how to update model from the Route function

I am trying to write small search application but am struck at updating the model based on some action.

---

import Ember from 'ember';

model/index.js: import DS from 'ember-data';

 export default  DS.Model.extend({
 searchText: DS.attr('string'),
 title: DS.attr('string'),
 description: DS.attr('string'),
 url: DS.attr('string'),
 source: DS.attr('string')
});

route/index.js: export default Ember.Route.extend({

  actions:{

    submitsearch: function(inputsearchtext) {
    var data = {
      "searchText": inputsearchtext
    }

     var models = this.model.values;
     alert(models);
    Ember.$.ajax('http://c6403:2222/server/getkb', {
      type: 'POST',
      dataType: 'json',
      contentType: "application/json",
      data: JSON.stringify(data),
      async: false,
      context: this,
  }).then(function(response) {
      var type = response.type;
      var payload = response.payload;
      alert(payload);
      this.store.pushPayload(type, payload);
   });

   }

 }
});

---

Basically I wanted to update my model based on the searchtext user has provided. As part of this I am making "submitsearch" call and from there trying to make a AJAX/json call - once I get the json response I will have to update model so that my view will be updated/refreshed.

here is my questions:

1. json response "payload" is undefined though server returns proper response - I could validate the response in browser.

2. after getting the payload what is the correct way to update the model so that component should be refreshed to show the results.