Search Results

You are looking at 1 - 8 of 8 items for :

  • Boundary currents x
  • Progress in Advancing Drought Monitoring and Prediction x
  • All content x
Clear All
Anthony M. DeAngelis, Hailan Wang, Randal D. Koster, Siegfried D. Schubert, Yehui Chang, and Jelena Marshak

moisture content is provided for four model layers. We analyze VISM directly from models that provide it, and for GEFS we compute VISM by scaling each layer’s volumetric soil moisture content by the layer depth and summing over all layers. Daily averages over the period 0000–0000 UTC are provided for P , T2m, and VISM for all models except GEOS, for which the daily average is calculated over 2100 UTC of the previous day to 2100 UTC of the current day due to the initialization time of the model (see

Restricted access
Richard Seager, Jennifer Nakamura, and Mingfang Ting

seasonal to interannual time scale, their onsets and terminations are likely controlled by internal atmosphere variability and fall between the initial value and ocean boundary condition sources of predictability. However, SNT was a purely observational study. Here we report on how well DO&Ts are forecast in the operational seasonal predictions systems of the National Multimodel Ensemble (NMME; Kirtman et al. 2014 ). These systems forecast SST from imposed initial conditions. Several of the models

Restricted access
Chul-Su Shin, Bohua Huang, Paul A. Dirmeyer, Subhadeep Halder, and Arun Kumar

temperature (e.g., Yoon et al. 2012 ; Yuan and Wood 2013 ; Dutra et al. 2014 ; Mo and Lyon 2015 ). Current seasonal coupled forecast systems can predict major oceanic and atmospheric anomalies at useful lead times (e.g., Jin et al. 2008 ; Kirtman et al. 2014 ; Huang et al. 2017a ; Shin et al. 2019 ). However, the current level of skill in forecasting drought onset, development, and demise is limited (e.g., Quan et al. 2012 ; Mo and Lyon 2015 ), possibly because other sources of predictability

Restricted access
Keyhan Gavahi, Peyman Abbaszadeh, Hamid Moradkhani, Xiwu Zhan, and Christopher Hain

, land surface and hydrologic properties can be simulated and predicted by land surface models which provide a simplified representation of physical processes. However, an accurate prediction of these components, such as SM, ET, and streamflow, is highly dependent on the quality of model forcing data, the model parameters (measured or estimated through calibration), initial and boundary conditions, and model structure. For land surface and hydrologic models, the integration of data assimilation (DA

Open access
Yaling Liu, Dongdong Chen, Soukayna Mouatadid, Xiaoliang Lu, Min Chen, Yu Cheng, Zhenghui Xie, Binghao Jia, Huan Wu, and Pierre Gentine

water demand, and thus SM could also be a crucial factor affecting socioeconomic conditions. Despite the criticality of SM in the Earth system, accurate estimation of large-scale soil moisture is still a challenge, mainly due to its rapid fluctuations and the lack of sufficient ground truth observations. Currently, most large-scale SM products are either retrieved from satellite data or produced from land surface models (LSMs). As an example of product derived from satellites, the European Space

Restricted access
Chul-Su Shin, Paul A. Dirmeyer, Bohua Huang, Subhadeep Halder, and Arun Kumar

. 2016 ; Dirmeyer and Halder 2016 , 2017 ; Dirmeyer et al. 2018b ; Halder et al. 2018 ). Model fidelity in representing coupled land–atmosphere processes is also necessary, including proper simulation of variability, covariability, sensitivity, and critical transitions in the chain of processes linking land surface states to surface fluxes, near-surface atmospheric states, boundary layer characteristics, cloud formation, and precipitation ( Dirmeyer and Halder 2017 ; Santanello et al. 2018

Restricted access
Lu Su, Qian Cao, Mu Xiao, David M. Mocko, Michael Barlage, Dongyue Li, Christa D. Peters-Lidard, and Dennis P. Lettenmaier

the land surface, as groundwater can reduce or even reverse the downward flux (drainage) of moisture from the surface ( Barlage et al. 2015 ; Martinez et al. 2016 ). In addition, where groundwater is shallow, or where roots are deep enough, groundwater can be accessed directly by plants, affecting the fluxes of moisture via transpiration ( Fan 2015 ). However, the abovementioned objective drought monitors do not currently consider groundwater, nor have many studies of drought trends (e.g., Mo

Restricted access
David M. Mocko, Sujay V. Kumar, Christa D. Peters-Lidard, and Shugong Wang

departure of the current state of the variable of interest relative to the long-term average. Despite the stated emphasis, most near-real-time LDAS environments only include limited assimilation of terrestrial hydrological observations. Several recent efforts have focused on mitigating this limitation in the NLDAS environment through assimilation studies of soil moisture, snow, and terrestrial water storage, both serially and concurrently (e.g., Kumar et al. 2014 , 2016 , 2019a ). Studies in other

Restricted access