coupling Behavior in Modern Reanalysis Products over the U.S. Southern Great Plains

Abstract The coupling of the land with the planetary boundary layer (PBL) on diurnal time scales is critical to regulating the strength of the connection between soil moisture and precipitation. To improve understanding of land–atmosphere (L–A) interactions, recent studies have focused on the development of diagnostics to quantify the strength and accuracy of the land–PBL coupling at the process level. In this paper, the authors apply a suite of local land–atmosphere coupling (LoCo) metrics to modern reanalysis (RA) products and observations during a 17-yr period over the U.S. southern Great Plains. Specifically, a range of diagnostics exploring the links between soil moisture, evaporation, PBL height, temperature, humidity, and precipitation is applied to the summertime monthly mean diurnal cycles of the North American Regional Reanalysis (NARR), Modern-Era Retrospective Analysis for Research and Applications (MERRA), and Climate Forecast System Reanalysis (CFSR). Results show that CFSR is the driest and MERRA the wettest of the three RAs in terms of overall surface–PBL coupling. When compared against observations, CFSR has a significant dry bias that impacts all components of the land–PBL system. CFSR and NARR are more similar in terms of PBL dynamics and response to dry and wet extremes, while MERRA is more constrained in terms of evaporation and PBL variability. Each RA has a unique land–PBL coupling that has implications for downstream impacts on the diurnal cycle of PBL evolution, clouds, convection, and precipitation as well as representation of extremes and drought. As a result, caution should be used when treating RAs as truth in terms of their water and energy cycle processes.

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A Modified Framework for Quantifying Land–Atmosphere Covariability during Hydrometeorological and Soil Wetness Extremes in Oklahoma

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-18-0230.1 ◽

2019 ◽

Vol 58 (7) ◽

pp. 1465-1483 ◽

Cited By ~ 2

Author(s):

Ryann A. Wakefield ◽

Jeffrey B. Basara ◽

Jason C. Furtado ◽

Bradley G. Illston ◽

Craig. R. Ferguson ◽

...

Keyword(s):

Soil Moisture ◽

Great Plains ◽

Hot Spot ◽

Extreme Rainfall ◽

Southern Great Plains ◽

Low Level ◽

Oklahoma Mesonet ◽

Humidity Index ◽

Grid Points ◽

Regional Reanalysis

AbstractGlobal “hot spots” for land–atmosphere coupling have been identified through various modeling studies—both local and global in scope. One hot spot that is common to many of these analyses is the U.S. southern Great Plains (SGP). In this study, we perform a mesoscale analysis, enabled by the Oklahoma Mesonet, that bridges the spatial and temporal gaps between preceding local and global analyses of coupling. We focus primarily on east–west variations in seasonal coupling in the context of interannual variability over the period spanning 2000–15. Using North American Regional Reanalysis (NARR)-derived standardized anomalies of convective triggering potential (CTP) and the low-level humidity index (HI), we investigate changes in the covariance of soil moisture and the atmospheric low-level thermodynamic profile during seasonal hydrometeorological extremes. Daily CTP and HI z scores, dependent upon climatology at individual NARR grid points, were computed and compared to in situ soil moisture observations at the nearest mesonet station to provide nearly collocated annual composites over dry and wet soils. Extreme dry and wet year CTP and HI z-score distributions are shown to deviate significantly from climatology and therefore may constitute atmospheric precursors to extreme events. The most extreme rainfall years differ from climatology but also from one another, indicating variability in the strength of land–atmosphere coupling during these years. Overall, the covariance between soil moisture and CTP/HI is much greater during drought years, and coupling appears more consistent. For example, propagation of drought during 2011 occurred under antecedent CTP and HI conditions that were identified by this study as being conducive to positive dry feedbacks demonstrating potential utility of this framework in forecasting regional drought propagation.

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Seasonal and interannual variability of land-atmosphere coupling across the Southern Great Plains of North America using the North American regional reanalysis

International Journal of Climatology ◽

10.1002/joc.5223 ◽

2017 ◽

Vol 38 (2) ◽

pp. 964-978 ◽

Cited By ~ 10

Author(s):

Jeffrey B. Basara ◽

Jordan I. Christian

Keyword(s):

North America ◽

Interannual Variability ◽

Great Plains ◽

North American ◽

Southern Great Plains ◽

Seasonal And Interannual Variability ◽

The North ◽

North American Regional Reanalysis ◽

Regional Reanalysis

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Assessment of Remotely Sensed and Modelled Soil Moisture Data Products in the U.S. Southern Great Plains

Remote Sensing ◽

10.3390/rs12122030 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2030

Author(s):

Bo Jiang ◽

Hongbo Su ◽

Kai Liu ◽

Shaohui Chen

Keyword(s):

Soil Moisture ◽

Great Plains ◽

Land Surface ◽

European Space Agency ◽

Remotely Sensed ◽

The Other ◽

Short Term ◽

Southern Great Plains ◽

The U.S

Soil moisture (SM) plays a crucial role in the water and energy flux exchange between the atmosphere and the land surface. Remote sensing and modeling are two main approaches to obtain SM over a large-scale area. However, there is a big difference between them due to algorithm, spatial-temporal resolution, observation depth and measurement uncertainties. In this study, an assessment of the comparison of two state-of-the-art remotely sensed SM products, Soil Moisture Active Passive (SMAP) and European Space Agency Climate Change Initiative (ESACCI), and one land surface modeled dataset from the North American Land Data Assimilation System project phase 2 (NLDAS-2), were conducted using 17 permanent SM observation sites located in the Southern Great Plains (SGP) in the U.S. We first compared the daily mean SM of three products with in-situ measurements; then, we decompose the raw time series into a short-term seasonal part and anomaly by using a moving smooth window (35 days). In addition, we calculate the daily spatial difference between three products based on in-situ data and assess their temporal evolution. The results demonstrate that (1) in terms of temporal correlation R, the SMAP (R = 0.78) outperforms ESACCI (R = 0.62) and NLDAS-2 (R = 0.72) overall; (2) for the seasonal component, the correlation R of SMAP still outperforms the other two products, and the correlation R of ESACCI and NLDAS-2 have not improved like the SMAP; as for anomaly, there is no difference between the remotely sensed and modeling data, which implies the potential for the satellite products to capture the variations of short-term rainfall events; (3) the distribution pattern of spatial bias is different between the three products. For NLDAS-2, it is strongly dependent on precipitation; meanwhile, the spatial distribution of bias represents less correlation with the precipitation for two remotely sensed products, especially for the SMAP. Overall, the SMAP was superior to the other two products, especially when the SM was of low value. The difference between the remotely sensed and modeling products with respect to the vegetation type might be an important reason for the errors.

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The Heated Condensation Framework. Part I: Description and Southern Great Plains Case Study

Journal of Hydrometeorology ◽

10.1175/jhm-d-14-0117.1 ◽

2015 ◽

Vol 16 (5) ◽

pp. 1929-1945 ◽

Cited By ~ 23

Author(s):

Ahmed B. Tawfik ◽

Paul A. Dirmeyer ◽

Joseph A. Santanello

Keyword(s):

Great Plains ◽

Companion Paper ◽

Layer Growth ◽

Moisture Profile ◽

Convective Initiation ◽

Southern Great Plains ◽

Clear Sky ◽

The North ◽

Convective State ◽

Regional Reanalysis

Abstract This study extends the heated condensation framework (HCF) presented in Tawfik and Dirmeyer to include variables for describing the convective background state of the atmosphere used to quantify the contribution of the atmosphere to convective initiation within the context of land–atmosphere coupling. In particular, the ability for the full suite of HCF variables to 1) quantify the amount of latent and sensible heat energy necessary for convective initiation, 2) identify the transition from moistening advantage to boundary layer growth advantage, 3) identify locally originating convection, and 4) compare models and observations, directly highlighting biases in the convective state, is demonstrated. These capabilities are illustrated for a clear-sky and convectively active day over the Atmospheric Radiation Measurement Program Southern Great Plains central station using observations, the Rapid Update Cycle (RUC) operational model, and the North American Regional Reanalysis (NARR). The clear-sky day had a higher and unattainable convective threshold, making convective initiation unlikely. The convectively active day had a lower threshold that was attained by midafternoon, reflecting local convective triggering. Compared to observations, RUC tended to have the most difficulty representing the convective state and captured the threshold for the clear-sky case only because of compensating biases in the moisture and temperature profiles. Despite capturing the observed moisture profile very well, a stronger surface inversion in NARR returned overestimates in the convective threshold. The companion paper applies the HCF variables introduced here across the continental United States to examine the climatological behavior of convective initiation and local land–atmosphere coupling.

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A Method for Estimating Planetary Boundary Layer Heights and Its Application over the ARM Southern Great Plains Site

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-11-00118.1 ◽

2012 ◽

Vol 29 (3) ◽

pp. 316-322 ◽

Cited By ~ 24

Author(s):

Paul Schmid ◽

Dev Niyogi

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Great Plains ◽

Potential Temperature ◽

Free Atmosphere ◽

Southern Great Plains ◽

The North ◽

Atmospheric Radiation Measurement ◽

Regional Reanalysis ◽

Future Work

Abstract A new objective method to determine the height of the planetary boundary layer (PBL) is presented here. PBL heights are computed using the statistical variance and kurtosis of dewpoint and virtual potential temperature differences measured from radio soundings at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) program at the Southern Great Plains (SGP) site. These heights are compared with those derived from lidar, also on the site, and with gridded model data from the North American Regional Reanalysis (NARR). A climatology of mean heights in the early (1800 UTC) and late (0000 UTC) afternoon from 2002 to 2010 is presented to show the effectiveness of the method. Future work using the new method include producing an observational climatology of PBL heights and understanding the aerosol loading within the PBL as well as a better understanding of the coupling between the surface and free atmosphere.

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